A Guide to the Study of Fishes, Volume 2 (of 2)
Date: 2016-04-09T00:00:00+00:00
Keywords: Zoology -- History; Fishes; Fishes -- Bibliography

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Title: A Guide to the Study of Fishes, Volume 2 (of 2)

Author: David Starr Jordan

Release date: April 9, 2016 [eBook #51702]

Language: English

Credits: Produced by Richard Tonsing, Chris Curnow, Bryan Ness and
the Online Distributed Proofreading Team at
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*** START OF THE PROJECT GUTENBERG EBOOK A GUIDE TO THE STUDY OF FISHES, VOLUME 2 (OF 2) ***

Transcriber's Note:

The cover image was created by the transcriber and is placed in the public domain.

GUIDE TO THE STUDY OF FISHES

VARIATIONS IN THE COLOR OF FISHES

The Oniokose or Demon Stinger, Inimicus japonicus (Cuv. and Val.), from Wakanoura, Japan. From nature by Kako Morita.

Surface coloration about lava rocks.

Coloration of specimens living among red algæ.

Coloration in deep water; Inimicus aurantiacus (Schlegel).

A GUIDE
TO
THE STUDY OF FISHES

BY

DAVID STARR JORDAN

President of Leland Stanford Junior University

With Colored Frontispieces and 507 Illustrations

IN TWO VOLUMES

Vol II.

"I am the wiser in respect to all knowledge
and the better qualified for all fortunes
for knowing that there is a minnow in that
brook."—Thoreau

NEW YORK
HENRY HOLT AND COMPANY
1905

Copyright, 1905
BY
HENRY HOLT AND COMPANY
Published March, 1905

CONTENTS
VOL. II.

CHAPTER I.
THE GANOIDS.
| PAGE

Subclass Actinopteri.—The Series Ganoidei.—Are the Ganoids a Natural Group?—Systematic Position of Lepidosteus.—Gill on the Ganoids as a Natural Group.

1

CHAPTER II.
THE GANOIDS (Continued).

Classification of Ganoids.—Order Lysopteri.—The Palæoniscidæ.—The Platysomidæ.—The Dorypteridæ.—The Dictyopygidæ.—Order Chondrostei.—Order Selachostomi: the Paddle-fishes.—Order Pycnodonti.—Order Lepidostei.—Family Lepisosteidæ.—Embryology of the Garpike.—Fossil Garpikes.—Order Halecomorphi.—Pachycormidæ.—The Bowfins: Amiidæ.—The Oligopleuridæ.

13

CHAPTER III.
ISOSPONDYLI.

The Subclass Teleostei, or Bony Fishes.—Order Isospondyli.—The Classification of the Bony Fishes.—Relationships of Isospondyli.—The Clupeoidea.—The Leptolepidæ.—The Elopidæ.—The Albulidæ.—The Chanidæ.—The Hiodontidæ.—The Pterothrissidæ.—The Ctenothrissidæ.—The Notopteridæ.—The Clupeidæ.—The Dorosomatidæ.—The Engraulididæ.—Gonorhynchidæ.—The Osteoglossidæ.—The Pantodontidæ.

37

CHAPTER IV.
SALMONIDÆ.

The Salmon Family.—Coregonus, the Whitefish.—Argyrosomus, the Lake Herring.—Brachymystax and Stenodus, the Inconnus.—Oncorhynchus, the Quinnat Salmon.—The Parent-stream Theory.—The Jadgeska Hatchery.—Salmon-packing.

61

CHAPTER V.
SALMONIDÆ (Continued).

Salmo, the Trout and Atlantic Salmon.—The Atlantic Salmon.—The Ouananiche.—The Black-spotted Trout.—The Trout of Western America.—Cutthroat or Red-throated Trout.—Hucho, the Huchen.—Salvelinus, the Charr.—Cristivomer, the Great Lake Trout.—The Ayu, or Sweetfish.—Cormorant-fishing.—Fossil Salmonidæ.

89

CHAPTER VI.
THE GRAYLING AND THE SMELT.

The Grayling, or Thymallidæ.—The Argentinidæ.—The Microstomidæ.—The Salangidæ, or Icefishes.—The Haplochitonidæ.—Stomiatidæ.—Suborder Iniomi, the Lantern-fishes.—Aulopidæ.—The Lizard-fishes.—Ipnopidæ.—Rondeletiidæ.—Myctophidæ.—Chirothricidæ.—Maurolicidæ.—The Lancet-fishes.—The Sternoptychidæ.—Order Lyopomi.

120

CHAPTER VII.
THE APODES, OR EEL-LIKE FISHES.

The Eels.—Order Symbranchia.—Order Apodes, or True Eels.—Suborder Archencheli.—Suborder Enchelycephali.—Family Anguillidæ.—Reproduction of the Eel.—Food of the Eel.—Larva of the Eel.—Species of Eels.—Pug-nosed Eels.—Conger-eels.—The Snake-eels.—Suborder Colocephali, or Morays.—Family Moringuidæ.—Order Carencheli, the Long-necked Eels.—Order Lyomeri or Gulpers.—Order Heteromi.

139

CHAPTER VIII.
SERIES OSTARIOPHYSI.

Ostariophysi.—The Heterognathi.—The Eventognathi.—The Cyprinidæ.—Species of Dace and Shiner.—Chubs of the Pacific Slope.—The Carp and Goldfish.—The Catostomidæ.—Fossil Cyprinidæ.—The Loaches.

159

CHAPTER IX.
THE NEMATOGNATHI, OR CATFISHES.

The Nematognathi.—Families of Nematognathi.—The Siluridæ.—The Sea Catfish.—The Channel Cats.—Horned Pout.—The Mad-toms.—The Old World Catfishes.—The Sisoridæ.—The Plotosidæ.—The Chlariidæ.—The Hypophthalmidæ or Pygidiidæ.—The Loricariidæ.—The Callichthyidæ.—Fossil Catfishes.—Order Gymnonoti.

177

CHAPTER X.
THE SCYPHOPHORI, HAPLOMI, AND XENOMI.

Order Scyphophori.—The Mormyridæ.—The Haplomi.—The Pikes.—The Mud minnows.—The Killifishes.—Amblyopsidæ.—Kneriidæ, etc.—The Galaxiidæ.—Order Xenomi.

188

CHAPTER XI.
ACANTHOPTERYGII; SYNENTOGNATHI.

Order Acanthopterygii, the Spiny-rayed Fishes.—Suborder Synentognathi.—The Garfishes: Belonidæ.—The Flying-fishes: Exocœtidæ.

208

CHAPTER XII.
PERCESOCES AND RHEGNOPTERI.

Suborder Percesoces.—The Silversides: Atherinidæ.—The Mullets: Mugilidæ.—The Barracudas: Sphyrænidæ.—Stephanoberycidæ.—Crossognathidæ.—Cobitopsidæ.—Suborder Rhegnopteri.

215

CHAPTER XIII.
PHTHINOBRANCHII: HEMIBRANCHII, LOPHOBRANCHII, AND
HYPOSTOMIDES.

Suborder Hemibranchii.—The Sticklebacks: Gasterosteidæ.—The Aulorhynchidæ.—Cornet-fishes: Fistulariidæ.—The Trumpet-fishes: Aulostomidæ.—The Snipefishes: Macrorhamphosidæ.—The Shrimp-fishes: Centriscidæ.—The Lophobranchs.—The Solenostomidæ.—The Pipefishes: Syngnathidæ.—The Sea-horses: Hippocampus.—Suborder Hypostomides, the Sea-moths: Pegasidæ.

227

CHAPTER XIV.
SALMOPERCÆ AND OTHER TRANSITIONAL GROUPS.

Suborder Salmopercæ, the Trout-perches: Percopsidæ.—Erismatopteridæ.—Suborder Selenichthyes, the Opahs: Lamprididæ.—Suborder Zeoidea.—Amphistiidæ.—The John Dories: Zeidæ.—Grammicolepidæ.

241

CHAPTER XV.
BERYCOIDEI.

The Berycoid Fishes.—The Alfonsinos: Berycidæ.—The Soldier-fishes: Holocentridæ.—The Polymixiidæ.—The Pine-cone Fishes: Monocentridæ.

250

CHAPTER XVI.
PERCOMORPHI.

Suborder Percomorphi, the Mackerels and Perches.—The Mackerel Tribe: Scombroidea.—The True Mackerels: Scombridæ.—The Escolars: Gempylidæ.—Scabbard and Cutlass-fishes: Lepidopidæ and Trichiuridæ.—The Palæorhynchidæ.—The Sailfishes: Istiophoridæ.—The Swordfishes: Xiphiidæ.

258

CHAPTER XVII.
CAVALLAS AND PAMPANOS.

The Pampanos: Carangidæ.—The Papagallos: Nematistiidæ.—The Bluefishes: Cheilodipteridæ.—The Sergeant-fishes: Rachycentridæ.—The Butter-fishes: Stromateidæ.—The Rag-fishes: Icosteidæ.—The Pomfrets: Bramidæ.—The Dolphins: Coryphænidæ.—The Menidæ.—The Pempheridæ.—Luvaridæ.—The Square-tails: Tetragonuridæ.—The Crested Bandfishes: Lophotidæ.

272

CHAPTER XVIII.
PERCOIDEA, OR PERCH-LIKE FISHES.

Percoid Fishes.—The Pirate-perches: Aphredoderidæ.—The Pigmy Sunfishes: Elassomidæ.—The Sunfishes: Centrarchidæ.—Crappies and Rock Bass.—The Black Bass.—The Saleles: Kuhliidæ.—The True Perches: Percidæ.—Relations of Darters to Perches.—The Perches.—The Darters: Etheostominæ.

293

CHAPTER XIX.
THE BASS AND THEIR RELATIVES.

The Cardinal-fishes: Apogonidæ.—The Anomalopidæ.—The Asineopidæ—The Robalos: Oxylabracidæ.—The Sea-bass: Serranidæ.—The Jewfishes.—The Groupers.—The Serranos.—The Flashers: Lobotidæ.—The Big eyes: Priacanthidæ.—The Pentacerotidæ.—The Snappers: Lutianidæ.—The Grunts: Hæmulidæ.—The Porgies: Sparidæ.—The Picarels: Mænidæ.—The Mojarras: Gerridæ.—The Rudder-fishes: Kyphosidæ.

316

CHAPTER XX.
THE SURMULLETS, THE CROAKERS AND THEIR RELATIVES.

The Surmullets, or Goatfishes: Mullidæ.—The Croakers: Sciænidæ.—The Sillaginidæ, etc.—The Jawfishes: Opisthognathidæ, etc.—The Stone-wall Perch: Oplegnathidæ.—The Swallowers: Chiasmodontidæ.—The Malacanthidæ.—The Blanquillos: Latilidæ.—The Bandfishes: Cepolidæ.—The Cirrhitidæ.—The Sandfishes: Trichodontidæ.

351

CHAPTER XXI.
LABYRINTHICI AND HOLCONOTI.

The Labyrinthine Fishes.—The Climbing-perches: Anabantidæ.—The Gouramis: Osphromenidæ.—The Snake-head Mullets: Ophicephalidæ.—Suborder Holconoti, the Surf-fishes.—The Embiotocidæ.

365

CHAPTER XXII.
CHROMIDES AND PHARYNGOGNATHI.

Suborder Chromides.—The Cichlidæ.—The Damsel-fishes: Pomacentridæ.—Suborder Pharyngognathi.—The Wrasse Fishes: Labridæ.—The Parrot-fishes: Scaridæ.

380

CHAPTER XXIII.
THE SQUAMIPINNES.

The Squamipinnes.—The Scorpididæ.—The Boarfishes: Antigoniidæ.—The Arches: Toxotidæ.—The Ephippidæ.—The Spadefishes: Ilarchidæ.—The Platacidæ.—The Butterfly-fishes: Chætodontidæ.—The Pygæidæ.—The Moorish Idols: Zanclidæ.—The Tangs: Acanthuridæ.—Suborder Amphacanthi, the Siganidæ.

397

CHAPTER XXIV.
SERIES PLECTOGNATHI.

The Plectognaths.—The Scleroderms.—The Trigger-fishes: Balistidæ.—The File-fishes: Monacanthidæ.—The Spinacanthidæ.—The Trunkfishes: Ostraciidæ.—The Gymnodontes.—The Triodontidæ.—The Globefishes: Tetraodontidæ.—The Porcupine-fishes: Diodontidæ.—The Head-fishes: Molidæ.

411

CHAPTER XXV.
PAREIOPLITÆ, OR MAILED-CHEEK FISHES.

The Mailed-cheek Fishes.—The Scorpion-fishes: Scorpænidæ.—The Skilfishes: Anoplopomidæ.—The Greenlings: Hexagrammidæ.—The Flatheads or Kochi: Platycephalidæ.—The Sculpins: Cottidæ.—The Sea-poachers: Agonidæ.—The Lump-suckers: Cyclopteridæ.—The Sea-snails: Liparididæ.—The Baikal Cods: Comephoridæ.—Suborder Craniomi: the Gurnards, Triglidæ.—The Peristediidæ.—The Flying Gurnards: Cephalacanthidæ.

426

CHAPTER XXVI.
GOBIOIDEI, DISCOCEPHALI, AND TÆNIOSOMI.

Suborder Gobioidei, the Gobies: Gobiidæ.—Suborder Discocephali, the Shark-suckers: Echeneididæ.—Suborder Tæniosomi, the Ribbon-fishes.—The Oarfishes: Regalecidæ.—The Dealfishes: Trachypteridæ.

459

CHAPTER XXVII.
SUBORDER HETEROSOMATA.

The Flatfishes.—Optic Nerves of Flounders.—Ancestry of Flounders.—The Flounders: Pleuronectidæ.—The Turbot Tribe: Bothinæ.—The Halibut Tribe: Hippoglossinæ.—The Plaice Tribe: Pleuronectinæ.—The Soles: Soleidæ.—The Broad Soles: Achirinæ.—The European Soles (Soleinæ).—The Tongue-fishes: Cynoglossinæ.

481

CHAPTER XXVIII.
SUBORDER JUGULARES.

The Jugular-fishes.—The Weevers: Trachinidæ.—The Nototheniidæ.—The Leptoscopidæ.—The Star-gazers: Uranoscopidæ.—The Dragonets: Callionymidæ.—The Dactyloscopidæ.

499

CHAPTER XXIX.
THE BLENNIES: BLENNIIDÆ.

The Northern Blennies: Xiphidiinæ, Stichæiniæ, etc.—The Quillfishes: Ptilichthyidæ.—The Blochiidæ.—The Patæcidæ, etc.—The Gadopsidæ, etc.—The Wolf-fishes: Anarhichadidæ.—The Eel-pouts: Zoarcidæ.—The Cusk-eels: Ophidiidæ.—Sand-lances: Ammodytidæ.—The Pearlfishes: Fierasferidæ.—The Brotulidæ.—Ateleopodidæ.—Suborder Haplodoci.—Suborder Xenopterygii.

507

CHAPTER XXX.
OPISTHOMI AND ANACANTHINI.
Order Opisthomi.—Order Anacanthini.—The Codfishes: Gadidæ.—The Hakes: Merluciidæ.—The Grenadiers: Macrouridæ. | 532
CHAPTER XXXI.
ORDER PEDICULATI: THE ANGLERS.

The Angler-fishes.—The Fishing-frogs: Lophiidæ.—The Sea-devils: Ceratiidæ.—The Frogfishes: Antennariidæ.—The Batfishes: Ogcocephalidæ.

542

LIST OF ILLUSTRATIONS
VOL. II.

| PAGE
Shoulder-girdle of a Flounder, Paralichthys californicus | 2
Palæoniscum frieslebenense | 14
Eurynotus crenatus | 15
Dorypterus hoffmani | 16
Chondrosteus acipenseroides | 18
Acipenser sturio, Common Sturgeon | 19
Acipenser rubicundus, Lake Sturgeon | 20
Scaphirhynchus platyrhynchus, Shovel-nosed Sturgeon | 20
Polyodon spathula, Paddle-fish, side-view | 21
Polyodon spathula, Paddle-fish, view from below | 21
Psephurus gladius | 21
Gyrodus hexagonus | 22
Mesturus verrucosus | 23
Semionotus kapffi | 24
Dapedium politum | 25
Tetragonolepis semicinctus | 26
Isopholis orthostomus | 27
Lepisosteus osseus, Long-nosed Garpike | 27
Caturus elongatus | 28
Notagogus pentlandi | 28
Ptycholepis curtus | 28
Pholidophorus crenulatus | 29
Lepisosteus tristœchus, Alligator-gar | 31
Lower Jaw of Amia calva, showing the gular plate | 33
Amia calva, Bowfin (female) | 35
Megalurus elegantissimus | 36
Leptolepis dubius | 41
Elops saurus, Ten-pounder | 42
Holcolepis lewesiensis | 42
Tarpon atlanticus, Tarpon or Grand Écaille | 43
Albula vulpes, Lady-fish | 44
Chanos chanos, Milkfish | 45
Hiodon tergisus, Mooneye | 45
Istieus grandis | 46
Chirothrix libanicus | 46
Skeleton of Portheus molossus | 47
Ctenothrissa vexillifera | 48
Clupea harengus, Herring | 49
Pomolobus pseudoharengus, Alewife | 50
Brevoortia tyrannus, Menhaden | 51
Diplomystus humilis | 52
Dorosoma cepedianum, Hickory-shad | 53
Anchovia perthecata, Silver Anchovy | 54
Notogoneus osculus | 55
Phareodus testis | 57
Deposits of Green River Shales, bearing Phareodus, at Fossil, Wyoming | 58
A Day's Catch of fossil-fishes, Green River Eocene Shales | 59
Alepocephalus agassizii | 60
Coregonus williamsoni, Rocky Mountain Whitefish | 63
Coregonus clupeiformis, Whitefish | 64
Argyrosomus nigripinnis, Bluefin Cisco | 66
Stenodus mackenziei, Inconnu | 67
Oncorhynchus tschawytscha, Quinnat Salmon (female) | 69
Oncorhynchus tschawytscha, King-salmon (grilse) | 70
Oncorhynchus nerka, Male Red Salmon | 70
Oncorhynchus gorbuscha, Humpback Salmon (female) | 72
Oncorhynchus masou, Masu | 72
Oncorhynchus nerka, Red Salmon (mutilated dwarf male after spawning) | 76
Oncorhynchus tschawytscha, Quinnat Salmon (dying after spawning) | 77
Oncorhynchus tschawytscha, Quinnat Salmon | 79
Salmo irideus shasta, Rainbow Trout (male) | 98
Salmo irideus shasta, Rainbow Trout (female) | 99
Salmo rivularis, Steelhead Trout | 101
Head of Adult Trout-worm, Dibothrium cordiceps. From intestine of white pelican | 103
Median segments of Dibothrium cordiceps | 103
Salmo henshawi, Tahoe Trout | 104
Salmo stomias, Green-back Trout | 105
Salmo macdonaldi, Yellow-fin Trout of Twin Lakes | 105
Salmo clarkii spilurus, Rio Grande Trout | 106
Salmo clarkii pleuriticus, Colorado River Trout | 106
Hucho blackistoni, Ito | 107
Salvelinus oquassa, Rangeley Trout | 108
Salvelinus aureolus, Sunapee Trout | 109
Salvelinus fontinalis, Speckled Trout (male) | 110
Salvelinus fontinalis, Speckled Trout | 111
Salvelinus malma, Malma Trout | 113
Salvelinus malma, Dolly Varden Trout | 114
Cristivomer namaycush, Great Lake Trout | 114
Plecoglossus altivelis, Ayu, or Japanese Samlet | 116
Thymallus signifer, Alaska Grayling | 120
Thymallus tricolor, Michigan Grayling | 122
Osmerus mordax, Smelt | 123
Thaleichthys pretiosus, Eulachon or Ulchen | 124
Page of William Clark's Handwriting with Sketch of the Eulachon (Thaleichthys pacificus) | 125
Mallotus villosus, Capelin | 126
Salanx hyalocranius, Icefish | 128
Stomias ferox | 128
Chauliodus sloanei | 129
Synodus fætens, Lizard-fish | 130
Ipnops murrayi | 131
Cetomimus gillii | 132
Diaphus lucidus, Headlight-fish | 132
Myctophum opalinum, Lantern-fish | 133
Ceratoscopelus madeirensis, Lantern-fish | 133
Rhinellus furcatus | 134
Plagyodus ferox, Lancet-fish | 135
Eurypholis sulcidens | 136
Eurypholis freyeri | 137
Argyropelecus olfersi | 137
Aldrovandia gracilis | 138
Anguilla chrisypa, Common Eel | 143
Anguilla chrisypa, Larva of Common Eel | 148
Simenchelys parasiticus, Pug-nosed Eel | 149
Synaphobranchus pinnatus | 149
Leptocephalus conger, Conger-eel | 150
Larva of Conger-eel, Leptocephalus conger | 150
Xyrias revulsus | 151
Myrichthys pantostigmius | 151
Ophichthus ocellatus | 151
Nemichthys avocetta, Thread-eel | 152
Jaws of Nemichthys avocetta | 152
Muræna retifera | 153
Gymnothorax berndti | 154
Gymnothorax jordani | 155
Gymnothorax moringa, Moray | 155
Derichthys serpentinus | 156
Gastrostomus bairdi, Gulper-eel | 156
Notacanthus phasganorus | 158
Inner view of shoulder-girdle of Buffalo-fish (Ictiobus bubalus), showing the mesocoracoid | 160
Weberian apparatus and air-bladder of Carp | 160
Brycon dentex | 162
Pharyngeal bones and teeth of European Chub, Leuciscus cephalus | 163
Rhinichthys dulcis, Black-nosed Dace | 164
Notropis hudsonius, White Chub | 165
Ericymba buccata, Silver-jaw Minnow | 165
Notropis whipplei, Silverfin | 166
Campostoma anomalum, Stone-roller | 167
Head of Day-chub, Exoglossum maxillingua | 167
Semotilus atromaculatus, Horned Dace | 168
Abramis chrysoleucus, Shiner | 168
Ptychocheilus grandis, Squawfish | 169
Leuciscus lineatus, Chub of the Great Basin | 169
Lower Pharyngeal of Placopharynx duquesnii | 171
Erimyzon sucetta, Creekfish or Chub-sucker | 172
Ictiobus cyprinella, Buffalo-fish | 173
Carpiodes cyprinus, Carp-sucker | 173
Catostomus commersoni, Common Sucker | 174
Catostomus occidentalis, California Sucker | 174
Pharyngeal teeth of Oregon Sucker, Catostomus macrocheilus | 175
Xyrauchen cypho, Razor-back Sucker | 175
Felichthys felis, Gaff-topsail Cat | 179
Galeichthys milberti, Sea Catfish | 179
Ictalurus punctatus, Channel Catfish | 180
Ameiurus nebulosus, Horned Pout | 181
Schilbeodes furiosus, Mad-tom. Showing the poisoned pectoral spine | 182
Torpedo electricus, Electric Catfish | 183
Chlarias breviceps, African Catfish | 185
Loricaria aurea, Mailed Catfish from Venezuela | 186
Gnathonemus curvirostris | 189
Esox lucius, Pike | 191
Esox masquinongy, Muskallunge | 192
Umbra pygmæa, Mud-minnow | 193
Anableps dovii, Four-eyed Fish | 195
Cyprinodon variegatus, Round Minnow | 196
Jordanella floridæ, Everglade Minnow | 197
Fundulis majalis, Mayfish (male) | 198
Fundulis majalis, Mayfish (female) | 198
Zygonectes notatus, Top-minnow | 198
Empetrichthys merriami, Death Valley Fish | 199
Xiphophorus helleri, Sword-tail Minnow (male) | 199
Goodea luitpoldi, a Viviparous Fish | 200
Chologaster cornutus, Dismal Swamp Fish | 201
Typhlichthys subterraneus, Blind Cave-fish | 202
Amblyopsis spelæus, Blindfish of the Mammoth Cave | 203
Dallia pectoralis, Alaska Blackfish | 206
Tylosurus acus, Needle-fish | 210
Scombresox saurus, Saury | 212
Hyporhamphus unifasciatus, Halfbeak | 212
Fodiator acutus, Sharp-nosed Flying-fish | 213
Cypselurus californicus, Catalina Flying-fish | 214
Chirostoma humboldtianum, Pescado blanco | 217
Kirtlandia vagrans, Silverside or Brit | 217
Atherinopsis californiensis, Blue Smelt or Pez del Rey | 218
Iso flos-maris, Flower of the Waves | 218
Mugil cephalus, Striped Mullet | 221
Joturus pichardi, Joturo or Bobo | 222
Sphyræna barracuda, Barracuda | 223
Cobitopsis acuta | 224
Shoulder-girdle of a Threadfin, Polydactylus approximans | 225
Polydactylus octonemus, Threadfin | 225
Shoulder-girdle of a Stickleback, Gasterosteus aculeatus | 227
Shoulder-girdle of Fistularia petimba, showing greatly extended interclavicle, the surface ossified | 227
Gasterosteus aculeatus, Three-spined Stickleback | 232
Apeltes quadracus, Four-spined Stickleback | 232
Aulostomus chinensis, Trumpet-fish | 234
Macrorhamphosus sagifue, Japanese Snipefish | 234
Æoliscus strigatus, Shrimp-fish | 235
Æoliscus heinrichi | 235
Solenostomus cyanopterus | 237
Hippocampus hudsonius, Sea-horse | 238
Zalises umitengu, Sea-moth | 240
Percopsis guttatus, Sand-roller | 241
Erismatopterus endlicheri | 242
Columbia transmontana, Oregon Trout-perch | 242
Shoulder-girdle of the Opah, Lampris guttatus (Brünnich), showing the enlarged infraclavicle | 243
LigaturesSemiophorus velifer | 246
Amphistium paradoxum | 247
Zeus faber, John Dory | 248
Skull of a Berycoidfish, Beryx splendens, showing the orbitosphenoid | 250
Beryx splendens | 251
Hoplopteryx lewesiensis | 252
Paratrachichthys prosthemius | 253
Holocentrus ascenscionis, Soldier-fish | 254
Holocentrus ittodai | 254
Ostichthys japonicus | 255
Monocentris japonicus, Pine-cone Fish | 256
Scomber scombrus, Mackerel | 260
Germo alalunga, Long-fin Albacore | 263
Scomberomorus maculatus, Spanish Mackerel | 264
Trichiurus lepturus, Cutlass-fish | 268
Palæorhynchus glarisianus | 268
Xiphias gladius, Young Swordfish | 269
Xiphias gladius, Swordfish | 270
Naucrates ductor, Pilot-fish | 273
Seriola lalandi, Amber-fish | 273
Trachurus trachurus, Saurel | 274
Carangus chrysos, Yellow Mackerel | 275
Trachinotus carolinus, the Pampano | 277
Cheilodipterus saltatrix, Bluefish | 279
Rachycentron canadum, Sergeant-fish | 282
Peprilus paru, Harvest-fish | 284
Gobiomorus gronovii, Portuguese Man-of-War Fish | 285
Coryphæna hippurus, Dolphin or Dorado | 287
Mene maculata | 288
Gasteronemus rhombeus | 289
Pempheris mulleri, Catalufa de lo Alto | 289
Pempheris nyctereutes | 290
Luvarus imperialis, Louvar | 290
Aphredoderus sayanus, Pirate Perch | 295
Elassoma evergladei, Everglade Pigmy Perch | 295
Skull of the Rock Bass, Ambloplites rupestris | 296
Pomoxis annularis, Crappie | 297
Pomoxis annularis, Crappie (from life) | 298
Ambloplites rupestris, Rock Bass | 299
Mesogonistius chætodon, Banded Sunfish | 299
Lepomis pallidus, Blue-gill | 300
Lepomis megalotis, Long-eared Sunfish | 300
Eupomotis gibbosus, Common Sunfish | 301
Micropterus dolomieu, Small Mouth Black Bass | 303
Micropterus salmoides, Large Mouth Black Bass | 305
Perca flavescens, Yellow perch | 308
Stizostedion canadense, Sauger | 309
Aspro asper, Aspron | 309
Zingel zingel, Zingel | 310
Percina caprodes, Log-perch | 311
Hadropterus aspro, Black-sided Darter | 311
Diplesion blennioides, Green-sided Darter | 312
Boleosoma olmstedi, Tessellated Darter | 312
Crystallaria asprella, Crystal Darter | 313
Ammocrypta clara, Sand-darter | 313
Etheostoma jordani | 314
Etheostoma camurum, Blue-breasted Darter | 314
Apogon retrosella, Cardinal-fish | 316
Telescopias gilberti, Kuromutsu | 318
Apogon semilineatus | 319
Oxylabrax undecimalis, Robalo | 319
Morone americana, White Perch | 322
Promicrops itaiara, Florida Jewfish | 323
Epinephelus striatus, Nassau Grouper: Cherna criolla | 324
Epinephelus drummond-hayi, John Paw or Speckled Hind | 325
Epinephelus morio, Red Grouper | 325
Epinephelus adscensionis, Red Hind | 326
Mycteroperca venenosa, Yellow-fin Grouper | 327
Hypoplectrus unicolor nigricans | 328
Epinephelus niveatus, Snowy Grouper | 329
Rypticus bistrispinus, Soapfish | 330
Lobotes surinamensis, Flasher | 331
Priacanthus arenatus, Catalufa | 331
Pseudopriacanthus altus, Bigeye | 332
Lutianus griseus, Gray Snapper | 334
Lutianus apodus, Schoolmaster | 335
Hoplopagrus guntheri | 336
Lutianus synagris, Lane Snapper or Biajaiba | 336
Ocyurus chrysurus, Yellow-tail Snapper | 337
Etelis oculatus, Cachucho | 337
Xenocys jessiæ | 338
Aphareus furcatus | 339
Hæmulon plumieri, Grunt | 340
Anisotremus virginicus, Porkfish | 341
Pagrus major, Red Tai of Japan | 342
Ebisu, the Fish-god of Japan, bearing a Red Tai | 343
Stenotomus chrysops, Scup | 344
Calamus bajonado, Jolt-head Porgy | 345
Calamus proridens, Little-head Porgy | 345
Diplodus holbrooki | 346
Archosargus unimaculatus, Salema, Striped Sheepshead | 347
Xystæma cinereum, Mojarra | 348
Gerres olisthostomus, Irish Pampano | 349
Kyphosus sectatrix, Chopa or Rudder-fish | 349
Apomotis cyanellus, Blue-green Sunfish | 350
Pseudupeneus maculatus, Red Goatfish or Salmonete | 351
Mullus auratus, Golden Surmullet | 352
Cynoscion nebulosus, Spotted Weakfish | 353
Bairdiella chrysura, Mademoiselle | 355
Sciænops ocellata, Red Drum | 356
Umbrina sinaloæ, Yellow-fin Roncador | 357
Menticirrhus americanus, Kingfish | 357
Pogonias chromis, Drum | 358
Gnathypops evermanni | 359
Opisthognathus macrognathus, Jawfish | 359
Opisthognathus nigromarginatus | 360
Chiasmodon niger, Black Swallower | 360
Cirrhitus rivulatus | 364
Trichodon trichodon, Sandfish | 364
Anabas scandens, Climbing Perch | 366
Channa formosana | 371
Ophicephalus barca, Snake-headed China-fish | 371
Cymatogaster aggregatus, White Surf-fish | 372
Hysterocarpus traski, Fresh-water Viviparous Perch | 373
Hypsurus caryi | 373
Damalichthys argyrosomus, White Surf-fish | 374
Rhacochilus toxotes, Thick-lipped Surf-fish | 374
Hypocritichthys analis, Silver Surf-fish, Viviparous | 375
Hysterocarpus traski, Viviparous Perch (male) | 379
Hypsypops rubicunda, Garibaldi | 382
Pomacentrus leucostictus, Damsel-fish | 382
Glyphisodon marginatus, Cockeye Pilot | 383
Microspathodon dorsalis, Indigo Damsel-fish | 384
Tautoga onitis, Tautog | 384
Tautoga onitis, Tautog | 386
Lachnolaimus falcatus, Capitaine or Hogfish | 387
Xyrichthys psittacus, Razor-fish | 388
Pimelometopon pulcher, Redfish (male) | 389
Lepidaplois perditio | 389
Pharyngeals of Italian Parrot-fish, Sparisoma cretense. a, Upper; b, Lower | 391
Jaws of Parrot-fish, Calotomus xenodon | 391
Cryptotomus beryllinus | 391
Sparisoma hoplomystax | 392
Sparisoma abildgaardi, Red Parrot-fish | 392
Jaws of Blue Parrot-fish, Scarus cæruleus | 393
Upper pharyngeals of a Parrot-fish, Scarus strongylocephalus | 393
Lower pharyngeals of a Parrot-fish, Scarus strongylocephalus | 393
Scarus emblematicus | 394
Scarus cæruleus, Blue Parrot-fish | 394
Scarus vetula, Parrot-fish | 395
Halichæres bivittatus, Slippery Dick or Doncella, a fish of the coral-reefs | 399
Monodactylus argenteus | 397
Psettus sebæ | 399
Chætodipterus faber, Spadefish | 401
Chætodon capistratus, Butterfly-fish | 402
Pomacanthus arcuatus, Black Angel-fish | 403
Holacanthus ciliaris, Angel-fish or Isabelita | 404
Holacanthus tricolor, Rock Beauty | 405
Zanclus canescens, Moorish Idol | 406
Teuthis cæruleus, Blue Tang | 407
Teuthis bahianus, Brown Tang | 408
Balistes carolinensis, Trigger-fish | 412
Osbeckia lævis, File-fish | 414
Amanses scopas, Needle-bearing File-fish | 414
Stephanolepis hispidus, Common File-fish | 415
Lactophrys tricornis, Horned Trunkfish, Cowfish, or Cuckold | 416
Ostracion cornutum, Horned Trunkfish | 416
Lactophrys bicaudalis, Spotted Trunkfish | 416
Lactophrys bicaudalis, Spotted Trunkfish (face view) | 417
Lactophrys triqueter, Spineless Trunkfish | 417
Lactophrys trigonus, Hornless Trunkfish | 418
Skeleton of the Cowfish, Lactophrys tricornis | 418
Lagocephalus lævigatus, Silvery Puffer | 419
Spheroides spengleri, Puffer, Inflated | 420
Spheroides maculatus, Puffer | 420
Tetraodon meleagris | 421
Tetraodon setosus, Bristly Globefish | 422
Diodon hystrix, Porcupine-fish | 422
Chilomycterus schœpfi, Rabbit-fish | 423
Mola mola, Headfish (adult) | 424
Ranzania makua, King of the Mackerel, from Honolulu | 425
Sebastes marinus, Rosefish | 427
Skull of Scorpænichthys marmoratus | 427
Sebastolobus altivelis | 428
Sebastodes mystinus, Priest-fish | 430
Sebastichthys serriceps | 431
Sebastichthys nigrocinctus, Banded Rockfish | 432
Scorpæna grandicornis, Lion-fish | 433
Scorpæna mystes, Sea-scorpion | 434
Pterois volitans, Lion-fish or Sausolele | 435
Emmydrichthys vulcanus, Black Nohu or Poison-fish | 436
Snyderina yamanokami | 437
Trachicephalus uranoscopus | 438
Anoplopoma fimbria, Skilfish | 438
Pleurogrammus monopterygius, Atka-fish | 439
Hexagrammos decagrammus, Greenling | 440
Ophiodon elongatus, Cultus Cod | 440
Jordania zonope | 442
Astrolytes notospilotus | 442
Hemilepidotus jordani, Irish Lord | 443
Triglops pingeli | 443
Enophrys bison, Buffalo Sculpin | 443
Ceratocottus diceraus | 444
Elanura forficata | 444
Cottus punctulatus, Yellowstone Miller's Thumb | 444
Uranidea tenuis, Miller's Thumb | 445
Cottus evermanni | 445
Cottus gulosus, California Miller's Thumb | 446
Myxocephalus niger, Pribilof Sculpin | 446
Myxocephalus octodecimspinosus, 18-spined Sculpin | 447
Oncocottus quadricornis | 447
Blepsias cirrhosus | 448
Hemitripterus americanus, Sea-raven | 448
Oligocottus maculosus | 449
Ereunias grallator | 450
Psychrolutes paradoxus, Sleek Sculpin | 451
Gilbertidia sigolutes | 451
Rhamphocottus richardsoni, Richardson's Sculpin | 451
Stelgis vulsus | 451
Draciscus sachi | 452
Pallasina barbata, Agonoid-fish | 453
Aspidophoroides monopterygius | 453
Cyclopterus lumpus, Lumpfish | 454
Crystallias matsushimæ, Liparid | 454
Neoliparis mucosus, Snailfish | 455
Prionotus evolans, Sea-robin | 456
Cephalacanthus volitans, Flying Gurnard | 457
Peristedion miniatum | 457
Philypnus dormitor, Guavina de Rio | 460
Eleotris pisonis, Dormeur | 460
Dormitator maculatus, Guavina mapo | 461
Vireosa hanæ | 461
Gobionellus oceanicus, Esmeralda de Mar | 461
Pterogobius daimio | 462
Aboma etheostoma, Darter Goby | 462
Gillichthys mirabilis, Long-jawed Goby | 463
Boleophthalmus chinensis, Pond-skipper | 466
Periophthalmus barbarus, Mud-skippy | 466
Eutæniichthys gillii | 467
Leptecheneis naucrates, Sucking-fish or Pegador | 468
Rhombochirus osteochir | 469
Regalecus russelli, Glesnæs Oarfish | 476
Trachypterus rex-salmonorum, Dealfish or King of the Salmon | 478
Young Flounder just hatched | 482
Pseudopleuronectes americanus, Larval Flounder | 483
Larval Stages of Platophrys podas, a Flounder | 484
Platophrys lunatus, Peacock Flounder | 485
Heterocercal Tail of Young Trout, Salmo fario | 486
Homocercal Tail of a Flounder, Paralichthys californicus | 486
Lophopsetta maculata, Window-pane | 487
Syacium papillosum, Wide-eyed Flounder | 488
Etropus crossotus | 489
Hippoglossus hippoglossus, Halibut | 492
Paralichthys dentatus, Wide-mouthed Flounder | 493
Liopsetta putnami, Eel-back Flounder | 494
Platichthys stellatus, Starry Flounder | 495
Achirus lineatus, Hog-choker Sole | 496
Symphurus plagiusa | 498
Pteropsaron evolans | 502
Bathymaster signatus | 503
Ariscopus iburius | 504
Astroscopus guttatus, Star-gazer | 505
Neoclinus satiricus, Sarcastic Blenny | 507
Gibbonsia evides, Kelp Blenny | 508
Blennius cristatus | 508
Alticus atlanticus, Rock-skipper | 509
Alticus saliens, Lizard-skipper | 509
Emblemaria atlantica | 510
Scartichthys enosimæ, Fish of the rock-pools of the sacred island of Enoshima, Japan | 510
Zacalles bryope | 511
Bryostemma tarsodes | 511
Exerpes asper | 511
Pholis gunnellus, Gunnel | 512
Xiphistes chirus | 512
Ozorthe dictyogramma | 513
Stichæus punctatus | 513
Bryostemma otohime | 514
Ptilichthys goodei, Quillfish | 514
Blochius longirostris | 514
Xiphasia setifera | 515
Cryptacanthodes maculatus, Wrymouth | 516
Anarhichas lupus, Wolf-fish | 517
Skull of Anarrhichthys ocellatus | 517
Zoarces anguillaris, Eel-pout | 518
Lycodes reticulatus, Eel-pout | 519
Lycenchelys verrilli | 519
Scytalina cerdale | 519
Rissola marginata, Cusk-eel | 520
Lycodapus dermatinus | 520
Ammodytes americanus, Sand-lance | 521
Embolichthys mitsukurii | 521
Fierasfer dubius, Pearlfish, Embedded in Pearl | 522
Fierasfer acus, Pearlfish | 523
Brotula barbata | 524
Lucifuga subterranea, Blind Brotula | 524
Opsanus pardus, Leopard Toadfish | 525
Porichthys porosissimus, Singing Fish (with Many Lateral Lines) | 526
Aspasma ciconiæ | 530
Caularchus mæandricus, Clingfish | 531
Mastacembelus ellipsifer | 532
Gadus callarias, Codfish | 533
Skull of Haddock, Melanogrammus æglifinus | 536
Melanogrammus æglifinus, Haddock | 536
Theragra chalcogramma, Pollock | 537
Microgadus tomcod, Tomcod | 538
Lota maculosa, Burbot | 539
Enchelyopus cimbrius, Four-bearded Rockling | 539
Merluccius productus, California Hake | 540
Coryphænoides carapinus, showing leptocercal tail | 540
Cælorhynchus carminatus, Grenadier | 541
Steindachnerella argentea | 541
Lophius litulon, Anko or Fishing-frog | 545
Cryptopsaras couesi | 547
Ceratias holbolli, Deep-sea Angler | 548
Caulophryne jordani | 548
Pterophryne tumida, Sargassum-fish, one of the Anglers | 549
Antennarius nox, Fishing-frog | 550
Shoulder-girdle of a Batfish, Ogcocephalus radiatus | 551
Antennarius scaber, Frogfish | 551
Ogcocephalus vespertilio | 552
Ogcocephalus vespertilio, Batfish | 553
Ogcocephalus vespertilio, Batfish | 553

ERRATA[1]
Vol. II

Page | xviii, | line | 7, | for Ophicæphalus read Ophicephalus
| xviii, | " | 37, | for Mononactylus read Monodactylus
| xix, | " | 33, | for Trachicephales read Trachicephalus
| xx, | " | 37, | for Regaleaus glesneacsanius read Regalecus russelli
| xxi, | " | 2, | for Etopus read Etropus
| xxi, | " | 35, | for Zoacres read Zoarces
| 1, | " | 7, | for jaws read jaw
| 14, | " | 9, | for hetercoercal read heterocercal
| 136, | " | 3, | for Evermannellus read Evermannella
| 170, | " | 11, | for the fin read the dorsal fin
| 171, | " | 10, | for have read has
| 303, | legend, | | for Lacepède read Lacépède
| 307, | line | 14, | for vertebrate read vertebral
| 311, | " | 12, | not clearly stated. The air-bladder is least developed in those species which cling closest to the bottom of the stream
| 350, | legend, | | for Apomotes read Apomotis
| 355, | line | 18, | for ours read our
| 357, | " | 14, | for chætodon read Chætodon
| 358, | " | 17, | for Scriænidæ read Sciænidæ
| 360, | " | 14, | for Percesoces read Percesoces
| 409, | " | 16, | for naseus read Naseus
| 419, | " | 23, | for of the generic of this group read separating the group into genera
| 440, | " | 17, | for Chinnook read Chinook
| 459, | " | 24, | for but the most read but most
| 459, | " | 25, | for thme read them
| 467, | " | 14, | for Typhogobius read Typhlogobius

472,

lines

34, 35,

omit "but never in the United States". Specimens of Regalecus have been taken at Anclote Key, Florida, and at the Tortugas.

| 580, | col. | 3, | line 17, for 165 read 105

The adoption of the Code of the International Congress of Zoology necessitates a few changes in generic names used in this book.

Thus | Amia (ganoid) | becomes | Amiatus
| Apogon | becomes | Amia
| Scarus | becomes | Callyodon
| Teuthis | becomes | Hepatus
| Acanthurus | becomes | Monoceros
| Paramia | becomes | Cheilodipterus
| Centropomus (Oxylabrax) | remains | Centropomus
| Lucioperca (Centropomus) | becomes | Sander
| Pomatomus (Cheilodipterus) | remains | Pomatomus
| Nomeus (Gobiomorus) | remains | Nomeus
| Galeus (Galeorhinus) | remains | Galeus
| Carcharias (Carcharhinus) | remains | Carcharias

1.  For most of this list of errata I am indebted to the kindly interest of Dr. B. W. Evermann.

CHAPTER I
THE GANOIDS

Subclass Actinopteri.—In our glance over the taxonomy of the earlier Chordates, or fish-like vertebrates, we have detached from the main stem one after another a long series of archaic or primitive types. We have first set off those with rudimentary notochord, then those with retrogressive development who lose the notochord, then those without skull or brain, then those without limbs or lower jaw. The residue assume the fish-like form of body, but still show great differences among themselves. We have then detached those without membrane-bones, or trace of lung or air-bladder. We next part company with those having the air-bladder a veritable lung, and those with an ancient type of paired fins, a jointed axis fringed with rays, and those having the palate still forming the upper jaw. We have finally left only those having fish-jaws, fish-fins, and in general the structure of the modern fish. For all these in all their variety, as a class or subclass, the name Actinopteri, or Actinopterygii, suggested by Professor Cope, is now generally adopted. The shorter form, Actinopteri, being equally correct is certainly preferable. This term (ακτίς, ray; πτερόν or πτερύξ, fin) refers to the structure of the paired fins. In all these fishes the bones supporting the fin-rays are highly specialized and at the same time concealed by the general integument of the body. In general two bones connect the pectoral fin with the shoulder-girdle. The hypercoracoid is a flat square bone, usually perforated by a foramen. Lying below it and parallel with it is the irregularly formed hypocoracoid. Attached to them is a row of bones, the actinosts, or pterygials, short, often hour-glass-shaped, which actually support the fin-rays. In the more specialized forms, or Teleosts, the actinosts are few (four to six) in number, but in the more primitive types, or Ganoids, they may remain numerous, a reminiscence of the condition seen in the Crossopterygians, and especially in Polypterus. Other variations may occur; the two coracoids sometimes are imperfect or specially modified, the upper sometimes without a foramen, and the actinosts may be distorted in form or position.

Fig. 1.—Shoulder-girdle of a Flounder, Paralichthys californicus (Ayres).

The Series Ganoidei.—Among the lower Actinopteri many archaic traits still persist, and in its earlier representatives the group approaches closely to the Crossopterygii, although no forms actually intermediate are known either living or fossil. The great group of Actinopteri may be divided into two series or subclasses, the Ganoidei, or Chrondrostei, containing those forms, mostly extinct, which retain archaic traits of one sort or another, and the Teleostei, or bony fishes, in which most of the primitive characters have disappeared. Doubtless all of the Teleostei are descended from a ganoid ancestry.

Even among the Ganoidei, as the term is here restricted, there remains a very great variety of form and structure. The fossil and existing forms do not form continuous series, but represent the tips and remains of many diverging branches perhaps from some Crossopterygian central stock. The group constitutes at least three distinct orders and, as a whole, does not admit of perfect definition. In most but not all of the species the tail is distinctly and obviously heterocercal, the lack of symmetry of the tail in some Teleosts being confined to the bones and not evident without dissection. Most of the Ganoids have the skeleton still cartilaginous, and in some it remains in a very primitive condition. Usually the Ganoids have an armature of bony plates, diamond-shaped, with an enamel like that developed on the teeth. In all of them the pectoral fin has numerous basal bones or actinosts. All of them have the air-bladder highly developed, usually cellular and functional as a lung, but connecting with the dorsal side of the gullet, not with the ventral side as in the Dipnoans. In all living forms there is a more or less perfect optic chiasma. These ancient forms retain also the many valves of the arterial bulb and the spiral valve of the intestines found in the more archaic types of fishes. But traces of some or all of these structures are found in some bony fishes, and their presence in the Ganoids by no means justifies the union of the Ganoids with the sharks, Dipnoans, and Crossopterygians to form a great primary class, Palæichthyes, as proposed by Dr. Günther. Almost every form of body may be found among the Ganoids. In the Mesozoic seas these fishes were scarcely less varied and perhaps scarcely less abundant than the Teleosts in the seas of to-day. They far exceed the Crossopterygians in number and variety of forms. Transitional forms connecting the two groups are thus far not recognized. So far as fossils show, the characteristic actinopterous fin with its reduced and altered basal bones appeared at once without intervening gradations.

The name Ganoidei (γάνος, brightness; εἶδος, resemblance), alluding to the enameled plates, was first given by Agassiz to those forms, mostly extinct, which were covered with bony scales or hard plates of one sort or another. As the term was originally defined, mailed catfishes, sea-horses, Agonidæ, Arthrodires, Ostracophores, and other wholly unrelated types were included with the garpikes and sturgeons as Ganoids. Most of these intruding forms among living fishes were eliminated by Johannes Müller, who recognized the various archaic characters common to the existing forms after the removal of the mailed Teleosts. Still later Huxley separated the Crossopterygians as a distinct group, while others have shown that the Ostracophori and Arthrodira should be placed far from the garpike in systematic classification. Cope, Woodward, Hay, and others have dropped the name Ganoid altogether as productive of confusion through the many meanings attached to it. Others have kept it as a convenient group name for the orders of archaic Actinopteri. For these varied and more or less divergent forms it seems convenient to retain it. As an adjective "ganoid" is sometimes used as descriptive of bony plates or enameled scales, some-in the sense of archaic, as applied to fishes.

Are the Ganoids a Natural Group?—Several writers have urged that the Ganoidei, even as thus restricted, should not be considered as a natural group, whether subclass, order, or group of orders. The reasons for this view in brief are the following:

1. The group is heterogeneous. The Amiidæ differ more from the other Ganoids than they do from the herring-like Teleosts. The garpikes, sturgeons, paddle-fishes likewise diverge widely from each other and from the Palæoniscidæ and the Platysomidæ. Each of the living families represents the residue or culmination of a long series, in some cases advancing, as in the case of the bowfin, sometimes perhaps degenerating, as in the case of the sturgeons.

2. Of the traits possessed in common by these forms, several (the cellular air-bladder, the many valves in the heart, the spiral valve in the intestine, the heterocercal tail) are all possessed in greater or less degree by certain Isospondyli or allies of the herring. All these characters are still better developed in Crossoptergyii and Dipneusti, and each one disappears by degrees. Of the characters drawn from the soft parts we can know nothing so far as the extinct Ganoids are concerned.

3. The optic chiasma, thus far characteristic of Ganoids as distinct from Teleosts, may have no great value. It is urged that in closely related species of lizards some have the optic chiasma and others do not. This, however, proves nothing as to the value of the same character among fishes.

4. The transition from Ganoids to Teleosts is of much the same character as the transition from spiny-rayed to soft-rayed fishes, or that from fishes with a duct to the air-bladder to those without such duct.

Admitting all this, it is nevertheless natural and convenient to retain the Ganoidei (or Chrondrostei if the older name be discarded on account of the many meanings attached to it) as a group equivalent to that of Teleostei within the class or subclass of Actinopteri. It comprises the transitional forms between the Crossopterygii and the bony fishes, and its members are especially characteristic of the Mesozoic age, ranging from the Devonian to the present era.

Of the extensive discussion relating to this important question we may quote two arguments for the retention of the subclass of Ganoids, the first by Francis M. Balfour and William Kitchen Parker, the second from the pen of Theodore Gill.

Balfour and Parker ("Structure and Development of Lepidosteus," pp. 430-433) thus discuss the

Systematic Position of Lepidosteus.—"Alexander Agassiz concludes his memoir on the development of Lepidosteus by pointing out that in spite of certain affinities in other directions this form is 'not so far removed from the bony fishes as has been supposed.' Our own observations go far to confirm Agassiz's opinion.

"Apart from the complete segmentation, the general development of Lepidosteus is strikingly Teleostean. In addition to the general Teleostean features of the embryo and larva, which can only be appreciated by those who have had an opportunity of practically working at the subject, we may point to the following developmental features[2] as indicative of Teleostean affinities:

"(1) The formation of the nervous system as a solid keel of the epiblast.

"(2) The division of the epiblast into a nervous and epidermic stratum.

"(3) The mode of development of the gut.

"(4) The mode of development of the pronephros; though the pronephros of Lepidosteus has primitive characters not retained by Teleostei.

"(5) The early stages in the development of the vertebral column.

2.  The features enumerated above are not in all cases confined to Lepidosteus and Teleostei, but are always eminently characteristic of the latter.

"In addition to these, so to speak, purely embryonic characters there are not a few important adult characters:

"(1) The continuity of the oviducts with the genital glands.

"(2) The small size of the pancreas, and the presence of numerous so-called pancreatic cæca.

"(3) The somewhat coiled small intestine.

"(4) Certain characters of the brain, e.g., the large size of the cerebellum; the presence of the so-called lobi inferiores on the infundibulum, and of tori semi-circulares in the mid-brain.

"In spite of the undoubtedly important list of features to which we have just called attention, a list containing not less important characters, both embryological and adult, separating Lepidosteus from the Teleostei, can be drawn up:

"(1) The character of the truncus arteriosus.

"(2) The fact of the genital ducts joining the ureters.

"(3) The presence of vasa efferentia in the male carrying the semen from the testes to the kidney, and through the tubules of the latter into the kidney-duct.

"(4) The presence of a well-developed opercular gill.

"(5) The presence of a spiral valve; though this character may possibly break down with the extension of our knowledge.

"(6) The typical Ganoid characters of the thalamencephalon and the cerebral hemispheres.

"(7) The chiasma of the optic nerves.

"(8) The absence of a pecten, and presence of a vascular membrane between the vitreous humor and the retina.

"(9) The opisthocœlous form of the vertebræ.

"(10) The articulation of the ventral parts of the hæmal arches of the tail with the processes of the vertebral column.

"(11) The absence of a division of the muscles into dorso-lateral and ventro-lateral divisions.

"(12) The complete segmentation of the ovum.

"The list just given appears to us sufficient to demonstrate that Lepidosteus cannot be classed with the Teleostei; and we hold that Müller's view is correct, according to which Lepidosteus is a true Ganoid.

"The existence of the Ganoids as a distinct group has, however, recently been challenged by so distinguished an ichthyologist as Günther, and it may therefore be well to consider how far the group as defined by Müller is a natural one for living forms, and how far recent researches enable us to improve upon Müller's definitions. In his classical memoir the characters of the Ganoids are thus shortly stated:

"'These fishes are either provided with plate-like angular or rounded cement-covered scales, or they bear osseous plates, or are quite naked. The fins are often, but not always, beset with a double or single row of spinous plates or splints. The caudal fin embraces occasionally in its upper lobe the end of the vertebral column, which may be prolonged to the end of the upper lobe. Their double nasal openings resemble those of Teleostei. The gills are free, and lie in a branchial cavity under an operculum, like those of Teleostei. Many of them have an accessory organ of respiration, in the form of an opercular gill, which is distinct from the pseudobranch, and can be present together with the latter; many also have spiracles like Elasmobranchii. They have many valves in the stem of the aorta like the latter, also a muscular coat in the stem of the aorta. Their ova are transported from the abdominal cavity by oviducts. Their optic nerves do not cross each other. The intestine is often provided with a spiral valve, like Elasmobranchii. They have a swimming-bladder with a duct, like many Teleostei. Their pelvic fins are abdominal.

"'If we include in a definition only those characters which are invariable, the Ganoids may be shortly defined as being those fish with numerous valves to the stem of the aorta, which is also provided with a muscular coat, with free gills, and an operculum, and with abdominal pelvic fins.'

"To these distinctive characters he adds, in an appendix to his paper, the presence of the spiral valve, and the absence of a processus falciformis and a choroid gland.

"To the distinctive set of characters given by Müller we may probably add the following:

"(1) Oviducts and urinary ducts always unite, and open by a common urogenital aperture behind the anus.

"(2) Skull hyostylic.

"(3) Segmentation complete in the types so far investigated, though perhaps Amia may be found to resemble the Teleostei in this particular.

"(4) A pronephros of the Teleostean type present in the larva.

"(5) Thalamencephalon very large and well developed.

"(6) The ventricle in the posterior part of the cerebrum is not divided behind into lateral halves, the roof of the undivided part being extremely thin.

"(7) Abdominal pores always present.

"The great number of characters just given are amply sufficient to differentiate the Ganoids as a group; but, curiously enough, the only characters, amongst the whole series which have been given, which can be regarded as peculiar to the Ganoids are (1) the characters of the brain, and (2) the fact of the oviducts and kidney-ducts uniting together and opening by a common pore to the exterior.

"This absence of characters peculiar to the Ganoids is an indication of how widely separated in organization are the different members of this great group.

"At the same time, the only group with which existing Ganoids have close affinities is the Teleostei. The points they have in common with the Elasmobranchii are merely such as are due to the fact that both retain numerous primitive vertebrate characters,[3] and the gulf which really separates them is very wide.

3.  As instances of this we may cite (1) the spiral valve; (2) the frequent presence of a spiracle; (3) the frequent presence of a communication between the pericardium and the body-cavity; (4) the heterocercal tail.

"There is again no indication of any close affinity between the Dipnoans and, at any rate, existing Ganoids.

"Like the Ganoids, the Dipnoans are no doubt remnants of a very primitive stock; but in the conversion of the air-bladder into a true lung, the highly specialized character of their limbs,[4] their peculiar autostylic skulls, the fact of their ventral nasal openings leading directly into the mouth, their multi-segmented bars (interspinous bars) directly prolonged from the neural and hæmal and supporting the fin-rays of the unpaired dorsal and ventral fins, and their well-developed cerebral hemispheres, very unlike those of Ganoids and approaching the Amphibian type, they form a very well-defined group and one very distinctly separated from the Ganoids.

4.  Vide F. M. Balfour, "On the Development of the Skeleton of the Paired Fins of Elasmobranchs," Proc. Zool. Soc., 1881.

"No doubt the Chondrostean Ganoids are nearly as far removed from the Teleostei as from the Dipnoans, but the links uniting these Ganoids with the Teleostei have been so fully preserved in the existing fauna of the globe that the two groups almost run into each other. If, in fact, we were anxious to make any radical change in the ordinary classification of fishes, it would be by uniting the Teleostei and Ganoids, or rather constituting the Teleostei into one of the subgroups of the Ganoids, equivalent to the Chondrostei. We do not recommend such an arrangement, which in view of the great preponderance of the Teleostei amongst living fishes would be highly inconvenient, but the step from Amia to the Teleostei is certainly not so great as that from the Chondrostei to Amia, and is undoubtedly less than that from the Selachii to the Holocephali."

Gill on the Ganoids as a Natural Group.—Dr. Gill observes ("Families of Fishes," 1872): "The name Ganoides (or Ganiolepedoti) was originally framed by Prof. Agassiz as an ordinal term for fishes having the scales (when present) angular and covered with enamel; and in the group so characterized were combined the Ganoids of subsequent authors as well as the Teleostean orders Plectognathi, Lophobranchii, and Nematognathi, and (subsequently) the genus Sudis (Arapaima), the last being regarded as a Cœlacanth. The group has not been accepted with these limits or characters.

"But the researches of Prof. Johannes Müller on the anatomy and classification of the fishes culminated at length in his celebrated memoirs on those fishes for which he retained the ordinal name Ganoidei; those memoirs have left an impression on ichthyology perhaps more decided than made by any other contributions to science, and that published in extenso will ever be classical; numerous as have been the modifications since introduced into the system, no forms except those recognized by Müller (unless it be Dipnoi) have been interjected since among the Ganoids.

"It has been objected that the Ganoids do not constitute a natural group, and that the characters (i.e., chiasma of optic nerves and multivalvular bulbus arteriosus) alleged by Müller to be peculiar to the teleostomous forms combined therein are problematical, and only inferentially supposed to be common to the extinct Ganoids so called, and, finally, such objections couched in too strong language have culminated in the assertion that the characters in question are actually shared by other physostome fishes.

"No demonstration, however, has been presented as yet that any physostome fishes do really have the optic chiasma and multivalvular bulbus arteriosus, and the statement to the contrary seems to have been the result of a venial misapprehension of Prof. Kner's statements, or the offspring of impressions left on the memory by his assertions, in forgetfulness of his exact words.

"But Prof. Kner, in respect to the anatomical characters referred to, merely objects: (1) that they are problematical, are not confirmable for the extinct types, and were probably not existent in certain forms that have been referred to the Ganoids; (2) the difference in number of the valves of the bulbus arteriosus among recent Ganoids is so great as to show the unreliability of the character; (3) a spiral valve is developed in the intestine of several osseous fishes ('genera of the so-called intermediate clupeoid groups'), as well as in Ganoids; and (4) the chiasma of the optic nerves in no wise furnishes a positive character for the Ganoids.

"It will be noticed that all these objections (save in the case of the intestinal spiral valve) are hypothetical and vague. The failure of the intestinal spiral valve, as a diagnostic character, has long been conceded, and in this case only have the forms that prove the failure been referred to; in the other cases, where it would be especially desirable to have indicated the actual types falsifying the universality or exclusiveness of the characters, they have not been referred to, and the objections must be met as if they were not known to exist.

"(1) The characters in question are, in the sense used, problematical, inasmuch as no examination can be made of the soft parts of extinct forms, but with equal force may it be urged that any characters that have not been or cannot be directly confirmed are problematical in the case of all other groups (e.g., mammals), and it can only be replied that the coordination of parts has been so invariably verified that all probabilities are in favor of similar coordination in any given case.

"(2) There is doubtless considerable difference in the number of valves of the bulbus arteriosus among the various Ganoids, and even among the species of a single family (e.g., Lepidosteidæ), but the character of Ganoids lies not in the number, more or less, but in the greater number and relations (in contradistinction to the opposite pair of the Teleosts) in conjunction with the development of a bulbus arteriosus. In no other forms of Teleostomes have similar relations and structures been yet demonstrated.

"(3) The failure of the spiral intestinal valve has already been conceded, and no great stress has ever been laid on the character.

"(4) The chiasma of the optic nerves is so common to all the known Ganoids, and has not been found in those forms (e.g., Arapaima, Osteoglossum, and Clupeiform types) agreeing with typical physostome Teleosts in the skeleton, heart, etc., but which at the same time simulate most certain Ganoids (e.g., Amia) in form.

"Therefore, in view of the evidence hitherto obtained, the arguments against the validity of title, to natural association, of the Ganoids, have to meet the positive evidence of the coordinations noted; the value of such characteristics and coordinations can only be affected or destroyed by the demonstration that in all other respects there is (1) very close agreement of certain of the constituents of the subclass with other forms, and (2) inversely proportionate dissimilarity of those forms from any (not all) other of the Ganoids, and consequently evidence ubi plurima nitent against the taxonomic value of the characters employed for distinction.

"And it is true that there is a greater superficial resemblance between the Hyoganoids (Lepisosteus, Amia, etc.) and ordinary physostome Teleosts than between the former and the other orders of Ganoids, but it is equally true that they agree in other respects than in the brain and heart with the more generalized Ganoids. They all have, for example, (1) the paraglenal elements undivided (not disintegrated into hypercoracoid, hypocoracoid, and mesocoracoid); (2) a humerus (simple or divided, that is, differentiated into metapterygium and mesopterygium); and (3) those with ossified skeletons agree in the greater number of elements in the lower jaw. Therefore, until these coordinates fail, it seems advisable to recognize the Ganoids as constituents of a natural series; and especially on account of the superior taxonomic value of modifications of the brain and heart in other classes of vertebrates, for the same reason, and to keep prominently before the mind the characters in question, it appears also advisable to designate the series, until further discovery, as a subclass.

"But it is quite possible that among some of the generalized Teleosts at least traces of some of the characters now considered to be peculiar to the Ganoids may be discovered. In anticipation of such a possibility, the author had at first discarded the subclass, recognizing the group only as one of the 'superorders' of the Teleostomes, but reconsideration convinces him of the propriety of classification representing known facts and legitimate inferences rather than too much anticipation.

"It is remembered that all characters are liable to fail with increasing knowledge, and the distinctness of groups are but little more than the expressions of our want of knowledge of the intermediate forms; it may in truth be said that ability to segregate a class into well-defined groups is in ratio to our ignorance of all the terms."

CHAPTER II
THE GANOIDS—Continued

Classification of Ganoids.—The subdivision of the series of Ganoidei into orders offers great difficulty from the fact of the varying relationships of the members of the group and the fact that the great majority of the species are known only from broken skeletons preserved in the rocks. It is apparently easy to separate those with cartilaginous skeletons from those with these bones more or less ossified. It is also easy to separate those with bony scales or plates from those having the scales cycloid. But the one type of skeleton grades into the other, and there is a bony basis even to the thinnest of scales found in this group. Among the multitude of names and divisions proposed we may recognize six orders, for which the names Lysopteri, Chondrostei, Selachostomi, Pycnodonti, Lepidostei, and Halecomorphi are not inappropriate. Each of these seems to represent a distinct offshoot from the first primitive group.

Order Lysopteri.—In the most primitive order, called Lysopteri (λυσός, loose; πτερόν, fin) by Cope, Heterocerci by Zittel and Eastman, and the "ascending series of Chondrostei" by Woodward, we find the nearest approach to the Chondropterygians. In this order the arches of the vertebræ are more or less ossified, the body is more or less short and deep, covered with bony dermal plates. The opercular apparatus is well developed, with numerous branchiostegals. Infraclavicles are present, and the fins provided with fulcra. Dorsal and anal fins are present, with rays more numerous than their supports; ventral fin with basal supports which are imperfectly ossified; caudal fin mostly heterocercal, the scales mostly rhombic in form. All the members of this group are now extinct.

The Palæoniscidæ.—The numerous genera of this order are referred to three families, the Palæoniscidæ, Platysomidæ, and Dictyopygidæ; a fourth family, Dorypteridæ, of uncertain relations, being also tentatively recognized. The family of Palæoniscidæ is the most primitive, ranging from the Devonian to the Lias, and some of them seem to have entered fresh waters in the time of the coal-measures. These fishes have the body elongate and provided with one short dorsal fin. The tail is heterocercal and the body covered with rhombic plates. Fulcra or rudimentary spine-like scales are developed on the upper edge of the caudal fin in most recent Ganoids, and often the back has a median row of undeveloped scales. A multitude of species and genera are recorded. A typical form is the genus Palæoniscum,[5] with many species represented in the rocks of various parts of the world. The longest known species is Palæoniscum frieslebenense from the Permian of Germany and England. Palæoniscum magnum, sixteen inches long, occurs in the Permian of Germany. From Canobius, the most primitive genus, to Coccolepis, the most modern, is a continuous series, the suspensorium of the lower jaw becoming more oblique, the basal bones of the dorsal fewer, the dorsal extending farther forward, and the scales more completely imbricate. Other prominent genera are Amblypterus, Eurylepis, Cheirolepis, Rhadinichthys, Pygopterus, Elonichthys, Ærolepis, Gyrolepis, Myriolepis, Oxygnathus, Centrolepis, and Holurus.

5.  This word is usually written Palæoniscus, but Blainville, its author (1818), chose the neuter form.

Fig. 2.—Palæoniscum frieslebenense Blainville. Family Palæoniscidæ. (After Zittel.)

The Platysomidæ.—The Platysomidæ are different in form, the body being deep and compressed, often diamond-shaped, with very long dorsal and anal fins. In other respects they are very similar to the Palæoniscidæ, the osteology being the same. The Palæoniscidæ were rapacious fishes with sharp teeth, the Platysomidæ less active, and, from the blunter teeth, probably feeding on small animals, as crabs and snails.

The rhombic enameled scales are highly specialized and held together as a coat of mail by peg-and-socket joints. The most extreme form is Platysomus, with the body very deep. Platysomus gibbosus and other species occur in the Permian rocks of Germany. Cheirodus is similar to Platysomus, but without ventral fins. Eurynotus, the most primitive genus, is remarkable for its large pectoral fins. Eurynotus crenatus occurs in the Subcarboniferous of Scotland. Other genera are Mesolepis, Globulodus, Wardichthys, and Cheirodopsis.

Fig. 3.—Eurynotus crenatus Agassiz, restored. Carboniferous. Family Platysomidæ. (After Traquair.)

Some of the Platysomidæ have the interneural spines projecting through the skin before the dorsal fin. This condition is found also in certain bony fishes allied to the Carangidæ.

The Dorypteridæ.—Dorypterus hoffmani, the type of the singular Palæozoic family of Dorypteridæ, with thoracic or sub-jugular many-rayed ventrals, is Stromateus-like to all appearance, with distinct resemblances to certain Scombroid forms, but with a heterocercal tail like a ganoid, imperfectly ossified back-bone, and other very archaic characters. The body is apparently scaleless, unlike the true Platysomidæ, in which the scales are highly developed. A second species, Dorypterus althausi, also from the German copper shales, has been described. This species has lower fins than Dorypterus hoffmani, but may be the adult of the same type. Dorypterus is regarded by Woodward as a specialized offshoot from the Platysomidæ. The many-rayed ventrals and the general form of the body and fins suggest affinity with the Lampridæ.

Fig. 4.—Dorypterus hoffmani Germar, restored. (After Hancock and Howse.)

Dictyopygidæ.—In the Dictyopygidæ (Catopteridæ), the body is gracefully elongate, less compressed, the heterocercal tail is short and abruptly turned upwards, the teeth are sharp and usually hooked, and the bony plates well developed. Of this group two genera are recognized, each containing numerous species. In Redfieldius (= Catopterus Redfield, not of Agassiz) the dorsal is inserted behind the anal, while in Dictyopyge this is not the case. Redfieldius gracilis and other species are found in the Triassic of the Connecticut River. Dictyopyge macrura is found in the same region, and Dictyopyge catoptera and other species in Europe.

Order Chondrostei.—The order Chondrostei (χόνδρος, cartilage; ὀστέον, bone), as accepted by Woodward, is characterized by the persistence of the notochord in greater or less degree, the endoskeleton remaining cartilaginous. In all, the axonosts and baseosts of the median fins are arranged in simple regular series and the rays are more numerous than the supporting elements. The shoulder-girdle has a pair of infraclavicular plates. The pelvic fins have well-developed baseosts. The branchiostegals are few or wanting. In the living forms, and probably in all others, a matter which can never be ascertained, the optic nerves are not decussating, but form an optic chiasma, and the intestine is provided with a spiral valve. In all the species there is one dorsal and one anal fin, separate from the caudal. The teeth are small or wanting, the body naked or covered with bony plates; the caudal fin is usually heterocercal, and on the tail are rhombic plates. To this order, as thus defined, about half of the extinct Ganoids belong, as well as the modern degenerate forms known as sturgeons and perhaps the paddle-fishes, which are apparently derived from fishes with rhombic enameled scales. The species extend from the Upper Carboniferous to the present time, being most numerous in the Triassic.

At this point in Woodward's system diverges a descending series, characterized as a whole by imperfect squamation and elongate form, this leading through the synthetic type of Chondrosteidæ to the modern sturgeon and paddle-fish, which are regarded as degenerate types.

The family of Saurorhynchidæ contains pike-like forms, with long jaws, and long conical teeth set wide apart. The tail is not heterocercal, but short-diphycercal; the bones of the head are covered with enamel, and those of the roof of the skull form a continuous shield. The opercular apparatus is much reduced, and there are no branchiostegals. The fins are all small, without fulcra, and the skin has isolated longitudinal series of bony scutes, but is not covered with continuous scales. The principal genus is Saurorhynchus (= Belonorhynchus; the former being the earlier name) from the Triassic. Saurorhynchus acutus from the English Triassic is the best known species.

The family of Chondrosteidæ includes the Triassic precursors of the sturgeons. The general form is that of the sturgeon, but the body is scaleless except on the upper caudal lobe, and there are no plates on the median line of the skull. The opercle and subopercle are present, the jaws are toothless, and there are a few well-developed caudal rays. The caudal has large fulcra. The single well-known species of this group, Chondrosteus acipenseroides, is found in the Triassic rocks of England and reaches a length of about three feet. It much resembles a modern sturgeon, though differing in several technical respects. Chondrosteus pachyurus is based on the tail of a species of much larger size and Gyrosteus mirabilis, also of the English Triassic, is known from fragments of fishes which must have been 18 to 20 feet in length.

Fig. 5.—Chondrosteus acipenseroides Egerton. Family Chondrosteidæ. (After Woodward.)

The sturgeons constitute the recent family of Acipenseridæ, characterized by the prolonged snout and toothless jaws and the presence of four barbels below the snout. In the Acipenseridæ there are no branchiostegals and a median series of plates is present on the head. The body is armed with five rows of large bony bucklers,—each often with a hooked spine, sharpest in the young. Besides these, rhombic plates are developed on the tail, besides large fulcra. The sturgeons are the youngest of the Ganoids, not occurring before the Lower Eocene, one species, Acipenser toliapicus occurring in the London clay. About thirty living species of sturgeon are known, referred to three genera: Acipenser, found throughout the Northern Hemisphere, Scaphirhynchus, in the Mississippi Valley, and Kessleria (later called Pseudoscaphirhynchus), in Central Asia alone. Most of the species belong to the genus Acipenser, which abounds in all the rivers and seas in which salmon are found. Some of the smaller species spend their lives in the rivers, ascending smaller streams to spawn. Other sturgeons are marine, ascending fresh waters only for a moderate distance in the spawning season. They range in length from 2½ to 30 feet.

All are used as food, although the flesh is rather coarse and beefy. From their large size and abundance they possess great economic value. The eggs of some species are prepared as caviar.

Fig. 6.—Common Sturgeon, Acipenser sturio Mitchill. Potomac River.

The sturgeons are sluggish, clumsy, bottom-feeding fish. The mouth, underneath the long snout, is very protractile, sucker-like, and without teeth. Before it on the under side of the snout are four long feelers. Ordinarily the sturgeon feeds on mud and snails with other small creatures, but I have seen large numbers of Eulachon (Thaleichthys) in the stomach of the Columbia River sturgeon (Acipenser transmontanus). This fish and the Eulachon run in the Columbia at the same time, and the sucker-mouth of a large sturgeon will draw into it numbers of small fishes who may be unsuspiciously engaged in depositing their spawn. In the spawning season in June these clumsy fishes will often leap wholly out of the water in their play. The sturgeons have a rough skin besides five series of bony plates which change much with age and which in very old examples are sometimes lost or absorbed in the skin. The common sturgeon of the Atlantic on both shores is Acipenser sturio. Acipenser huso and numerous other species are found in Russia and Siberia. The great sturgeon of the Columbia is Acipenser transmontanus, and the great sturgeon of Japan Acipenser kikuchii. Smaller species are found farther south, as in the Mediterranean and along the Carolina coast. Other small species abound in rivers and lakes. Acipenser rubicundus is found throughout the Great Lake region and the Mississippi Valley, never entering the sea. It is four to six feet long, and at Sandusky, Ohio, in one season 14,000 sturgeons were taken in the pound nets. A similar species, Acipenser mikadoi, is abundant and valuable in the streams of northern Japan.

Fig. 7.—Lake Sturgeon, Acipenser rubicundus Le Sueur. Ecorse, Mich.

In the genus Acipenser the snout is sharp and conical, and the shark-like spiracle is still retained.

Fig. 8.—Shovel-nosed Sturgeon. Scaphirhynchus platyrhynchus (Rafinesque). Ohio River.

The shovel-nosed sturgeon (Scaphirhynchus platyrhynchus) has lost the spiracles, the tail is more slender, its surface wholly bony, and the snout is broad and shaped like a shovel. The single species of Scaphirhynchus abounds in the Mississippi Valley, a fish more interesting to the naturalist than to the fisherman. It is the smallest of our sturgeons, often taken in the nets in large numbers.

In Scaphirhynchus the tail is covered by a continuous coat of mail. In Kessleria[6] fedtschenkoi, rossikowi, and other Asiatic species the tail is not mailed.

6.  These species have also been named Pseudoscaphirhynchus. Kessleria is the earlier name, left undefined by its describer, although the type was indicated.

Order Selachostomi: the Paddle-fishes.—Another type of Ganoids, allied to the sturgeons, perhaps still further degenerate, is that of the paddle-fishes, called by Cope Selachostomi (σέλαχος, shark; στόμα, mouth). This group consists of a single family, Polyodontidæ, having apparently little in common with the other Ganoids, and in appearance still more suggestive of the sharks. The common name of paddle-fishes is derived from the long flat blade in which the snout terminates. This extends far beyond the mouth, is more or less sensitive, and is used to stir up the mud in which are found the minute organisms on which the fish feeds. Under the paddle are four very minute barbels corresponding to those of the sturgeons. The vernacular names of spoonbill, duckbill cat, and shovel-fish are also derived from the form of the snout. The skin is nearly smooth, the tail is heterocercal, the teeth are very small, and a long fleshy flap covers the gill-opening. The very long and slender gill-rakers serve to strain the food (worms, leeches, water-beetles, crustaceans, and algæ) from the muddy waters from which they are taken. The most important part of this diet consists of Entomostracans. The single American species, Polyodon spathula, abounds through the Mississippi Valley in all the larger streams. It reaches a length of three or four feet. It is often taken in the nets, but the coarse tough flesh, like that of our inferior catfish, is not much esteemed. In the great rivers of China, the Yangtse and the Hoang Ho, is a second species, Psephurus gladius, with narrower snout, fewer gill-rakers, and much coarser fulcra on the tail. The habits, so far as known, are much the same.

Fig. 9.—Paddle-fish, Polyodon spathula (Walbaum). Ohio River.

Fig. 10.—Paddle-fish. Polyodon Spathula (Walbaum). Ohio River.

Fig. 11.—Psephurus gladius Günther. Yangtse River. (After Günther.)

Crossopholis magnicaudatus of the Green River Eocene shales is a primitive member of the Polyodontidæ. Its rostral blade is shorter than that of Polyodon, and the body is covered with small thin scales, each in the form of a small grooved disk with several posterior denticulations, arranged in oblique series but not in contact. The scales are quadrate in form, and more widely separated anteriorly than posteriorly. As in Polyodon, the teeth are minute and there are no branchiostegals. The squamation of this fish shows that Polyodon as well as Acipenser may have sprung from a type having rhombic scales. The tail of a Cretaceous fish, Pholidurus disjectus from the Cretaceous of Europe, has been referred with doubt to this family of Polyodontidæ.

Order Pycnodonti.—In the extinct order Pycnodonti, as recognized by Dr. O. P. Hay, the notochord is persistent and without ossification, the body is very deep, the teeth are always blunt, the opercular apparatus is reduced, the dorsal fin many-rayed, and the fins without fulcra. The scales are rhombic, but are sometimes wanting, at least on the tail. Many genera and species of Pycnodontidæ are described, mostly from Triassic and Jurassic rocks of Europe. Leading European genera are Pycnodus, Typodus (Mesodon), Gyrodus, and Palæobalistum. The numerous American species belong to Typodus, Cœlodus, Pycnodus, Hadrodus, and Uranoplosus. These forms have no affinity with Balistes, although there is some resemblance in appearance, which has suggested the name of Palæobalistum.

Fig. 12.—Gyrodus hexagonus Agassiz. Family Pycnodontidæ. Lithographic Shales.

Woodward places these fishes with the Semionotidæ and Halecomorphi in his suborder of Protospondyli. It seems preferable, however, to consider them as forming a distinct order.

Fig. 13.—Mesturus verrucosus Wagner. Family Pycnodontidæ. (After Woodward.)

Order Lepidostei.—We may place, following Eastman's edition of Zittel, the allies and predecessors of the garpike in a single order, for which Huxley's name Lepidostei may well be used. In this group the notochord is persistent, and the vertebræ are in various degrees of ossification and of different forms. The opercles are usually complete, the branchiostegals present, and there is often a gular plate. There is no infraclavicle and the jaws have sharp teeth. The fins have fulcra, and the supports of the fins agree in number with the rays. The tail is more or less heterocercal. The scales are rhombic, arranged in oblique series, which are often united above and below with peg-and-socket articulations. This group contains among recent fishes only the garpikes (Lepisosteus). They are closely allied to the Palæoniscidæ, but the skeleton is more highly ossified. On the other hand they approach very closely to the ancestors of the bowfin, Amia. One genus, Acentrophorus, appears in the Permian; the others are scattered through Mesozoic and Tertiary rocks, the isolated group of gars still persisting. In the gars the vertebræ are concavo-convex, with ball-and-socket joints. In the others the vertebræ are incomplete or else double-concave, as in fishes generally.

For the group here called Lepidostei numerous other names have been used corresponding wholly or in part. Rhomboganoidea of Gill covers nearly the same groups; Holostei of Müller and Hyoganoidea of Gill include the Halecomorphi also; Ginglymodi of Cope includes the garpikes only, while Ætheospondyli of Woodward includes the Aspidorhynchidæ and the garpikes.

Fig. 14.—Semionotus kapffi Fraas, restored. Family Semionotidæ. (After Fraas, per Nicholson.)

The Semionotidæ (Stylodontidæ) are robust-bodied Ganoids, having the vertebræ developed as rings, the jaws with several rows of teeth, those of the outer row styliform.

Semionotus bergeri is a well-known species, with the body moderately elongate. Semionotus agassizi and many other species occur in the Triassic of the Connecticut valley and in New Jersey. The body is very deep in the related genus Dapedium, and the head is covered with strong bony plates. Dapedium politum is a well-known species of the English Triassic. Tetragonolepis (Pleurolepis) is a similar form, very deep and compressed, with strong, firm scales.

In the extinct family of Lepidotidæ the teeth are conical or chisel-shaped, while blunt or molar teeth are on the inside of the mouth, which is small, and the suspensorium of the mandible is vertical or inclined forward. The body is robust-fusiform, covered with rhomboid scales; the vertebræ form rings about the notochord; the teeth are either sharp or blunt. The dorsal fin is short, with large fulcra.

The best known of the numerous genera are Lepidotes, rather elongate in body, with large, blunt teeth. Of the many species of Lepidotes, Lepidotes elvensis abounds in the English and German Triassic, and Lepidotes minor in the English Triassic. Another well-known European species is Lepidotes mantelli.

Fig. 15.—Dapedium politum Leach, restored. Family Semionotidæ. (After Woodward.)

The Isopholidæ (Eugnathidæ) differ from the families last named in the large pike-like mouth with strong teeth. The mandibular suspensorium is inclined backwards. The body is elongate, the vertebræ forming incomplete rings; the dorsal fin is short with large fulcra.

Isopholis dentosus is found with numerous other species in the British Triassic. Caturus furcatus is especially characteristic of Triassic rocks in Germany. Ptycholepis marshi occurs in the Connecticut valley.

Fig. 16.—Tetragonolepis semicinctus Brown. Lias. Family Semionotidæ. (After Woodward.)

The Macrosemiidæ are elongate fishes with long dorsal fin, the numerous species being found in the Triassic, Jurassic, and Cretaceous of Europe. Macrosemius rostratus has a very high, continuous dorsal. Macropistius arenatus is found in the Cretaceous of Texas, the only American species known. Prominent European genera are Notagogus, Ophiopsis, and Petalopteryx.

Fig. 17.—Isopholis orthostomus (Agassiz). Lias. (After Woodward.)

Fig. 18.—The Long-nosed Garpike, Lepisosteus osseus (Linnæus). Fox River, Wisconsin. (From nature; D. S. Jordan and M. L. McDonald, 1874.)

Intermediate between the allies of the gars and the modern herrings is the large extinct family of Pholidophoridæ, referred by Woodward to the Isospondyli, and by Eastman to the Lepidostei. These are small fishes, fusiform in shape, chiefly of the Triassic and Jurassic. The fins are fringed with fulcra, the scales are ganoid and rhombic, and the vertebræ reduced to rings. The mouth is large, with small teeth, and formed as in the Isospondyli. The caudal is scarcely heterocercal.

Fig. 19.—Caturus elongatus Agassiz. Jurassic. Family Isopholidæ. (After Zittel.)

Fig. 20.—Notagogus pentlandi Agassiz. Jurassic. Family Macrosemiidæ. (After Woodward.)

Fig. 21.—Ptycholepis curtus Egerton. Lias. Family Isopholidæ. (After Woodward.)

Of Pholidophorus, with scales joined by peg-and-socket joints and uniform in size, there are many species. Pholidophorus latiusculus and many others are found in the Triassic of England and the Continent. Pholidophorus americanus occurs in the Jurassic of South Dakota. Pleuropholis, with the scales on the lateral line, which runs very low, excessively deepened, is also widely distributed. I have before me a new species from the Cretaceous rocks near Los Angeles. The Archæomænidæ differ from Pholidophoridæ in having cycloid scales. In both families the vertebræ are reduced to rings about the notochord. From fishes allied to the Pholidophoridæ the earliest Isospondyli are probably descended.

Fig. 22.—Pholidophorus crenulatus Egerton. Lias. (After Woodward.)

In the Aspidorhynchidæ the snout is more or less produced, the mandible has a distinct presymphysial bone, the vertebræ are double-concave or ring-like, and the fins are without fulcra. This family constitutes the suborder Ætheospondyli. In form these fishes resemble Albula and other modern types, but have mailed heads and an ancient type of scales. Two genera are well known, Aspidorhynchus and Belonostomus. Aspidorhynchus acutirostris reaches a length of three feet, and is found in the Triassic lithographic stone of Bavaria. Other species occur in rocks of Germany and England.

Belonostomus has the snout scarcely produced. Belonostomus sphyrænoides is the best known of the numerous species, all of the Triassic, Jurassic, and Cretaceous.

Family Lepisosteidæ.—The family of Lepisosteidæ, constituting the suborder Ginglymodi (γιγγλυμός, hinge), is characterized especially by the form of the vertebræ.

These are opisthocœlian, convex in front and concave behind, as in reptiles, being connected by ball-and-socket joints. The tail is moderately heterocercal, less so than in the Halecomorphi, and the body is covered with very hard, diamond-shaped, enameled scales in structure similar to that of the teeth. A number of peculiar characters are shown by these fishes, some of them having often been regarded as reptilian traits. Notable features are the elongate, crocodile-like jaws, the upper the longer, and both armed with strong teeth. The mandible is without presymphysial bone. The fins are small with large fulcra, and the scales are nearly uniform in size.

All the species belong to a single family, Lepisosteidæ, which includes the modern garpikes and their immediate relatives, some of which occur in the early Tertiary. These voracious fishes are characterized by long and slender cylindrical bodies, with enameled scales and mailed heads and heterocercal tail. The teeth are sharp and unequal. The skeleton is well ossified, and the animal itself is extremely voracious. The vertebræ, reptile-like, are opisthocœlian, that is, convex in front, concave behind, forming ball-and-socket joints. In almost all other fishes they are amphicœlian or double-concave, the interspace filled with gelatinous substance. The recent species, and perhaps all the extinct species also, belong to the single genus Lepisosteus (more correctly, but also more recently, spelled Lepidosteus). Of existing forms there are not many species, three to five at the most, and they swarm in the lakes, bayous, and sluggish streams from Lake Champlain to Cuba and along the coast to Central America. The best known of the species is the long-nosed garpike, Lepisosteus osseus, which is found throughout most of the Great Lake region and the Mississippi Valley, and in which the long and slender jaws are much longer than the rest of the head. The garpike frequents quiet waters and is apparently of sleepy habit. It often lies quiet for a long time, carried around and around by the eddies. It does not readily take the hook and seldom feeds in the aquarium. It feeds on crayfishes and small fishes, to which it is exceedingly destructive, as its bad reputation indicates. Fishermen everywhere destroy it without mercy. Its flesh is rank and tough and unfit even for dogs.

In the young garpike the caudal fin appears as a second dorsal and anal, the filamentous tip of the tail passing through and beyond it.

The short-nosed garpike, Lepisosteus platystomus, is generally common throughout the Mississippi Valley. It has a short broad snout like the alligator-gar, but seldom exceeds three feet in length. In size, color, and habits it agrees closely with the common gar, differing only in the form of the snout. The form is subject to much variation, and it is possible that two or more species have been confounded.

Fig. 23.—Alligator-gar, Lepisosteus tristœchus (Bloch). Cuba.

The great alligator-gar, Lepisosteus tristœchus, reaches a length of twenty feet or more, and is a notable inhabitant of the streams about the Gulf of Mexico. Its snout is broad and relatively wide, and its teeth are very strong. It is very destructive to all sorts of food-fishes. Its flesh is worthless, and its enameled scales resist a spear or sometimes even shot. It breathes air to a certain extent by its lungs, but soon dies in foul water, not having the tenacity of life seen in Amia.

Embryology of the Garpike.—Mr. Alexander Agassiz has given an account of the embryology of the garpike, of which the following is an abstract:

"The garpike comes up the St. Lawrence in May, lays its eggs about the 20th, and then disappears. The eggs are large, viscous, stick fast in an isolated way to whatever they fall upon, and look much like those of toads, having a large outer membrane and a small yolk. Artificial fecundation failed, but about 500 naturally-laid eggs were secured, of which all but 30 perished through mold. The young began to hatch in six days. Out of 30 young hatched, 27 lived until the 15th of July. Connection with the sharks appears in the similarity of the branchial arches and by the presence of the lateral fold in which the pectoral fins are formed; the way the tail is developed is very like that of the bony fishes. Among the Ganoids it appears, as well as in ordinary fishes, the dorsal cord is straight at first, then assumes a slightly upward curve at the extremity, when finally there appears the beginning of a lobe underneath, pointing to a complete heterocercal tail. All this is as in the bony fishes, but this is the permanent condition of the garpike, while in the bony fishes the extremity of the dorsal cord becomes extinct. The mode of development of the pectoral lobe (very large in this species) furnishes another resemblance. In the brain, and in the mode of formation of the gills, a likeness to the sharks is noticeable. The young garpikes move very slowly, and seem to float quietly, save an exceedingly rapid vibration of the pectorals and the tip of the tail. They do not swim about much, but attach themselves to fixed objects by an extraordinary horseshoe-shaped ring of sucker-appendages about the mouth. These appendages remain even after the snout has become so extended that the ultimate shape is hinted at; and furthermore, it is a remnant of this feature that forms the fleshy bulb at the end of the snout in the adult. The investigations thus far show that the young garpike has many characteristics in common with the sharks and skates, but it is not so different from the bony fishes as has been supposed."

Fossil Garpikes.—A number of fossil garpikes, referred by Cope to the genus Clastes and by Eastman and Woodward to Lepidosteus, are found in the Eocene of Europe and America. The most perfect of these remains is called Lepisosteus atrox, upward of four feet long, as large as an alligator-gar, which the species much resembles. Although found in the Eocene, Dr. C. R. Eastman declares that "it has no positively archaic features. If we inquire into the more remote or pre-Eocene history of Lepidosteids, palæontology gives no answer. They blossom forth suddenly and fully differentiated at the dawn of the Tertiary, without the least clue to their ancestry, unheralded and unaccompanied by any intermediate forms, and they have remained essentially unchanged ever since."

Another fossil species is Lepisosteus fimbriatus, from the Upper Eocene of England. Scales and other fragments of garpikes are found in Germany, Belgium, and France, in Eocene and Miocene rocks. On some of these the nominal genera Naisia, Trichiurides, and Pneumatosteus are founded. Clastes, regarded by Eastman as fully identical with Lepisosteus, is said to have the "mandibular ramus without or with a reduced fissure of the dental foramen, and without the groove continuous with it in Lepisosteus. One series of large teeth, with small ones external to them on the dentary bone." Most of the fossil forms belong to Clastes, but the genus shows no difference of importance which will distinguish it from the ordinary garpike.

Fig. 24.—Lower jaw of Amia calva Linnæus, showing the gular plate.

Order Halecomorphi.—To this order belong the allies, living or extinct, of the bowfin (Amia), having for the most part cycloid scales and vertebræ approaching those of ordinary fishes. The resemblance to the Isospondyli, or herring group, is indicated in the name (Halec, a herring; μορφή, form). The notochord is persistent, the vertebræ variously ossified. The opercles are always complete. The branchiostegals are broad and there is always a gular plate. The teeth are pointed, usually strong. There is no infraclavicle. Fulcra are present or absent. The supports of the dorsal and anal are equal in number to the rays. Tail heterocercal. Scales thin, mostly cycloid, but bony at base, not jointed with each other. Mandible complex, with well-developed splenial rising into a coronoid process, which is completed by a distinct coronoid bone. Pectoral fin with more than five actinosts; scales ganoid or cycloid. In the living forms the air-bladder is connected with the œsophagus through life; optic chiasma present; intestine with a spiral valve. This group corresponds to the Amioidei of Lütken and essentially to the Cycloganoidei of Gill. The Protospondyli (προτός, before; σπόνδυλος, vertebra) of Woodward contains essentially the same elements.

Pachycormidæ.—In the family of Pachycormidæ the notochord is persistent, the ethmoids and vomer fused and projecting between the maxillaries to form the prominent snout, the teeth large, the body fusiform, the dorsal short, with slender rays and few fulcra or none, and the scales are thin and rhombic. The numerous species are characteristic of the Triassic, Jurassic, and Cretaceous. In Sauropsis (longimana) the body is elongate, and the pectoral fins are large and sickle-shaped. Euthynotus has small fulcra. In Pachycormus (macropterus, esocinus, etc.) the form is robust and the ventral fins are wanting. In Hypsycormus ventrals are present, and the caudal deeply forked.

In the American family of Protosphyrænidæ the jaws are armed with very strong teeth, as in the Barracuda, which, however, the species do not resemble in other respects. Protosphyræna nitida, perniciosa, and numerous other extinct forms, some of them of large size, were voracious inhabitants of the Cretaceous seas, and are found fossil, especially in North Carolina and Kansas. Numerous species called Erisichthe and Pelecopterus are all referred by Hay to Protosphyræna. In this family the scapula and coracoids are ossified, and perhaps the vertebræ also, and, as Dr. Hay has recently suggested, the Protosphyrænidæ may really belong to the Isospondyli. In any event, they stand on the border-line between the most fish-like of the Ganoids and the most archaic of the bony fishes.

The Liodesmidæ (genus Liodesmus) are much like Amia, but the notochord is persistent, its sheath without ossification. Liodesmus gracilis and L. sprattiformis occur in the lithographic stones of Bavaria. Woodward places Liodesmus with Megalurus among the Amiidæ.

The Bowfins: Amiidæ.—The Amiidæ have the vertebræ more complete. The dorsal fin is many-rayed and is without distinct fulcra. The diamond-shaped enameled scales disappear, giving place to cycloid scales, which gradually become thin and membranous in structure. A median gular plate is developed between the branchiostegals. The tail is moderately heterocercal, and the head covered with a bony coat of mail.

The family of Amiidæ contains a single recent species, Amia calva, the only living member of the order Halecomorphi. The bowfin, or grindle, is a remarkable fish abounding in the lakes and swamps of the Mississippi Valley, the Great Lake region, and southward to Virginia, where it is known by the imposing but unexplained title of John A. Grindle. In the Great Lakes it is usually called "dogfish," because even the dogs will not eat it, and "lawyer," because, according to Dr. Kirtland, "it will bite at anything and is good for nothing when caught."

The bowfin reaches a length of two and one half feet, the male being smaller than the female and marked by an ocellated black spot on the tail. Both sexes are dark mottled green in color. The flesh of the species is very watery, pasty, much of the substance evaporating when exposed to the air. It is ill-flavored, and is not often used as food. The species is very voracious and extremely tenacious of life. Its well-developed lung enables it to breathe even when out of the water, and it will live in the air longer than any other fish of American waters, longer even than the horned pout (Ameiurus) or the mud-minnow (Umbra). As a game fish the grindle is one of the very best, if the angler does not care for the flesh of what he catches, it being one of the hardest fighters that ever took the hook.

Fig. 25.—Bowfin (female), Amia calva Linnæus. Lake Michigan.

The Amiidæ retain many of the Ganoid characters, though approaching more nearly than any other of the Ganoids to the modern herring tribe. For this reason the name Halecomorphi (shad-formed) was given to this order by Professor Cope. The gular plate found in Amia and other Ganoids reappears in the herring-like family of Elopidæ, which includes the tarpon and the ten-pounder.

Woodward unites the extinct genera called Cyclurus, Notæus, Amiopsis, Protamia, Hypamia, and Pappichthys with Amia. Pappichthys (corsoni, etc.), from the Wyoming Eocene, is doubtless a valid genus, having but one row of teeth in each jaw, and Amiopsis is also recognized by Hay. Woodward refers to Amia the following extinct species: Amia valenciennesi, from the Miocene of France; Amia macrocephala, from the Miocene of Bohemia; and Amia ignota, from the Eocene of Paris. Other species of Amia are known from fragments. Several of these are from the Eocene of Wyoming and Colorado. Some of them have a much shorter dorsal fin than that of Amia calva and may be generically different.

Fig. 26.—Megalurus elegantissimus Wagner. Family Amiidæ. (After Zittel.)

The genus Megalurus differs from Amia in the still shorter dorsal fin, less than one-third the length of the back. The body is elongate and much depressed. Megalurus lepidotus and several other species are found in the lithographic stones of Bavaria and elsewhere.

The Oligopleuridæ.—In the extinct family Oligopleuridæ the scales are cycloid, the bones of the head scarcely enameled, and the vertebræ well ossified. Fulcra are present, and the mouth is large, with small teeth. The genera are Oligopleurus, Ionoscopus, and Spathiurus, the species not very numerous and chiefly of the Cretaceous. Ionoscopus cyprinoides of the lithographic shales of Bavaria is a characteristic species.

From the three families last named, with the Pholidophoridæ, there is an almost perfect transition from the Ganoid fishes to teleosteans of the order of Isospondyli, the primitive order from which all other bony fishes are perhaps descended. The family of Leptolepidæ, differing from Oligopleuridæ in the absence of fulcra, is here placed with the Isospondyli, but it might about as well be regarded as Ganoid.

CHAPTER III
ISOSPONDYLI

The Subclass Teleostei, or Bony Fishes.—The fishes which still remain for discussion constitute the great subclass or series of Teleostei (τελεός, true; οστέον, bone), or bony fishes. They lack wholly or partly the Ganoid traits, or show them only in the embryo. The tail is slightly, if at all, heterocercal; the actinosts of the pectoral fins are few and large, rarely over five in number, except among the eels; the fulcra disappear; the air-bladder is no longer cellular, except in very rare cases, nor does it assist in respiration. The optic nerves are separate, one running to each eye without crossing; the skeleton is almost entirely bony, the notochord usually disappearing entirely with age; the valves in the arterial bulb are reduced in number, and the spiral valve of the intestines disappears. Traces of each of the Ganoid traits may persist somewhere in some group, but as a whole we see a distinct specialization and a distinct movement toward the fish type, with the loss of characters distinctive of sharks, Dipnoans, and Ganoids. In a general way the skeleton of all Teleosts corresponds with that of the striped bass (see Figs. 22, 23, Vol. I), and the visceral anatomy is in all cases sufficiently like that of the sunfish (Fig. 16, Vol. I).

The mesocoracoid or precoracoid arch, found in all Ganoids, persists in the less specialized types of bony fishes, although no trace of it is found in the perch-like forms. With all this, there is developed among the bony fishes an infinite variety in details of structure. For this reason the Teleostei must be broken into many orders, and these orders are very different in value and in degrees of distinctness, the various groups being joined by numerous and puzzling intergradations.

Order Isospondyli.—Of the various subordinate groups of bony fishes, there can be no question as to which is most primitive in structure, or as to which stands nearest the orders of Ganoids. Earliest of the bony fishes in geological time is the order of Isospondyli (ἴσος, equal; σπόνδυλος, vertebra), containing the allies, recent or fossil, of the herring and the trout. This order contains those soft-rayed fishes in which the ventral fins are abdominal, a mesocoracoid or precoracoid arch is developed, and the anterior vertebræ are unmodified and essentially similar to the others. The orbitosphenoid is present in all typical forms. In certain forms of doubtful affinity (Iniomi) the mesocoracoid is wanting or lost in degeneration. Through the Isospondyli all the families of fishes yet to be considered are apparently descended, their ancestors being Ganoid fishes and, still farther back, the Crossopterygians.

Woodward gives this definition of the Isospondyli: "Notochord varying in persistence, the vertebral centra usually complete, but none coalesced; tail homocercal, but hæmal supports not much expanded or fused. Symplectic bone present, mandible simple, each dentary consisting only of two elements (dentary and articulo-angular), with rare rudiments of a splenoid on the inner side. Pectoral arch suspended from the cranium; precoracoid (mesocoracoid) arch present; infraclavicular plates wanting. Pelvic (ventral) fins abdominal. Scales ganoid only in the less specialized families. In the living forms air-bladder connected with the œsophagus in the adult; optic nerves decussating (without chiasma), and intestine either wanting spiral valve or with an incomplete representative of it."

The Classification of the Bony Fishes.—The classification of fishes has been greatly complicated by the variety of names applied to groups which are substantially but not quite identical one with another. The difference in these schemes of classification lies in the point of view. In all cases a single character must be brought to the front; such characters never stand quite alone, and to lay emphasis on another character is to make an alteration large or small in the name or in the boundaries of a class or order. Thus the Ostariophysi with the Isospondyli, Haplomi, and a few minor groups make up the great division of the Abdominales. These are fishes in which the ventral fins are abdominal, that is, inserted backward, so that the pelvis is free from the clavicle, the two sets of limbs being attached to different parts of the skeleton. Most of the abdominal fishes are also soft-rayed fishes, that is, without consecutive spines in the dorsal and anal fins, and they show a number of other archaic peculiarities. The Malacopterygians (μαλακός, soft; πτερύξ, fin) of Cuvier therefore correspond very nearly to the Abdominales. But they are not quite the same, as the spiny-rayed barracudas and mullets have abdominal ventrals, and many unquestioned thoracic or jugular fishes, as the sea-snails and brotulids, have lost, through degeneration, all of their fin-spines.

In nearly but not quite all of the Abdominal fishes the slender tube connecting the air-bladder with the œsophagus persists through life. This character defines Müller's order of Physostomi (φυσός, bladder; στόμα, mouth), as opposed to his Physoclysti (φυσός, bladder; κλεῖστός, closed), in which this tube is present in the embryo or larva only. Thus the Thoracices and Jugulares, or fishes having the ventrals thoracic or jugular, together correspond almost exactly to the Acanthopterygians, (ακανθα, spine; πτερύξ, fin), or spiny-rayed fishes of Cuvier, or to the Physoclysti of Müller. The Malacopterygians, the Abdominales, and the Physostomi are in the same way practically identical groups. As the spiny-rayed fishes have mostly ctenoid scales, and the soft-rayed fishes cycloid scales, the Physostomi correspond roughly to Agassiz's Cycloidei, and the Physoclysti to his Ctenoidei.

But in none of these cases is the correspondence perfectly exact, and in any system of classification we must choose characters for primary divisions so ancient and therefore so permanent as to leave no room for exceptions. The extraordinary difficulty of doing this, with the presence of most puzzling intergradations, has led Dr. Gill to suggest that the great body of bony fishes, soft-rayed and spiny-rayed, abdominal, thoracic, and jugular alike, be placed in a single great order which he calls Teleocephali (τελεός, perfect; κεφαλή, head). The aberrant forms with defective skull and membrane-bones he would separate as minor offshoots from this great mass with the name of separate orders. But while the divisions of Teleocephali are not strongly differentiated, their distinctive characters are real, ancient, and important, while those of the aberrant groups, called orders by Gill (as Plectognathi, Pediculati, Hemibranchii), are relatively modern and superficial, which is one reason why they are more easily defined. There seems to us no special advantage in the retention of a central order Teleocephali, from which the divergent branches are separated as distinct orders.

While our knowledge of the osteology and embryology of most of the families of fishes is very incomplete, it is evident that the relationships of the groups cannot be shown in any linear series or by any conceivable arrangement of orders and suborders. The living teleost fishes have sprung from many lines of descent, their relationships are extremely diverse, and their differences are of every possible degree of value. The ordinary schemes have magnified the value of a few common characters, at the same time neglecting other differences of equal value. No system of arrangement which throws these fishes into large groups can ever be definite or permanent.

Relationships of Isospondyli.—For our purposes we may divide the physostomous fishes as understood by Müller into several orders, the most primitive, the most generalized, and economically the most important being the order of Isospondyli. This order contains those bony fishes which have the anterior vertebræ unaltered (as distinguished from the Ostariophysi), the skull relatively complete, or at least not eel-like, the mesocoracoid typically developed, but atrophied in deep-sea forms and finally lost, the orbitosphenoid present. In all the species the ventral fins are abdominal and normally composed of more than six rays; the air-duct is developed. The scales are chiefly cycloid and the fins are without true spines. In many ways the order is more primitive than Nematognathi, Plectospondyli, or Apodes. It is certain that it began earlier in geological time than any of these. On the other hand, the Isospondyli are closely connected through the Berycoidei with the highly specialized fishes. The continuity of the natural series is therefore interrupted by the interposition of the side branches of Ostariophysans and eels before considering the Haplomi and the other transitional forms. The forms called Iniomi, which lack the mesocoracoid and the orbitosphenoid, have been lately transferred to the Haplomi by Boulenger. This arrangement is probably a step in advance.

Ganoid traits are present in certain families of Isospondyli. Among these are the gular plate (found in Amia and the Elopidæ), doubtless derived from the similar structure in earlier Ganoids; additional valves in the arterial bulb in the cellular air-bladder of Notopterus and Osteoglossum, the spiral intestinal valve in Chirocentridæ, and the ganoid scales of the extinct Leptolepidæ.

The Clupeoidea.—The Isospondyli are divisible into numerous families, which may be grouped roughly under three subdivisions, Clupeoidea, the herring-like forms; the Salmonoidea, the trout-like forms; and the Iniomi, or lantern-fishes, and their allies. The last-named group should probably be removed from the order of Isospondyli. In the Clupeoidea, the allies of the great family of the herring, the shoulder-girdle is normally developed, retaining the mesocoracoid arch on its inner edge, and through the post-temporal is articulated above with the cranium. The fishes in this group lack the adipose fin which is characteristic of most of the higher or salmon-like families.

Fig. 27.—Leptolepis dubius Blainville, Lithographic Stone. (After Woodward.)

The Leptolepidæ.—Most primitive of the Isospondyli is the extinct family of Leptolepidæ, closely allied to the Ganoid families of Pholidophoridæ and Oligopleuridæ. It is composed of graceful, herring-like fishes, with the bones of the head thin but covered with enamel, and the scales thin but firm and enameled on their free portion. There are no fulcra and there is no lateral line. The vertebræ are well developed, but always pierced by the notochord. The genera are Lycoptera, Leptolepis, Æthalion, and Thrissops. In Lycoptera of the Jurassic of China the vertebral centra are feebly developed, and the dorsal fin short and posterior. In Leptolepis the anal is short and placed behind the dorsal. There are many species, mostly from the Triassic and lithographic shales of Europe, one being found in the Cretaceous. Leptolepis coryphænoides and Leptolepis dubius are among the more common species. Æthalion (knorri) differs in the form of the jaws. In Thrissops the anal fin is long and opposite the dorsal. Thrissops salmonea is found in the lithographic stone; Thrissops exigua in the Cretaceous. In all these early forms there is a hard casque over the brain-cavity, as in the living types, Amia and Osteoglossum.

Fig. 28.—Ten-pounder, Elops saurus L. An ally of the earliest bony fishes. Virginia.

Fig. 29.—A primitive Herring-like fish, Holcolepis lewesiensis, Mantell, restored. Family Elopidæ. English Chalk. (After Woodward.)

The Elopidæ.—The family of Elopidæ contains large fishes herring-like in form and structure, but having a flat membrane-bone or gular plate between the branches of the lower jaw, as in the Ganoid genus Amia. The living species are few, abounding in the tropical seas, important for their size and numbers, though not valued as food-fishes save to those who, like the Hawaiians and Japanese, eat fishes raw. These people prefer for that purpose the white-meated or soft-fleshed forms like Elops or Scarus to those which yield a better flavor when cooked.

The ten-pounder (Elops saurus), pike-like in form but with very weak teeth, is found in tropical America. Elops machnata, the jack mariddle, the awaawa of the Hawaiians, abounding in the Pacific, is scarcely if at all different.

Fig. 30.—Tarpon or Grande Écaille, Tarpon atlanticus Cuv. & Val. Florida.

The tarpon, called also grande écaille, silver-king, and sable (Tarpon atlanticus), is a favorite game-fish along the coasts of Florida and Carolina. It takes the hook with great spirit, and as it reaches a length of six feet or more it affords much excitement to the successful angler. The very large scales are much used in ornamental work.

A similar species of smaller size, also with the last ray of the dorsal very much produced, is Megalops cyprinoides of the East Indies. Other species occur in the South Seas.

Numerous fossil genera related to Elops are found in the Cretaceous and Tertiary rocks. Holcolepis lewesiensis (wrongly called Osmeroides) is the best-known European species. Numerous species are referred to Elopopsis. Megalops prisca and species of Elops also occur in the London Eocene.

In all these the large parietals meet along the median line of the skull. In the closely related family of Spaniodontidæ the parietals are small and do not meet. All the species of this group, united by Woodward with the Elopidæ, are extinct. These fishes preceded the Elopidæ in the Cretaceous period. Leading genera are Thrissopater and Spaniodon, the latter armed with large teeth. Spaniodon blondeli is from the Cretaceous of Mount Lebanon. Many other species are found in the European and American Cretaceous rocks, but are known from imperfect specimens only.

Sardinius, an American Cretaceous fossil herring, may stand near Spaniodon. Rhacolepis buccalis and Notelops brama are found in Brazil, beautifully preserved in concretions of calcareous mud supposed to be of Cretaceous age.

The extinct family of Pachyrhizodontidæ is perhaps allied to the Elopidæ. Numerous species of Pachyrhizodus are found in the Cretaceous of southern England and of Kansas.

The Albulidæ.—The Albulidæ, or lady-fishes, characterized by the blunt and rounded teeth, are found in most warm seas. Albula vulpes is a brilliantly silvery fish, little valued as food. The metamorphosis (see Fig. 112, Vol. I) which the larva undergoes is very remarkable. It is probably, however, more or less typical of the changes which take place with soft-rayed fishes generally, though more strongly marked in Albula and in certain eels than in most related forms. Fossils allied to Albula, Albula oweni, Chanoides macropomus, are found in the Eocene of Europe; Syntegmodus altus in the Cretaceous of Kansas. In Chanoides, the most primitive genus, the teeth are much fewer than in Albula. Plethodus and Thryptodus, with peculiar dental plates on the roof and floor of the mouth, probably constitute a distinct family, Thryptodontidæ. The species are found in European and American rocks, but are known from imperfect specimens only.

Fig. 31.—The Lady-fish, Albula vulpes (Linnæus). Florida.

The Chanidæ.—The Chanidæ, or milkfishes, constitute another small archaic type, found in the tropical Pacific. They are large, brilliantly silvery, toothless fishes, looking like enormous dace, swift in the water, and very abundant in the Gulf of California, Polynesia, and India. The single living species is the Awa, or milkfish, Chanos chanos, largely used as food in Hawaii. Species of Prochanos and Chanos occur in the Cretaceous, Eocene, and Miocene. Allied to Chanos is the Cretaceous genus Ancylostylos (gibbus), probably the type of a distinct family, toothless and with many-rayed dorsal.

Fig. 32.—Milkfish, Chanos chanos (L.). Mazatlan.

Fig. 33.—Mooneye, Hiodon tergisus Le Sueur. Ecorse, Mich.

The Hiodontidæ.—The Hiodontidæ, or mooneyes, inhabit the rivers of the central portion of the United States and Canada. They are shad-like fishes with brilliantly silvery scales and very strong sharp teeth, those on the tongue especially long. They are very handsome fishes and take the hook with spirit, but the flesh is rather tasteless and full of small bones, much like that of the milkfish. The commonest species is Hiodon tergisus. No fossil Hiodontidæ are known.

Fig. 34.—Istieus grandis Agassiz. Family Pterothrissidæ. (After Zittel.)

Fig. 35.—Chirothrix libanicus Pictet & Humbert. Cretaceous of Mt. Lebanon. (After Woodward.)

The Pterothrissidæ.—The Pterothrissidæ are sea-fishes like Albula, but more slender and with a long dorsal fin. They live in deep or cold waters along the coasts of Japan, where they are known as gisu. The single species is Pterothrissus gissu. The fossil genus Istieus, from the Upper Cretaceous, probably belongs near the Pterothrissidæ. Istieus grandis is the best-known species. Another ancient family, now represented by a single species, is that of the Chirocentridæ, of which the living type is Chirocentrus dorab, a long, slender, much compressed herring-like fish, with a saw-edge on the belly, found in the East Indies, in which region Chirocentrus polyodon occurs as a fossil. Numerous fossil genera related to Chirocentrus are enumerated by Woodward, most of them to be referred to the related family of Ichthyodectidæ (Saurodontidæ). Of these, Portheus, Ichthyodectes, Saurocephalus (Saurodon), and Gillicus are represented by numerous species, some of them fishes of immense size and great voracity. Portheus molossus, found in the Cretaceous of Nebraska, is remarkable for its very strong teeth. Species of other genera are represented by numerous species in the Cretaceous of both the Rocky Mountain region and of Europe.

Fig. 36.—Gigantic skeleton of Portheus molossus Cope. (Photograph by Charles H. Sternberg.)

The Ctenothrissidæ.—A related family, Ctenothrissidæ, is represented solely by extinct Cretaceous species. In this group the body is robust with large scales, ctenoid in Ctenothrissa, cycloid in Aulolepis. The fins are large, the belly not serrated, and the teeth feeble. Ctenothrissa vexillifera is from Mount Lebanon. Other species occur in the European chalk. In the small family of Phractolæmidæ the interopercle, according to Boulenger, is enormously developed.

Fig. 37.—Ctenothrissa vexillifera Pictet, restored. Mt. Lebanon Cretaceous. (After Woodward.)

The Notopteridæ.—The Notopteridæ is another small family in the rivers of Africa and the East Indies. The body ends in a long and tapering fin, and, as usual in fishes which swim by body undulations, the ventral fins are lost. The belly is doubly serrate. The air-bladder is highly complex in structure, being divided into several compartments and terminating in two horns anteriorly and posteriorly, the anterior horns being in direct communication with the auditory organ. A fossil Notopterus, N. primævus, is found in the same region.

The Clupeidæ.—The great herring family, or Clupeidæ, comprises fishes with oblong or herring-shaped body, cycloid scales, and feeble dentition. From related families it is separated by the absence of lateral line and the division of the maxillary into three pieces. In most of the genera the belly ends in a serrated edge, though in the true herring this is not very evident, and in some the belly has a blunt edge. Some of the species live in rivers, some ascend from the sea for the purpose of spawning. The majority are confined to the ocean. Among all the genera, the one most abundant in individuals is that of Clupea, the herring. Throughout the North Atlantic are immense schools of Clupea harengus. In the North Pacific on both shores another herring, Clupea pallasi, is equally abundant, and with the same market it would be equally valuable. As salted, dried, or smoked fish the herring is found throughout the civilized world, and its spawning and feeding-grounds have determined the location of cities.

Fig. 38.—Herring, Clupea harengus L. New York.

The genus Clupea, of northern distribution, has the vertebræ in increased number (56), and there are weak teeth on the vomer. Several other genera are very closely related, but ranging farther south they have, with other characters, fewer (46 to 50) vertebræ. The alewife, or branch-herring (Pomolobus pseudoharengus), ascends the rivers to spawn and has become landlocked in the lakes of New York. The skipjack of the Gulf of Mexico, Pomolobus chrysochloris, becomes very fat in the sea. The species becomes landlocked in the Ohio River, where it thrives as to numbers, but remains lean and almost useless as food. The glut-herring, Pomolobus æstivalis, and the sprat, Pomolobus sprattus, of Europe are related forms.

Fig. 39.—Alewife, Pomolobus pseudoharengus (Wilson). Potomac River.

Very near also to the herring is the shad (Alosa sapidissima) of the eastern coasts of America, and its inferior relatives, the shad of the Gulf of Mexico (Alosa alabamæ), the Ohio River shad (Alosa ohiensis), very lately discovered, the Allice shad (Alosa alosa) of Europe, and the Thwaite shad (Alosa finta). In the genus Alosa the cheek region is very deep, giving the head a form different from that seen in the herring.

The American shad is the best food-fish in the family, peculiarly delicate in flavor when broiled, but, to a greater degree than occurs in any other good food-fish, its flesh is crowded with small bones. The shad has been successfully introduced into the waters of California, where it abounds from Puget Sound to Point Concepcion, ascending the rivers to spawn in May as in its native region, the Atlantic coast.

The genus Sardinella includes species of rich flesh and feeble skeleton, excellent when broiled, when they may be eaten bones and all. This condition favors their preservation in oil as "sardines." All the species are alike excellent for this purpose. The sardine of Europe is the Sardinella pilchardus, known in England as the pilchard. The "Sardina de España" of Cuba is Sardinella pseudohispanica, the sardine of California, Sardinella cærulea. Sardinella sagax abounds in Chile, and Sardinella melanosticta is the valued sardine of Japan.

In the tropical Pacific occur other valued species, largely belonging to the genus Kowala. The genus Harengula contains small species with very large, firm scales which do not fall when touched, as is generally the case with the sardines. Most common of these is Harengula sardina of the West Indies. Similar species occur in southern Europe and in Japan.

Fig. 40.—Menhaden, Brevoortia tyrannus (Latrobe). Wood's Hole, Mass.

In Opisthonema, the thread-herring, the last dorsal ray is much produced, as in the gizzard-shad and the tarpon. The two species known are abundant, but of little commercial importance. Of greater value are the menhaden, or the moss-bunker, Brevoortia tyrannus, inhabiting the sandy coasts from New England southward. It is a coarse and bony fish, rarely eaten when adult, although the young in oil makes acceptable sardines. It is used chiefly for oil, the annual yield exceeding in value that of whale-oil. The refuse is used as manure, a purpose for which the fishes are often taken without preparation, being carried directly to the cornfields. From its abundance this species of inferior flesh exceeds in commercial value almost all other American fishes excepting the cod, the herring, and the quinnat salmon.

One of the most complete of fish biographies is that of Dr. G. Brown Goode on the "Natural and Economic History of Menhaden."

Numerous other herring-like forms, usually with compressed bodies, dry and bony flesh, and serrated bellies, abound in the tropics and are largely salted and dried by the Chinese. Among these are Ilisha elongata of the Chinese coast. Related forms occur in Mexico and Brazil.

The round herrings, small herrings which have no serrations on the belly, are referred by Dr. Gill to the family of Dussumieriidæ. These are mostly small tropical fishes used as food or bait. One of these, the Kobini-Iwashi of Japan (Stolephorus japonicus), with a very bright silver band on the side, has considerable commercial importance. Very small herrings of this type in the West Indies constitute the genus Jenkinsia, named for Dr. Oliver P. Jenkins, the first to study seriously the fishes of Hawaii. Other species constitute the widely distributed genera Etrumeus and Dussumieria. Etrumeus sardina is the round herring of the Virginia coast. Etrumeus micropus is the Etrumei-Iwashi of Japan and Hawaii.

Fig. 41.—A fossil Herring, Diplomystus humilis Leidy. (From a specimen obtained at Green River, Wyo.) The scutes along the back lost in the specimen. Family Clupeidæ.

Fossil herring are plentiful and exist in considerable variety, even among the Clupeidæ as at present restricted. Histiothrissa of the Cretaceous seems to be allied to Dussumieria and Stolephorus. Another genus, from the Cretaceous of Palestine, Pseudoberyx (syriacus, etc.), having pectinated scales, should perhaps constitute a distinct subfamily, but the general structure is like that of the herring. More evidently herring-like is Scombroclupea (macrophthalma). The genus Diplomystus, with enlarged scales along the back, is abundantly represented in the Eocene shales of Green River, Wyoming. Species of similar appearance, usually but wrongly referred to the same genus, occur on the coasts of Peru, Chile, and New South Wales. A specimen of Diplomystus humilis from Green River is here figured. Numerous herring, referred to Clupea, but belonging rather to Pomolobus, or other non-Arctic genera, have been described from the Eocene and later rocks.

Several American fossil herring-like fishes, of the genus Leptosomus, as Leptosomus percrassus, are found in the Cretaceous of South Dakota.

Fossil species doubtfully referred to Dorosoma, but perhaps allied rather to the thread-herring (Opisthonema), being herrings with a prolonged dorsal ray, are recorded from the early Tertiary of Europe. Among these is Opisthonema doljeanum from Austria.

Fig. 42.—Hickory-shad, Dorosoma cepedianum (Le Sueur). Potomac River.

The Dorosomatidæ.—The gizzard-shad, Dorosomatidæ, are closely related to the Clupeidæ, differing in the small contracted toothless mouth and reduced maxillary. The species are deep-bodied, shad-like fishes of the rivers and estuaries of eastern America and eastern Asia. They feed on mud, and the stomach is thickened and muscular like that of a fowl. As the stomach has the size and form of a hickory-nut, the common American species is often called hickory-shad. The gizzard-shad are all very poor food-fish, bony and little valued, the flesh full of small bones. The belly is always serrated. In three of the four genera of Dorosomatidæ the last dorsal ray is much produced and whip-like. The long and slender gill-rakers serve as strainers for the mud in which these fishes find their vegetable and animal food. Dorosoma cepedianum, the common hickory-shad or gizzard-shad, is found in brackish river-mouths and ponds from Long Island to Texas, and throughout the Mississippi Valley in all the large rivers. Through the canals it has entered Lake Michigan. The Konoshiro, Clupanodon thrissa, is equally common in China and Japan.

The Engraulididæ.—The anchovies (Engraulididæ) are dwarf herrings with the snout projecting beyond the very wide mouth. They are small in size and weak in muscle, found in all warm seas, and making a large part of the food of the larger fish. The genus Engraulis includes the anchovy of Europe, Engraulis encrasicholus, with similar species in California, Chile, Japan, and Australia. In this genus the vertebræ are numerous, the bones feeble, and the flesh tender and oily. The species of Engraulis are preserved in oil, often with spices, or are made into fish-paste, which is valued as a relish. The genus Anchovia replaces Engraulis in the tropics. The vertebræ are fewer, the bones firm and stiff, and the flesh generally dry. Except as food for larger fish, these have little value, although existing in immense schools. Most of the species have a bright silvery band along the side. The most familiar of the very numerous species is the silver anchovy, Anchovia browni, which abounds in sandy bays from Cape Cod to Brazil. Several other genera occur farther southward, as well as in Asia, but Engraulis only is found in Europe. Fossil anchovies called Engraulis are recorded from the Tertiary of Europe.

Fig. 43.—A Silver Anchovy, Anchovia perthecata (Goode & Bean). Tampa.

Fig. 44.—Notogoneus osculus Cope. Green River Eocene. Family Gonorhynchidæ.

Gonorhynchidæ.—To the Isospondyli belongs the small primitive family of Gonorhynchidæ, elongate fishes with small mouth, feeble teeth, no air-bladder, small scales of peculiar structure covering the head, weak dentition, the dorsal fin small, and posterior without spines. The mesocoracoid is present as in ordinary Isospondyli. Gonorhynchus abbreviatus occurs in Japan, and Gonorhynchus gonorhynchus is found in Australia and about the Cape of Good Hope. Numerous fossil species occur. Charitosomus lineolatus and other species are found in the Cretaceous of Mount Lebanon and elsewhere. Species without teeth from the Oligocene of Europe and America are referred to the genus Notogoneus. Notogoneus osculus occurs in the Eocene fresh-water deposits at Green River, Wyoming. It bears a very strong resemblance in form to an ordinary sucker (Catostomus), for which reason it was once described by the name of Protocatostomus. The living Gonorhynchidæ are all strictly marine.

In the small family of Cromeriidæ the head and body are naked.

The Osteoglossidæ.—Still less closely related to the herring is the family of Osteoglossidæ, huge pike-like fishes of the tropical rivers, armed with hard bony scales formed of pieces like mosaic. The largest of all fresh-water fishes is Arapaima gigas of the Amazon region, which reaches a length of fifteen feet and a weight of 400 pounds. It has naturally considerable commercial importance, as have species of Osteoglossum, coarse river-fishes which occur in Brazil, Egypt, and the East Indies. Heterotis nilotica is a large fish of the Nile. In some or all of these the air-bladder is cellular or lung-like, like that of a Ganoid.

Allied to the Osteoglossidæ is Phareodus (Dapedoglossus), a group of large shad-like fossil fishes, with large scales of peculiar mosaic texture and with a bony casque on the head, found in fresh-water deposits of the Green River Eocene. In the perfect specimens of Phareodus (or Dapedoglossus) testis the first ray of the pectoral is much enlarged and serrated on its inner edge, a character which may separate these fishes as a family from the true Osteoglossidæ. It does not, however, appear in Cope's figures, none of his specimens having the pectorals perfect. In these fishes the teeth are very strong and sharp, the scales are very large and thin, looking like the scales of a parrot-fish, the long dorsal is opposite to the anal and similar to it, and the caudal is truncate. The end of the vertebral column is turned upward.

Other species are Phareodus acutus, known from the jaws; P. encaustus is known from a mass of thick scales with reticulate or mosaic-like surface, much as in Osteoglossum, and P. æquipennis from a small example, perhaps immature. Phareodus testis is frequently found well preserved in the shales at Fossil Station, to the northwestward of Green River. Whether all these species possess the peculiar structure of the scales, and whether all belong to one genus, is uncertain.

Fig. 45.—Phareodus testis (Cope). From a specimen 20 inches long collected at Fossil, Wyo., in the Museum of the Univ. of Wyoming. (Photograph by Prof. Wilbur C. Knight.)

In Eocene shales of England occurs Brychætus muelleri, a species closely related to Phareodus, but the scales smaller and without the characteristic reticulate or mosaic structure seen in Phareodus encaustus.

Fig. 46.—Deposits of Green River Shales, bearing Phareodus, at Fossil, Wyoming. (Photograph by Wilbur C. Knight.)

Fig. 47.—A day's catch of Fossil fishes, Phareodus, Diplomystus, etc. Green River Eocene Shales, Fossil, Wyoming. (Photograph by Prof. Wilbur C. Knight.)

The Pantodontidæ.—The bony casque of Osteoglossum is found again in the Pantodontidæ, consisting of one species, Pantodon buchholzi, a small fish of the brooks of West Africa. As in the Osteoglossidæ and in the Siluridæ, the subopercle is wanting in Pantodon.

Fig. 48.—Alepocephalus agassizii Goode & Bean. Gulf Stream.

The Alepocephalidæ are deep-sea herring-like fishes very soft in texture and black in color, taken in the oceanic abysses. Some species may be found in almost all seas below the depth of half a mile. Alepocephalus rostratus of the Mediterranean has been long known, but most of the other genera, Talismania, Mitchillina, Conocara, etc., are of very recent discovery, having been brought to the surface by the deep-sea dredging of the Challenger, the Albatross, the Blake, the Travailleur, the Talisman, the Investigator, the Hirondelle, and the Violante.

CHAPTER IV
SALMONIDÆ

The Salmon Family.—The series or suborder Salmonoidea, or allies of the salmon and trout, are characterized as a whole by the presence of the adipose fin, a structure also retained in Characins and catfishes, which have no evident affinity with the trout, and in the lantern-fishes, lizard-fishes, and trout-perches, in which the affinity is very remote. Probably these groups all have a common descent from some primitive fish having an adipose fin, or at least a fleshy fold on the back.

Of all the families of fishes, the one most interesting from almost every point of view is that of the Salmonidæ, the salmon family. As now restricted, it is not one of the largest families, as it comprises less than a hundred species; but in beauty, activity, gaminess, quality as food, and even in size of individuals, different members of the group stand easily with the first among fishes. The following are the chief external characteristics which are common to the members of the family:

Body oblong or moderately elongate, covered with cycloid, in scales of varying size. Head naked. Mouth terminal or somewhat inferior, varying considerably among the different species, those having the mouth largest usually having also the strongest teeth. Maxillary provided with a supplemental bone, and forming the lateral margin of the upper jaw. Pseudobranchiæ present. Gill-rakers varying with the species. Opercula complete. No barbels. Dorsal fin of moderate length, placed near the middle of the length of the body. Adipose fin well developed. Caudal fin forked. Anal fin moderate or rather long. Ventral fins nearly median in position. Pectoral fins inserted low. Lateral line present. Outline of belly rounded. Vertebræ in large number, usually about sixty.

The stomach in all the Salmonidæ is siphonal, and at the pylorus are many (15 to 200) comparatively large pyloric cœca. The air-bladder is large. The eggs are usually much larger than in fishes generally, and the ovaries are without special duct, the ova falling into the cavity of the abdomen before exclusion. The large size of the eggs, their lack of adhesiveness, and the readiness with which they may be impregnated, render the Salmonidæ peculiarly adapted for artificial culture.

The Salmonidæ are peculiar to the north temperate and Arctic regions, and within this range they are almost equally abundant wherever suitable waters occur. Some of the species, especially the larger ones, are marine and anadromous, living and growing in the sea, and ascending fresh waters to spawn. Still others live in running brooks, entering lakes or the sea when occasion serves, but not habitually doing so. Still others are lake fishes, approaching the shore or entering brooks in the spawning season, at other times retiring to waters of considerable depth. Some of them are active, voracious, and gamy, while others are comparatively defenseless and will not take the hook. They are divisible into ten easily recognized genera: Coregonus, Argyrosomus, Brachymystax, Stenodus, Oncorhynchus, Salmo, Hucho, Cristivomer, Salvelinus, and Plecoglossus.

Fragments of fossil trout, very imperfectly known, are recorded chiefly from Pleistocene deposits of Idaho, under the name of Rhabdofario lacustris. We have also received from Dr. John C. Merriam, from ferruginous sands of the same region, several fragments of jaws of salmon, in the hook-nosed condition, with enlarged teeth, showing that the present salmon-runs have been in operation for many thousands of years. Most other fragments hitherto referred to Salmonidæ belong to some other kind of fish.

Coregonus, the Whitefish.—The genus Coregonus, which includes the various species known in America as lake whitefish, is distinguishable in general by the small size of its mouth, the weakness of its teeth, and the large size of its scales. The teeth, especially, are either reduced to slight asperities, or else are altogether wanting. The species reach a length of one to three feet. With scarcely an exception they inhabit clear lakes, and rarely enter streams except to spawn. In far northern regions they often descend to the sea; but in the latitude of the United States this is never possible for them, as they are unable to endure warm or impure water. They seldom take the hook, and rarely feed on other fishes. Numerous local varieties characterize the lakes of Scandinavia, Scotland, and Arctic Asia and America. Largest and most desirable of all these as a food-fish is the common whitefish of the Great Lakes (Coregonus clupeiformis), with its allies or variants in the Mackenzie and Yukon.

The species of Coregonus differ from each other in the form and size of the mouth, in the form of the body, and in the development of the gill-rakers.

Coregonus oxyrhynchus—the Schnäbel of Holland, Germany, and Scandinavia—has the mouth very small, the sharp snout projecting far beyond it. No species similar to this is found in America.

The Rocky Mountain whitefish (Coregonus williamsoni) has also a small mouth and projecting snout, but the latter is blunter and much shorter than in C. oxyrhynchus. This is a small species abounding everywhere in the clear lakes and streams of the Rocky Mountains and the Sierra Nevada, from Colorado to Vancouver Island. It is a handsome fish and excellent as food.

Fig. 49.—Rocky Mountain Whitefish, Coregonus williamsoni Girard.

Closely allied to Coregonus williamsoni is the pilot-fish, shad-waiter, roundfish, or Menomonee whitefish (Coregonus quadrilateralis). This species is found in the Great Lakes, the Adirondack region, the lakes of New Hampshire, and thence northwestward to the Yukon, abounding in cold deep waters, its range apparently nowhere coinciding with that of Coregonus williamsoni.

Fig. 50.—Whitefish, Coregonus clupeiformis Mitchill. Ecorse, Mich.

The common whitefish (Coregonus clupeiformis) is the largest in size of the species of Coregonus, and is unquestionably the finest as an article of food. It varies considerably in appearance with age and condition, but in general it is proportionately much deeper than any of the other small-mouthed Coregoni. The adult fishes develop a considerable fleshy hump at the shoulders, which causes the head, which is very small, to appear disproportionately so. The whitefish spawns in November and December, on rocky shoals in the Great Lakes. Its food was ascertained by Dr. P. R. Hoy to consist chiefly of deep-water crustaceans, with a few mollusks, and larvæ of water insects. "The whitefish," writes Mr. James W. Milner, "has been known since the time of the earliest explorers as preeminently a fine-flavored fish. In fact there are few table-fishes its equal. To be appreciated in its fullest excellence it should be taken fresh from the lake and broiled. Father Marquette, Charlevoix, Sir John Richardson—explorers who for months at a time had to depend upon the whitefish for their staple article of food—bore testimony to the fact that they never lost their relish for it, and deemed it a special excellence that the appetite never became cloyed with it." The range of the whitefish extends from the lakes of New York and New England northward to the Arctic Circle. The "Otsego bass" of Otsego Lake in New York, celebrated by De Witt Clinton, is a local form of the ordinary whitefish.

Allied to the American whitefish, but smaller in size, is the Lavaret, Weissfisch, Adelfisch, or Weissfelchen (Coregonus lavaretus), of the mountain lakes of Switzerland, Germany, and Sweden. Coregonus kennicotti, the muksun, and Coregonus nelsoni, the humpback whitefish, are found in northern Alaska and in the Yukon. Several other related species occur in northern Europe and Siberia.

Another American species is the Sault whitefish, Lake Whiting or Musquaw River whitefish (Coregonus labradoricus). Its teeth are stronger, especially on the tongue, than in any of our other species, and its body is slenderer than that of the whitefish. It is found in the upper Great Lakes, in the Adirondack region, in Lake Winnipeseogee, and in the lakes of Maine and New Brunswick. It is said to rise to the fly in the Canadian lakes. This species runs up the St. Mary's River, from Lake Huron to Lake Superior, in July and August. Great numbers are snared or speared by the Indians at this season at the Sault Ste. Marie.

In the breeding season the scales are sometimes thickened or covered with small warts, as in the male Cyprinidæ.

Argyrosomus, the Lake Herring.—In the genus Argyrosomus the mouth is larger, the premaxillary not set vertical, but extending forward on its lower edge, and the body is more elongate and more evenly elliptical. The species are more active and predaceous than those of Coregonus and are, on the whole, inferior as food.

The smallest and handsomest of the American whitefish is the cisco of Lake Michigan (Argyrosomus hoyi). It is a slender fish, rarely exceeding ten inches in length, and its scales have the brilliant silvery luster of the mooneye and the ladyfish.

The lake herring, or cisco (Argyrosomus artedi), is, next to the whitefish, the most important of the American species. It is more elongate than the others, and has a comparatively large mouth, with projecting under-jaw. It is correspondingly more voracious, and often takes the hook. During the spawning season of the whitefish the lake herring feeds on the ova of the latter, thereby doing a great amount of mischief. As food this species is fair, but much inferior to the whitefish. Its geographical distribution is essentially the same, but to a greater degree it frequents shoal waters. In the small lakes around Lake Michigan, in Indiana and Wisconsin (Tippecanoe, Geneva, Oconomowoc, etc.), the cisco has long been established; and in these waters its habits have undergone some change, as has also its external appearance. It has been recorded as a distinct species, Argyrosomus sisco, and its excellence as a game-fish has been long appreciated by the angler. These lake ciscoes remain for most of the year in the depths of the lake, coming to the surface only in search of certain insects, and to shallow water only in the spawning season. This periodical disappearance of the cisco has led to much foolish discussion as to the probability of their returning by an underground passage to Lake Michigan during the periods of their absence. One author, confounding "cisco" with "siscowet," has assumed that this underground passage leads to Lake Superior, and that the cisco is identical with the fat lake trout which bears the latter name. The name "lake herring" alludes to the superficial resemblance which this species possesses to the marine herring, a fish of quite a different family.

Fig. 51.—Bluefin Cisco, Argyrosomus nigripinnis Gill. Sheboygan.

Closely allied to the lake herring is the bluefin of Lake Michigan and of certain lakes in New York (Argyrosomus nigripinnis), a fine large species inhabiting deep waters, and recognizable by the blue-black color of its lower fins. In the lakes of central New York are found two other species, the so-called lake smelt (Argyrosomus osmeriformis) and the long-jaw (Argyrosomus prognathus). Argyrosomus lucidus is abundant in Great Bear Lake. In Alaska and Siberia are still other species of the cisco type (Argyrosomus laurettæ, A. pusillus, A. alascanus); and in Europe very similar species are the Scotch vendace (Argyrosomus vandesius) and the Scandinavian Lok-Sild (lake herring), as well as others less perfectly known.

The Tullibee, or "mongrel whitefish" (Argyrosomus tullibee), has a deep body, like the shad, with the large mouth of the ciscoes. It is found in the Great Lake region and northward, and very little is known of its habits. A similar species (Argyrosomus cyprinoides) is recorded from Siberia—a region which is peculiarly suited for the growth of the Coregoni, but in which the species have never received much study.

Brachymystax and Stenodus, the Inconnus.—Another little-known form, intermediate between the whitefish and the salmon, is Brachymystax lenock, a large fish of the mountain streams of Siberia. Only the skins brought home by Pallas a century ago are yet known. According to Pallas, it sometimes reaches a weight of eighty pounds.

Fig. 52.—Inconnu, Stenodus mackenziei (Richardson). Nulato, Alaska.

Still another genus, intermediate between the whitefish and the salmon, is Stenodus, distinguished by its elongate body, feeble teeth, and projecting lower jaw. The Inconnu, or Mackenzie River salmon, known on the Yukon as "charr" (Stenodus mackenziei), belongs to this genus. It reaches a weight of twenty pounds or more, and in the far north is a food-fish of good quality. It runs in the Yukon as far as White Horse Rapids. Not much is recorded of its habits, and few specimens exist in museums. A species of Stenodus called Stenodus leucichthys inhabits the Volga, Obi, Lena, and other northern rivers; but as yet little is definitely known of the species.

Oncorhynchus, the Quinnat Salmon.—The genus Oncorhynchus contains the salmon of the Pacific. They are in fact, as well as in name, the king salmon. The genus is closely related to Salmo, with which it agrees in general as to the structure of its vomer, and from which it differs in the increased number of anal rays, branchiostegals, pyloric cœca, and gill-rakers. The character most convenient for distinguishing Oncorhynchus, young or old, from all the species of Salmo, is the number of developed rays in the anal fin. These in Oncorhynchus are thirteen to twenty, in Salmo nine to twelve.

The species of Oncorhynchus have long been known as anadromous salmon, confined to the North Pacific. The species were first made known nearly one hundred and fifty years ago by that most exact of early observers, Steller, who, almost simultaneously with Krascheninnikov, another early investigator, described and distinguished them with perfect accuracy under their Russian vernacular names. These Russian names were, in 1792, adopted by Walbaum as specific names in giving to these animals a scientific nomenclature. Five species of Oncorhynchus are well known on both shores of the North Pacific, besides one other in Japan. These have been greatly misunderstood by early observers on account of the extraordinary changes due to differences in surroundings, in sex, and in age, and in conditions connected with the process of reproduction.

There are five species of salmon (Oncorhynchus) in the waters of the North Pacific, all found on both sides, besides one other which is known only from the waters of Japan. These species may be called: (1) the quinnat, or king-salmon, (2) the blue-back salmon, or redfish, (3) the silver salmon, (4) the dog-salmon, (5) the humpback salmon, and (6) the masu; or (1) Oncorhynchus tschawytscha, (2) Oncorhynchus nerka, (3) Oncorhynchus milktschitsch, (4) Oncorhynchus keta, (5) Oncorhynchus gorbuscha, (6) Oncorhynchus masou. All these species save the last are now known to occur in the waters of Kamchatka, as well as in those of Alaska and Oregon. These species, in all their varied conditions, may usually be distinguished by the characters given below. Other differences of form, color, and appearance are absolutely valueless for distinction, unless specimens of the same age, sex, and condition are compared.

The quinnat salmon (Oncorhynchus tschawytscha),[7] called quinnat, tyee, chinook, or king-salmon, has an average weight of 22 pounds, but individuals weighing 70 to 100 pounds are occasionally taken. It has about 16 anal rays, 15 to 19 branchiostegals, 23 (9 + 14) gill-rakers on the anterior gill-arch, and 140 to 185 pyloric cœca. The scales are comparatively large, there being from 130 to 155 in a longitudinal series. In the spring the body is silvery, the back, dorsal fin, and caudal fin having more or less of round black spots, and the sides of the head having a peculiar tin-colored metallic luster. In the fall the color is often black or dirty red, and the species can then be distinguished from the dog-salmon by its larger size and by its technical characters. The flesh is rich and salmon-red, becoming suddenly pale as the spawning season draws near.

7.  For valuable accounts of the habits of this species the reader is referred to papers by the late Cloudsley Rutter, ichthyologist of the Albatross, in the publications of the United States Fish Commission, the Popular Science Monthly, and the Overland Monthly.

Fig. 53.—Quinnat Salmon (female), Oncorhynchus tschawytscha (Walbaum). Columbia River.

Fig. 54.—King-salmon grilse, Oncorhynchus tschawytscha (Walbaum). (Photograph by Cloudsley Rutter.)

Fig. 55.—Male Red Salmon in September, Oncorhynchus nerka (Walbaum). Payette Lake, Idaho.

The blue-back salmon (Oncorhynchus nerka),[8] also called red salmon, sukkegh, or sockeye, usually weighs from 5 to 8 pounds. It has about 14 developed anal rays, 14 branchiostegals, and 75 to 95 pyloric cœca. The gill-rakers are more numerous than in any other salmon, the number being usually about 39 (16 + 23). The scales are larger, there being 130 to 140 in the lateral line. In the spring the form is plumply rounded, and the color is a clear bright blue above, silvery below, and everywhere immaculate. Young fishes often show a few round black spots, which disappear when they enter the sea. Fall specimens in the lakes are bright crimson in color, the head clear olive-green, and they become in a high degree hook-nosed and slab-sided, and bear little resemblance to the spring run. Young spawning male grilse follow the changes which take place in the adult, although often not more than half a pound in weight. These little fishes often appear in mountain lakes, but whether they are landlocked or have come up from the sea is still unsettled. These dwarf forms, called kokos by the Indians and benimasu in Japan, form the subspecies Oncorhynchus nerka kennerlyi. The flesh in this species is firmer than that of any other and very red, of good flavor, though drier and less rich than the king-salmon.

8.  For valuable records of the natural history of this species the reader is referred to various papers by Dr. Barton Warren Evermann in the Bulletins of the United States Fish Commission and elsewhere.

The silver salmon, or coho (Oncorhynchus milktschitsch, or kisutch), reaches a weight of 5 to 8 pounds. It has 13 developed rays in the anal, 13 branchiostegals, 23 (10 + 13) gill-rakers, and 45 to 80 pyloric cœca. There are about 127 scales in the lateral line. The scales are thin and all except those of the lateral line readily fall off. This feature distinguishes the species readily from the red salmon. In color it is silvery in spring, greenish above, and with a few faint black spots on the upper parts only. In the fall the males are mostly of a dirty red. The flesh in this species is of excellent flavor, but pale in color, and hence less valued than that of the quinnat and the red salmon.

The dog-salmon, calico salmon, or chum, called saké in Japan (Oncorhynchus keta), reaches an average weight of about 7 to 10 pounds. It has about 14 anal rays, 14 branchiostegals, 24 (9 + 15) gill-rakers, and 140 to 185 pyloric cœca. There are about 150 scales in the lateral line. In spring it is dirty silvery, immaculate, or sprinkled with small black specks, the fins dusky, the sides with faint traces of gridiron-like bars. In the fall the male is brick-red or blackish, and its jaws are greatly distorted. The pale flesh is well flavored when fresh, but pale and mushy in texture and muddy in taste when canned. It is said to take salt well, and great numbers of salt dog-salmon are consumed in Japan.

The humpback salmon, or pink salmon (Oncorhynchus gorbuscha), is the smallest of the American species, weighing from 3 to 5 pounds. It has usually 15 anal rays, 12 branchiostegals, 28 (13 + 15) gill-rakers, and about 180 pyloric cœca. Its scales are much smaller than in any other salmon, there being 180 to 240 in the lateral line. In color it is bluish above, silvery below, the posterior and upper parts with many round black spots, the caudal fin always having a few large black spots oblong in form. The males in fall are dirty red, and are more extravagantly distorted than in any other of the Salmonidæ. The flesh is softer than in the other species; it is pale in color, and, while of fair flavor when fresh, is distinctly inferior when canned.

Fig. 56.—Humpback Salmon (female), Oncorhynchus gorbuscha (Walbaum). Cook's Inlet.

The masu, or yezomasu (Oncorhynchus masou), is very similar to the humpback, the scales a little larger, the caudal without black spots, the back usually immaculate. It is one of the smaller salmon, and is fairly abundant in the streams of Hokkaido, the island formerly known as Yezo.

Fig 57.—Masu (female), Oncorhynchus masou (Brevoort). Aomori, Japan.

Of these species the blue-back or red salmon predominates in Frazer River and in most of the small rivers of Alaska, including all those which flow from lakes. The greatest salmon rivers of the world are the Nushegak and Karluk in Alaska, with the Columbia River, Frazer River, and Sacramento River farther south. The red and the silver salmon predominate in Puget Sound, the quinnat in the Columbia and the Sacramento, and the silver salmon in most of the smaller streams along the coast. All the species occur, however, from the Columbia northward; but the blue-back is not found in the Sacramento. Only the quinnat and the dog-salmon have been noticed south of San Francisco. In Japan keta is by far the most abundant species of salmon. It is known as saké, and largely salted and sold in the markets. Nerka is known in Japan only as landlocked in Lake Akan in northern Hokkaido. Milktschitsch is generally common, and with masou is known as masu, or small salmon, as distinguished from the large salmon, or saké. Tschawytscha and gorbuscha are unknown in Japan. Masou has not been found elsewhere.

The quinnat and blue-back salmon, the "noble salmon," habitually "run" in the spring, the others in the fall. The usual order of running in the rivers is as follows: tschawytscha, nerka, milktschitsch, gorbuscha, keta. Those which run first go farthest. In the Yukon the quinnat runs as far as Caribou Crossing and Lake Bennett, 2250 miles. The red salmon runs to "Forty-Mile," which is nearly 1800 miles. Both ascend to the head of the Columbia, Fraser, Nass, Skeena, Stikeen, and Taku rivers. The quinnat runs practically only in the streams of large size, fed with melting snows; the red salmon only in streams which pass through lakes. It spawns only in small streams at the head of a lake. The other species spawn in almost any fresh water and only close to the sea.

The economic value of the spring-running salmon is far greater than that of the other species, because they can be captured in numbers when at their best, while the others are usually taken only after deterioration.

The habits of the salmon in the ocean are not easily studied. Quinnat and silver salmon of all sizes are taken with the seine at almost any season in Puget Sound and among the islands of Alaska. This would indicate that these species do not go far from the shore. The silver salmon certainly does not. The quinnat pursues the schools of herring. It takes the hook freely in Monterey Bay, both near the shore and at a distance of six to eight miles out. We have reason to believe that these two species do not necessarily seek great depths, but probably remain not very far from the mouth of the rivers in which they were spawned. The blue-back or red salmon certainly seeks deeper water, as it is seldom or never taken with the seine along shore, and it is known to enter the Strait of Fuca in July, just before the running season, therefore coming in from the open sea. The great majority of the quinnat salmon, and probably all the blue-back salmon, enter the rivers in the spring. The run of the quinnat begins generally at the last of March; it lasts, with various modifications and interruptions, until the actual spawning season in November, the greatest run being in early June in Alaska, in July in the Columbia. The run begins earliest in the northernmost rivers, and in the longest streams, the time of running and the proportionate amount in each of the subordinate runs varying with each different river. In general the runs are slack in the summer and increase with the first high water of autumn. By the last of August only straggling blue-backs can be found in the lower course of any stream; but both in the Columbia and in the Sacramento the quinnat runs in considerable numbers at least till October. In the Sacramento the run is greatest in the fall, and more run in the summer than in spring. In the Sacramento and the smaller rivers southward there is a winter run, beginning in December. The spring quinnat salmon ascends only those rivers which are fed by the melting snows from the mountains and which have sufficient volume to send their waters well out to sea. Those salmon which run in the spring are chiefly adults (supposed to be at least three years old). Their milt and spawn are no more developed than at the same time in others of the same species which have not yet entered the rivers. It would appear that the contact with cold fresh water, when in the ocean, in some way causes them to run towards it, and to run before there is any special influence to that end exerted by the development of the organs of generation. High water on any of these rivers in the spring is always followed by an increased run of salmon. The salmon-canners think—and this is probably true—that salmon which would not have run till later are brought up by the contact with the cold water. The cause of this effect of cold fresh water is not understood. We may call it an instinct of the salmon, which is another way of expressing our ignorance. In general it seems to be true that in those rivers and during those years when the spring run is greatest the fall run is least to be depended on.

The blue-back salmon runs chiefly in July and early August, beginning in late June in Chilcoot River, where some were found actually spawning July 15; beginning after the middle of July in Frazer River.

As the season advances, smaller and younger salmon of these species (quinnat and blue-back) enter the rivers to spawn, and in the fall these young specimens are very numerous. We have thus far failed to notice any gradations in size or appearance of these young fish by which their ages could be ascertained. It is, however, probable that some of both sexes reproduce at the age of one year. In Frazer River, in the fall, quinnat male grilse of every size, from eight inches upwards, were running, the milt fully developed, but usually not showing the hooked jaws and dark colors of the older males. Females less than eighteen inches in length were not seen. All of either sex, large and small, then in the river had the ovaries or milt developed. Little blue-backs of every size, down to six inches, are also found in the upper Columbia in the fall, with their organs of generation fully developed. Nineteen-twentieths of these young fish are males, and some of them have the hooked jaws and red color of the old males. Apparently all these young fishes, like the old ones, die after spawning.

The average weight of the adult quinnat in the Columbia, in the spring, is twenty-two pounds; in the Sacramento, about sixteen. Individuals weighing from forty to sixty pounds are frequently found in both rivers, and some as high as eighty or even one hundred pounds are recorded, especially in Alaska, where the species tends to run larger. It is questionable whether these large fishes are those which, of the same age, have grown more rapidly; those which are older, but have for some reason failed to spawn; or those which have survived one or more spawning seasons. All these origins may be possible in individual cases. There is, however, no positive evidence that any salmon of the Pacific survives the spawning season.

Those fish which enter the rivers in the spring continue their ascent till death or the spawning season overtakes them. Doubtless not one of them ever returns to the ocean, and a large proportion fail to spawn. They are known to ascend the Sacramento to its extreme head-waters, about four hundred miles. In the Columbia they ascend as far as the Bitter Root and Sawtooth mountains of Idaho, and their extreme limit is not known. This is a distance of nearly a thousand miles. In the Yukon a few ascend to Caribou Crossing and Lake Bennett, 2250 miles. At these great distances, when the fish have reached the spawning grounds, besides the usual changes of the breeding season their bodies are covered with bruises, on which patches of white fungus (Saprolegnia) develop. The fins become mutilated, their eyes are often injured or destroyed, parasitic worms gather in their gills, they become extremely emaciated, their flesh becomes white from the loss of oil; and as soon as the spawning act is accomplished, and sometimes before, all of them die. The ascent of the Cascades and the Dalles of the Columbia causes the injury or death of a great many salmon.

Fig. 58.—Red Salmon (mutilated dwarf male, after spawning), Oncorhynchus nerka (Walbaum). Alturas Lake, Idaho.

When the salmon enter the river they refuse to take bait, and their stomachs are always found empty and contracted. In the rivers they do not feed; and when they reach the spawning grounds their stomachs, pyloric cœca and all, are said to be no larger than one's finger. They will sometimes take the fly, or a hook baited with salmon-roe, in the clear waters of the upper tributaries, but this is apparently solely out of annoyance, snapping at the meddling line. Only the quinnat and blue-back (there called redfish) have been found at any great distance from the sea, and these (as adult fishes) only in late summer and fall.

Fig. 59.—Young Male Quinnat Salmon, Oncorhynchus tschawytscha, dying after spawning. Sacramento River. (Photograph by Cloudsley Rutter.)

The spawning season is probably about the same for all the species. It varies for each of the different rivers, and for different parts of the same river. It doubtless extends from July to December, and takes place usually as soon as the temperature of the water falls to 54°. The manner of spawning is probably similar for all the species. In the quinnat the fishes pair off; the male, with tail and snout, excavates a broad, shallow "nest" in the gravelly bed of the stream, in rapid water, at a depth of one to four feet and the female deposits her eggs in it. They then float down the stream tail foremost, the only fashion in which salmon descend to the sea. As already stated, in the head-waters of the large streams, unquestionably, all die; it is the belief of the writer that none ever survive. The young hatch in sixty days, and most of them return to the ocean during the high water of the spring. They enter the river as adults at the age of about four years.

The salmon of all kinds in the spring are silvery, spotted or not according to the species, and with the mouth about equally symmetrical in both sexes. As the spawning season approaches the female loses her silvery color, becomes more slimy, the scales on the back partly sink into the skin, and the flesh changes from salmon-red and becomes variously paler, from the loss of oil; the degree of paleness varying much with individuals and with inhabitants of different rivers. In the Sacramento the flesh of the quinnat, in either spring or fall, is rarely pale. In the Columbia a few with pale flesh are sometimes taken in spring, and an increasing number from July on. In Frazer River the fall run of the quinnat is nearly worthless for canning purposes, because so many are "white-meated." In the spring very few are "white-meated"; but the number increases towards fall, when there is every variation, some having red streaks running through them, others being red toward the head and pale toward the tail. The red and pale ones cannot be distinguished externally, and the color is dependent on neither age nor sex. There is said to be no difference in the taste, but there is little market for canned salmon not of the conventional orange-color.

Fig. 60.—Quinnat Salmon, Oncorhynchus tschawytscha (Walbaum). Monterey Bay. (Photograph by C. Rutter.)

As the season advances the difference between the males and females becomes more and more marked, and keeps pace with the development of the milt, as is shown by dissection. The males have (1) the premaxillaries and the tip of the lower jaw more and more prolonged, both of the jaws becoming finally strongly and often extravagantly hooked, so that either they shut by the side of each other like shears, or else the mouth cannot be closed. (2) The front teeth become very long and canine-like, their growth proceeding very rapidly, until they are often half an inch long. (3) The teeth on the vomer and tongue often disappear. (4) The body grows more compressed and deeper at the shoulders, so that a very distinct hump is formed; this is more developed in the humpback salmon, but is found in all. (5) The scales disappear, especially on the back, by the growth of spongy skin. (6) The color changes from silvery to various shades of black and red, or blotchy, according to the species. The blue-back turns rosy-red, the head bright olive; the dog-salmon a dull red with blackish bars, and the quinnat generally blackish. The distorted males are commonly considered worthless, rejected by the canners and salmon-salters, but preserved by the Indians. These changes are due solely to influences connected with the growth of the reproductive organs. They are not in any way due to the action of fresh water. They take place at about the same time in the adult males of all species, whether in the ocean or in the rivers. At the time of the spring runs all are symmetrical. In the fall all males, of whatever species, are more or less distorted. Among the dog-salmon, which run only in the fall, the males are hook-jawed and red-blotched when they first enter the Strait of Fuca from the outside. The humpback, taken in salt water about Seattle, have the same peculiarities. The male is slab-sided, hook-billed, and distorted, and is rejected by the canners. No hook-jawed females of any species have been seen.

On first entering a stream the salmon swim about as if playing. They always head towards the current, and this appearance of playing may be simply due to facing the moving tide. Afterwards they enter the deepest parts of the stream and swim straight up, with few interruptions. Their rate of travel at Sacramento is estimated by Stone at about two miles per day; on the Columbia at about three miles per day. Those which enter the Columbia in the spring and ascend to the mountain rivers of Idaho must go at a more rapid rate than this, as they must make an average of nearly four miles per day.

As already stated, the economic value of any species depends in great part on its being a "spring salmon." It is not generally possible to capture salmon of any species in large numbers until they have entered the estuaries or rivers, and the spring salmon enter the large rivers long before the growth of the organs of reproduction has reduced the richness of the flesh. The fall salmon cannot be taken in quantity until their flesh has deteriorated; hence the dog-salmon is practically almost worthless except to the Indians, and the humpback salmon was regarded as little better until comparatively recently, when it has been placed on the market in cans as "Pink Salmon." It sells for about half the price of the red salmon and one-third that of the quinnat. The red salmon is smaller than the quinnat but, outside the Sacramento and the Columbia, far more abundant, and at present it exceeds the quinnat in economic value. The pack of red salmon in Alaska amounted in 1902 to over two million cases (48 pounds each), worth wholesale about $4.00 per case, or about $8,000,000. The other species in Alaska yield about one million cases, the total wholesale value of the pack for 1902 being $8,667,673. The aggregate value of the quinnat is considerably less, but either species far exceed in value all other fishes of the Pacific taken together. The silver salmon is found in the inland waters of Puget Sound for a considerable time before the fall rains cause the fall runs, and it may be taken in large numbers with seines before the season for entering the rivers.

The fall salmon of all species, but especially of the dog-salmon, ascend streams but a short distance before spawning. They seem to be in great anxiety to find fresh water, and many of them work their way up little brooks only a few inches deep, where they perish miserably, floundering about on the stones. Every stream of whatever kind, from San Francisco to Bering Sea, has more or less of these fall salmon.

The absence of the fine spring salmon in the streams of Japan is the cause of the relative unimportance of the river fisheries of the northern island of Japan, Hokkaido. It is not likely that either the quinnat or the red salmon can be introduced into these rivers, as they have no snow-fed streams, and few of them pass through lakes which are not shut off by waterfalls. For the same reason neither of these species is likely to become naturalized in the waters of our Eastern States, though it is worth while to bring the red salmon to the St. Lawrence. The silver salmon, already abundant in Japan, should thrive in the rivers and bays of New England.

The Parent-stream Theory.—It has been generally accepted as unquestioned by packers and fishermen that salmon return to spawn to the very stream in which they were hatched. As early as 1880 the present writer placed on record his opinion that this theory was unsound. In a general way most salmon return to the parent stream, because when in the sea the parent stream is the one most easily reached. The channels and runways which directed their course to the sea may influence their return trip in the same fashion. When the salmon is mature it seeks fresh water. Other things being equal, about the same number will run each year in the same channel. With all this, we find some curious facts. Certain streams will have a run of exceptionally large or exceptionally small red salmon. The time of the run bears some relation to the length of the stream: those who have farthest to go start earliest. The time of running bears also a relation to the temperature of the spawning grounds: where the waters cool off earliest the fish run soonest.

The supposed evidence in favor of the parent-stream theory may be considered under three heads:[9] (1) Distinctive runs in various streams. (2) Return of marked salmon. (3) Introduction of salmon into new streams followed by their return.

9.  See an excellent article by H. S. Davis in the Pacific Fisherman for July, 1903.

Under the first head it is often asserted of fishermen that they can distinguish the salmon of different streams. Thus the Lynn Canal red salmon are larger than those in most waters, and it is claimed that those of Chilcoot Inlet are larger than those of the sister stream at Chilcat. The red salmon of Red Fish Bay on Baranof Island are said to be much smaller than usual, and those of the neighboring Necker Bay are not more than one-third the ordinary size. Those of a small rapid stream near Nass River are more wiry than those of the neighboring large stream. The same claim is made for the different streams of Puget Sound, each one having its characteristic run. In all this there is some truth and perhaps some exaggeration. I have noticed that the Chilcoot fish seem deeper in body than those at Chilcat. The red salmon becomes compressed before spawning, and the Chilcoot fishes having a short run spawn earlier than the Chilcat fishes, which have many miles to go, the water being perhaps warmer at the mouth of the river. Perhaps some localities may meet the nervous reactions of small fishes, while not attracting the large ones. Mr. H. S. Davis well observes that "until a constant difference has been demonstrated by a careful examination of large numbers of fish from each stream taken at the same time, but little weight can be attached to arguments of this nature."

It is doubtless true as a general proposition that nearly all salmon return to the region in which they were spawned. Most of them apparently never go far away from the mouth of the stream or the bay into which it flows. It is true that salmon are occasionally taken well out at sea, and it is certain that the red salmon runs of Puget Sound come from outside the Straits of Fuca. There is, however, evidence that they rarely go so far as that. When seeking shore they do not reach the original channels.

In 1880 the writer, studying the salmon of the Columbia, used the following words, which he has not had occasion to change:

"It is the prevailing impression that the salmon have some special instinct which leads them to return to spawn in the same spawning grounds where they were originally hatched. We fail to find any evidence of this in the case of the Pacific-coast salmon, and we do not believe it to be true. It seems more probable that the young salmon hatched in any river mostly remain in the ocean within a radius of twenty, thirty, or forty miles of its mouth. These, in their movements about in the ocean, may come into contact with the cold waters of their parent rivers, or perhaps of any other river, at a considerable distance from the shore. In the case of the quinnat and the blue-back their 'instinct' seems to lead them to ascend these fresh waters, and in a majority of cases these waters will be those in which the fishes in question were originally spawned. Later in the season the growth of the reproductive organs leads them to approach the shore and search for fresh waters, and still the chances are that they may find the original stream. But undoubtedly many fall salmon ascend, or try to ascend, streams in which no salmon was ever hatched. In little brooks about Puget Sound, where the water is not three inches deep, are often found dead or dying salmon which have entered them for the purpose of spawning. It is said of the Russian River and other California rivers that their mouths, in the time of low water in summer, generally become entirely closed by sand-bars, and that the salmon, in their eagerness to ascend them, frequently fling themselves entirely out of water on the beach. But this does not prove that the salmon are guided by a marvelous geographical instinct which leads them to their parent river in spite of the fact that the river cannot be found. The waters of Russian River soak through these sand-bars, and the salmon instinct, we think, leads them merely to search for fresh waters. This matter is much in need of further investigation; at present, however, we find no reason to believe that the salmon enter the Rogue River simply because they were spawned there, or that a salmon hatched in the Clackamas River is more likely, on that account, to return to the Clackamas than to go up the Cowlitz or the Des Chûtes."

Attempts have been made to settle this question by marking the fry. But this is a very difficult matter indeed. Almost the only structure which can be safely mutilated is the adipose fin, and this is often nipped off by sticklebacks and other meddling fish. The following experiments have been tried, according to Mr. Davis:

In March, 1896, 5000 king-salmon fry were marked by cutting off the adipose fin, then set free in the Clackamas River. Nearly 400 of these marked fish are said to have been taken in the Columbia in 1898, and a few more in 1899. In addition a few were taken in 1898, 1899, and 1900 in the Sacramento River, but in much less numbers than in the Columbia. In the Columbia most were taken at the mouth of the river, where nearly all of the fishing was done, but a few were in the original stream, the Clackamas. It is stated that the fry thus set free in the Clackamas came from eggs obtained in the Sacramento—a matter which has, however, no bearing on the present case.

In the Kalama hatchery on the Columbia River, Washington, 2000 fry of the quinnat or king-salmon were marked in 1899 by a V-shaped notch in the caudal fin. Numerous fishes thus marked were taken in the lower Columbia in 1901 and 1902. A few were taken at the Kalama hatchery, but some also at the hatcheries on Wind River and Clackamas River. At the hatchery on Chehalis River six or seven were taken, the stream not being a tributary of the Columbia, but flowing into Shoalwater Bay. None were noticed in the Sacramento. The evidence shows that the most who are hatched in a large stream tend to return to it, and that in general most salmon return to the parent region. There is no evidence that a salmon hatched in one branch of a river tends to return there rather than to any other. Experiments of Messrs. Rutter and Spaulding in marking adult fish at Karluk would indicate that they roam rather widely about the island before spawning. An adult spawning fish, marked and set free at Karluk, was taken soon after on the opposite side of the island of Kadiak.

The introduction of salmon into new streams may throw some light on this question. In 1897 and 1898 3,000,000 young quinnat-salmon fry were set free in Papermill Creek near Olema, California. This is a small stream flowing into the head of Tomales Bay, and it had never previously had a run of salmon. In 1900, and especially in 1901, large quinnat salmon appeared in considerable numbers in this stream. One specimen weighing about sixteen pounds was sent to the present writer for identification. These fishes certainly returned to the parent stream, although this stream was one not at all fitted for their purpose.

But this may be accounted for by the topography of the bay. Tomales Bay is a long and narrow channel, about twenty miles long and from one to five in width, isolated from other rivers and with but one tributary stream. Probably the salmon had not wandered far from it; some may not have left it at all. In any event, a large number certainly came back to the same place.

That the salmon rarely go far away is fairly attested. Schools of king-salmon play in Monterey Bay, and chase the herring about in the channels of southeastern Alaska. A few years since Captain J. F. Moser, in charge of the Albatross, set gill-nets for salmon at various places in the sea off the Oregon and Washington coast, catching none except in the bays.

Mr. Davis gives an account of the liberation of salmon in Chinook River, which flows into the Columbia at Baker's Bay:

"It is a small, sluggish stream and has never been frequented by Chinook salmon, although considerable numbers of silver and dog salmon enter it late in the fall. A few years ago the State established a hatchery on this stream, and since 1898 between 1,000,000 and 2,000,000 Chinook fry have been turned out here annually. The fish are taken from the pound-nets in Baker's Bay, towed into the river in crates and then liberated above the dike, which prevents their return to the Columbia. When ripe the salmon ascend to the hatchery, some two or three miles farther up the river, where they are spawned.

"The superintendent of the hatchery, Mr. Hansen, informs me that in 1902, during November and December, quite a number of Chinook salmon ascended the Chinook River. About 150 salmon of both sexes were taken in a trap located in the river about four miles from its mouth. At first thought it would appear that these were probably fish which, when fry, had been liberated in the river, but unfortunately there is no proof that this was the case. According to Mr. Hansen, the season of 1902 was remarkable in that the salmon ran inshore in large schools, a thing which they had not done before for years. It is possible that the fish, being forced in close to the shore, came in contact with the current from the Chinook River, which, since the stream is small and sluggish, would not be felt far from shore. Once brought under the influence of the current from the river, the salmon would naturally ascend that stream, whether they had been hatched there or not."

The general conclusion, apparently warranted by the facts at hand, is that salmon, for the most part, do not go to a great distance from the stream in which they are hatched, that most of them return to the streams of the same region, a majority to the parent stream, but that there is no evidence that they choose the parental spawning grounds in preference to any other, and none that they will prefer an undesirable stream to a favorable one for the reason that they happen to have been hatched in the former.

The Jadgeska Hatchery.—Mr. John C. Callbreath of Wrangel, Alaska, has long conducted a very interesting but very costly experiment in this line. About 1890 he established himself in a small stream called Jadgeska on the west coast of Etolin Island, tributary to McHenry Inlet, Clarence Straits. This stream led from a lake, and in it a few thousand red salmon spawned, besides multitudes of silver salmon, dog-salmon, and humpback salmon. Making a dam across the stream, he helped the red salmon over it, destroying all of the inferior kinds which entered the stream. He also established a hatchery for the red salmon, turning loose many fry yearly for ten or twelve years. This was done in the expectation that all the salmon hatched would return to Jadgeska in about four years. By destroying all individuals of other species attempting to run, it was expected that they would become extinct so far as the stream is concerned.

The result of this experiment has been disappointment. After twelve years or more there has been no increase of red salmon in the stream, and no decrease of humpbacks and other humbler forms of salmon. Mr. Callbreath draws the conclusion that salmon run at a much greater age than has been supposed—at the age of sixteen years, perhaps, instead of four. A far more probable conclusion is that his salmon have joined other bands bound for more suitable streams. It is indeed claimed that since the establishment of Callbreath's hatchery on Etolin Island there has been a notable increase of the salmon run in the various streams of Prince of Wales Island on the opposite side of Clarence Straits. But this statement, while largely current among the cannerymen, and not improbable, needs verification.

We shall await with much interest the return of the thousands of salmon hatched in 1902 in Naha stream. We may venture the prophecy that while a large percentage will return to Loring, many others will enter Yes Bay, Karta Bay, Moira Sound, and other red salmon waters along the line of their return from Dixon Entrance or the open sea.

Salmon-packing.—The canning of salmon, that is, the packing of the flesh in tin cases, hermetically sealed after boiling, was begun on the Columbia River by the Hume Brothers in 1866. In 1874 canneries were established on the Sacramento River, in 1876 on Puget Sound and on Frazer River, and in 1878 in Alaska. At first only the quinnat salmon was packed; afterwards the red salmon and the silver salmon, and finally the humpback, known commercially as pink salmon. In most cases the flesh is packed in one-pound tins, forty-eight of which constitute a case. The wholesale price in 1903 was for quinnat salmon $5.60 per case, red salmon $4.00, silver salmon $2.60, humpback salmon $2.00, and dog-salmon $1.50. It costs in round numbers $2.00 to pack a case of salmon. The very low price of the inferior brands is due to overproduction.

The output of the salmon fishery of the Pacific coast amounts to about fifteen millions per year, that of Alaska constituting seven to nine millions of this amount. Of this amount the red salmon constitutes somewhat more than half, the quinnat about four-fifths of the rest.

In almost all salmon streams there is evidence of considerable diminution in numbers, although the evidence is sometimes conflicting. In Alaska this has been due to the vicious custom, now done away with, of barricading the streams so that the fish could not reach the spawning grounds, but might be all taken with the net. In the Columbia River the reduction in numbers is mainly due to stationary traps and salmon-wheels, which leave the fish relatively little chance to reach the spawning grounds. In years of high water doubtless many salmon run in the spring which might otherwise have waited until fall.

The key to the situation lies in the artificial propagation of salmon by means of well-ordered hatcheries. By this means the fisheries of the Sacramento have been fully restored, those of the Columbia approximately maintained, and a hopeful beginning has been made in hatching red salmon in Alaska.

CHAPTER V
SALMONIDÆ—(Continued)

Salmo, the Trout and Atlantic Salmon.—The genus Salmo comprises those forms of salmon which have been longest known. As in related genera, the mouth is large, and the jaws, palatines, and tongue are armed with strong teeth. The vomer is flat, its shaft not depressed below the level of the head or chevron (the anterior end). There are a few teeth on the chevron; and behind it, on the shaft, there is either a double series of teeth or an irregular single series. These teeth in the true salmon disappear with age, but in the others (the black-spotted trout) they are persistent. The scales are silvery and moderate or small in size. There are 9 to 11 developed rays in the anal fin. The caudal fin is truncate, or variously concave or forked. There are usually 40 to 70 pyloric cœca, 11 or 12 branchiostegals, and about 20 (8 + 12) gill-rakers. The sexual peculiarities are in general less marked than in Oncorhynchus; they are also greater in the anadromous species than in those which inhabit fresh waters. In general the male in the breeding season is redder, its jaws are prolonged, the front teeth enlarged, the lower jaw turned upwards at the end, and the upper jaw notched, or sometimes even perforated, by the tip of the lower. All the species of Salmo (like those of Oncorhynchus) are more or less spotted with black. Unlike the species of Oncorhynchus, the species of Salmo feed more or less while in fresh water, and the individuals for the most part do not die after spawning, although many old males do thus perish.

The Atlantic Salmon.—The large species of Salmo, called salmon by English-speaking people (Salmo salar, Salmo trutta), are marine and anadromous, taking the place in the North Atlantic occupied in the North Pacific by the species of Oncorhynchus. Two others more or less similar in character occur in Japan and Kamchatka. The others (trout), forming the subgenus Salar, are non-migratory, or at least irregularly or imperfectly anadromous. The true or black-spotted trout abound in all streams of northern Europe, northern Asia, and in that part of North America which lies west of the Mississippi Valley. The black-spotted trout are entirely wanting in eastern America—a remarkable fact in geographical distribution, perhaps explained only on the hypothesis of the comparatively recent and Eurasiatic origin of the group, which, we may suppose, has not yet had opportunity to extend its range across the plains, unsuitable for salmon life, which separate the upper Missouri from the Great Lakes.

The salmon (Salmo salar) is the only black-spotted salmonoid found in American waters tributary to the Atlantic. In Europe, where other species similarly colored occur, the species may be best distinguished by the fact that the teeth on the shaft of the vomer mostly disappear with age. From the only other species positively known, the salmon trout (Salmo trutta), which shares this character, the true salmon may be distinguished by the presence of but eleven scales between the adipose fin and the lateral line, while Salmo trutta has about fourteen. The scales are comparatively large in the salmon, there being about one hundred and twenty-five in the lateral line. The caudal fin, which is forked in the young, becomes, as in other species of salmon, more or less truncate with age. The pyloric cœca are fifty to sixty in number.

The color in adults, according to Dr. Day, is "superiorly of a steel-blue, becoming lighter on the sides and beneath. Mostly a few rounded or X-shaped spots scattered above the lateral line and upper half of the head, being more numerous in the female than in the male. Dorsal, caudal, and pectoral fins dusky; ventrals and anal white, the former grayish internally. Prior to entering fresh waters these fish are of a brilliant steel-blue along the back, which becomes changed to a muddy tinge when they enter rivers. After these fish have passed into the fresh waters for the purpose of breeding, numerous orange streaks appear in the cheeks of the male, and also spots or even marks of the same, and likewise of a red color, on the body. It is now termed a 'redfish.' The female, however, is dark in color and known as 'blackfish.' 'Smolts' (young river fish) are bluish along the upper half of the body, silvery along the sides, due to a layer of silvery scales being formed over the trout-like colors, while they have darker fins than the yearling 'ping,' but similar bands and spots, which can be seen (as in the parr) if the example be held in certain positions of light. 'Parr' (fishes of the year) have two or three black spots only on the opercle, and black spots and also orange ones along the upper half of the body, and no dark ones below the lateral line, although there may be orange ones which can be seen in its course. Along the side of the body are a series (12 to 15) of transverse bluish bands, wider than the ground color and crossing the lateral line, while in the upper half of the body the darker color of the back forms an arch over each of these bands, a row of spots along the middle of the rayed dorsal fin, and the adipose orange-tipped."

The dusky cross-shades found in the young salmon or parr are characteristic of the young of salmon, trout, grayling, and nearly all the other Salmonidæ.

The salmon of the Atlantic is, as already stated, an anadromous fish, spending most of its life in the sea, and entering the streams in the fall for the purpose of reproduction. The time of running varies much in different streams and also in different countries. As with the Pacific species, these salmon are not easily discouraged in their progress, leaping cascades and other obstructions, or, if these prove impassable, dying after repeated fruitless attempts.

The young salmon, known as the "parr," is hatched in the spring. It usually remains about two years in the rivers, descending at about the third spring to the sea, when it is known as "smolt." In the sea it grows much more rapidly, and becomes more silvery in color, and is known as "grilse." The grilse rapidly develop into the adult salmon; and some of them, as in the case with the grilse of the Pacific salmon, are capable of reproduction.

After spawning the salmon are very lean and unwholesome in appearance, as in fact. They are then known as "kelts." The Atlantic salmon does not ascend rivers to any such distances as those traversed by the quinnat and the blue-back. Its kelts, therefore, for the most part survive the act of spawning. Dr. Day thinks that they feed upon the young salmon in the rivers, and that, therefore, the destruction of the kelts might increase the supply of salmon.

As a food-fish the Atlantic salmon is very similar to the quinnat salmon, neither better nor worse, so far as I can see, when equally fresh. In both the flesh is rich and finely flavored; but the appetite of man becomes cloyed with salmon-flesh sooner than with that of whitefish, smelt, or charr. In size the Atlantic salmon does not fall far short of the quinnat. The average weight of the adult is probably less than fifteen pounds. The largest one of which I find a record was taken on the coast of Ireland in 1881, and weighed 84¾ pounds.

The salmon is found in Europe between the latitude of 45° and 75°. In the United States it is now rarely seen south of Cape Cod, although formerly the Hudson and numerous other rivers were salmon-streams. Overfishing, obstructions in the rivers, and pollution of the water by manufactories and by city sewage are agencies against which the salmon cannot cope.

Seven species of salmon (as distinguished from trout) are recognized by Dr. Günther in Europe, and three in America. The landlocked forms, abundant in Norway, Sweden, and Maine, which cannot, or at least do not, descend to the sea, are regarded by him as distinct species. "The question," observes Dr Günther, "whether any of the migratory species can be retained by artificial means in fresh water, and finally accommodate themselves to a permanent sojourn therein, must be negatived for the present." On this point I think that the balance of evidence leads to a different conclusion. These fresh-water forms (Sebago and Ouananiche) are actually salmon which have become landlocked. I have compared numerous specimens of the common landlocked salmon (Salmo salar sebago) of the lakes of Maine and New Brunswick with landlocked salmon (Salmo salar hardini) from the lakes of Sweden, and with numerous migratory salmon, both from America and Europe. I see no reason for regarding them as specifically distinct. The differences are very trivial in kind, and not greater than would be expected on the hypothesis of recent adaptation of the salmon to lake life. We have therefore on our Atlantic coast but one species of salmon, Salmo salar. The landlocked form of the lakes of Maine is Salmo salar sebago. The Ouananiche of Lake St. John and the Saguenay, beloved of anglers, is Salmo salar ouananiche.

The Ouananiche.—Dr. Henry Van Dyke writes thus of the Ouananiche: "But the prince of the pool was the fighting Ouananiche, the little salmon of St. John. Here let me chant thy praise, thou noblest and most high-minded fish, the cleanest feeder, the merriest liver, the loftiest leaper, and the bravest warrior of all creatures that swim! Thy cousin, the trout, in his purple and gold with crimson spots, wears a more splendid armor than thy russet and silver mottled with black, but thine is the kinglier nature.

"The old salmon of the sea who begat thee long ago in these inland waters became a backslider, descending again to the ocean, and grew gross and heavy with coarse feeding. But thou, unsalted salmon of the foaming floods, not landlocked as men call thee, but choosing of thine own free will to dwell on a loftier level in the pure, swift current of a living stream, hath grown in grace and risen to a better life.

"Thou art not to be measured by quantity but by quality, and thy five pounds of pure vigor will outweigh a score of pounds of flesh less vitalized by spirit. Thou feedest on the flies of the air, and thy food is transformed into an aerial passion for flight, as thou springest across the pool, vaulting toward the sky. Thine eyes have grown large and keen by piercing through the foam, and the feathered hook that can deceive thee must be deftly tied and delicately cast. Thy tail and fins, by ceaseless conflict with the rapids, have broadened and strengthened, so that they can flash thy slender body like a living arrow up the fall. As Launcelot among the knights, so art thou among the fish, the plain-armored hero, the sunburnt champion of all the water-folk."

Dr. Francis Day, who has very thoroughly studied these fishes, takes, in his memoir on "The Fishes of Great Britain and Ireland," and in other papers, a similar view in regard to the European species. Omitting the species with permanent teeth on the shaft of the vomer (subgenus Salar), he finds among the salmon proper only two species, Salmo salar and Salmo trutta. The latter species, the sea-trout or salmon-trout of England and the estuaries of northern Europe, is similar to the salmon in many respects, but has rather smaller scales, there being fourteen in an oblique series between the adipose fin and the lateral line. It is not so strong a fish as the salmon, nor does it reach so large a size. Although naturally anadromous, like the true salmon, landlocked forms of the salmon-trout are not uncommon. These have been usually regarded as different species, while aberrant or intermediate individuals are usually regarded as hybrids. The salmon-trout of Europe have many analogies with the steelhead of the Pacific.

The present writer has examined many thousands of American Salmonidæ, both of Oncorhynchus and Salmo. While many variations have come to his attention, and he has been compelled more than once to modify his views as to specific distinctions, he has never yet seen an individual which he had the slightest reason to regard as a "hybrid." It is certainly illogical to conclude that every specimen which does not correspond to our closet-formed definition of its species must therefore be a "hybrid" with some other. There is no evidence worth mentioning, known to me, of extensive hybridization in a state of nature in any group of fishes. This matter is much in need of further study; for what is true of the species in one region, in this regard, may not be true of others. Dr. Günther observes:

"Johnson, a correspondent of Willughby, had already expressed his belief that the different salmonoids interbreed; and this view has since been shared by many who have observed these fishes in nature. Hybrids between the sewin (Salmo trutta cambricus) and the river-trout (Salmo fario) were numerous in the Rhymney and other rivers of South Wales before salmonoids were almost exterminated by the pollutions allowed to pass into these streams, and so variable in their characters that the passage from one species to the other could be demonstrated in an almost unbroken series, which might induce some naturalists to regard both species as identical. Abundant evidence of a similar character has accumulated, showing the frequent occurrence of hybrids between Salmo fario and S. trutta.... In some rivers the conditions appear to be more favorable to hybridism than in others in which hybrids are of comparatively rare occurrence. Hybrids between the salmon and other species are very scarce everywhere."

Very similar to the European Salmo trutta is the trout of Japan (Salmo perryi), the young called yamabe, the adult kawamasu, or river-salmon. This species abounds everywhere in Japan, the young being the common trout of the brooks, black-spotted and crossed by parr-marks, the adult reaching a weight of ten or twelve pounds in the larger rivers and descending to the sea. In Kamchatka is another large, black-spotted, salmon-like species properly to be called a salmon-trout. This is Salmo mykiss, a name very wrongly applied to the cutthroat trout of the Columbia.

The black-spotted trout, forming the subgenus Salar, differ from Salmo salar and Salmo trutta in the greater development of the vomerine teeth, which are persistent throughout life, in a long double series on the shaft of the vomer. About seven species are laboriously distinguished by Dr. Günther in the waters of western Europe. Most of these are regarded by Dr. Day as varieties of Salmo fario. The latter species, the common river-trout or lake-trout of Europe, is found throughout northern and central Europe, wherever suitable waters occur. It is abundant, gamy, takes the hook readily, and is excellent as food. It is more hardy than the different species of charr, although from an æsthetic point of view it must be regarded as inferior to all of the Salvelini. The largest river-trout recorded by Dr. Day weighed twenty-one pounds. Such large individuals are usually found in lakes in the north, well stocked with smaller fishes on which trout may feed. Farther south, where the surroundings are less favorable to trout-life, they become mature at a length of less than a foot, and a weight of a few ounces. These excessive variations in the size of individuals have received too little notice from students of Salmonidæ. Similar variations occur in all the non-migratory species of Salmo and of Salvelinus. Numerous river-trout have been recorded from northern Asia, but as yet nothing can be definitely stated as to the number of species actually existing.

The Black-spotted Trout.—In North America only the region west of the Mississippi Valley, the streams of southeastern Alaska, and the valley of Mackenzie River have species of black-spotted trout. There are few of these north of Sitka in Alaska, although black-spotted trout are occasionally taken on Kadiak and about Bristol Bay, and none east of the Rocky Mountain region. If we are to follow the usage of the names "salmon" and "trout" which prevails in England, we should say that, in America, it is only these western regions which have any trout at all. Of the number of species (about twenty-five in all) which have been indicated by authors, certainly not more than about 8 to 10 can possibly be regarded as distinct species. The other names are either useless synonyms, or else they have been applied to local varieties which pass by degrees into the ordinary types.

The Trout of Western America.—In the western part of America are found more than a score of forms of trout of the genus Salmo, all closely related and difficult to distinguish. There are representatives in the head-waters of the Rio Grande, Arkansas, South Platte, Missouri, and Colorado rivers; also in the Great Salt Lake basin, throughout the Columbia basin, in all suitable waters from southern California and Chihuahua to Sitka, and even to Bristol Bay, similar forms again appearing in Kamchatka and Japan.

Among the various more or less tangible species that may be recognized, three distinct series appear. These have been termed the cutthroat-trout series (allies of Salmo clarkii), the rainbow-trout series (allies of Salmo irideus), and the steelhead series (allies of Salmo rivularis, a species more usually but wrongly called Salmo gairdneri).

The steelhead, or rivularis series, is found in the coastwise streams of California and in the streams of Oregon and Washington, below the great Shoshone Falls of Snake River, and northward in Alaska along the mainland as far as Skaguay. The steelhead-trout reach a large size (10 to 20 pounds). They spend a large part of their life in the sea. In all the true steelheads the head is relatively very short, its length being contained about five times in the distance from tip of snout to base of caudal fin. The scales in the steelhead are always rather small, about 150 in a linear series, and there is no red under the throat. The spots on the dorsal fin are fewer in the steelhead (4 to 6 rows) than in the other American trout.

The rainbow forms are chiefly confined to the streams of California and Oregon. In these the scales are large (about 135 in a lengthwise series) and the head is relatively large, forming nearly one-fourth of the length to base of caudal. These enter the sea only when in the small coastwise streams. Usually they have no red under the throat. The cutthroat forms are found from Humboldt Bay northward as far as Sitka, in the coastwise streams of northern California, Oregon, Washington, and Alaska, and all the clear streams on both sides of the Rocky Mountains, and in the Great Basin and the head-waters of the Colorado. The cutthroat-trout have the scales small, about 180, and there is always a bright dash of orange-red on each side concealed beneath the branches of the lower jaw. Along the western slope of the Sierra Nevada there are also forms of trout with the general appearance of rainbow-trout and evidently belonging to that species, but with scales intermediate in number (in McCloud River), var. shasta, or with scales as small as in the typical cutthroat (Kern River), var. gilberti. In these small-scaled forms more or less red appears below the lower jaw, and they are doubtless what they appear to be, really intermediate between clarkii and irideus, although certainly nearest the latter. A similar series of forms occurs in the Columbia basin, the upper Snake being inhabited by clarkii and the lower Snake by clarkii and rivularis, together with a medley of forms apparently intermediate.

It seems probable that the American trout originated in Asia, extended its range to southeast Alaska, thence southward to the Fraser and Columbia, thence to the Yellowstone and the Missouri via Two-Ocean Pass; from the Snake River to the Great Basins of Utah and Nevada; from the Missouri southward to the Platte and the Arkansas, thence from the Platte to the Rio Grande and the Colorado, and then from Oregon southward coastwise and along the Sierras to northern Mexico, thence northward and coastwise, the sea-running forms passing from stream to stream.

Fig. 61.—Rainbow Trout (male), Salmo irideus shasta Jordan. (Photograph by Cloudsley Rutter.)

Of the American species the rainbow trout of California (Salmo irideus) most nearly approaches the European Salmo fario. It has the scales comparatively large, although rather smaller than in Salmo fario, the usual number in a longitudinal series being about 135. The mouth is smaller than in other American trout; the maxillary, except in old males, rarely extending beyond the eye. The caudal fin is well forked, becoming in very old fishes more nearly truncate. The head is relatively large, about four times in the total length. The size of the head forms the best distinctive character. The color, as in all the other species, is bluish, the sides silvery in the males, with a red lateral band, and reddish and dusky blotches. The head, back, and upper fins are sprinkled with round black spots, which are very variable in number, those on the dorsal usually in about nine rows. In specimens taken in the sea this species, like most other trout in similar conditions, is bright silvery, and sometimes immaculate. This species is especially characteristic of the waters of California. It abounds in every clear brook, from the Mexican line northward to Mount Shasta, or beyond, the species passing in the Columbia region by degrees into the species or form known as Salmo masoni, the Oregon rainbow trout, a small rainbow trout common in the forest streams of Oregon, with smaller mouth and fewer spots on the dorsal. No true rainbow trout have been anywhere obtained to the eastward of the Cascade Range or of the Sierra Nevada, except as artificially planted in the Truckee River. The species varies much in size; specimens from northern California often reach a weight of six pounds, while in the streams above Tia Juana in Lower California the southernmost locality from which I have obtained trout, they seldom exceed a length of six inches. Although not usually an anadromous species, the rainbow trout frequently moves about in the rivers, and it often enters the sea, large sea-run specimens being often taken for steelheads. Several attempts have been made to introduce it in Eastern streams, but it appears to seek the sea when it is lost. It is apparently more hardy and less greedy than the American charr, or brook-trout (Salvelinus fontinalis). On the other hand, it is distinctly inferior to the latter in beauty and in gaminess.

Fig. 62.—Rainbow Trout (female), Salmo irideus shasta Jordan. (Photograph by Cloudsley Rutter.)

Three varieties of some importance have been indicated, Salmo irideus stonei, the Nissui trout of the Klamath, with spots on the posterior parts only, Salmo irideus shasta of the upper Sacramento, and the small-scaled Salmo irideus gilberti of the Kings and Kern rivers. In the head-waters of the Kern, in a stream called Volcano Creek or Whitney Creek, the waterfall sometimes called Agua-Bonita shuts off the movements of the trout. Above this fall is a dwarf form with bright golden fins, and the scales scarcely imbricated. This is the "golden trout of Mount Whitney," Salmo irideus agua-bonita. It will possibly be found to change back to the original type if propagated in different waters.

In beauty of color, gracefulness of form and movement, sprightliness when in the water, reckless dash with which it springs from the water to meet the descending fly ere it strikes the surface, and the mad and repeated leaps from the water when hooked, the rainbow trout must ever hold a very high rank. "The gamest fish we have ever seen," writes Dr. Evermann, "was a 16-inch rainbow taken on a fly in a small spring branch tributary of Williamson River in southern Oregon. It was in a broad and deep pool of exceedingly clear water. As the angler from behind a clump of willows made the cast the trout bounded from the water and met the fly in the air a foot or more above the surface; missing it, he dropped upon the water, only to turn about and strike viciously a second time at the fly just as it touched the surface; though he again missed the fly, the hook caught him in the lower jaw from the outside, and then began a fight which would delight the heart of any angler. His first effort was to reach the bottom of the pool, then, doubling upon the line, he made three jumps from the water in quick succession, clearing the surface in each instance from one to four feet, and every time doing his utmost to free himself from the hook by shaking his head as vigorously as a dog shakes a rat. Then he would rush wildly about in the large pool, now attempting to go down over the riffle below the pool, now trying the opposite direction, and often striving to hide under one or the other of the banks. It was easy to handle the fish when the dash was made up or down stream or for the opposite side, but when he turned about and made a rush for the protection of the overhanging bank upon which the angler stood it was not easy to keep the line taut. Movements such as these were frequently repeated, and two more leaps were made. But finally he was worn out after as honest a fight as trout ever made."

"The rainbow takes the fly so readily that there is no reason for resorting to grasshoppers, salmon-eggs, or other bait. It is a fish whose gaminess will satisfy the most exacting of expert anglers and whose readiness to take any proper line will please the most impatient of inexperienced amateurs."

The steelhead (Salmo rivularis) is a large trout, reaching twelve to twenty pounds in weight, found abundantly in river estuaries and sometimes in lakes from Lynn Canal to Santa Barbara. The spent fish abound in the rivers in spring at the time of the salmon-run. The species is rarely canned, but is valued for shipment in cold storage. Its bones are much more firm than those of the salmon—a trait unfavorable for canning purposes. The flesh when not spent after spawning is excellent. The steelhead does not die after spawning, as all the Pacific salmon do.

Fig. 63.—Steelhead Trout, Salmo rivularis Ayres. Columbia River.

It is thought by some anglers that the young fish hatched in the brooks from eggs of the steelhead remain in mountain streams from six to thirty-six months, going down to the sea with the high waters of spring, after which they return to spawn as typical steelhead trout. I now regard this view as unfounded. In my experience the rainbow and the steelhead are always distinguishable: the steelhead abounds where the rainbow trout is unknown; the scales in the steelhead are always smaller (about 155) than in typical rainbow trout; finally, the small size of the head in the steelhead is always distinctive.

The Kamloops trout, described by the writer from the upper Columbia, seems to be a typical steelhead as found well up the rivers away from the sea. Derived from the steelhead, but apparently quite distinct from it, are three very noble trout, all confined so far as yet known to Lake Crescent in northwestern Washington. These are the crescent trout, Salmo crescentis, the Beardslee trout, Salmo beardsleei, and the long-headed trout, Salmo bathæcetor. The first two, discovered by Admiral L. A. Beardslee, are trout of peculiar attractiveness and excellence. The third is a deep-water form, never rising to the surface, and caught only on set lines. Its origin is still uncertain, and it may be derived from some type other than the steelhead.

Cutthroat or Red-throated Trout.—This species has much smaller scales than the rainbow trout or steelhead, the usual number in a longitudinal series being 160 to 170. Its head is longer (about four times in length to base of caudal). Its mouth is proportionately larger, and there is always a narrow band of small teeth on the hyoid bone at the base of the tongue. These teeth are always wanting in Salmo irideus and rivularis in which species the rim of the tongue only has teeth. The color in Salmo clarkii is, as in other species, exceedingly variable. In life there is always a deep-red blotch on the throat, between the branches of the lower jaw and the membrane connecting them. This is not found in other species, or is reduced to a narrow strip or pinkish shade. It seems to be constant in all varieties of Salmo clarkii, at all ages, thus furnishing a good distinctive character. It is the sign manual of the Sioux Indians, and the anglers have already accepted from this mark the name of cutthroat-trout. The cutthroat-trout of some species is found in every suitable river and lake in the great basin of Utah, in the streams of Colorado, Wyoming, and Montana, on both sides of the Rocky Mountains. It is also found throughout Oregon, Washington, Idaho, British Columbia, the coastwise islands of southeastern Alaska (Baranof, etc.), to Kadiak and Bristol Bay, probably no stream or lake suitable for trout-life being without it. In California the species seems to be comparatively rare, and its range rarely extending south of Cape Mendocino. Large sea-run individuals analogous to the steelheads are sometimes found in the mouth of the Sacramento. In Washington and Alaska this species regularly enters the sea. In Puget Sound it is a common fish. These sea-run individuals are more silvery and less spotted than those found in the mountain streams and lakes. The size of Salmo clarkii is subject to much variation. Ordinarily four to six pounds is a large size; but in certain favored waters, as Lake Tahoe, and the fjords of southeastern Alaska, specimens from twenty to thirty pounds are occasionally taken.

Those species or individuals dwelling in lakes of considerable size, where the water is of such temperature and depth as insures an ample food-supply, will reach a large size, while those in a restricted environment, where both the water and food are limited, will be small directly in proportion to these environing restrictions. The trout of the Klamath Lakes, for example, reach a weight of at least 17 pounds, while in Fish Lake in Idaho mature trout do not exceed 8 to 9¼ inches in total length or one-fourth pound in weight. In small creeks in the Sawtooth Mountains and elsewhere they reach maturity at a length of 5 or 6 inches, and are often spoken of as brook-trout and with the impression that they are a species different from the larger ones found in the lakes and larger streams. But as all sorts and gradations between these extreme forms may be found in the intervening and connecting waters, the differences are not even of sub-specific significance.

Fig. 64.—Head of adult Trout-worm, Dibothrium cordiceps Leidy, a parasite of Salmo clarkii. From intestine of white pelican, Yellowstone Lake. (After Linton.)

Fig. 65.—Median segments of Dibothrium cordiceps.

Dr. Evermann observes: "The various forms of cutthroat-trout vary greatly in game qualities; even the same subspecies in different waters, in different parts of its habitat, or at different seasons, will vary greatly in this regard. In general, however, it is perhaps a fair statement to say that the cutthroat-trout are regarded by anglers as being inferior in gaminess to the Eastern brook-trout. But while this is true, it must not by any means be inferred that it is without game qualities, for it is really a fish which possesses those qualities in a very high degree. Its vigor and voraciousness are determined largely, of course, by the character of the stream or lake in which it lives. The individuals which dwell in cold streams about cascades and seething rapids will show marvelous strength and will make a fight which is rarely equaled by its Eastern cousin; while in warmer and larger streams and lakes they may be very sluggish and show but little fight. Yet this is by no means always true. In the Klamath Lakes, where the trout grow very large and where they are often very logy, one is occasionally hooked which tries to the utmost the skill of the angler to prevent his tackle from being smashed and at the same time save the fish."

Of the various forms derived from Salmo clarkii some mere varieties, some distinct species, the following are among the most marked:

Salmo henshawi, the trout of Lake Tahoe and its tributaries and outlet, Truckee River, found in fact also in the Humboldt and the Carson and throughout the basin of the former glacial lake called Lake Lahontan. This is a distinct species from Salmo clarkii and must be regarded as the finest of all the cutthroat-trout. It is readily known by its spotted belly, the black spots being evenly scattered over the whole surface of the body, above and below. This is an excellent game-fish, and from Lake Tahoe and Pyramid Lake it is brought in large numbers to the markets of San Francisco. In the depths of Lake Tahoe, which is the finest mountain lake of the Sierra Nevada, occurs a very large variety which spawns in the lake, Salmo henshawi tahoensis. This reaches a weight of twenty-eight pounds.

Fig. 66.—Tahoe Trout, Salmo henshawi Gill & Jordan. Lake Tahoe, California.

In the Great Basin of Utah is found a fine trout, very close to the ordinary cutthroat of the Columbia, from which it is derived. This is known as Salmo clarkii virginalis. In Utah Lake it reaches a large size.

In Waha Lake in Washington, a lake without outlet, is found a small trout with peculiar markings called Salmo clarkii bouvieri.

In the head-waters of the Platte and Arkansas rivers is the small green-back trout, green or brown, with red throat-patch and large black spots. This is Salmo clarkii stomias, and it is especially fine in St. Vrain's River and the streams of Estes Park. In Twin Lakes, a pair of glacial lakes tributary of the Arkansas near Leadville, is found Salmo clarkii macdonaldi, the yellow-finned trout, a large and very handsome species living in deep water, and with the fins golden yellow. This approaches the Colorado trout, Salmo clarkii pleuriticus, and it may be derived from the latter, although it occurs in the same waters as the very different green-back trout, or Salmo clarkii stomias.

Fig. 67.—Green-back Trout, Salmo stomias Cope. Arkansas River, Leadville, Colo.

Fig. 68.—Yellow-fin Trout of Twin Lakes, Salmo macdonaldi Jordan & Evermann. Twin Lakes, Colo.

Two fine trout derived from Salmo clarkii have been lately discovered by Dr. Daniel G. Elliot in Lake Southerland, a mountain lake near Lake Crescent, but not connected with it, the two separated from the sea by high waterfalls. These have been described by Dr. Seth E. Meek as Salmo jordani, the "spotted trout" of Lake Southerland, and Salmo declivifrons, the "salmon-trout." These seem to be distinct forms or subspecies produced through isolation.

Fig. 69.—Rio Grande Trout, Salmo clarkii spilurus Cope. Del Norte, Colo.

Fig. 70.—Colorado River Trout, Salmo clarkii pleuriticus Cope. Trapper's Lake, Colo.

The Rio Grande trout (Salmo clarkii spilurus) is a large and profusely spotted trout, found in the head-waters of the Rio Grande, the mountain streams of the Great Basin of Utah, and as far south as the northern part of Chihuahua. Its scales are still smaller than those of the ordinary cutthroat-trout, and the black spots are chiefly confined to the tail. Closely related to it is the trout of the Colorado Basin, Salmo clarkii pleuriticus, a large and handsome trout with very small scales, much sought by anglers in western Colorado, and abounding in all suitable streams throughout the Colorado Basin.

Hucho, the Huchen.—The genus Hucho has been framed for the Huchen or Rothfisch (Hucho hucho) of the Danube, a very large trout, differing from the genus Salmo in having no teeth on the shaft of the vomer, and from the Salvelini at least in form and coloration. The huchen is a long and slender, somewhat pike-like fish, with depressed snout and strong teeth. The color is silvery, sprinkled with small black dots. It reaches a size little inferior to that of the salmon, and it is said to be an excellent food-fish. In northern Japan is a similar species, Hucho blackistoni, locally known as Ito, a large and handsome trout with very slender body, reaching a length of 2½ feet. It is well worthy of introduction into American and European waters.

Fig. 71.—Ito, Hucho blackistoni (Hilgendorf). Hokkaido, Japan.

Salvelinus, the Charr.—The genus Salvelinus comprises the finest of the Salmonidæ, from the point of view of the angler or the artist. In England the species are known as charr or char, in contradistinction to the black-spotted species of Salmo, which are called trout. The former name has unfortunately been lost in America, where the name "trout" is given indiscriminately to both groups, and, still worse, to numerous other fishes (Micropterus, Hexagrammos, Cynoscion, Agonostomus) wholly unlike the Salmonidæ in all respects. It is sometimes said that "the American brook-trout is no trout, nothing but a charr," almost as though "charr" were a word of reproach. Nothing higher, however, can be said of a salmonoid than that it is a "charr." The technical character of the genus Salvelinus lies in the form of its vomer. This is deeper than in Salmo; and when the flesh is removed the bone is found to be somewhat boat-shaped above, and with the shaft depressed and out of the line of the head of the vomer. Only the head or chevron is armed with teeth, and the shaft is covered by skin.

In color all the charrs differ from the salmon and trout. The body in all is covered with round spots which are paler than the ground color, and crimson or gray. The lower fins are usually edged with bright colors. The sexual differences are not great. The scales, in general, are smaller than in other Salmonidæ, and they are imbedded in the skin to such a degree as to escape the notice of casual observers and even of most anglers.

"One trout scale in the scales I'd lay
(If trout had scales), and 'twill outweigh
The wrong side of the balances."—Lowell.

The charrs inhabit, in general, only the clearest and coldest of mountain streams and lakes, or bays of similar temperature. They are not migratory, or only to a limited extent. In northern regions they descend to the sea, where they grow much more rapidly and assume a nearly uniform silvery-gray color. The different species are found in all suitable waters throughout the northern parts of both continents, except in the Rocky Mountains and Great Basin, where only the black-spotted trout occur. The number of species of charr is very uncertain, as, both in America and Europe, trivial variations and individual peculiarities have been raised to the rank of species. More types, however, seem to be represented in America than in Europe.

Fig. 72.—Rangeley Trout, Salvelinus oquassa (Girard). Lake Oquassa, Maine.

The only really well-authenticated species of charr in European waters is the red charr, sälbling, or ombre chevalier (Salvelinus alpinus). This species is found in cold, clear streams in Switzerland, Germany, and throughout Scandinavia and the British Islands. Compared with the American charr or brook-trout, it is a slenderer fish, with smaller mouth, longer fins, and smaller red spots, which are confined to the sides of the body. It is a "gregarious and deep-swimming fish, shy of taking the bait and feeding largely at night-time. It appears to require very pure and mostly deep water for its residence." It is less tenacious of life than the trout. It reaches a weight of from one to five pounds, probably rarely exceeding the latter in size. The various charr described from Siberia are far too little known to be enumerated here.

Of the American charr the one most resembling the European species is the Rangeley Lake trout (Salvelinus oquassa). The exquisite little fish is known in the United States only from the Rangeley chain of lakes in western Maine. This is very close to the Greenland charr, Salvelinus stagnalis, a beautiful species of the far north. The Rangeley trout is much slenderer than the common brook-trout, with much smaller head and smaller mouth. In life it is dark blue above, and the deep-red spots are confined to the sides of the body. The species rarely exceeds the length of a foot in the Rangeley Lakes, but in some other waters it reaches a much larger size. So far as is known it keeps itself in the depths of the lake until its spawning season approaches, in October, when it ascends the stream to spawn.

Fig. 73.—Sunapee Trout, Salvelinus aureolus Bean. Sunapee Lake, N. H.

Still other species of this type are the Sunapee trout, Salvelinus aureolus, a beautiful charr almost identical with the European species, found in numerous ponds and lakes of eastern New Hampshire and neighboring parts of Maine. Mr. Garman regards this trout as the offspring of an importation of the ombre chevalier and not as a native species, and in this view he may be correct. Salvelinus alipes of the far north may be the same species. Another remarkable form is the Lac de Marbre trout of Canada, Salvelinus marstoni of Garman.

In Arctic regions another species, called Salvelinus naresi, is very close to Salvelinus oquassa and may be the same.

Another beautiful little charr, allied to Salvelinus stagnalis, is the Floeberg charr (Salvelinus arcturus). This species has been brought from Victoria Lake and Floeberg Beach, in the extreme northern part of Arctic America, the northernmost point whence any salmonoid has been obtained.

Fig. 74.—Speckled Trout (male), Salvelinus fontinalis (Mitchill). New York.

Fig. 75.—Brook Trout, Salvelinus fontinalis (Mitchill), natural size. (From life by Dr. R. W. Shufeldt.)

The American charr, or, as it is usually called, the brook-trout (Salvelinus fontinalis), although one of the most beautiful of fishes, is perhaps the least graceful of all the genuine charrs. It is technically distinguished by the somewhat heavy head and large mouth, the maxillary bone reaching more or less beyond the eye. There are no teeth on the hyoid bone, traces at least of such teeth being found in nearly all other species. Its color is somewhat different from that of the others, the red spots being large and the black more or less mottled and barred with darker olive. The dorsal and caudal fins are likewise barred or mottled, while in the other species they are generally uniform in color. The brook-trout is found only in streams east of the Mississippi and Saskatchewan. It occurs in all suitable streams of the Alleghany region and the Great Lake system, from the Chattahoochee River in northern Georgia northward at least to Labrador and Hudson Bay, the northern limits of its range being as yet not well ascertained. It varies greatly in size, according to its surroundings, those found in lakes being larger than those resident in small brooks. Those found farthest south, in the head-waters of the Chattahoochee, Savannah, Catawba, and French Broad, rarely pass the dimensions of fingerlings. The largest specimens are recorded from the sea along the Canadian coast. These frequently reach a weight of ten pounds; and from their marine and migratory habits, they have been regarded as forming a distinct variety (Salvelinus fontinalis immaculatus), but this form is merely a sea-run brook-trout. The largest fresh-water specimens rarely exceed seven pounds in weight. Some unusually large brook-trout have been taken in the Rangeley Lakes, the largest known to me having a reputed weight of eleven pounds. The brook-trout is the favorite game-fish of American waters, preëminent in wariness, in beauty, and in delicacy of flesh. It inhabits all clear and cold waters within its range, the large lakes and the smallest ponds, the tiniest brooks and the largest rivers; and when it can do so without soiling its aristocratic gills on the way, it descends to the sea and grows large and fat on the animals of the ocean. Although a bold biter it is a wary fish, and it often requires much skill to capture it. It can be caught, too, with artificial or natural flies, minnows, crickets, worms, grasshoppers, grubs, the spawn of other fish, or even the eyes or cut pieces of other trout. It spawns in the fall, from September to late in November. It begins to reproduce at the age of two years, then having a length of about six inches. In spring-time the trout delight in rapids and swiftly running water; and in the hot months of midsummer they resort to deep, cool, and shaded pools. Later, at the approach of the spawning season, they gather around the mouths of cool, gravelly brooks, whither they resort to make their beds.[10]

10.  Hallock.

The trout are rapidly disappearing from our streams through the agency of the manufacturer and the summer boarder. In the words of an excellent angler, the late Myron W. Reed of Denver: "This is the last generation of trout-fishers. The children will not be able to find any. Already there are well-trodden paths by every stream in Maine, in New York, and in Michigan. I know of but one river in North America by the side of which you will find no paper collar or other evidence of civilization. It is the Nameless River. Not that trout will cease to be. They will be hatched by machinery and raised in ponds, and fattened on chopped liver, and grow flabby and lose their spots. The trout of the restaurant will not cease to be. He is no more like the trout of the wild river than the fat and songless reedbird is like the bobolink. Gross feeding and easy pond-life enervate and deprave him. The trout that the children will know only by legend is the gold-sprinkled, living arrow of the white water; able to zigzag up the cataract; able to loiter in the rapids; whose dainty meat is the glancing butterfly."

The brook-trout adapts itself readily to cultivation in artificial ponds. It has been successfully transported to Europe, and it is already abundant in certain streams in England, in California, and elsewhere.

In Dublin Pond, New Hampshire, is a gray variety without red spots, called Salvelinus agassizi.

Fig. 76.—Malma Trout, or "Dolly Varden," Salvelinus malma (Walbaum). Cook Inlet, Alaska.

The "Dolly Varden" trout, or malma (Salvelinus malma), is very similar to the brook-trout, closely resembling it in size, form, color, and habits. It is found always to the westward of the Rocky Mountains, in the streams of northern California, Oregon, Washington, and British Columbia, Alaska, and Kamchatka, as far as the Kurile Islands. It abounds in the sea in the northward, and specimens of ten to twelve pounds weight are not uncommon in Puget Sound and especially in Alaska. The Dolly Varden trout is, in general, slenderer and less compressed than the Eastern brook-trout. The red spots are found on the back of the fish as well as on the sides, and the back and upper fins are without the blackish marblings and blotches seen in Salvelinus fontinalis. In value as food, in beauty, and in gaminess Salvelinus malma is very similar to its Eastern cousin.

Fig. 77.—The Dolly Varden Trout, Salvelinus malma (Walbaum). Lake Pend d'Oreille, Idaho. (After Evermann.)

In Alaska the Dolly Varden, locally known as salmon-trout, is very destructive to the eggs of the salmon, and countless numbers are taken in the salmon-nets of Alaska and thrown away as useless by the canners. In every coastwise stream of Alaska the water fairly "boils" with these trout. They are, however, not found in the Yukon. In northern Japan occurs Salvelinus pluvius, the iwana, a species very similar to the Dolly Varden, but not so large or so brightly colored. In the Kurile region and Kamchatka is another large charr, Salvelinus kundscha, with the spots large and cream-color instead of crimson.

Fig. 78.—Great Lake Trout, Cristivomer namaycush (Walbaum). Lake Michigan.

Cristivomer, the Great Lake Trout.—Allied to the true charrs, but now placed by us in a different genus, Cristivomer, is the Great Lake trout, otherwise known as Mackinaw trout, longe, or togue (Cristivomer namaycush). Technically this fish differs from the true charrs in having on its vomer a raised crest behind the chevron and free from the shaft. This crest is armed with strong teeth. There are also large hooked teeth on the hyoid bone, and the teeth generally are proportionately stronger than in most of the other species. The Great Lake trout is grayish in color, light or dark according to its surroundings; and the body is covered with round paler spots, which are gray instead of red. The dorsal and caudal fins are marked with darker reticulations, somewhat as in the brook-trout. This noble species is found in all the larger lakes from New England and New York to Wisconsin, Montana, the Mackenzie River, and in all the lakes tributary to the Yukon in Alaska. We have taken examples from Lake Bennett, Lake Tagish, Summit Lake (White Pass), and have seen specimens from Lake La Hache in British Columbia. It reaches a much larger size than any Salvelinus, specimens of from fifteen to twenty pounds weight being not uncommon, while it occasionally attains a weight of fifty to eighty pounds. As a food-fish it ranks high, although it may be regarded as somewhat inferior to the brook-trout or the whitefish. Compared with other salmonoids, the Great Lake trout is a sluggish, heavy, and ravenous fish. It has been known to eat raw potato, liver, and corn-cobs,—refuse thrown from passing steamers. According to Herbert, "a coarse, heavy, stiff rod, and a powerful oiled hempen or flaxen line, on a winch, with a heavy sinker; a cod-hook, baited with any kind of flesh, fish, or fowl,—is the most successful, if not the most orthodox or scientific, mode of capturing him. His great size and immense strength alone give him value as a fish of game; but when hooked he pulls strongly and fights hard, though he is a boring, deep fighter, and seldom if ever leaps out of the water, like the true salmon or brook-trout."

In the depths of Lake Superior is a variety of the Great Lake trout known as the Siscowet (Cristivomer namaycush siskawitz), remarkable for its extraordinary fatness of flesh. The cause of this difference lies probably in some peculiarity of food as yet unascertained.

The Ayu, or Sweetfish.—The ayu, or sweetfish, of Japan, Plecoglossus altivelis, resembles a small trout in form, habits, and scaling. Its teeth are, however, totally different, being arranged on serrated plates on the sides of the jaws, and the tongue marked with similar folds. The ayu abounds in all clear streams of Japan and Formosa. It runs up from the sea like a salmon. It reaches the length of about a foot. The flesh is very fine and delicate, scarcely surpassed by that of any other fish whatsoever. It should be introduced into clear short streams throughout the temperate zones.

Fig. 79.—Ayu, or Japanese Samlet, Plecoglossus altivelis Schlegel. Tamagawa, Tokyo, Japan.

In the river at Gifu in Japan and in some other streams the ayu is fished for on a large scale by means of tamed cormorants. This is usually done from boats in the night by the light of torches.

Cormorant-fishing.—The following account of cormorant-fishing is taken, by the kind permission of Mr. Caspar W. Whitney, from an article contributed by the writer to Outing, April, 1902:

Tamagawa means Jewel River, and no water could be clearer. It rises somewhere up in the delectable mountains to the eastward of Musashi, among the mysterious pines and green-brown fir-trees, and it flows across the plains bordered by rice-fields and mulberry orchards to the misty bay of Tokyo. It is, therefore, a river of Japan, and along its shores are quaint old temples, each guarding its section of primitive forest, picturesque bridges, huddling villages, and torii, or gates through which the gods may pass.

The stream itself is none too large—a boy may wade it—but it runs on a wide bed, which it will need in flood-time, when the snow melts in the mountains. And this broad flood-bed is filled with gravel, with straggling willows, showy day-lilies, orange amaryllis, and the little sky-blue spider-flower, which the Japanese call chocho, or butterfly-weed.

In the Tamagawa are many fishes: shining minnows in the white ripples, dark catfishes in the pools and eddies, and little sculpins and gobies lurking under the stones. Trout dart through its upper waters, and at times salmon run up from the sea.

But the one fish of all its fishes is the ayu. This is a sort of dwarf salmon, running in the spring and spawning in the rivers just as a salmon does. But it is smaller than any salmon, not larger than a smelt, and its flesh is white and tender, and so very delicate in its taste and odor that one who tastes it crisply fried or broiled feels that he has never tasted real fish before. In all its anatomy the ayu is a salmon, a dwarf of its kind, one which our ancestors in England would have called a "samlet." Its scientific name is Plecoglossus altivelis. Plecoglossus means plaited tongue, and altivelis, having a high sail; for the skin of the tongue is plaited or folded in a curious way, and the dorsal fin is higher than that of the salmon, and one poetically inclined might, if he likes, call it a sail. The teeth of the ayu are very peculiar, for they constitute a series of saw-edged folds or plaits along the sides of the jaws, quite different from those of any other fish whatsoever.

In size the ayu is not more than a foot to fifteen inches long. It is like a trout in build, and its scales are just as small. It is light yellowish or olive in color, growing silvery below. Behind its gills is a bar of bright shining yellow, and its adipose fin is edged with scarlet. The fins are yellow, and the dorsal fin shaded with black, while the anal fin is dashed with pale red.

So much for the river and the ayu. It is time for us to go afishing. It is easy enough to find the place, for it is not more than ten miles out of Tokyo, on a fine old farm just by the ancient Temple of Tachikawa, with its famous inscribed stone, given by the emperor of China.

At the farmhouse, commodious and hospitable, likewise clean and charming after the fashion of Japan, we send for the boy who brings our fishing-tackle.

They come waddling into the yard, the three birds with which we are to do our fishing. Black cormorants they are, each with a white spot behind its eye, and a hoarse voice, come of standing in the water, with which it says y-eugh whenever a stranger makes a friendly overture. The cormorants answer to the name of Ou, which in Japanese is something like the only word the cormorants can say. The boy puts them in a box together and we set off across the drifted gravel to the Tamagawa. Arrived at the stream, the boy takes the three cormorants out of the box and adjusts their fishing-harness. This consists of a tight ring about the bottom of the neck, of a loop under each wing, and a directing line.

Two other boys take a low net. They drag it down the stream, driving the little fishes—ayu, zakko, haë, and all the rest—before it. The boy with the cormorants goes in advance. The three birds are eager as pointer dogs, and apparently full of perfect enjoyment. To the right and left they plunge with lightning strokes, each dip bringing up a shining fish. When the bird's neck is full of fishes down to the level of the shoulders, the boy draws him in, grabs him by the leg, and shakes him unceremoniously over a basket until all the fishes have flopped out.

The cormorants watch the sorting of the fish with eager eyes and much repeating of y-eugh, the only word they know. The ayu are not for them, and some of the kajikas and hazés were prizes of science. But zakko (the dace) and haë (the minnow) were made for the cormorant. The boy picks out the chubs and minnows and throws them to one bird and then another. Each catches his share on the fly, swallows it at one gulp, for the ring is off his neck by this time, and then says y-eugh, which means that he likes the fun, and when we are ready will be glad to try again. And no doubt they have tried it many times since, for there are plenty of fishes in the Jewel River, zakko and haë as well as ayu.

Fossil Salmonidæ.—Fossil salmonidæ are rare and known chiefly from detached scales, the bones in this family being very brittle and easily destroyed. Nothing is added to our knowledge of the origin of these fishes from such fossils.

A large fossil trout or salmon, called Rhabdofario lacustris, has been brought from the Pliocene at Catherine's Creek, Idaho. It is known from the skull only. Thaumaturus luxatus, from the Miocene of Bohemia, shows the print of the adipose fin. As already stated (p. 62), fragments of the hooked jaws of salmon, from pleistocene deposits in Idaho, are in the museum of the University of California.

CHAPTER VI
THE GRAYLING AND THE SMELT

The Grayling, or Thymallidæ.—The small family of Thymallidæ, or grayling, is composed of finely organized fishes allied to the trout, but differing in having the frontal bones meeting on the middle line of the skull, thus excluding the frontals from contact with the supraoccipital. The anterior half of the very high dorsal is made up of unbranched simple rays. There is but one genus, Thymallus, comprising very noble game-fishes characteristic of subarctic streams.

Fig. 80.—Alaska Grayling, Thymallus signifer Richardson. Nulato, Alaska.

The grayling, Thymallus, of Europe, is termed by Saint Ambrose "the flower of fishes." The teeth on the tongue, found in all the trout and salmon, are obsolete in the grayling. The chief distinctive peculiarity of the genus Thymallus is the great development of the dorsal fin, which has more rays (20 to 24) than are found in any of the Salmonidæ, and the fin is also higher. All the species are gaily colored, the dorsal fin especially being marked with purplish or greenish bands and bright rose-colored spots; while the body is mostly purplish gray, often with spots of black. Most of the species rarely exceed a foot in length, but northward they grow larger. Grayling weighing five pounds have been taken in England; and according to Dr. Day they are said in Lapland to reach a weight of eight or nine pounds. The grayling in all countries frequent clear, cold brooks, and rarely, if ever, enter the sea, or even the larger lakes. They congregate in small shoals in the streams, and prefer those which have a succession of pools and shallows, with a sandy or gravelly rather than rocky bottom. The grayling spawns on the shallows in April or May (in England). It is non-migratory in its habits, depositing its ova in the neighborhood of its usual haunts. The ova are far more delicate and easily killed than those of the trout or charr. The grayling and the trout often inhabit the same waters, but not altogether in harmony. It is said that the grayling devours the eggs of the trout. It is certain that the trout feed on the young grayling. As a food-fish, the grayling of course ranks high; and it is beloved by the sportsman. They are considered gamy fishes, although less strong than the brook-trout, and perhaps less wary. The five or six known species of grayling are very closely related, and are doubtless comparatively recent offshoots from a common stock, which has now spread itself widely through the northern regions.

The common grayling of Europe (Thymallus thymallus) is found throughout northern Europe, and as far south as the mountains of Hungary and northern Italy. The name Thymallus was given by the ancients, because the fish, when fresh, was said to have the odor of water-thyme. Grayling belonging to this or other species are found in the waters of Russia and Siberia.

The American grayling (Thymallus signifer) is widely distributed in British America and Alaska. In the Yukon it is very abundant, rising readily to the fly. In several streams in northern Michigan, Au Sable River, and Jordan River in the southern peninsula, and Otter Creek near Keweenaw in the northern peninsula, occurs a dwarfish variety or species with shorter and lower dorsal fins, known to anglers as the Michigan grayling (Thymallus tricolor). This form has a longer head, rather smaller scales, and the dorsal fin rather lower than in the northern form (signifer); but the constancy of these characters in specimens from intermediate localities is yet to be proved. Another very similar form, called Thymallus montanus, occurs in the Gallatin, Madison, and other rivers of Western Montana tributary to the Missouri. It is locally still abundant and one of the finest of game-fishes. It is probable that the grayling once had a wider range to the southward than now, and that so far as the waters of the United States are concerned it is tending toward extinction. This tendency is, of course, being accelerated in Michigan by lumbermen and anglers. The colonies of grayling in Michigan and Montana are probably remains of a post-glacial fauna.

Fig. 81.—Michigan Grayling, Thymallus tricolor Cope. Au Sable River, Mich.

The Argentinidæ.—The family of Argentinidæ, or smelt, is very closely related to the Salmonidæ, representing a dwarf series of similar type. The chief essential difference lies in the form of the stomach, which is a blind sac, the two openings near together, and about the second or pyloric opening there are few if any pyloric cæca. In all the Salmonidæ the stomach has the form of a siphon, and about the pylorus there are very many pyloric cæca. The smelt have the adipose fin and the general structure of the salmon. All the species are small in size, and most of them are strictly marine, though some of them ascend the rivers to spawn, just as salmon do, but not going very far. A few kinds become landlocked in ponds. Most of the species are confined to the north temperate zone, and a few sink into the deep seas. All that are sufficiently abundant furnish excellent food, the flesh being extremely delicate and often charged with a fragrant oil easy of digestion.

Fig. 82.—Smelt, Osmerus mordux (Mitchill). Wood's Hole, Mass.

The best-known genus, Osmerus, includes the smelt, or spirling (éperlan), of Europe, and its relatives, all excellent food-fishes, although quickly spoiling in warm weather. Osmerus eperlanus is the European species; Osmerus mordax of our eastern coast is very much like it, as is also the rainbow-smelt, Osmerus dentex of Japan and Alaska. A larger smelt, Osmerus albatrossis, occurs on the coast of Alaska, and a small and feeble one, Osmerus thaleichthys, mixed with other small or delicate fishes, is the whitebait of the San Francisco restaurants. The whitebait of the London epicure is made up of the young of herrings and sprats of different species. The still more delicate whitebait of the Hong Kong hotels is the icefish, Salanx chinensis. Retropinna retropinna, so called from the backward insertion of its dorsal, is the excellent smelt of the rivers of New Zealand. All the other species belong to northern waters. Mesopus, the surf-smelt, has a smaller mouth than Osmerus and inhabits the North Pacific. The California species, Mesopus pretiosus, of Neah Bay has, according to James G. Swan, "the belly covered with a coating of yellow fat which imparts an oily appearance to the water where the fish has been cleansed or washed and makes them the very perfection of pan-fish." This species spawns in late summer along the surf-line. According to Mr. Swan the water seems to be filled with them. "They come in with the flood-tide, and when a wave breaks upon the beach they crowd up into the very foam, and as the surf recedes many will be seen flapping on the sand and shingle, but invariably returning with the undertow to deeper water." The Quilliute Indians of Washington believe that "the first surf-smelts that appear must not be sold or given away to be taken to another place, nor must they be cut transversely, but split open with a mussel-shell."

The surf-smelt is marine, as is also a similar species, Mesopus japonicus, in Japan. Mesopus olidus, the pond-smelt of Alaska, Kamchatka, and Northern Japan, spawns in fresh-water ponds.

Fig. 83.—Eulachon, or Ulchen. Thaleichthys pretiosus Girard. Columbia River. Family Argentinidæ.

Still more excellent as a food-fish than even these exquisite species is the famous eulachon, or candle-fish (Thaleichthys pacificus). The Chinook name, usually written eulachon, is perhaps more accurately represented as ulchen. This little fish has the form of a smelt and reaches the length of nearly a foot. In the spring it ascends in enormous numbers all the rivers north of the Columbia, as far as Skaguay, for a short distance for the purpose of spawning. These runs take place usually in advance of the salmon-runs. Various predatory fishes and sea-birds persecute the eulachon during its runs, and even the stomachs of the sturgeons are often found full of the little fishes, which they have taken in by their sucker-like mouths. At the time of the runs the eulachon are extremely fat, so much so that it is said that when dried and a wick drawn through the body they may be used as candles. On Nass River, in British Columbia, a stream in which their run is greatest, there is a factory for the manufacture of eulachon-oil from them. This delicate oil is proposed as a substitute for cod-liver oil in medicine. Whatever may be its merits in this regard, it has the disadvantage in respect to salability of being semi-solid or lard-like at ordinary temperatures, requiring melting to make it flow as oil. The eulachon is a favorite pan-fish in British Columbia. The writer has had considerable experience with it, broiled and fried, in its native region, and has no hesitation in declaring it to be the best-flavored food-fish in American waters. It is fat, tender, juicy, and richly flavored, with comparatively few troublesome bones. It does not, however, bear transportation well. The Indians in Alaska bury the eulachon in the ground in great masses. After the fish are well decayed they are taken out and the oil pressed from them. The odor of the fish and the oil is then very offensive, less so, however, than that of some forms of cheese eaten by civilized people.

Fig. 84.—Page of William Clark's handwriting with sketch of the Eulachon (Thaleichthys pacificus), the first notice of the species. Columbia River, 1805. (Expedition of Lewis & Clark.) (Reproduced from the original in the possession of his granddaughter Mrs. Julia Clark Voorhis, through the courtesy of Messrs. Dodd, Mead & Company, publishers of the "Original Journals of the Lewis and Clark Expedition.")

The capelin (Mallotus villosus) closely resembles the eulachon, differing mainly in its broader pectorals and in the peculiar scales of the males. In the male fish a band of scales above the lateral line and along each side of the belly become elongate, closely imbricated, with the free points projecting, giving the body a villous appearance. It is very abundant on the coasts of Arctic America, both in the Atlantic and the Pacific, and is an important source of food for the natives of those regions.

Fig. 85.—Capelin, Mallotus villosus L. Crosswater Bay.

This species spawns in the surf, and the writer has seen them in August cast on the shores of the Alaskan islands (as at Metlakahtla in 1897), living and dead, in numbers which seem incredible. The males are then distorted, and it seems likely that all of them perish after spawning. The young are abundant in all the northern fiords. Even more inordinate numbers are reported from the shores of Greenland.

The capelin seems to be inferior to the eulachon as a food-fish, but to the natives of arctic regions in both hemispheres it is a very important article of food. Fossil capelin are found in abundance in recent shales in Greenland enveloped in nodules of clay. In the open waters about the Aleutian Islands a small smelt, Therobromus callorhini, occurs in very great abundance and forms the chief part of the summer food of the fur-seal. Strangely enough, no complete specimen of this fish has yet been seen by man, although thousands of fragments have been taken from seals' stomachs. From these fragments Mr. Frederick A. Lucas has reconstructed the fish, which must be an ally of the surf-smelt, probably spawning in the open ocean of the north.

The silvery species called Argentina live in deeper water and have no commercial importance. Argentina silus, with prickly scales, occurs in the North Sea. Several fossils have been doubtfully referred to Osmerus.

The Microstomidæ.—The small family of Microstomidæ consists of a few degraded smelt, slender in form, with feeble mouth and but three or four branchiostegals, rarely taken in the deep seas. Nansenia grœnlandica was found by Reinhardt off the coast of Greenland, and six or eight other species of Microstoma and Bathylagus have been brought in by the deep-sea explorations.

The Salangidæ, or Icefishes.—Still more feeble and insignificant are the species of Salangidæ, icefishes, or Chinese whitebait, which may be described as Salmonidæ reduced to the lowest terms. The body is long and slender, perfectly translucent, almost naked, and with the skeleton scarcely ossified. The fins are like those of the salmon, the head is depressed, the jaws long and broad, somewhat like the bill of a duck, and within there are a few disproportionately strong canine teeth, those of the lower jaw somewhat piercing the upper. The alimentary canal is straight for its whole length, without pyloric cæca. These little fishes, two to five inches long, live in the sea in enormous numbers and ascend the rivers of eastern Asia for the purpose of spawning. It is thought by some that they are annual fishes, all dying in the fall after reproduction, the species living through the winter only within its eggs. But this is only suspected, not proved, and the species will repay the careful study which some of the excellent naturalists of Japan are sure before long to give to it. The species of Salanx are known as whitebait, in Japan as Shiro-uwo, which means exactly the same thing. They are also sometimes called icefish (Hingio), which, being used for no other fish, may be adopted as a group name for Salanx.

The species are Salanx chinensis from Canton, Salanx hyalo cranius from Korea and northern China, Salanx microdon from northern Japan, and Salanx ariakensis from the southern island of Kiusiu. The Japanese fishes are species still smaller and feebler than their relatives from the mainland.

The Haplochitonidæ.—The Haplochitonidæ are trout-like fishes of the south temperate zone, differing from the Salmonidæ mainly in the extension of the premaxillary until, as in the perch-like fishes, it forms the outer border of the upper jaw. The adipose fin is present as in all the salmon and smelt. Haplochiton of Tierra del Fuego and the Falkland Islands is naked, while in Prototroctes of Australia and New Zealand the body, as in all salmon, trout, and smelt, is covered with scales. Prototroctes maræna is the yarra herring of Australia. The closely related family of Galaxiidæ, also Australian, but lacking the adipose fin, is mentioned in a later chapter.

Fig. 86.—Icefish, Salanx hyalocranius Abbott. Family Salangidæ. Tientsin, China.

Stomiatidæ.—The Stomiatidæ, with elongate bodies, have the mouth enormous, with fang-like teeth, usually barbed. Of the several species Stomias ferox is best known. According to Dr. Boulenger, these fishes are true Isospondyli.

Fig. 87.—Stomias ferox Reinhardt. Banquereau.

Astronesthidæ is another small group of small fishes naked and black, with long canines, found in the deep sea.

The Malacosteidæ is a related group with extremely distensible mouth, the species capable of swallowing fishes much larger than themselves.

The viper-fishes (Chauliodontidæ) are very feeble and very voracious little fishes occasionally brought up from the depths. Chauliodus sloanei is notable for the length of the fangs.

Much smaller and feebler are the species of the closely related family of Gonostomidæ. Gonostoma and Cyclothone dwell in oceanic abysses. One species, Cyclothone elongata, occurs at the depth of from half a mile to nearly four miles almost everywhere throughout the oceans. It is probably the most widely distributed, as well as one of the feeblest and most fragile, of all bassalian or deep-sea fishes.

Fig. 88.—Chauliodus sloanei Schneider. Grand Banks.

Suborder Iniomi, the Lantern-fishes.—The suborder Iniomi (ἰνίον, nape; ὤμος, shoulder) comprises soft-rayed fishes, in which the shoulder-girdle has more or less lost its completeness of structure as part of the degradation consequent on life in the abysses of the sea. These features distinguish these forms from the true Isospondyli, but only in a very few of the species have these characters been verified by actual examination of the skeleton. The mesocoracoid arch is wanting or atrophied in all of the species examined, and the orbitosphenoid is lacking, so far as known. The group thus agrees in most technical characters with the Haplomi, in which group they are placed by Dr. Boulenger. On the other hand the relationships to the Isospondyli are very close, and the Iniomi have many traits suggesting degenerate Isospondyli. The post-temporal has lost its usual hold on the skull and may touch the occiput on the sides of the cranium. Nearly all the species are soft in body, black or silvery over black in color, and all that live in the deep sea are provided with luminous spots or glands giving light in the abysmal depths. These spots are wanting in the few shore species, as also in those which approach most nearly to the Salmonidæ, these being presumably the most primitive of the group. In these also the post-temporal touches the back of the cranium near the side. In the majority of the Iniomi the adipose fin of the Salmonidæ is retained. From the phosphorescent spots is derived the general name of lantern-fishes applied of late years to many of the species. Most of these are of recent discovery, results of the remarkable work in deep-sea dredging begun by the Albatross and the Challenger. All of the species are carnivorous, and some, in spite of their feeble muscles, are exceedingly voracious, the mouth being armed with veritable daggers and spears.

Aulopidæ.—Most primitive of the Iniomi is the family of Aulopidæ, having an adipose fin, a normal maxillary, and no luminous spots. The rough firm scales suggest those of the berycoid fishes. The few species of Aulopus and Chlorophthalmus are found in moderate depths. Aulopus purpurissatus is the "Sergeant Baker" of the Australian fishermen.

Fig. 89.—Lizard-fish, Synodus fætens L. Charleston, S. C.

The Lizard-fishes.—The Synodontidæ, or lizard-fishes, have lizard-like heads with very large mouth. The head is scaly, a character rare among the soft-rayed fishes. The slender maxillary is grown fast to the premaxillary, and the color is not black. Most of the species are shore-fishes and some are brightly colored. Synodus fætens is the common lizard-fish, or galliwasp, of our Atlantic coast. Synodus varius of the Pacific is brightly colored, olive-green and orange-red types of coloration existing at different depths. Most of the species lie close to the bottom and are mottled gray like coral sand. A few occur in oceanic depths. The "Bombay duck" of the fishermen of India is a species of Harpodon, H. nehereus, with large mouth and arrow-shaped teeth. The dried fish is used as a relish.

The Benthosauridæ are deep-sea fishes of similar type, but with distinct maxillaries. The Bathypteroidæ, of the deep seas, resemble Aulopus, but have the upper and lower pectoral rays filiform, developed as organs of touch in the depths in which the small eyes become practically useless.

Ipnopidæ.—In the Ipnopidæ the head is depressed above and the two eyes are flattened and widened so as to occupy most of its upper surface. These structures were at first supposed to be luminous organs, but Professor Moseley has shown them to be eyes. "They show a flattened cornea extending along the median line of the snout, with a large retina composed of peculiar rods which form a complicated apparatus destined undoubtedly to produce an image and to receive especial luminous rays." The single species, Ipnops murrayi, is black in color and found at the depth of 2½ miles in various seas.

Fig. 90.—Ipnops murrayi Günther.

The existence of well-developed eyes among fishes destined to live in the dark abysses of the ocean seems at first contradictory, but we must remember that these singular forms are descendants of immigrants from the shore and from the surface. "In some cases the eyes have not been specially modified, but in others there have been modifications of a luminous mucous membrane leading on the one hand to phosphorescent organs more or less specialized, or on the other to such remarkable structures as the eyes of Ipnops, intermediate between true eyes and phosphorescent plates. In fishes which cannot see, and which retain for their guidance only the general sensibility of the integuments and the lateral line, these parts soon acquire a very great delicacy. The same is the case with tactile organs (as in Bathypterois and Benthosaurus), and experiments show that barbels may become organs of touch adapted to aquatic life, sensitive to the faintest movements or the slightest displacement, with power to give the blinded fishes full cognizance of the medium in which they live."

Rondeletiidæ.—The Rondeletiidæ are naked black fishes with small eyes, without adipose fin and without luminous spots, taken at great depths in the Atlantic. The relationship of these fishes is wholly uncertain.

Fig. 91.—Cetomimus gillii Goode & Bean. Gulf Stream.

The Cetomimidæ are near allies of the Rondeletiidæ, having the mouth excessively large, with the peculiar form seen in the right whales, which these little fishes curiously resemble.

Fig. 92.—Headlight Fish, Diaphus lucidus Goode & Bean. Gulf Stream.

Myctophidæ.—The large family of Myctophidæ, or lantern-fishes, is made up of small fishes allied to the Aulopidæ, but with the body covered with luminous dots, highly specialized and symmetrically arranged. Most of them belong to the deep sea, but others come to the surface in the night or during storms when the sunlight is absent. Through this habit they are often thrown by the waves on the decks of small vessels. Largely from Danish merchant-vessels, Dr. Lütken has obtained the unrivaled collection of these sea-waifs preserved in the Museum of the University of Copenhagen. The species are all small in size and feeble in structure, the prey of the larger fishes of the depths, from which their lantern-like spots and large eyes help them to escape. The numerous species are now ranged in about fifteen genera, although earlier writers placed them all in a single genus Myctophum (Scopelus).

Fig. 93.—Lantern-fish, Myctophum opalinum Goode & Bean. Gulf Stream.

In the genus Diaphus (Æthoprora) there is a large luminous gland on the end of the short snout, like the headlight of an engine. In Dasyscopelus the scales are spinescent, but in most of the genera, as in Myctophum, the scales are cycloid and caducous, falling at the touch. In Diaphus the luminous spots are crossed by a septum giving them the form of the Greek letter θ (theta). One of the commonest species is Myctophum humboldti.

Fig. 94.—Lantern-fish, Ceratoscopelus madeirensis (Lowe). Gulf Stream.

Chirothricidæ.—The remarkable extinct family of Chirothricidæ may be related to the Synodontidæ, or Myctophidæ. In this group the teeth are feeble, the paired fins much enlarged, and the ventrals are well forward. The dorsal fin, inserted well forward, has stout basal bones. Chirothrix libanicus of the Cretaceous of Mt. Lebanon is remarkable for its excessively large ventral fins. Telepholis is a related genus. Exocœtoides with rounded caudal fin is probably the type of a distinct family, Exocœtoididæ, the caudal fin being strongly forked in Chirothrix. The small extinct group of Rhinellidæ is usually placed near the Myctophidæ. They are distinguished by the very long gar-like jaws; whether they possessed adipose fins or luminous spots cannot be determined. Rhinellus furcatus and other species occur in the Cretaceous of Europe and Asia. Fossil forms more or less distinctly related to the Myctophidæ are numerous. Osmeroides monasterii (wrongly called Sardinioides), from the German Cretaceous, seems allied to Myctophum, although, of course, luminous spots leave no trace among fossils. Acrognathus boops is remarkable for the large size of the eyes.

Fig. 95.—Rhinellus furcatus Agassiz. Upper Cretaceous of Mt. Lebanon. (After Woodward.)

Maurolicidæ.—The Maurolicidæ are similar in form and habit, but scaleless, and with luminous spots more highly specialized. Maurolicus pennanti, the "Sleppy Argentine," is occasionally taken on either side of the Atlantic. Other genera are Zalarges, Vinciguerria, and Valenciennellus.

The Lancet-fishes.—The Plagyodontidæ (Alepisauridæ) contains the lancet-fishes, large, swift, scaleless fishes of the ocean depths with very high dorsal fin, and the mouth filled with knife-like teeth. These large fish are occasionally cast up by storms or are driven to the shores by the torments of a parasite, Tetrarhynchus, found imbedded in the flesh.

It is probable that they are sometimes killed by being forced above their level by fishes which they have swallowed. In such cases they are destroyed through the reduction of pressure.

Every part of the body is so fragile that perfect specimens are rare. The dorsal fin is readily torn, the bones are very feebly ossified, and the ligaments connecting the vertebræ are very loose and extensible, so that the body can be considerably stretched. "This loose connection of the parts of the body is found in numerous deep-sea fishes, and is merely the consequence of their withdrawal from the pressure of the water to which they are exposed in the depths inhabited by them. When within the limits of their natural haunts, the osseous, muscular, and fibrous parts of the body will have that solidity which is required for the rapid and powerful movements of a predatory fish. That the fishes of this genus (Plagyodus) belong to the most ferocious of the class is proved by their dentition and the contents of their stomach." (Günther.) Dr. Günther elsewhere observes: "From the stomach of one example have been taken several octopods, crustaceans, ascidians, a young Brama, twelve young boarfishes (Capros), a horse-mackerel, and one young of its own species."

Fig. 96.—Lancet-fish, Plagyodus ferox (Lowe). New York.

The lancet-fish, Plagyodus ferox, is occasionally taken on either side of the Atlantic and in Japan. The handsaw-fish, called Plagyodus æsculapius, has been taken at Unalaska, off San Luis Obispo, and in Humboldt Bay. It does not seem to differ at all from Plagyodus ferox. The original type from Unalaska had in its stomach twenty-one lumpfishes (Eumicrotremus spinosus). This is the species described from Steller's manuscripts by Pallas under the name of Plagyodus. Another species, Plagyodus borcalis, is occasionally taken in the North Pacific.

The Evermannellidæ is a small family of small deep-sea fishes with large teeth, distensible muscles, and an extraordinary power of swallowing other fishes, scarcely surpassed by Chiasmodon or Saccopharynx. Evermannella (Odontostomus, the latter name preoccupied) and Omosudis are the principal genera.

The Paralepidæ are reduced allies of Plagyodus, slender, silvery, with small fins and fang-like jaws. As in Plagyodus, the adipose fin is developed and there are small luminous dots. The species are few and mostly northern; one of them, Sudis ringens, is known only from a single specimen taken by the present writer from the stomach of a hake (Merluccius productus), the hake in turn swallowed whole by an albacore in the Santa Barbara Channel. The Sudis had been devoured by the hake, the hake by the albacore, and the albacore taken on the hook before the feeble Sudis had been digested.

Fig. 97.—Eurypholis sulcidens Pictet, restored. Family Enchodontidæ. Upper Cretaceous of Mt. Lebanon. (After Woodward, as E. boissieri.)

Perhaps allied to the Plagyodontidæ is also the large family of Enchodontidæ, widely represented in the Cretaceous rocks of Syria, Europe, and Kansas. The body in this group is elongate, the teeth very strong, and the dorsal fin short. Enchodus lewesiensis is found in Mount Lebanon, Halec sternbergi in the German Cretaceous, and many species of Enchodus in Kansas; Cimolichthys dirus in North Dakota.

Remotely allied to these groups is the extinct family of Dercetidæ from the Cretaceous of Germany and Syria. These are elongate fishes, the scales small or wanting, but with two or more series of bony scutes along the flanks. In Dercetis scutatus the scutes are large and the dorsal fin is very long. Other genera are Leptotrachelus and Pelargorhynchus. Dr. Boulenger places the Dercetidæ in the order Heteromi. This is an expression of the fact that their relations are still unknown. Probably related to the Dercetidæ is the American family of Stratodontidæ with its two genera, Stradodus and Empo from the Cretaceous (Niobrara) deposits of Kansas. Empo nepaholica is one of the best-known species.

Fig. 98.—Eurypholis freyeri Heckel. Family Enchodontidæ. Cretaceous. (After Heckel; the restoration of the jaws incorrect.)

Fig. 99.—Argyropelecus olfersi Cuvier. Gulf Stream.

The Sternoptychidæ.—The Sternoptychidæ differ materially from all these forms in the short, compressed, deep body and distorted form. The teeth are small, the body bright silvery, with luminous spots. The species live in the deep seas, rising in dark or stormy weather. Sternoptyx diaphana is found in almost all seas, and species of Argyropelecus are almost as widely distributed. After the earthquakes in 1896, which engulfed the fishing villages of Rikuzen, in northern Japan, numerous specimens of this species were found dead, floating on the water, by the steamer Albatross.

The Idiacanthidæ are small deep-sea fishes, eel-shaped and without pectorals, related to the Iniomi.

Order Lyopomi.—Other deep-sea fishes constitute the order or suborder Lyopomi (λυός, loose; πῶμα, opercle). These are elongate fishes having no mesocoracoid, and the preopercle rudimentary and connected only with the lower jaw, the large subopercle usurping its place. The group, which is perhaps to be regarded as a degenerate type of Isospondyli, contains the single family of Halosauridæ, with several species, black in color, soft in substance, with small teeth and long tapering tail, found in all seas. The principal genera are Halosaurus and Aldrovandia (Halosauropsis). Aldrovandia macrochira is the commonest species on our Atlantic coast.

Fig. 100.—Aldrovandia gracilis (Goode & Bean). Guadaloupe Island, West Indies. Family Halosauridæ.

Several fossil Halosauridæ are described from the Cretaceous of Europe and Syria, referred to the genera Echidnocephalus and Enchelurus. Boulenger refers the Lyopomi to the suborder Heteromi.

CHAPTER VII
THE APODES, OR EEL-LIKE FISHES

The Eels.—We may here break the sequence from the Isospondyli to the other soft-rayed fishes, to interpolate a large group of uncertain origin, the series or subclass of eels.

The mass of apodal or eel-like fishes has been usually regarded as constituting a single order, the Apodes (ἄ, without; ποῦς, foot). The group as a whole is characterized by the almost universal separation of the shoulder-girdle from the skull, by the absence of the mesocoracoid arch on the shoulder-girdle, by the presence of more than five pectoral actinosts, as in the Ganoid fishes, by the presence of great numbers of undifferentiated vertebræ, giving the body a snake-like form, by the absence in all living forms of the ventral fins, and, in all living forms, by the absence of a separate caudal fin. These structures indicate a low organization. Some of them are certainly results of degeneration, and others are perhaps indications of primitive simplicity. Within the limits of the group are seen other features of degeneration, notably shown in the progressive loss of the bones of the upper jaw and the membrane-bones of the head and the degradation of the various fins. The symplectic bone is wanting, the notochord is more or less persistent, the vertebral centra always complete constricted cylinders, none coalesced. But, notwithstanding great differences in these regards, the forms have been usually left in a single order, the more degraded forms being regarded as descended from the types which approach nearest to the ordinary fishes. From this view Professor Cope dissents. He recognizes several orders of eels, claiming that we should not unite all these various fishes into a single order on account of the eel-like form. If we do so, we should place in another order those with the fish-like form. It is probable, though not absolutely certain, that the Apodes are related to each other. The loss among them, first, of the connection of the post-temporal with the skull; second, of the separate caudal fin and its hypural support; third, of the distinct maxillary and premaxillary; and fourth, of the pectoral fins, must be regarded as successive phases of a general line of degradation. The large number of actinosts, the persistence of the notochord, the absence of spines, and the large numbers of vertebræ seem to be traits of primitive simplicity. Special lines of degeneration are further shown by deep-sea forms. What the origin of the Apodes may have been is not known with any certainty. They are soft-rayed fishes, with the air-bladder connected by a tube with the œsophagus, and with the anterior vertebræ not modified. In so far they agree with the Isospondyli. In some other respects they resemble the lower Ostariophysi, especially the electric eel and the eel-like catfishes. But these resemblances, mainly superficial, may be wholly deceptive; we have no links which certainly connect the most fish-like Apodes with any of the other orders. Probably Woodward's suggestion that they may form a series parallel with the Isospondyli and independently descended from Tertiary Ganoids deserves serious consideration. Perhaps the most satisfactory arrangement of these fishes will be to regard them as constituting four distinct orders for which we may use the names Symbranchia (including Ichthyocephali and Holostomi), Apodes (including Enchelycephali and Colocephali), Carencheli, and Lyomeri.

Order Symbranchia.—The Symbranchia are distinguished by the development of the ordinary fish mouth, the maxillary and premaxillary being well developed. The gill-openings are very small, and usually confluent below. These fresh-water forms of the tropics, however eel-like in form, may have no real affinity with the true eels. In any event, they should not be placed in the same order with the latter.

The eels of the suborder Ichthyocephali (ιχθύς, fish; κεφαλή, head) have the head distinctly fish-like. The maxillary, premaxillary, and palatines are well developed, and the shoulder-girdle is joined by a post-temporal to the skull. The body is distinctly eel-like, the tail being very short and the fins inconspicuous. The number of vertebræ is unusually large. The order contains the single family Monopteridæ, the rice-field eels, one species, Monopterus albus, being excessively common in pools and ditches from China and southern Japan to India.

The eels of the suborder Holostomi (ὀλός, complete; στόμα, mouth) differ from these mainly in the separation of the shoulder-girdle from the skull, a step in the direction of the true eels. The Symbranchidæ are very close to the Monopteridæ in external appearance, small, dusky, eel-like inhabitants of sluggish ponds and rivers of tropical America and the East Indies. The gill-openings are confluent under the throat. Symbranchus marmoratus ranges northward as far as Vera Cruz, having much the habit of the rice-field eel of Japan and China. The Amphipnoidæ, with peculiar respiratory structures, abound in India. Amphipnous cuchia, according to Günther, has but three gill-arches, with rudimentary lamina and very narrow slits. To supplement this insufficient branchial apparatus, a lung-like sac is developed on each side of the body behind the head, opening between the hyoid and the first branchial arch. The interior of the sac is abundantly provided with blood-vessels, the arterial coming from the branchial arch, whilst those issuing from it unite to form the aorta. Amphipnous has rudimentary scales. The other Holostomi and Ichthyocephali are naked and all lack the pectoral fin.

The Chilobranchidæ are small sea-fishes from Australia, with the tail longer than the rest of the body, instead of much shorter as in the others.

No forms allied to Symbranchus or Monopterus are recorded as fossils.

Order Apodes, or True Eels.—In this group the shoulder-girdle is free from the skull, and the bones of the jaws are reduced in number, through coalescence of the parts.

Three well-marked suborders may be recognized, groups perhaps worthy of still higher rank: Archencheli, Enchelycephali, and Colocephali.

Suborder Archencheli.—The Archencheli, now entirely extinct, are apparently the parents of the eels, having, however, certain traits characteristic of the Isospondyli. They retain the separate caudal fin, with the ordinary hypural plate, and Professor Hay has recently found, in an example from the Cretaceous of Mount Lebanon, remains of distinct ventral fins. These traits seem to indicate an almost perfect transition from the Isospondyli to the Archencheli.

One family may be recognized at present, Urenchelyidæ.

The earliest known eel, Urenchelys avus, occurs in the upper Cretaceous at Mount Lebanon. It represents the family Urenchelyidæ, apparently allied to the Anguillidæ, but having a separate caudal fin. Its teeth are small, conical, blunt, in many series. There are more than 100 vertebræ, the last expanded in a hypural. Pectorals present. Scales rudimentary; dorsal arising at the occiput. Branchiostegals slender, not curved around the opercle. Urenchelys anglicus is another species, found in the chalk of England.

Suborder Enchelycephali.—The suborder Enchelycephali (ἔγχελυς, eel; κεφαλή, head) contains the typical eels, in which the shoulder-girdle is free from the skull, the palatopterygoid arch relatively complete, the premaxillaries wanting or rudimentary, the ethmoid and vomer coalesced, forming the front of the upper jaw, the maxillaries lateral, and the cranium with a single condyle. In most of the species pectoral fins are present, and the cranium lacks the combined degradation and specialization shown by the morays (Colocephali).

Family Anguillidæ.—The most primitive existing family is that of the typical eels, Anguillidæ, which have rudimentary scales oblong in form, and set separately in groups at right angles with one another. These fishes are found in the fresh and brackish waters of all parts of the world, excepting the Pacific coast of North America and the islands of the Pacific. In the upper Great Lakes and the upper Mississippi they are also absent unless introduced. The species usually spawn in the sea and ascend the rivers to feed. But some individuals certainly spawn in fresh water, and none go far into the sea, or where the water is entirely salt. The young eels sometimes ascend the brooks near the sea in incredible numbers, constituting what is known in England as "eel-fairs." They will pass through wet grass to surmount ordinary obstacles. Niagara Falls they cannot pass, and according to Professor Baird "in the spring and summer the visitor who enters under the sheet of water at the foot of the falls will be astonished at the enormous numbers of young eels crawling over the slippery rocks and squirming in the seething whirlpools. An estimate of hundreds of wagon-loads, as seen in the course of the perilous journey referred to, would hardly be considered excessive by those who have visited the spot at a suitable season of the year." "At other times large eels may be seen on their way down-stream, although naturally they are not as conspicuous then as are the hosts of the young on their way upstream. Nevertheless it is now a well-assured fact that the eels are catadromous, that is, that the old descend the watercourses to the salt water to spawn, and the young, at least of the female sex, ascend them to enjoy life in the fresh water."

Fig. 101.—Common Eel, Anguilla chrisypa Rafinesque. Holyoke, Mass.

Reproduction of the Eel.—Dr. Gill ("Riverside Natural History," p. 103) gives the following account of the reproduction of Anguilla:

"The generation of the eel was long involved in great mystery, and the knowledge thereof is one of the recent acquisitions of scientific investigation. So late, indeed, as 1880 it was declared that 'their mode of propagation is still unknown.' In want of positive knowledge the rein has been given to loose hypothesis and conjecture. It has been variously asserted that eels were generated from slime, from dew, and from the skins of old eels or of snakes. The statement that they come from horse-hairs is familiar to many country boys, and the origin of this belief is due simply to the fact that there are certain aquatic worms, known under the generic name Gordius, which are elongated and apparently smooth like the eel, and which may be found in the same waters. It was one of the ideas of the Greek to attribute their paternity, as of many other doubtful offspring, to the convenient Jupiter. The statement that they are viviparous has arisen from two causes: one the existence of intestinal worms, and the other from the confusion of the eel with an elongated and consequently eel-like but otherwise very different form, the Zoarces viviparus. The Zoarces is indeed, in Germany as well as in the Scandinavian countries, generally known as the Aal-mutter, or eel-mother, and thus in its name perpetuates the fancy. Even where eels are to be found in extreme abundance, and where they are the objects of a special culture, like erroneous opinions prevail. Thus, according to Jacoby, about the lagoon of Comacchio there is an 'ineradicable belief among the fishermen that the eel is born of other fishes; they point to special differences in color and especially in the common mullet, Mugil cephalus, as the causes of variation in color and form among eels. It is a very ancient belief, widely prevalent to the present day, that eels pair with water-snakes. In Sardinia the fishermen cling to the belief that a certain beetle, the so-called water-beetle, Dytiscus ræselii, is the progenitor of eels, and they therefore call this "mother of eels."' The assignment of such maternity to the water-beetle is doubtless due to the detection of the hair-worm, or Gordius, in the insect by sharp-sighted but unscientific observers, and, inasmuch as the beetle inhabits the same waters as the eel, a very illogical deduction has led to connect the two together.

"All such beliefs as have been thus recounted are due to the inconspicuous nature of the generative organs in eels found in fresh waters and at most seasons—a characteristic which is in strong contrast to the development of corresponding parts in fishes generally. Nevertheless the ovaries of the eel were discovered, as long ago as 1707, by Dr. Sancassini of Comacchio, and described by the celebrated Valisneri (after whom the plant Valisneria was named) in 1710, again by Mondini in 1777, and almost contemporaneously by O. J. Müller of Denmark. Later the illustrious Rathke (in 1824, 1838, and 1850) and also Hornbaum-Hornschuch published the results of special investigations, and figured the eggs. But it was only in 1873 (after several futile endeavors by others) that the male organ of the eel was recognized, also by an Italian naturalist, Dr. Syrski, in small individuals of the species, and a previous idea that the eel was hermaphroditic thereby dispelled. The sexual differences are correlated with external ones, and generally the males and females, when adult, can be told apart. Jacoby testifies that he examined large numbers with a view to solve this question. The most important differences relate to (1) size; (2) form of the snout; (3) color; (4) dorsal fin; and (5) size of the eyes. (1) The males rarely attain a length of more than seventeen to nineteen inches, while adult females are generally much larger; (2) the snout in the male is attenuated and rather pointed, while in the female it is comparatively broad and blunt; (3) the male is of a deep darkish green, or often a deep black with a shining luster and a whitish belly, while the female has a clearer color, usually of a greenish hue on the back and yellowish on the belly; (4) the dorsal fin is lower and less developed in the male than in the female; and (5) the eye of the male is large and that of the female, as a rule, comparatively small. These characters, however, do not always hold good. Jacoby remarked that 'special reference having been paid to the height and narrowness of the dorsal fin, much success has been met with in picking out, in the fish-market of Trieste, the eels which possessed the organ of Syrski (that is, the male organ); absolute certainty, however, in recognizing them cannot be guaranteed. If one is searching among living eels with no characters in mind,—with the exception of the first, that of length,—he will find in every ten eels, on an average, eight females and two with the supposed male organ; but if the selection is made with a careful reference to all these marks of difference, the proportion changes, and out of every ten examples about eight will be found with the supposed male organ.'

"According to Herr Benecke, 'it may be assumed with the greatest safety that the eel lays its eggs like most other fish, and that, like the lamprey, it spawns only once and then dies. All the eggs of a female show the same degree of maturity, while in the fish which spawn every year, besides the large eggs which are ready to be deposited at the next spawning period, there exist very many of much smaller size, which are destined to mature hereafter and be deposited in other years. It is very hard to understand how young eels could find room in the body of their mother if they were retained until they had gained any considerable size. The eel embryo can live and grow for a long time supported by the little yolk, but, when this is done, it can only obtain food outside of the body of its mother. The following circumstances lead us to believe that the spawning of the eel takes place only in the sea: (1) that the male eel is found only in the sea or brackish water, while female eels yearly undertake a pilgrimage from the inland waters to the sea, a circumstance which has been known since the time of Aristotle, and upon the knowledge of which the principal capture of eels by the use of fixed apparatus is dependent; (2) that the young eels, with the greatest regularity, ascend from the sea into the rivers and lakes.'"

All statements in opposition to this theory are untenable, since the young eels never find their way into landlocked ponds in the course of their wanderings, while eels planted in such isolated bodies of water thrive and grow rapidly, but never increase in numbers. Another still more convincing argument is the fact that in lakes which formerly contained many eels, but which, by the erection of impassable weirs, have been cut off from the sea, the supply of eels has diminished, and after a time only scattering individuals, old and of great size, are taken in them. An instance of this sort occurred in Lake Muskengorf in West Prussia. If an instance of the reproduction of the eel in fresh water could be found, such occurrences as these would be quite inexplicable.

In the upper stretches of long rivers the migration of the eels begins in April or in May; in their lower stretches and shorter streams, later in the season. In all running waters the eel-fishery depends upon the downward migrations; the eels press up the streams with occasional halts, remaining here and there for short periods, but always make their way above. They appear to make the most progress during dark nights, when the water is troubled and stormy, for at this time they are captured in the greatest numbers. It is probable that after the eels have once returned to the sea and there deposited their spawn, they never can return into fresh water, but remain there to die. A great migration of grown eels in spring or summer has never been reported, and it appears certain that all the female eels which have once found their way to the sea are lost to the fisherman.

Food of the Eel.—Eels, in the words of Mr. W. H. Ballou, are "among the most voracious of carnivorous fishes. They eat most inland fishes, except the garfish and the chub. Investigation of six hundred stomachs by Oswego fishermen showed that the latter bony fish never had a place in their bill of fare. They are particularly fond of game-fishes, and show the delicate taste of a connoisseur in their selection from choice trout, bass, pickerel, and shad. They fear not to attack any object when disposed, and their bite in human flesh shows even a vicious attitude towards man. On their hunting excursions they overturn huge and small stones alike, working for hours if necessary, beneath which they find species of shrimp and crayfish, of which they are exceedingly fond. Of shrimps they devour vast numbers. Their noses are poked into every imaginable hole in their search for food, to the terror of innumerable small fishes."

In the opinion of Mr. Ballou, too, "eels are to the water what the fishhawk is to the air. They are, perhaps, the most powerful and rapid of natatorians. Again, they hide in the mud beneath some log or overhanging rock, and dart out with tremendous fury at the unsuspecting prey. They attack the spawn of other fishes open-mouthed, and are even said to suck the eggs from an impaled female. They fearlessly and rapidly dive head-foremost in the mud, disappearing from view in the twinkling of a star. They are owl-like in their habits, committing many of their depredations at night.

"No fish is yet reported to utilize a full-grown eel as food. Pickerel, garfish, and bass, which are particularly numerous in these lakes, are supposed to literally devour the young fry. Mr. Sawyer describes the operation of the pickerel darting through a long column of young eels open-mouthed and devouring vast numbers of them."

Larva of the Eel.—The translucent band-shaped larva of the common eel has been very recently identified and described by Dr. Eigenmann. It is probable that all true eels, Enchelycephali, pass through a band-shaped or leptocephalous stage, as is the case with Albula and other Isospondyli. In the continued growth the body becomes firmer, and at the same time much shorter and thicker, gradually assuming the normal form of the species in question.

Fig. 102.—Larva of Common Eel, Anguilla chrisypa (Rafinesque), called Leptocephalus grassii. (After Eigenmann.)

In a recent paper Dr. Carl H. Eigenmann has very fully reviewed the life-history of the eel. The common species live in fresh waters, migrating to the sea in the winter. They deposit in deep water minute eggs that float at the surface. The next year they develop into the band-shaped larva. The young eels enter the streams two years after their parents drop down to the sea. It is doubtful whether eels breed in fresh water. The male eel is much smaller than the female.

The eel is an excellent food-fish, the flesh being tender and oily, of agreeable flavor, better than that of any of its relatives. Eels often reach a large size, old individuals of five or six feet in length being sometimes taken.

Species of Eels.—The different species are very closely related. Not more than four or five of them are sharply defined, and these mostly in the South Seas and in the East Indies. The three abundant species of the north temperate zone, Anguilla anguilla of Europe, Anguilla chrisypa of the eastern United States, and Anguilla japonica of Japan, are scarcely distinguishable. In color, size, form, and value as food they are all alike.

Fossil species referred to the Anguillidæ are known from the early Tertiary. Anguilla leptoptera occurs in the Eocene of Monte Bolea, and Anguilla elegans in the Miocene of Œningen in Baden. Other fossil eels seem to belong to the Nettastomidæ and Myridæ.

Pug-nosed Eels.—Allied to the true eel is the pug-nosed eel, Simenchelys parasiticus, constituting the family of Simenchelyidæ. This species is scaled like a true eel, has a short, blunt nose, and burrows its way into the bodies of halibut and other large fishes. It has been found in Newfoundland and Madeira. Another family possessing rudimentary scales is that of the Synaphobranchidæ, slender eels of the ocean depths, widely distributed. In these forms the gill-openings are confluent. Synaphobranchus pinnatus is the best-known species.

Fig. 103.—Pug-nosed Eel, Simenchelys parasiticus Gill. Sable Island Bank.

Fig. 104.—Synaphobranchus pinnatus (Gronow). Le Have Bank.

Conger-eels.—The Leptocephalidæ, or conger-eels, are very similar to the fresh-water eels, but are without scales and with a somewhat different mouth, the dorsal beginning nearer to the head.

The principal genus is Leptocephalus, including the common conger-eel (Leptocephalus conger) of eastern America and Europe and numerous very similar species in the tropics of both continents. These fishes are strictly marine and, reaching the length of five or six feet, are much valued as food. The eggs are much larger than those of the eel and are produced in great numbers, so that the female almost bursts with their numbers. Dr. Hermes calculated that 3,300,000 were laid by one female in an aquarium.

These eggs hatch out into transparent band-like larva, with very small heads formerly known as Leptocephalus, an ancient name which is now taken for the genus of congers, having been first used for the larva of the common conger-eel. The loose watery tissues of these "ghost-fishes" grow more and more compact and they are finally transformed into young congers.

Fig. 105.—Conger-eel, Leptocephalus conger (L.). Noank, Conn.

The Murænesocidæ are large eels remarkable for their strong knife-like teeth. Murænesox savanna occurs in the West Indies and in the Mediterranean, Murænesox cinereus in Japan, and Murænesox coniceps on the west coast of Mexico, all large and fierce, with teeth like shears. The Myridæ are small and worm-like eels closely allied to the congers, having the tail surrounded by a fin, but the nostrils labial. Myrus myrus is found in the Mediterranean. Species of Eomyrus, Rhynchorhinus, and Paranguilla apparently allied to Myrus occur in the Eocene. Other related families, mostly rare or living in the deep seas, are the Ilyophidæ, Heterocongridæ, and Dysommidæ.

Fig. 106.—Larva of Conger-eel (Leptocephalus conger), called Leptocephalus morrissi. (After Eigenmann.)

The Snake-eels.—Most varied of the families of eels is the Ophichthyidæ, snake-like eels recognizable by the form of the tail, which protrudes beyond the fins. Of the many genera found in tropical waters several are remarkable for the sharply defined coloration, suggesting that of the snake. Characteristic species are Chlevastes colubrinus and Leiuranus semicinctus, two beautifully banded species of Polynesia, living in the same holes in the reefs and colored in the same fashion. Another is Callechelys melanotænia. The commonest species on the Atlantic coast is the plainly colored Ophichthus gomesi.

Fig 107.—Xyrias revulsus Jordan & Snyder. Family Ophichthyidæ. Misaki, Japan.

In the genus Sphagebranchus, very slender eels of the reefs, the fins are almost wanting.

Fig. 108.—Myrichthys pantostigmius Jordan & McGregor. Clarion Island.

Fig. 109.—Ophichthus ocellatus (Le Sueur). Pensacola.

Allied to the Congers is the small family of duck-billed eels (Nettastomidæ) inhabiting moderate depths of the sea. Nettastoma bolcense occurs in the Eocene of Monte Bolca. The produced snout forms a transition to the really extraordinary type of thread-eels or snipe-eels (Nemichthyidæ), of which numerous genera and species live in the oceanic depths. In Nemichthys the long, very slender, needle-like jaws are each curved backward so that the mouth cannot by any possibility be shut. The body is excessively slender and the fish swims with swift undulations, often near the surface, and when seen is usually taken for a snake. The best-known species is Nemichthys scolopaceus of the Atlantic and Pacific. Nemichthys avocetta, very much like it, has been twice taken in Puget Sound.

Fig. 110.—Thread-eel, Nemichthys avocetta Jordan & Gilbert. Vancouver Island.

Suborder Colocephali, or Morays.—In the suborder Colocephali (κολός, deficient; κεφαλή, head) the palatopterygoid arch and the membrane-bones generally are very rudimentary. The skull is thus very narrow, the gill-structures are not well developed, and in the chief family there are no pectoral fins. This group is very closely related to the Enchelycephali, from which it is probably derived.

Fig. 111.—Jaws of Nemichthys avocetta Jordan & Gilbert.

In the great family of morays (Murænidæ) the teeth are often very highly developed. The muscles are always very strong and the spines bite savagely, a live moray being often able to drive men out of a boat. The skin is thick and leathery, and the coloration is highly specialized, the pattern of color being often elaborate and brilliant. In Echidna zebra for example the body is wine-brown, with cross-stripes of golden yellow. In Muræna each nostril has a barbel. Muræna helena, the oldest moray known, is found in Europe. In Gymnothorax, the largest genus, only the anterior nostrils are thus provided. Gymnothorax mordax of California is a large food-fish, as are also the brown Gymnothorax funebris and the spotted Gymnothorax moringa in the West Indies. These and many other species may coil themselves in crevices in the reefs, whence they strike out at their prey like snakes, taking perhaps the head of a duck or the finger of a man.

In many of the morays the jaws are so curved and the mouth so filled with knife-like teeth that the jaws cannot be closed. This fact, however, renders no assistance to their prey, as the teeth are adapted for holding as well as for cutting.

In Enchelynassa bleekeri, a huge wine-colored eel of the South Seas, the teeth are larger than in any other species. Evenchelys (macrurus) is remarkable for its extraordinary length of tail, Echidna for its blunt teeth, and Scuticaria, Uropterygius, and Channomuræna for the almost complete absence of fins. In Anarchias (allardicei; knighti), the anal fin is absent. The flesh of the morays is rather agreeable in taste, but usually oily and not readily digestible, less wholesome than that of the true eels.

Fig. 112.—Muræna retifera Garman. Charleston, S. C.

The Myrocongridæ are small morays with developed pectoral fins. The species are few and little known.

Family Moringuidæ.—Structurally one of the most peculiar of the groups of eels is the small family of Moringuidæ of the East and West Indies. In these very slender, almost worm-like fishes the heart is placed very far behind the gills and the tail is very short. The fins are very little developed, and some forms, as Gordiichthys irretitus of the Gulf of Mexico, the body as slender as a whiplash, possess a very great number of vertebræ. Moringua hawaiiensis occurs in Hawaii, M. edwardsi in the Bahamas. This family probably belongs with the morays to the group of Colocephali, although its real relationships are not wholly certain.

Order Carencheli, the Long-necked Eels.—Certain offshoots from the Apodes so widely diverging in structure that they must apparently be considered as distinct orders occur sparingly in the deep seas. One of these, Derichthys serpentinus, the long-necked eel, constitutes the sole known species of the suborder Carencheli (καρά, head; ἔγχελυς, eel). In this group the premaxillaries and maxillaries are present as in ordinary fishes, but united by suture and soldered to the cranium. As in true eels, the shoulder-girdle is remote from the skull. The head is set on a snake-like neck. The single species representing the family Derichthyidæ was found in the abysmal depths of the Gulf Stream.

Fig. 113.—Gymnothorax berndti Snyder. Hawaii. Family Murænidæ.

Fig. 114.—Gymnothorax jordani (Evermann & Marsh). Family Murænidæ. Puerto Rico.

Fig. 115.—Moray, Gymnothorax moringa Bloch. Family Murænidæ. Tortugas.

Fig. 116.—Derichthys serpentinus Gill. Gulf Stream.

Fig. 117.—Gulper-eel, Gastrostomus bairdi Gill & Ryder. Gulf Stream.

Order Lyomeri, or Gulpers.—Still more aberrent and in many respects extraordinary are the eels of the order or suborder Lyomeri (λυός, loose; μέρος, part), known as "Gulpers." These are degenerate forms, possibly degraded from some conger-like type, but characterized by an extreme looseness of structure unique among fishes. The gill-arches are reduced to five small bars of bone, not attached to the skull, the palatopterygoid arch is wholly wanting, the premaxillaries are wanting, as in all true eels, and the maxillaries loosely joined to the skull. The symplectic bone is wanting, and the lower jaw is so hinged to the skull that it swings freely in various directions. In place of the lateral line are singular appendages. Dr. Gill says of these fishes: "The entire organization is peculiar to the extent of anomaly, and our old conceptions of the characteristics of a fish require to be modified in the light of our knowledge of such strange beings." Special features are the extraordinary size of the mouth, which has a cavity larger than that of the rest of the body, the insertion of the very small eye at the tip of the snout, and the relative length of the tail. The whole substance is excessively fragile as usual with animals living in great depths and the color is jet black. Three species have been described, and these have been placed in two families, Saccopharyngidæ, with the trunk (gill-opening to the vent) much longer than the head, and Eurypharyngidæ, with the trunk very short, much shorter than the head. The best-known species is the pelican eel (Eurypharynx pelacanoides), of the coast of Morocco, described by Vaillant in 1882. Gastrostomus bairdi, very much like it, occurs in the great depths under the Gulf Stream. So fragile and so easily distorted are these fishes that it is possible that all three are really the same species, for which the oldest name would be Saccopharynx ampullaceus. Of this form four specimens have been taken in the Atlantic, one of them six feet long, carried to the surface through having swallowed fishes too large to be controlled. To be carried above its depth in a struggle with its prey is one of the greatest dangers to which the abysmal fishes are subject.

Order Heteromi.—The order of Heteromi (ἑτερός, different; ὤμος, shoulder), or spiny eels, may be here noticed for want of a better place, as its affinities are very uncertain. Some writers have regarded it as allied to the eels; some have placed it among the Ganoids. Others have found affinities with the sticklebacks, and still others with the singular fresh-water fishes called Mastacembelus. The Heteromi agree with the eels, as well as with Mastacembelus, in having the scapular arch separate from the cranium. Unlike all the true eels, most of the species have true dorsal and anal spines, as in the Percesoces and Hemibranchii. The ventral fins, when present, are abdominal and each with several spines in front, a character not found among the Acanthopteri. There is no mesocoracoid.

The air-bladder has a duct, and the coracoids, much as in the Xenomi, are reduced to a single lamellar imperforate plate. The two groups have little else in common, however, and this trait is possibly primitive in both cases, more likely to have arisen through independent degeneration. The separation of the shoulder-girdle doubtless indicates no affinity with the eels, as the bones of the jaws are quite normal. Two families are known, both from the deep sea, besides an extinct family in which spines are not developed.

The Notacanthidæ are elongate, compressed, ending in a band-shaped, tapering tail; the back has numerous free spines and few or no soft rays, and the mouth is normal, provided with teeth. The species of Notacanthus are few and scantily preserved. Those of Macdonaldia are more abundant. Macdonaldia challengeri is from the North Pacific, being once taken off Tokio. The extinct family of Protonotacanthidæ differs in the total absence of dorsal spines and fin-rays; the single species, Pronotocanthus sahel-almæ, originally described as a primitive eel, occurs in the Cretaceous of Mount Lebanon.

The Lipogenyidæ have a round, sucker-like mouth, with imperfect lower jaw, but are otherwise similar. Lipogenys gilli was dredged in the Gulf Stream.

Fig. 118.—Notacanthus phasganorus Goode & Bean. Grand Banks.

Dr. Boulenger has recently extended the group of Heteromi by the addition of the Dercetidæ, Halosauridæ (Lyopomi), and the Fierasferidæ. We can hardly suppose that all these forms are really allied to Notacanthus.

CHAPTER VIII
SERIES OSTARIOPHYSI

Ostariophysi.—A large group of orders, certainly of common descent, may be brought together under the general name of Ostariophysi (ὀσταρίον, a small bone; θυσός, inflated). These are in many ways allied to the Isospondyli, but they have undergone great changes of structure, some of the species being highly specialized, others variously degenerate. A chief character is shared by all the species. The anterior vertebræ are enlarged, interlocked, considerably modified, and through them a series of small bones connect the air-bladder with the ear. The air-bladder thus becomes apparently an organ of hearing through a form of connection which is lost in all the higher fishes.

In all the members of this group excepting perhaps the degraded eel-like forms called Gymnonoti, the mesocoracoid arch persists, a trait found in all the living types of Ganoids, as well as in the Teleost order of Isospondyli. Other traits of the Ostariophysan fishes are shared by the Isospondyli (herring, salmon) and other soft-rayed fishes. The air-bladder is large, but not cellular. It leads through life by an open duct to the œsophagus. The ventral fins are abdominal in position. The pectorals are inserted low. A mesocoracoid arch is developed on the inner side of the shoulder-girdle. (See Fig. 119.) There are no spines on the fins, except in many cases a single one, a modified soft ray at front of dorsal or pectoral. The scales, if present, are cycloid or replaced by bony plates.

Many of the species have an armature much like that of the sturgeon, but here the resemblance ends, the bony plates in the two cases being without doubt independently evolved. According to Cope, the affinities of the catfishes to the sturgeon are "seen in the absence of symplectic, the rudimentary maxillary bone, and, as observed by Parker, in the interclavicles. There is also a superficial resemblance in the dermal bones." But it is not likely that any real affinity exists.

Fig. 119.—Inner view of shoulder-girdle of the Buffalo-fish. Ictiobus bubalus Rafinesque, showing the mesocoracoid (59). (After Starks.)

The sturgeons lack the characteristic auditory ossicles, or "Weberian apparatus," which the catfishes possess in common with the carp family, the Characins, and the Gymnonoti. These orders must at least have a common origin, although this origin is obscure, and fossil remains give little help to the solution of the problem. Probably the ancestors of the Ostariophysi are to be found among the allies of the Osteoglossidæ. Gill has called attention to the resemblance of Erythrinus to Amia. In any event, all the Ostariophysi must be considered together, as it is not conceivable that so complex a structure as the Weberian apparatus should have been more than once independently evolved. The branchiostegals, numerous among the Isospondyli, are mostly few among the Ostariophysi.

Fig. 120.—Weberian apparatus and air-bladder of Carp. (From Günther, after Weber.)

To the Ostariophysi belong the vast majority of the fresh-water fishes of the world. Their primitive structure is shown in many ways; among others by the large number of vertebræ instead of the usual twenty-four among the more highly specialized families of fishes. We may group the Ostariophysi under four orders: Heterognathi, Eventognathi (Plectospondyli), Nematognathi, and Gymnonoti.

The Heterognathi.—Of these the order of Heterognathi seems to be the most primitive, but in some ways the most highly developed, showing fewer traits of degeneration than any of the others. The presence of the adipose fin in this group and in the catfishes seems to indicate some sort of real affinity with the salmon-like forms, although there has been great change in other regards.

The order Heterognathi, or Characini (ἕτερος, different; γνάθος, jaw), contains those Ostariophysi which retain the mesocoracoid and are not eel-like, and which have the lower pharyngeals developed as in ordinary fishes. In most cases an adipose fin is present and there are strong teeth in the jaws. There are no pseudobranchiæ, and, as in the Cyprinidæ, usually but three branchiostegals. The Characidæ constitute the majority of the fresh-water fishes in those regions which have neither Cyprinidæ nor Salmonidæ. Nearly four hundred species are known from the rivers of South America and Africa. A single species, Tetragonopterus argentatus, extends its range northward to the Rio Grande in Texas. None are found in Asia, Europe, or, with this single exception, in the United States. Most of them are small fishes with deep bodies and very sharp, serrated, incisor-like teeth. Some are as innocuous as minnows, which they very much resemble, but others are extremely voracious and destructive in the highest degree. Of the caribe, belonging to the genus Serrasalmo, known by its serrated belly, Dr. Günther observes:

"Their voracity, fearlessness and number render them a perfect pest in many rivers of tropical America. In all the teeth are strong, short, sharp, sometimes lobed incisors, arranged in one or more series; by means of them they cut off a mouthful of flesh as with a pair of scissors; and any animal falling into the water where these fish abound is immediately attacked and cut to pieces in an incredibly short time. They assail persons entering the water, inflicting dangerous wounds before the victims are able to make their escape. In some localities it is scarcely possible to catch fishes with the hook and line, as the fish hooked is immediately attacked by the 'caribe' (as these fish are called), and torn to pieces before it can be withdrawn from the water. The caribes themselves are rarely hooked, as they snap the hook or cut the line. The smell of blood is said to attract at once thousands of these fishes to the spot."

Two families of Heterognathi are recognized: the Erythrinidæ, which lack the adipose fin, and the Characidæ, in which this fin is developed. The Erythrinidæ are large pike-like fishes of the South American rivers, robust and tenacious of life, with large mouths armed with strong unequal teeth. The best-known species is the Trahira (Hoplias malabaricus).

Fig. 121.—Brycon dentex Günther. Family Characidæ. Nicaragua.

Among the Characidæ, Serrasalmo has been already noticed. Citharinus in Africa has very few teeth, and Curimatus in South America none at all. Nannocharax in Africa is composed of very diminutive fishes, Hydrocyon exceedingly voracious ones, reaching a length of four feet, with savage teeth. Many of the species are allies of Tetragonopterus, small, silvery, bream-like fishes with flat bodies and serrated incisor teeth. Most of these are American. A related genus is Brycon, found in the streams about the Isthmus of Panama.

Extinct Characins are very rare. Two species from the Tertiary lignite of São Paulo, Brazil, have been referred to Tetragonopterus—T. avus and T. ligniticus.

The Eventognathi.—The Eventognathi (ἔυ, well; ἔν, within; γνάθος, jaw) are characterized by the absence of teeth in the jaws and by the high degree of specialization of the lower pharyngeals, which are scythe-shaped and in typical forms are armed with a relatively small number of highly specialized teeth of peculiar shape and arranged in one, two, or three rows. In all the species the gill-openings are restricted to the sides; there is no adipose fin, and the broad, flat branchiostegals are but three in number. In all the species the scales, if present, are cycloid, and the ventral fins, of course, abdominal. The modification of the four anterior vertebræ and their connection with the air bladder are essentially as seen in the catfishes.

The name Plectospondyli is often used for this group (πλεκτός, interwoven; σπόνδυλος, vertebra), but that term originally included the Characins as well.

Fig. 122.—Pharyngeal bones and teeth of European Chub, Leuciscus cephalus (Linnæus). (After Seelye.)

The Cyprinidæ.—The chief family of the Eventognathi and the largest of all the families of fishes is that of Cyprinidæ, comprising 200 genera and over 2000 species, found throughout the north temperate zone but not extending to the Arctic Circle on the north, nor much beyond the Tropic of Cancer on the south. In this family belong all the fishes known as carp, dace, chub, roach, bleak, minnow, bream, and shiner. The essential character of the family lies in the presence of one, two, or three rows of highly specialized teeth on the lower pharyngeals, the main row containing 4, 5, 6, or 7 teeth, the others 1 to 3. The teeth of the main row differ in form according to the food of the fish. They may be coarse and blunt, molar-like in those which feed on shells; they may be hooked at tip in those which eat smaller fishes; they may be serrated or not; they may have an excavated "grinding surface," which is most developed in the species which feed on mud and have long intestines. In the Cyprinidæ, or carp family, the barbels are small or wanting, the head is naked, the caudal fin forked, the mouth is toothless and without sucking lips, and the premaxillaries form its entire margin. With a few exceptions the Cyprinidæ are small and feeble fishes. They form most of the food of the predatory river fishes, and their great abundance in competition with these is due to their fecundity and their insignificance. They spawn profusely and find everywhere an abundance of food. Often they check the increase of predatory fish by the destruction of their eggs.

In many of the genera the breeding color of the males is very brilliant, rendering these little creatures for a time the most beautifully colored of fishes. In spring and early summer the fins, sides, and head in the males are often charged with pigment, the prevailing color of which is rosy, though often satin-white, orange, crimson, yellow, greenish, or jet black. Among American genera Chrosomus, Notropis, and Rhinichthys are most highly colored. Rhodeus, Rutilus, and Zacco in the Old World are also often very brilliant.

Fig. 123.—Black-nosed Dace, Rhinichthys dulcis Girard. Yellowstone River.

In very many species, especially in America, the male in the breeding season is often more or less covered with small, grayish tubercles or pearly bodies, outgrowths of the epidermis. These are most numerous on the head and fall off after the breeding season. They are most developed in Campostoma.

The Cyprinidæ are little valued as food-fishes. The carp, largely domesticated in small ponds for food, is coarse and tasteless. Most of the others are flavorless and full of small bones. One species, Opsariichthys uncirostris, of Japan is an exception in this regard, being a fish of very delicate flavor.

Fig. 124.—White Chub, Notropis hudsonius (Clinton). Kilpatrick Lake, Minn.

Fig. 125.—Silver-jaw Minnow, Ericymba buccata Cope. Defiance, Ohio.

In America 225 species of Cyprinidæ are known. One hundred of these are now usually held to form the single genus Notropis. This includes the smaller and weaker species, from two to seven inches in length, characterized by the loss, mostly through degeneration, of special peculiarities of mouth, fins, and teeth. These have no barbels and never more than four teeth in the main row. Few, if any, Asiatic species have so small a number, and in most of these the maxillary still retains its rudimentary barbel. But one American genus (Orthodon) has more than five teeth in the main row and none have more than two rows or more than two teeth in the lower row. By these and other peculiarities it would seem that the American species are at once less primitive and less complex than the Old World forms. There is some evidence that the group is derived from Asia through western America, the Pacific Coast forms being much nearer the Old World types than the forms inhabiting the Mississippi Valley. Not many Cyprinidæ are found in Mexico, none in Cuba, South America, Australia, Africa, or the islands to the eastward of Borneo. Many species are very widely distributed, many others extremely local. In the genus Notropis, each river basin in the Southern States has its series of different and mostly highly colored species. The presence of Notropis niveus in the Neuse, Notropis pyrrhomelas in the Santee, Notropis zonistius in the Chattahoochee, Notropis callistius, trichroistius, and stigmaturus in the Alabama, Notropis whipplei in the Mississippi, Notropis galacturus in the Tennessee, and Notropis cercostigma in the Sabine forms an instructive series in this regard. These fishes and the darters (Etheostominæ) are, among American fishes, the groups best suited for the study of local problems in distribution.

Fig. 126.—Silverfin, Notropis whipplei (Girard). White River, Indiana. Family Cyprinidæ.

Species of Dace and Shiner.—Noteworthy species in other genera are the following:

Largest and best known of the species of Notropis is the familiar shiner or redfin, Notropis cornutus, found in almost every brook throughout the region east of the Missouri River.

Campostoma anomalum, the stone-roller, has the very long intestines six times the length of its body, arranged in fifteen coils around the air-bladder. This species feeds on mud and spawns in little brooks, swarming in early spring throughout the Mississippi Valley, and is notable for its nuptial tubercles and the black and orange fins.

Fig. 127.—Stone-roller, Campostoma anomalum (Rafinesque). Family Cyprinidæ. Showing nuptial tubercles and intestines coiled about the air-bladder.

In the negro-chub, Exoglossum maxillingua of the Pennsylvanian district, the rami of the lower jaw are united for their whole length, looking like a projecting tongue.

Fig. 128.—Head of Day-chub, Exoglossum maxillingua (Le Sueur). Shenandoah River.

The fallfish, Semotilus corporalis, is the largest chub of the Eastern rivers, 18 inches long, living in swift, clear rivers. It is a soft fish, and according to Thoreau "it tastes like brown paper salted" when it is cooked. Close to this is the horned dace, Semotilus atromaculatus, and the horny head, Hybopsis kentuckiensis, both among the most widely distributed of our river fishes. These are all allied to the gudgeon (Gobio gobio), a common boys' fish of the rivers of Europe, and much sought by anglers who can get nothing better. The bream, Abramis, represented by numerous species in Europe, has a deep compressed body and a very long anal fin. It is also well represented in America, the golden shiner, common in Eastern and Southern streams, being Abramis chrysoleucus. The bleak of Europe (Alburnus alburnus) is a "shiner" close to some of our species of Notropis, while the minnow of Europe, Phoxinus phoxinus, resembles our gorgeously colored Chrosomus erythrogaster. Other European forms are the roach (Rutilus rutilus), the chub (Leuciscus cephalus), the dace (Leuciscus leuciscus), the id (Idus idus), the redeye (Scardinius erythropthalmus), and the tench (Tinca tinca). The tench is the largest of the European species, and its virtues with those of its more or less insignificant allies are set forth in the pages of Izaak Walton. All of these receive more attention from anglers in England than their relatives receive in America. All the American Cyprinidæ are ranked as "boys' fish," and those who seek the trout or black bass or even the perch or crappie will not notice them. Thoreau speaks of the boy who treasures the yellow perch as a real fish: "So many unquestionable fish he counts, then so many chubs which he counts, then throws away."

Fig. 129.—Horned Dace, Semotilus atromaculatus (Mitchill). Aux Plaines River, Ill. Family Cyprinidæ.

Fig. 130.—Shiner, Abramis chrysoleucus (Mitchill). Hackensack River, N. J.

Fig. 131.—The Squawfish, Ptychocheilus grandis Agassiz. (Photograph by Cloudsley Rutter.)

Chubs of the Pacific Slope.—In the Western waters are numerous genera, some of the species reaching a large size. The species of squawfish (Ptychocheilus lucius in the Colorado, Ptychocheilus grandis in the Sacramento, and Ptychocheilus oregonensis in the Columbia) reach a length of 4 or 5 feet or even more. These fishes are long and slender, with large toothless mouths and the aspect of a pike.

Allied to these are the "hard tails" (Gila elegans and Gila robusta) of the Colorado Basin, strange-looking fishes scarcely eatable, with lean bodies, flat heads, and expanded tails. The split-tail, Pogonichthys macrolepidotus, is found in the Sacramento.

Fig. 132.—Chub of the Great Basin, Leuciscus lineatus (Girard). Heart Lake, Yellowstone Park. Family Cyprinidæ.

In the chisel-mouth, Acrocheilus alutaceus, of the Columbia the lips have a hard cutting edge. In Meda, very small fishes of the Colorado Basin, the dorsal has a compound spine of peculiar structure. Many of the species of Western waters belong to the genus Leuciscus, which includes also many species of Asia and Europe. The common Japanese dace (Leuciscus hakuensis) is often found out in the sea, but, in general, Cyprinidæ are only found in fresh waters. The genus of barbels (Barbus) contains many large species in Europe and Asia. In these the barbel is better developed than in most other genera, a character which seems to indicate a primitive organization. Barbus mosal of the mountains of India is said to reach a length of more than six feet and to have "scales as large as the palm of the hand."

The Carp and Goldfish.—In the American and European Cyprinidæ the dorsal fin is few-rayed, but in many Asiatic species it is longer, having 15 to 20 rays and is often preceded by a serrated spine like that of a catfish. Of the species with long dorsal the one most celebrated is the carp (Cyprinus carpio). This fish is a native of the rivers of China, where it has been domesticated for centuries. Nearly three hundred years ago it was brought to northern Europe, where it has multiplied in domestication and become naturalized in many streams and ponds. Of late years the cultivation of the carp has attracted much attention in America. It has been generally satisfactory where the nature of the fish is understood and where expectations have not been too high.

The carp is a dull and sluggish fish, preferring shaded, tranquil, and weedy waters with muddy bottoms. Its food consists of water insects and other small animals, and vegetable matter, such as the leaves of aquatic plants. They can be fed on much the same things as pigs and chickens, and they bear much the same relation to trout and bass that pigs and chickens do to wild game and game-birds. The carp is a very hardy fish, grows rapidly, and has immense fecundity, 700,000 eggs having been found in the ovaries of a single individual. It reaches sometimes a weight of 30 to 40 pounds. As a food-fish the carp cannot be said to hold a high place. It is tolerated in the absence of better fish.

The carp, either native or in domestication, has many enemies. In America, catfish, sunfish, and pike prey upon its eggs or its young, as well as water-snakes, turtles, kingfishes, crayfishes, and many other creatures which live about our ponds and in sluggish streams. In domestication numerous varieties of carp have been formed, the "leather-carp" (Lederkarpfen) being scaleless, others, "mirror-carp" (Spiegelkarpfen), having rows of large scales only along the lateral line or the bases of the fins.

Closely allied to the carp is the goldfish (Carassius auratus). This is also a common Chinese fish introduced in domestication into Europe and America. The golden-yellow color is found only in domesticated specimens, and is retained by artificial selection. The native goldfish is olivaceous in color, and where the species has become naturalized (as in the Potomac River, where it has escaped from fountains in Washington) it reverts to its natural greenish hue. The same change occurs in the rivers of Japan. The goldfish is valued solely for its bright colors as an ornamental fish. It has no beauty of form nor any interesting habits, and many of our native fishes (Percidæ, Cyprinidæ) far excel it in attractiveness as aquarium fishes. Unfortunately they are less hardy. Many varieties and monstrosities of the goldfish have been produced by domestication.

Fig. 133.—Lower pharyngeal of Placopharynx duquesnii (Le Sueur).

The Catostomidæ.—The suckers, or Catostomidæ, are an offshoot from the Cyprinidæ, differing chiefly in the structure of the mouth and of the lower pharyngeal bones. The border of the mouth above is formed mesially by the small premaxillaries and laterally by the maxillaries. The teeth of the lower pharyngeals are small and very numerous, arranged in one series like the teeth of a comb. The lips are usually thick and fleshy, and the dorsal fin is more or less elongate (its rays eleven to fifty in number), characters which distinguish the suckers from the American Cyprinidæ generally, but not from those of the Old World.

About sixty species of suckers are known, all of them found in the rivers of North America except two, which have been recorded on rather uncertain authority from Siberia and China. Only two or three of the species extend their range south of the Tropic of Cancer into Mexico or Central America, and none occur in Cuba nor in any of the neighboring islands. The majority of the genera are restricted to the region east of the Rocky Mountains, although species of Catostomus, Chasmistes, Deltistes, Xyrauchen, and Pantosteus are found in abundance in the Great Basin and the Pacific slope.

Fig. 134.—Creekfish or Chub-sucker, Erimyzon sucetta (Lacépède). Nipisink Lake, Illinois. Family Catostomidæ.

In size the suckers range from six inches in length to about three feet. As food-fishes they are held in low esteem, the flesh of all being flavorless and excessively full of small bones. Most of them are sluggish fishes; they inhabit all sorts of streams, lakes, and ponds, but even when in mountain brooks they gather in the eddies and places of greatest depth and least current. They feed on insects and small aquatic animals, and also on mud, taking in their food by suction. They are not very tenacious of life. Most of the species swarm in the spring in shallow waters. In the spawning season they migrate up smaller streams than those otherwise inhabited by them. The large species move from the large rivers into smaller ones; the small brook species go into smaller brooks. In some cases the males in spring develop black or red pigment on the body or fins, and in many cases tubercles similar to those found in the Cyprinidæ appear on the head, body, and anal and caudal fins.

Fig. 135.—Buffalo-fish, Ictiobus cyprinella (Cuv. & Val.). Normal, Ill.

Fig. 136.—Carp-sucker, Carpiodes cyprinus (Le Sueur). Havre de Grace.

The buffalo-fishes and carp-suckers, constituting the genera Ictiobus and Carpiodes, are the largest of the Catostomidæ, and bear a considerable resemblance to the carp. They have the dorsal fin many rayed and the scales large and coarse. They abound in the large rivers and lakes between the Rocky Mountains and the Alleghanies, one species being found in Central America and a species of a closely related genus (Myxocyprinus asiaticus) being reported from eastern Asia. They rarely ascend the smaller rivers except for the purpose of spawning. Although so abundant in the Mississippi Valley as to be of importance commercially, they are very inferior as food-fishes, being coarse and bony. The genus Cycleptus contains the black-horse, or Missouri sucker, a peculiar species with a small head, elongate body, and jet-black coloration, which comes up the smaller rivers tributary to the Mississippi and Ohio in large numbers in the spring. Most of the other suckers belong to the genera Catostomus and Moxostoma, the latter with the large-toothed Placopharynx being known, from the red color of the fins, as red-horse, the former as sucker. Some of the species are very widely distributed, two of them (Catostomus commersoni, Erimyzon sucetta) being found in almost every stream east of the Rocky Mountains and Catostomus catostomus throughout Canada to the Arctic Sea. The most peculiar of the suckers in appearance is the harelip sucker (Quassilabia lacera) of the Western rivers. Very singular in form is the humpback or razor-back sucker of the Colorado, Xyrauchen cypho.

Fig. 137.—Common Sucker, Catostomus commersoni (Le Sueur). Ecorse, Mich.

Fig. 138.—California Sucker, Catostomus occidentalis Agassiz. (Photograph by Cloudsley Rutter.)

Fossil Cyprinidæ.—Fossil Cyprinidæ, closely related to existing forms, are found in abundance in fresh-water deposits of the Tertiary, but rarely if ever earlier than the Miocene. Cyprinus priscus occurs in the Miocene of Germany, perhaps showing that Germany was the original home of the so-called "German carp," afterwards actually imported to Germany from China. Some specimens referred to Barbus, Tinca, Rhodeus, Aspius, and Gobio are found in regions now inhabited by these genera, and many species are referred to the great genus Leuciscus, Leuciscus œningensis from the Miocene of Germany being perhaps the best known. Several species of Leuciscus or related genera are found in the Rocky Mountain region. Among these is the recently described Leuciscus turneri.

Fig. 139.—Pharyngeal teeth of Oregon Sucker, Catostomus macrocheilus.

Fossil Catostomidæ are very few and chiefly referred to the genus Amyzon, supposed to be allied to Erimyzon, but with a longer dorsal. Amyzon commune and other species are found in the Rocky Mountains, especially in the Miocene of the South Park in Colorado and the Eocene of Wyoming. Two or three species of Catostomus, known by their skulls, are found in the Pliocene of Idaho.

Fig. 140.—Razor-back Sucker, Xyrauchen cypho (Lockington). Green River, Utah.

The Loaches.—The Cobitidæ, or loaches, are small fishes, all less than a foot in length, inhabiting streams and ponds of Europe and Asia. In structure they are not very different from minnows, but they are rather eel-like in form, and the numerous long barbels about the mouth strongly suggest affinity with the catfishes. The scales are small, the pharyngeal teeth few, and the air-bladder, as in most small catfishes, enclosed in a capsule. The loaches are all bottom fishes of dark colors, tenacious of life, feeding on insects and worms. The species often bury themselves in mud and sand. They lie quiet on the bottom and move very quickly when disturbed much after the manner of darters and gobies. Species of Cobitis and Misgurnus are widely distributed from England to Japan. Nemachilus barbatulus is the commonest European species. Cobitis tænia is found, almost unchanged, from England to the streams of Japan.

Remains of fossil loaches, mostly indistinguishable from Cobitis, occur in the Miocene and more recent rocks.

From ancestors of loaches or other degraded Cyprinidæ we may trace the descent of the catfishes.

The Homalopteridæ are small loaches in the mountain streams of the East Indies. They have no air-bladder and the number of pharyngeal teeth (10 to 16) is greater than in the loaches, carp, or minnows.

CHAPTER IX
THE NEMATOGNATHI, OR CATFISHES

The Nematognathi.—The Nematognathi (νῆμα, thread; γνάθος, jaw), known collectively as catfishes, are recognized at once by the fact that the rudimentary and usually toothless maxillary is developed as the bony base of a long barbel or feeler. Usually other feelers are found around the head, suggesting the "smellers" of a cat. The body is never scaly, being either naked and smooth or else more or less completely mailed with bony plates which often resemble superficially those of a sturgeon. Other distinctive characters are found in the skeleton, notably the absence of the subopercle, but the peculiar development of the maxillary and its barbel with the absence of scales is always distinctive. The symplectic is usually absent, and in some the air-bladder is reduced to a rudiment inclosed in a bony capsule. In almost all cases a stout spine exists in the front of the dorsal fin and in the front of each pectoral fin. This spine, made of modified or coalescent soft rays, is often a strong weapon with serrated edges and capable of inflicting a severe wound. When the fish is alarmed, it sets this spine by a rotary motion in its socket joint. It can then be depressed only by breaking it. By a rotary motion upward and toward the body the spine is again lowered. The wounds made by this spine are often painful, but this fact is due not to a specific poison but to the irregular cut and to the slime of the spine.

In two genera, Noturus and Schilbeodes, a poison-gland exists at the base of the pectoral spine, and the wound gives a sharp pain like the sting of a hornet and almost exactly like the sting of a scorpion-fish. Most of the Nematognathi possess a fleshy or adipose fin behind the dorsal, exactly as in the salmon. In a few cases the adipose fin develops an anterior spine and occasionally supporting rays.

All the Nematognathi are carnivorous bottom feeders, devouring any prey they can swallow. Only a few enter the sea, and they occur in the greatest abundance in the Amazon region. Upward of 1200 species, arranged in 150 genera, are recorded. They vary greatly in size, from two inches to six feet in length. All are regarded as food-fishes, but the species in the sea have very tough and flavorless flesh. Some of the others are extremely delicate, with finely flavored flesh and a grateful absence of small bones.

Families of Nematognathi.—According to Dr. Eigenmann's scheme of classification,[11] the most primitive family of Nematognathi is that of Diplomystidæ, characterized by the presence of a well-developed maxillary, as in other soft-rayed fishes. The single species, Diplomystes papillosus, is found in the waters of Chile.

11.  A Revision of the South American Nematognathi, 1890, p. 7.

Similar to the Diplomystidæ in all other respects is the great central family of Siluridæ, by far the most numerous and important of all the divisions of Nematognathi.

The Siluridæ.—This group has the skin naked or imperfectly mailed, the barbels on the head well developed, the dorsal short, inserted forward, the adipose fin without spine, and the lower pharyngeals separate. All the marine catfishes and most of the fresh-water species belong to this group, and its members, some 700 species, abound in all parts of the world where catfishes are known—"a bloodthirsty and bullying race of rangers inhabiting the river bottoms with ever a lance at rest and ready to do battle with their nearest neighbor."

The Sea Catfish.—In the tropical seas are numerous species of catfishes belonging to Tachysurus, Arius, Galeichthys, Felichthys, and other related genera. These are sleek, silvery fishes covered with smooth skin, the head usually with a coat of mail, pierced by a central fontanelle. Some of them reach a considerable size, swarming in sandy bays. None are valued as food, being always tough and coarsely flavored. Sea birds, as the pelican, which devour these catfishes are often destroyed by the sudden erection of the pectoral spines. None of these are found in Europe or in Japan. Of the very many American species the gaff-topsail catfish (Felichthys felis), noted for its very high spines, extends farthest north and is one of the very largest species. This genus has two barbels at the chin. Most others have four. The commonest sea catfish of the Carolina coast is Galeichthys milberti. In Tachysurus the teeth on the palate are rounded, in most of the others they are in villiform bands.

Fig. 141.—Gaff-topsail Cat, Felichthys felis (L.). Wood's Hole.

Fig. 142.—Sea Catfish, Galeichthys milberti (Cuv. & Val.). Pensacola.

In most or all of the sea catfish the eggs, as large as small peas, are taken into the mouth of the male and there cared for until hatched.

The Channel Cats.—In all the rivers of North America east of the Rocky Mountains are found catfishes in great variety. The channel cats, Ictalurus, known most readily by the forked tails, are the largest in size and most valued as food. The technical character of the genus is the backward continuation of the supraoccipital, forming a bony bridge to the base of the dorsal. The great blue cat, Ictalurus furcatus, abounds throughout the large rivers of the Southern States and reaches a weight of 150 pounds or more. It is an excellent food and its firm flesh is readily cut into steaks. In the Great Lakes and northward is a very similar species, also of large size, which has been called Ictalurus lacustris. Another similar species is the willow cat, Ictalurus anguilla. The white channel-cat, Ictalurus punctatus, reaches a much smaller size and abounds on the ripples in clear swift streams of the Southwest, such as the Cumberland, the Alabama, and the Gasconade. It is a very delicate food-fish, with tender white flesh of excellent flavor.

Fig. 143.—Channel Catfish, Ictalurus punctatus (Rafinesque). Illinois River. Family Siluridæ.

Horned Pout.—The genus Ameiurus includes the smaller brown catfish, horned pout, or bullhead. The body is more plump and the caudal fin is usually but not always rounded. The many species are widely diffused, abounding in brooks, lakes, and ponds. Ameiurus nebulosus is the best-known species, ranging from New England to Texas, known in the East as horned pout. It has been successfully introduced into the Sacramento, where it abounds, as well as its congener, Ameiurus catus (see Fig. 229, Vol. I), the white bullhead, brought with it from the Potomac. The latter species has a broader head and concave or notched tail. All the species are good food-fishes. All are extremely tenacious of life, and all are alike valued by the urchin, for they will bite vigorously at any sort of bait. All must be handled with care, for the sharp pectoral spines make an ugly cut, a species of wound from which few boys' hands in the catfish region are often free.

Fig. 144.—Horned pout, Ameiurus nebulosus (Le Sueur). (From life by Dr. R. W. Shufeldt.)

In the caves about Conestoga River in Lancaster County, Pennsylvania, is a partly blind catfish, evidently derived from local species outside the cave. It has been named Gronias nigrilabris.

A few species are found in Mexico, one of them, Ictalurus meridionalis, as far south as Rio Usamacinta on the boundary of Guatemala.

Besides these, a large channel-cat of peculiar dentition, known as Istlarius balsanus, abounds in the basin of Rio Balsas. In Mexico all catfishes are known as Bagre, this species as Bagre de Rio.

The genus Leptops includes the great yellow catfish, or goujon, known at once by the projecting lower jaw. It is a mottled olive and yellow fish of repulsive exterior, and it reaches a very great size. It is, however, a good food-fish.

The Mad-toms.—The genera Noturus and Schilbeodes are composed of diminutive catfishes, having the pectoral spine armed at base, with a poison sac which renders its sting extremely painful though not dangerous. The numerous species of this genus, known as "mad-toms" and "stone cats," live among weeds in brooks and sluggish streams. Most of them rarely exceed three inches in length, and their varied colors make them attractive in the aquarium.

Fig. 145.—Mad-tom, Schilbeodes furiosus Jordan & Meek. Showing the poisoned pectoral spine. Family Siluridæ. Neuse River.

The Old World Catfishes.—In the catfishes of the Old World and their relatives, the adipose fin is rudimentary or wanting. The chief species found in Europe is the huge sheatfish, or wels, Silurus glanis. This, next to the sturgeon, is the largest river fish in Europe, weighing 300 to 400 pounds. It is not found in England, France, or Italy, but abounds in the Danube. It is a lazy fish, hiding in the mud and thus escaping from nets. It is very voracious, and many stories are told of the contents of its stomach. A small child swallowed whole is recorded from Thorn, and there are still more remarkable stories, but not properly vouched for. The sheatfish is brown in color, naked, sleek, and much like an American Ameiurus save that its tail is much longer and more eel-like. Another large catfish, known to the ancients, but only recently rediscovered by Agassiz and Garman, is Parasilurus aristotelis of the rivers of Greece. In China and Japan is the very similar Namazu, or Japanese catfish, Parasilurus asotus, often found in ponds and used as food. Numerous smaller related catfishes, Porcus (Bagrus), Pseudobagrus, and related genera swarm in the brooks and ponds of the Orient.

Fig. 146.—Electric Catfish, Torpedo electricus (Gmelin). Congo River. (After Boulenger.)

In the genus Torpedo (Malapterurus) the dorsal fin is wanting. Torpedo electricus, the electric catfish of the Nile, is a species of much interest to anatomists. The shock is like that of a Leyden jar. The structures concerned are noticed on p. 186, Vol. I. The generic name Torpedo was applied to the electric catfish before its use for the electric ray.

In South America a multitude of genera and species cluster around the genus Pimelodus. Some of them have the snout very long and spatulate. Most of them possess a very long adipose fin. The species are generally small in size and with smooth skin like the North American catfishes. Still other species in great numbers are grouped around the genus Doras. In this group the snout projects, bearing the small mouth at its end, and the lateral line is armed behind with spinous shields. All but one of the genera belong to the Amazon district, Synodontis being found in Africa.

Concerning Doras, Dr. Günther observes: "These fishes have excited attention by their habit of traveling during the dry season from a piece of water about to dry up in quest of a pond of greater capacity. These journeys are occasionally of such a length that the fish spends whole nights on the way, and the bands of scaly travelers are sometimes so large that the Indians who happen to meet them fill many baskets of the prey thus placed in their hands. The Indians suppose that the fish carry a supply of water with them, but they have no special organs and can only do so by closing the gill-openings or by retaining a little water between the plates of their bodies, as Hancock supposes. The same naturalist adds that they make regular nests, in which they cover up their eggs with care and defend them, male and female uniting in this parental duty until the eggs are hatched. The nest is constructed, at the beginning of the rainy season, of leaves and is sometimes placed in a hole scooped out of the beach."

The Sisoridæ.—The Sisoridæ are small catfishes found in swift mountain streams of northern India. In some of the genera (Pseudecheneis) in swift streams a sucking-disk formed of longitudinal plates of skin is formed on the breast. This enables these fishes to resist the force of the water. In one genus, Exostoma, plates of skin about the mouth serve the same purpose.

The Bunocephalidæ are South American catfishes with the dorsal fin undeveloped and the top of the head rough. In Platystacus (Aspredo), the eggs are carried on the belly of the female, which is provided with spongy tentacles to which the eggs are attached. After the breeding season the ventral surface becomes again smooth.

The Plotosidæ.—The Plotosidæ are naked catfishes, largely marine, found along the coasts of Asia. In these fishes the second dorsal is very long. Plotosus anguillaris, the sea catfish of Japan, is a small species striped with yellow and armed with sharp pectoral spines which render it a very disagreeable object to the fishermen. In sandy bays like that of Nagasaki it is very abundant. Allied to this is the small Asiatic family of Chacidæ.

The Chlariidæ.—The Chlariidæ are eel-like, with a soft skeleton and a peculiar accessory gill. These abound in the swamps and muddy streams of India, where some species reach a length of six feet. One species, Chlarias magur, has been brought by the Chinese to Hawaii, where it flourishes in the same waters as Ameiurus nebulosus, brought from the Potomac and by Chinese carried from San Francisco.

The Hypophthalmidæ and Pygidiidæ.—The Hypophthalmidæ have the minute air-bladder inclosed in a long bony capsule. The eyes are placed very low and the skin is smooth. The statement that this family lacks the auditory apparatus is not correct. The few species belong to northern South America.

Fig. 147.—An African Catfish, Chlarias breviceps Boulenger. Congo River. Family Chlariidæ. (After Boulenger.)

Allied to this group is the family Pygidiidæ with a differently formed bony capsule and no adipose fin. The numerous species are all South American, mostly of mountain streams of high altitude. Some are very small. Certain species are said to flee for protection into the gill-cavity of larger catfishes. Some are reported to enter the urethra of bathers, causing severe injuries. The resemblance of certain species to the loaches, or Cobitidæ, is very striking. This similarity is due to the results of similar environment and necessarily parallel habits. The Argidæ have the capsule of the air-bladder formed in a still different fashion. The few species are very small, inhabitants of the streams of the high Andes.

The Loricariidæ.—In the family of Loricariidæ the sides and back are armed with rough bony plates. The small air-bladder is still in a bony capsule, and the mouth is small with thick fringed lips. The numerous species are all small fishes of the South American waters, bearing a strong external resemblance to Agonidæ, but wholly different in anatomy.

The Callichthyidæ.—The Callichthyidæ are also small fishes armed with a bony interlocking coat of mail. They are closely allied to the Pygidiidæ. The body is more robust than in the Callichthyidæ and the coat of mail is differently formed. The species swarm in the rivers of northern South America, where with the mailed Loricariidæ they form a conspicuous part of the fish fauna.

Fig. 148.—Loricaria aurea Steindachner, a mailed Catfish from Rio Meta, Venezuela. Family Loricariidæ. (After Steindachner.)

Fossil Catfishes.—Fossil catfishes are very few in number. Siluridæ, allied to Chlarias, Bagarius, Heterobranchus, and other fresh-water forms of India, are found in the late Tertiary rocks of Sumatra, and catfish spines exist in the Tertiary rocks of the United States. Vertebræ in the Canadian Oligocene have been referred by Cope to species of Ameiurus (A. cancellatus and A. maconnelli). Rhineastes peltatus and six other species, perhaps allied to Pimelodus, have been described by Cope from Eocene of Wyoming and Colorado. Bucklandium diluvii is found in the Eocene London clays, and several species apparently marine, referred to the neighborhood of Tachysurus or Arius, are found in Eocene rocks of England.

There is no evidence that the group of catfishes has any great antiquity, or that its members were ever so numerous and varied as at the present time. The group is evidently derived from scaly ancestors, and its peculiarities are due to specialization of certain parts and degeneration of others.

There is not the slightest reason for regarding the catfishes as direct descendants of the sturgeon or other Ganoid type. They should rather be looked upon as a degenerate and highly modified offshoot from the primitive Characins.

Order Gymnonoti.—At the end of the series of Ostariophysans we may place the Gymnonoti (γυμνός, bare; νῶτος, back). This group contains about thirty species of fishes from the rivers of South America and Central America. All are eel-like in form, though the skeleton with the shoulder-girdle suspended from the cranium is quite unlike that of a true eel. There is no dorsal fin. The vent is at the throat and the anal is excessively long. The gill-opening is small as in the eel, and as in most elongate fishes, the ventral fins are undeveloped. The body is naked or covered with small scales.

Two families are recognized, differing widely in appearance. The Electrophoridæ constitutes by itself Cope's order of Glanencheli (γλανίς, catfish; ἔγχελυς, eel). This group he regards as intermediate between the eel-like catfishes (Chlarias) and the true eels. It is naked and eel-shaped, with a short head and projecting lower jaw like that of the true eel. The single species, Electrophorus electricus, inhabits the rivers of Brazil, reaching a length of six feet, and is the most powerful of all electric fishes. Its electric organs on the tail are derived from modified muscular tissue. They are described on p. 170, Vol. I.

The Gymnotidæ are much smaller in size, with compressed scaly bodies and the mouth at the end of a long snout. The numerous species are all fishes without electric organs. Eigenmannia humboldti of the Panama region is a characteristic species. No fossil Gymnonoti are recorded.

CHAPTER X
THE SCYPHOPHORI, HAPLOMI, AND XENOMI

Order Scyphophori.—The Scyphophori (σκύφος, cup; φορέω, to bear) constitutes a small order which lies apparently between the Gymnonoti and the Isospondyli. Boulenger unites it with the Isospondyli. The species, about seventy-five in number, inhabit the rivers of Africa, where they are important as food-fishes. In all there is a deep cavity on each side of the cranium covered by a thin bony plate, the supertemporal bone. There is no symplectic bone, and the subopercle is very small or concealed. The gill-openings are narrow and there are no pharyngeal teeth. The air-bladder connects with the ear, but not apparently in the same way as with the Ostariophysan fishes, to which, however, the Scyphophori are most nearly related. In all the Scyphophori the body is oblong, covered with cycloid scales, the head is naked, there are no barbels, and the small mouth is at the end of a long snout. All the species possess a peculiar organ on the tail, which with reference to a similar structure in Torpedo and Electrophorus is held to be a degenerate electric organ. According to Günther, "it is without electric functions, but evidently representing a transitional condition from muscular substance to an electric organ. It is an oblong capsule divided into numerous compartments by vertical transverse septa and containing a gelatinous substance."

The Mormyridæ.—There are two families of Scyphophori. The Mormyridæ have the ordinary fins and tail of fishes and the Gymnarchidæ are eel-like, with ventrals, anal and caudal wanting. Gymnarchus miloticus of the Nile reaches a length of six feet, and it is remarkable as retaining the cellular structure of the air-bladder as seen in the garpike and bowfin. It doubtless serves as an imperfect lung.

The best-known genus of Scyphophori is Mormyrus. Species of this genus found in the Nile were worshiped as sacred by the ancient Egyptians and pictures of Mormyrus are often seen among the emblematic inscriptions. The Egyptians did not eat the Mormyrus because with two other fishes it was accused of having devoured a limb from the body of Osiris, so that Isis was unable to recover it when she gathered the scattered remains of her husband.

In Mormyrus the bones of the head are covered by skin, the snout is more or less elongated, and the tail is generally short and insignificant. One of the most characteristically eccentric species is Gnathonemus curvirostris, lately discovered by Dr. Boulenger from the Congo. Fossil Mormyridæ are unknown.

Fig. 149.—Gnathonemus curvirostris Boulenger. Family Mormyridæ. Congo River. (After Boulenger.)

The Haplomi.—In the groups called Iniomi and Lyopomi, the mesocoracoid arch is imperfect or wanting, a condition which in some cases may be due to the degeneration produced by deep-sea life. In the eels a similar condition obtains. In the group called Haplomi (ἁπλοός, simple; ὤμος, shoulder), as in all the groups of fishes yet to be discussed, this arch is wholly wanting at all stages of development. In common with the Isospondyli and with soft-rayed fishes in general the air-bladder has a persistent air-duct, all the fins are without true spines, the ventral fins are abdominal, and the scales are cycloid. The group is a transitional one, lying almost equidistant between the Isospondyli and the Acanthopterygii. Gill unites it with the latter and Woodward with the former. We may regard it for the present as a distinct order, although no character of high importance separates it from either. Hay unites the Haplomi with the Synentognathi to form the order of Mesichthyes, or transitional fishes, but the affinities of either with other groups are quite as well marked as their relation to each other. Boulenger unites the Iniomi with the Haplomi, an arrangement which apparently has merit, for the most primitive and non-degenerate Iniomi, as Aulopus and Synodus, lack both mesocoracoid and orbitosphenoid. These bones are characteristic of the Isospondyli, but are wanting in Haplomi.

There is no adipose dorsal in the typical Haplomi, the dorsal is inserted far back, and the head is generally scaly. Most but not all of the species are of small size, living in fresh or brackish water, and they are found in almost all warm regions, though scantily represented in California, Japan, and Polynesia. The four families of typical Haplomi differ considerably from one another and are easily distinguished, although obviously related. Several other families are provisionally added to this group on account of agreement in technical characters, but their actual relationships are uncertain.

The Pikes.—The Esocidæ have the body long and slender and the mouth large, its bones armed with very strong, sharp teeth of different sizes, some of them being movable. The upper jaw is not projectile, and its margin, as in the Salmonidæ, is formed by the maxillary. The scales are small, and the dorsal fin far back and opposite the anal, and the stomach is without pyloric cæca. There is but a single genus, Esox (Lucius of Rafinesque), with about five or six living species. Four of these are North American, the other one being found in Europe, Asia, and North America.

All the pikes are greedy and voracious fishes, very destructive to other species which may happen to be their neighbors; "mere machines for the assimilation of other organisms." Thoreau describes the pike as "the swiftest, wariest, and most ravenous of fishes, which Josselyn calls the river-wolf. It is a solemn, stately, ruminant fish, lurking under the shadow of a lily-pad at noon, with still, circumspect, voracious eye; motionless as a jewel set in water, or moving slowly along to take up its position; darting from time to time at such unlucky fish or frog or insect as comes within its range, and swallowing it at one gulp. Sometimes a striped snake, bound for greener meadows across the stream, ends its undulatory progress in the same receptacle."

Fig. 150.—The Pike, Esox-lucius L. (From life by R. W. Shufeldt.)

As food-fishes, all the Esocidæ rank high. Their flesh is white, fine-grained, disposed in flakes, and of excellent flavor.

The finest of the Esocidæ, a species to be compared, as a grand game fish, with the salmon, is the muskallunge (Esox masquinongy). Technically this species may be known by the fact that its cheeks and opercles are both naked on the lower half. It may be known also by its great size and by its color, young and old being spotted with black on a golden-olive ground.

Fig. 151.—Muskallunge, Esox masquinongy Mitchill. Ecorse, Mich.

The muskallunge is found only in the Great Lake region, where it inhabits the deeper waters, except for a short time in the spring, when it enters the streams to spawn. It often reaches a length of six feet and a weight of sixty to eighty pounds. It is necessarily somewhat rare, for no small locality would furnish food for more than one such giant. It is, says Hallock, "a long, slim, strong, and swift fish, in every way formed for the life it leads, that of a dauntless marauder."

A second species of muskallunge, Esox ohiensis, unspotted but vaguely cross-barred, occurs sparingly in the Ohio River and the upper Mississippi Valley. It is especially abundant in Chautauqua Lake.

The pike (Esox lucius) is smaller than the muskallunge, and is technically best distinguished by the fact that the opercles are naked below, while the cheeks are entirely scaly. The spots and cross-bars in the pike are whitish or yellowish, and always paler than the olive-gray ground color. It is the most widely distributed of all fresh-water fishes, being found from the upper Mississippi Valley, the Great Lakes, and New England to Alaska and throughout northern Asia and Europe. It reaches a weight of ten to twenty pounds or more, being a large strong fish in its way, inferior only to the muskallunge. In England Esox lucius is known as the pike, while its young are called by the diminutive term pickerel. In America the name pickerel is usually given to the smaller species, and sometimes even to Esox lucius itself, the word being with us a synonym for pike, not a diminutive.

Of the small pike or pickerel we have three species in the eastern United States. They are greenish in color and banded or reticulated, rather than spotted, and, in all, the opercles as well as the cheeks are fully covered with scales. One of these (Esox reticulatus) is the common pickerel of the Eastern States, which reaches a respectable size and is excellent as food. The others, Esox americanus along the Atlantic seaboard and Esox vermiculatus in the middle West, seldom exceed a foot in length and are of no economic importance.

Numerous fossil species are found in the Tertiary of Europe, Esox lepidotus from the Miocene of Baden being one of the earliest and the best known; in this species the scales are much larger than in the recent species. The fossil remains would seem to indicate that the origin of the family was in southern Europe, although most of the living species are American.

Fig. 152.—Mud-minnow, Umbra pygmæa (De Kay). New Jersey.

The Mud-minnows.—Close to the pike is the family of Umbridæ, or mud-minnows, which technically differ from the pikes only in the short snout, small mouth, and weak dentition. The mud-minnows are small, sluggish, carnivorous fishes living in the mud at the bottom of cold, clear streams and ponds. They are extremely tenacious of life, though soon suffocated in warm waters. The barred mud-minnow of the prairies of the middle West (Umbra limi) often remains in dried sloughs and bog-holes, and has been sometimes plowed up alive. Umbra pygmæa, a striped species, is found in the Eastern States and Umbra crameri in bogs and brooks along the Danube. This wide break in distribution seems to indicate a former wide extension of the range of Umbridæ, perhaps coextensive with Esox. Fossil Umbridæ are, however, not yet recognized.

The Killifishes.—Most of the recent Haplomi belong to the family of Pœciliidæ (killifishes, or Cyprinodonts). In this group the small mouth is extremely protractile, its margin formed by the premaxillaries alone much as in the spiny-rayed fishes. The teeth are small and of various forms according to the food. In most of the herbivorous forms they are incisor-like, serrate, and loosely inserted in the lips. In the species that eat insects or worms they are more firmly fixed. The head is scaly, the stomach without cæca, and the intestines are long in the plant-eating species and short in the others. There are nearly 200 species, very abundant from New England and California southward to Argentina, and in Asia and Africa also. In regions where rice is produced, they swarm in the rice swamps and ditches. Some of them enter the sea, but none of them go far from shore. Some are brilliantly colored, and in many species the males are quite unlike the females, being smaller and more showy. The largest species (Fundulus, Anableps) rarely reach the length of a foot, while Heterandria formosa, a diminutive inhabitant of the Florida rivers, scarcely reaches an inch. Some species are oviparous, but in most of the herbivorous forms, and some of the others, the eggs are hatched within the body, and the anal in the male is modified into a long sword-shaped intromittent organ, placed farther forward than the anal in the female. The young when born closely resemble the parent. Most of the insectivorous species swim at the surface, moving slowly with the eyes partly out of water. This habit in the genus Anableps (four-eyed fish, or Cuatro ojos) is associated with an extraordinary structure of the eye. This organ is prominent and is divided by a horizontal partition into two parts, the upper, less convex, adopted for sight in the air, the lower in the water. The few species of Anableps are found in tropical America. The species of some genera swim near the bottom, but always in very shallow waters. All are very tenacious of life, and none have any commercial value although the flesh is good.

Fig. 152a.—Four-eyed Fish, Anableps dovii Gill. Tehuantepec, Mexico.

The unique structure of the eye of this curious fish has been carefully studied by Mr. M. C. Marsh, pathologist of the U. S. Fish Commission, who furnishes the following notes published by Evermann & Goldsborough:

"The eye is crossed by a bar, like the diameter of a circle, and parallel with the length of the body. This bar is darker than the other external portions of the eyeball and has its edges darker still. Dividing the external aspect of the eye equally, it has its lower edge on the same level as the back of the fish, which is flat and straight from snout to dorsal, or nearly the whole length of the fish; so that when the body of the fish is just submerged the level of the water reaches to this bar, and the lower half of the eye is in water, the upper half in the air. Upon dissecting the eyeball from the orbit, it appears nearly round. A membranous sheath covers the external part and invests most of the ball. It may be peeled off, when the dark bar on the external portion of the eye is seen to be upon this membrane, which may correspond to the conjunctiva. The back portion of the eyeball being cut off, one lens is found. The lining of the ball consists, in front, of one black layer, evidently choroid. Behind there is a retinal layer. The choroid layer turns up anteriorly, making a free edge comparable to an iris. The free edge is chiefly evident in the lower part of the eye. A large pupil is left, but is divided by two flaps, continuations of the choroid coat, projecting from either side and overlapping. There are properly then two pupils, an upper and lower, separated by a band consisting of the two flaps, which may probably, by moving upward and downward, increase or diminish the size of either pupil; an upward motion of the flaps increasing the lower pupil at the expense of the other, and vice versa."

This division of the pupil into two parts permits the fish, when swimming at the surface of the water, as is its usual custom, to see in the air with the upper portion and in the water with the lower. It is thus able to see not only such insects as are upon the surface of the water or flying in the air above, but also any that may be swimming beneath the surface.

Fig. 153.—Round Minnow, Cyprinodon variegatus Lacépède. St. George Island, Maryland.

According to Mr. E. W. Nelson, "the individuals of this species swim always at the surface and in little schools arranged in platoons or abreast. They always swim headed upstream against the current, and feed upon floating matter which the current brings them. A platoon may be seen in regular formation breasting the current, either making slight headway upstream or merely maintaining their station, and on the qui vive for any suitable food the current may bring. Now and then one may be seen to dart forward, seize a floating food particle, and then resume its place in the platoon. And thus they may be observed feeding for long periods. They are almost invariably found in running water well out in the stream, or at least where the current is strongest and where floating matter is most abundant, for it is upon floating matter that they seem chiefly to depend. They are not known to jump out of the water to catch insects flying in the air or resting upon vegetation above the water surface, nor do they seem to feed to any extent upon all small crustaceans or other portions of the plankton beneath the surface.

Fig. 154.—Everglade Minnow, Jordanella floridæ Goode & Bean. Everglades of Florida.

"When alarmed—and they are wary and very easily frightened—they escape by skipping or jumping over the water, 2 or 3 feet at a skip. They rise entirely out of the water, and at a considerable angle, the head pointing upward. In descending the tail strikes the water first and apparently by a sculling motion new impetus is acquired for another leap. This skipping may continue until the school is widely scattered. When a school has become scattered, and after the cause of their fright has disappeared, the individuals soon rejoin each other. First two will join each other and one by one the others will join them until the whole school is together again. Rarely do they attempt to dive or get beneath the surface; when they do they have great difficulty in keeping under and soon come to the surface again."

Fig. 155.—Mayfish, Fundulus majalis (L.) (male). Wood's Hole.

Fig. 156.—Mayfish, Fundulus majalis (female). Wood's Hole.

Fig. 157.—Top-minnow, Zygonectes notatus (Rafinesque). Eureka Springs, Ark.

Fig. 158.—Death Valley Fish, Empetrichthys merriami Gilbert. Amargosa Desert, Cal. Family Pœciliidæ. (After Gilbert.)

Fig. 159.—Sword-tail Minnow, male, Xiphophorus helleri Heckel. The anal fin modified as an intromittent organ. Vera Cruz.

Of the many genera of Pœciliidæ, top-minnows, and killifishes we may mention the following: Cyprinodon is made up of chubby little fishes of eastern America with tricuspid, incisor teeth, oviparous and omnivorous. Very similar to these but smaller are the species of Lebias in southern Europe. Jordanella floridæ of the Florida everglades is similar, but with the dorsal fin long and its first ray enlarged and spine-like. It strongly resembles a young sunfish. Most of the larger forms belong to Fundulus, a genus widely distributed from Maine to Guatemala and north to Kansas and southern California. Fundulus majalis, the Mayfish of the Atlantic Coast, is the largest of the genus. Fundulus heteroclitus, the killifish, the most abundant. Fundulus diaphanus inhabits sea and lake indiscriminately. Fundulus stellifer of the Alabama is beautifully colored, as is Fundulus zebrinus of the Rio Grande. The genus Zygonectes includes dwarf species similar to Fundulus, and Adinia includes those with short, deep body. Goodea atripinnis with tricuspid teeth lives in warm springs in Mexico, and several species of Goodea, Gambusia, Pœcilia, and other genera inhabit hot springs of Mexico, Central America, and Africa. The genus Gambusia, the top-minnows, includes numerous species with dwarf males having the anal modified. Gambusia affinis abounds in all kinds of sluggish water in the southern lowlands, gutters and even sewers included. It brings forth its brood in early spring. Viviparous and herbivorous with modified anal fin are the species of Pœcilia, abundant throughout Mexico and southward to Brazil; Mollienesia very similar, with a banner-like dorsal fin, showily marked, occurs from Louisiana southward, and Xiphophorus, with a sword-shaped lobe on the caudal, abounds in Mexico; Characodon and Goodea (see Fig. 53, Vol. I) in Mexico have notched teeth, and finally, Heterandria contains some of the least of fishes, the handsomely colored males barely half an inch long.

Fig. 160.—Goodea luitpoldi (Steindachner). A viviparous fish from Lake Patzcuaro, Mexico. Family Pœciliidæ. (After Meek.)

In Lake Titicaca in the high Andes is a peculiar genus (Orestias) without ventral fins. Still more peculiar is Empetrichthys merriami of the desert springs of the hot and rainless Death Valley in California, similar to Orestias, but with enormously enlarged pharyngeals and pharyngeal teeth, an adaptation to some unknown purpose. Fossil Cyprinodonts are not rare from the Miocene in southern Europe. The numerous species are allied to Lebias and Cyprinodon, and are referred to Prolebias and Pachylebias. None are American, although two American extinct genera, Gephyrura and Proballostomus, are probably allied to this group.

Amblyopsidæ.—The cavefishes, Amblyopsidæ, are the most remarkable of the haplomous fishes. In this family the vent is placed at the throat. The form is that of the Pœciliidæ, but the mouth is larger and not protractile. The species are viviparous, the young being born at about the length of a quarter of an inch.

Fig. 161.—Dismal Swamp Fish, Chologaster cornutus Agassiz. Supposed ancestor of Typhlichthys. Virginia.

In the primitive genus Chologaster, the fish of the Dismal Swamp, the eyes are small but normally developed. Chologaster cornutus abounds in the black waters of the Dismal Swamp of Virginia, thence southward through swamps and rice-fields to Okefinokee Swamp in northern Florida. It is a small fish, less than two inches long, striped with black, and with the habit of a top-minnow. Other species of Chologaster, possessing eyes and color, but provided also with tactile papillæ, are found in cave springs in Tennessee and southern Illinois.

Fig. 162.—Blind Cave-fish, Typhlichthys subterraneus Girard. Mammoth Cave, Kentucky.

From Chologaster is directly descended the small blindfish Typhlichthys subterraneus of the caves of the Subcarboniferous limestone rocks of southern Indiana and southward to northern Alabama. As in Chologaster, the ventral fins are wanting. The eyes, present in the young, become defective and useless in the adult, when they are almost hidden by other tissues. The different parts of the eye are all more or less incomplete, being without function. The structure of the eye has been described in much detail in several papers by Dr. Carl H. Eigenmann. As to the cause of the loss of eyesight two chief theories exist—the Lamarckian theory of the inheritance in the species of the results of disuse in the individual and the Weissmannian doctrine that the loss of sight is a result of panmixia or cessation of selection. This may be extended to cover reversal of selection, as in the depths of the great caves the fish without eyes would be at some slight advantage. Dr. Eigenmann inclines to the Lamarckian doctrine, but the evidence brought forward fails to convince the present writer that results of individual use or disuse ever become hereditary or that they are ever incorporated in the characters of a species. In the caves of southern Missouri is an independent case of similar degradation. Troglichthys rosæ, the blindfish of this region, has the eye in a different phase of degeneration. It is thought to be separately descended from some other species of Chologaster. Of this species Mr. Garman and Mr. Eigenmann have given detailed accounts from somewhat different points of view.

Concerning the habits of the blindfish (Troglichthys rosæ), Mr. Garman quotes the following from notes of Miss Ruth Hoppin, of Jasper County, Missouri: "For about two weeks I have been watching a fish taken from a well. I gave him considerable water, changed once a day, and kept him in an uninhabited place subject to as few changes of temperature as possible. He seems perfectly healthy and as lively as when first taken from the well. If not capable of long fasts, he must live on small organisms my eye cannot discern. He is hardly ever still, but moves about the sides of the vessel constantly, down and up, as if needing the air. He never swims through the body of the water away from the sides unless disturbed. Passing the finger over the sides of the vessel under water I find it slippery. I am careful not to disturb this slimy coating when the water is changed.... Numerous tests convince me that it is through the sense of touch, and not through hearing, that the fish is disturbed; I may scream or strike metal bodies together over him as near as possible, yet he seems to take no notice whatever. If I strike the vessel so that the water is set in motion, he darts away from that side through the mass of water, instead of around in his usual way. If I stir the water or touch the fish, no matter how lightly, his actions are the same."

Fig. 163.—Blindfish of the Mammoth Cave, Amblyopsis spelæus (De Kay). Mammoth Cave, Kentucky.

The more famous blindfish of the Mammoth Cave, Amblyopsis spelæus, reaches a length of five inches. It possesses ventral fins. From this fact we may infer its descent from some extinct genus which, unlike Chologaster, retains these fins. The translucent body, as in the other blindfishes, is covered with very delicate tactile papillæ, which form a very delicate organ of touch.

The anomalous position of the vent in Amblyopsidæ occurs again in an equally singular fish, Aphredoderus sayanus, which is found in the same waters throughout the same region in which Chologaster occurs. It would seem as if these lowland fishes of the southern swamps were remains of a once much more extensive fauna.

No fossil allies of Chologaster are known.

Kneriidæ, etc.—The members of the order of Haplomi, recorded above, differ widely among themselves in various details of osteology. There are other families, probably belonging here, which are still more aberrant. Among these are the Kneriidæ, and perhaps the entire series of forms called Iniomi, most of which possess the osteological traits of the Haplomi.

The family of Kneriidæ includes a few very small fishes of the rivers of Africa.

The Galaxiidæ.—The Galaxiidæ are trout-like fishes of the southern rivers, where they take the place of the trout of the northern zones. The species lack the adipose fins and have the dorsal inserted well backward. According to Boulenger these fishes, having no mesocoraoid, should be placed among the Haplomi. Yet their relation to the Haplochitonidæ is very close and both families may really belong to the Isospondyli. Galaxias truttaceus is the kokopu, or "trout," of New Zealand. Galaxias ocellatus is the yarra trout of Australia. Several other species are found in southern Australia, Tasmania, Patagonia, and the Falkland Islands, and even in South Africa. This very wide distribution in the rivers remote from each other has given rise to the suggestion of a former land connection between Australia and Patagonia. Other similar facts have led some geologists to believe in the existence of a former great continent called Antarctica, now submerged except that part which constitutes the present unknown land of the Antarctic.

As intimated on p. 253, Vol. I, this distribution of Galaxias with similar anomalies in other groups could not if unsupported by geological evidence be held to prove the former extension of the Antarctic continent. Dr. Boulenger[12] has recently shown that Galaxias lives freely in salt water, a fact sufficient to account for its wide distribution in the rivers of the southern hemisphere.

12.  Dr. Boulenger (Nature, Nov. 27, 1902) has the following note on Galaxias: "Most text-books and papers discussing geographical distribution have made much of the range of a genus of small fishes, somewhat resembling trout, the Galaxias, commonly described as true fresh-water forms, which have long been known from the extreme south of South America, New Zealand, Tasmania, and southern Australia. The discovery, within the last few years, of a species of the same genus in fresh water near Cape Town, whence it had previously been described as a loach by F. de Castelnau, has added to the interest, and has been adduced as a further argument in support of the former existence of an Antarctic continent. In alluding to this discovery when discussing the distribution of African fresh-water fishes in the introduction to my work 'Les Poissons du Bassin du Congo,' in 1901, I observed that, contrary to the prevailing notion, all species of Galaxias are not confined to fresh water, and that the fact of some living both in the sea and in rivers suffices to explain the curious distribution of the genus; pointing out that in all probability these fishes were formerly more widely distributed in the seas south of the tropic of Capricorn, and that certain species, adapting themselves entirely to fresh-water life, have become localized at the distant points where they are now known to exist. Although as recently as October last the distinguished American ichthyologist D. S. Jordan wrote (Science, xiv, p. 20): 'We know nothing of the power of Galaxias to survive submergence in salt water, if carried in a marine current': it is an established fact, ascertained some years ago by F. E. Clarke in New Zealand and by R. Vallentin in the Falkland Islands, that Galaxias attenuatus lives also in the sea. In New Zealand it periodically descends to the sea, where it spawns, from January to March, and returns from March to May. In accordance with these marine habits, this species has a much wider range than any of the others, being known from Chile, Patagonia, Tierra del Fuego, the Falkland Islands, New Zealand, Tasmania, and southern Australia.

"I now wish to draw attention to a communication made by Captain F. W. Hutton in the last number of the Transactions of the New Zealand Institute (xxxiv, p. 198), 'On a Marine Galaxias from the Auckland Islands.' This fish, named Galaxias bollansi, was taken out of the mouth of a specimen of Merganser australis during the collection excursion to the southern islands of New Zealand made in January, 1901, by His Excellency the Earl of Ranfurly.

"It is hoped that by giving greater publicity to these discoveries the family Galaxiidæ will no longer be included among those strictly confined to fresh waters, and that students of the geographical distribution of animals will be furnished with a clue to a problem that has so often been discussed on insufficient data. As observed by Jordan (l. c.), all anomalies in distribution cease to be such when the facts necessary to understand them are at hand.'

"Of the fresh-water species of Galaxias, eight are known from New Zealand and the neighboring islands, seven from New South Wales, three or four from south Australia, one from west Australia, two from Tasmania, seven from South America, from Chile southwards, and one from the Cape of Good Hope."

Neochanna is an ally of Galaxias living in burrows in the clay or mud like a crayfish, often at a distance from water. As in various other mud-living types, the ventral fins are obsolete.

Order Xenomi.—We must place near the Haplomi the singular group of Xenomi (ξενός, strange; ὤμος, shoulder), regarded by Dr. Gill as a distinct order. Externally these fish much resemble the mud-minnows, differing mainly in the very broad pectorals. But the skeleton is thin and papery, the two coracoids forming a single cartilaginous plate imperfectly divided. The pectorals are attached directly to this without the intervention of actinosts, but in the distal third, according to Dr. Charles H. Gilbert, the coracoid plate begins to break up into a fringe of narrow cartilaginous strips. These about equal the very large number (33 to 36) of pectoral rays, the basal part of each ray being slightly forked to receive the tip of the cartilaginous strip.

Fig. 164.—Alaska Blackfish, Dallia pectoralis (Bean). St. Michaels, Alaska.

"In the deep-sea eels of the order Heteromi there is a somewhat similar condition of the coracoid elements inasmuch as the hypercoracoid and hypocoracoid though present are merely membranous elements surrounded by cartilage and the actinosts are greatly reduced. It seems probable that we are dealing in the two cases with independent degeneration of the shoulder-girdle and that the two groups (Xenomi and Heteromi) are not really related." (Gilbert.)

Of the single family Dalliidæ, one species is known, the Alaska blackfish, Dallia pectoralis.

This animal, formed like a mud-minnow, reaches a length of eight inches and swarms in the bogs and sphagnum swamps of northwestern Alaska and westward through Siberia. It is found in countless numbers according to its discoverer, Mr. L. M. Turner, "wherever there is water enough to wet the skin of a fish," and wherever it occurs it forms the chief food of the natives. Its vitality is most extraordinary. Blackfishes will remain frozen in baskets for weeks and when thawed out are as lively as ever. Turner gives an account of a frozen individual swallowed by a dog which escaped in safety after being thawed out by the heat of the dog's stomach.

CHAPTER XI
ACANTHOPTERYGII; SYNENTOGNATHI

Order Acanthopterygii, the Spiny-rayed Fishes.—The most of the remaining bony fishes constitute a natural group for which the name Acanthopterygii (ἄκανθα, spine; πτερύξ, πτερόν, fin or wing) may be used. This name is often written Actinopteri, a form equally correct and more euphonious and convenient. These fishes are characterized, with numerous exceptions, by the presence of fin spines, by the connection of the ventral fins with the shoulder-girdle, by the presence in general of more than one spine in the anterior part of dorsal and anal fins, and as a rule of one spine and five rays in the ventral fins, and by the absence in the adult of a duct to the air-bladder. Minor characters are these: the pectoral fins are inserted high on the shoulder-girdle, the scales are often ctenoid, and the edge of the upper jaw is formed by the premaxillary alone, the maxillary being always toothless.

But it is impossible to define or limit the group by any single character or group of characters. It is connected with the Malacopterygii through the Haplomi on the one hand by transitional groups of genera which may lack any one of these characters. On the other hand, in the extreme forms, each of these distinctive characters may be lost through degeneration. Thus fin spines, ctenoid scales, and the homocercal tail are lost in the codfishes, the connection of ventrals with shoulder-girdle fails in the Percesoces, etc., and the development of the air-duct is subject to all sorts of variations. In one family even the adipose fin remains through all the changes and modifications the species have undergone.

The various transitional forms between the Haplomi and the perch-like fishes have been from time to time regarded as separate orders. Some of them are more related to the perch, others rather to ancestors of salmon or pike, while still others are degenerate offshoots, far enough from either.

On the whole, all these forms, medium, extreme and transitional, may well be placed in one order, which would include the primitive flying-fishes and mullets, the degraded globefishes, and the specialized flounders. As for the most part these are spiny-rayed fishes, Cuvier's name Acanthopterygii, or Acanthopteri, will serve us as well as any. The Physoclysti of Müller, the Thoracices of older authors, and the Ctenoidei of Agassiz include substantially the same series of forms. The order Teleocephali of Gill (τελεός, perfect; κεφαλή, head) has been lately so restricted as to cover nearly the same ground. In Gill's most recent catalogue of families, the order Teleocephali includes the Haplomi and rejects the Hemibranchii, Lophobranchii, Plectognathi, and Pediculati, all of these being groups characterized by sharply defined but comparatively recent characters not of the highest importance. As originally arranged, the order Teleocephali included the soft-rayed fishes as well. From it the Ostariophysi were first detached, and still later the Isospondyli were regarded by Dr. Gill as a separate order.

We may first take up serially as suborders the principal groups which serve to effect the transition from soft-rayed to spiny-rayed fishes.

Suborder Synentognathi.—Among the transitional forms between the soft-rayed and the spiny-rayed fishes, one of the most important groups is that known as Synentognathi (σύν, together; ἔν, within; γνάθος, jaw). These have, in brief, the fins and shoulder-girdle of Haplomi, the ventral fins abdominal, the dorsal and anal without spines. At the same time, as in the spiny-rayed fishes, the air-bladder is without duct and the pectoral fins are inserted high on the side of the body. With these traits are two others which characterize the group as a suborder. The lower pharyngeal bones are solidly united into one bone and the lateral line forms a raised ridge along the lower side of the body. These forms are structurally allied to the pikes (Haplomi), on the one hand, and to the mullets (Percesoces), on the other, and this relationship accords with their general appearance. In this group as in all the remaining families of fishes, there is no mesocoracoid, and in very nearly all of these families the duct to the air-bladder disappears at an early stage of development.

Fig. 165.—Needle-fish, Tylosurus acus (Lacépède). New York.

The Garfishes: Belonidæ.—There are two principal groups or families among the Synentognathi, the Belonidæ, with strong jaws and teeth, and the Exocœtidæ, in which these structures are feeble. Much more important characters appear in the anatomy. In the Belonidæ the third upper pharyngeal is small, with few teeth, and the maxillary is firmly soldered to the premaxillary. The vertebræ are provided with zygapophyses. The species of Belonidæ are known as garfishes, or needle-fishes. They resemble the garpike in form, but have nothing else in common. The body is long and slender, covered with small scales. Sharp, unequal teeth fill the long jaws and the dorsal is opposite the anal, on the hinder part of the body. These fishes are green in color, even the bones being often bright green, while the scales on the sides have a silvery luster. The species are excellent as food, the green color being associated with nothing deleterious. All are very voracious and some of the larger species, 5 or 6 feet long, may be dangerous even to man. Fishermen have been wounded or killed by the thrust of the sharp snout of a fish springing into the air. The garfishes swim near the surface of the water and often move with great swiftness, frequently leaping from the water. The genus Belone is characterized by the presence of gill-rakers. Belone belone is a small garfish common in southern Europe. Belone platura occurs in Polynesia. The American species (Tylosurus) lack gill-rakers. Tylosurus marinus, the common garfish of the eastern United States, often ascends the rivers. Tylosurus raphidoma, Tylosurus fodiator, Tylosurus acus, and other species are very robust, with short strong jaws. Athlennes hians is a very large fish with the body strongly compressed, almost ribbon-like. It is found in the West Indies and across the Isthmus as far as Hawaii. Many other species, mostly belonging to Tylosurus, abound in the warm seas of all regions. Tylosurus ferox is the long tom of the Australian markets. Potamorrhaphis with the dorsal fin low is found in Brazilian rivers. A few fossil species are referred to Belone, Belone flava from the lower Eocene being the earliest.

The Flying-fishes: Exocœtidæ.—The family of Exocœtidæ includes the flying-fishes and several related forms more or less intermediate between these and the garfishes. In these fishes the teeth are small and nearly equal and the maxillary is separate from the premaxillary. The third upper pharyngeal is much enlarged and there are no zygapophyses to the vertebræ.

The skippers (Scombresox) have slender bodies, pointed jaws, and, like the mackerel, a number of detached finlets behind dorsal and anal, although in other respects they show no affinity to the mackerel. The common skipper, or saury (Scombresox saurus), is found on both shores of the North Atlantic swimming in large schools at the surface of the water, frequently leaping for a little distance like the flying-fish. They are pursued by the mackerel-like fishes, as the tunny or bonito, and sometimes by porpoises. According to Mr. Couch, the skippers, when pursued, "mount to the surface in multitudes and crowd on each other as they press forward. When still more closely pursued, they spring to the height of several feet, leap over each other in singular confusion, and again sink beneath. Still further urged, they mount again and rush along the surface, by repeated starts, for more than one hundred feet, without once dipping beneath or scarcely seeming to touch the water. At last the pursuer springs after them, usually across their course, and again they all disappear together. Amidst such multitudes—for more than twenty thousand have been judged to be out of the water together—some must fall a prey to the enemy; but so many hunting in company, it must be long before the pursuers abandon. From inspection we could scarcely judge the fish to be capable of such flights, for the fins, though numerous, are small, and the pectoral far from large, though the angle of their articulation is well adapted to raise the fish by the direction of their motions to the surface."

A similar species, Cololabis saira, with the snout very much shorter than in the Atlantic skipper, is the Samma of the fishermen of Japan.

The hard-head (Chriodorus atherinoides) has no beak at all and its tricuspid incisor teeth are fitted to feed on plants. In this genus, as in the flying-fishes, there are no finlets. The hard-head is an excellent food-fish abundant about the Florida Keys but not yet seen elsewhere.

Fig. 166.—Saury, Scombresox saurus (L.). Wood's Hole.

Fig. 167.—Halfbeak, Hyporhamphus unifasciatus (Ranzani). Chesapeake Bay.

Another group between the gars and the flying-fishes is that of the halfbeaks, or balaos, Hemirhamphus, etc. These are also vegetable feeders, but with much smaller teeth, and the lower jaw with a spear-like prolongation to which a bright-red membrane is usually attached. Of the halfbeaks there are several genera, all of the species swimming near the surface in schools and sometimes very swiftly. Some of them leap into the air and sail for a short distance like flying-fishes, with which group the halfbeaks are connected by easy gradations. The commonest species along our Atlantic coast is Hyporhamphus unifasciatus; a larger species, Hemirhamphus brasiliensis, abounds about the Florida Keys. Euleptorhamphus longirostris, a ribbon-shaped elongate fish, with long jaw and long pectorals, is taken in the open sea, both in the Atlantic and Pacific, being common in Hawaii. The Asiatic genus Zenarchopterus is viviparous, having the anal fin much modified in the male, forming an intromittent organ, as in the Pœciliidæ. One species occurs in the river mouths in Samoa.

The flying-fishes have both jaws short, and at least the pectoral fins much enlarged, so that the fish may sail in the air for a longer or shorter distance.

Fig. 168.—Sharp-nosed Flying-fish, Fodiator acutus (Val.). Panama.

The smaller species have usually shorter fins and approach more nearly to the halfbeaks. Fodiator acutus, with sharp jaws, and Hemiexocœtus, with a short beak on the lower jaw, are especially intermediate. The flight of the flying-fishes is described in detail on p. 157, Vol. I.

The Catalina flying-fish, Cypselurus californicus, of the shore of southern California is perhaps the largest of the known species, reaching a length of 18 inches. To this genus, Cypselurus, having a long dorsal and short anal, and with ventrals enlarged as well as pectorals, belong all the species strongest in flight, Cypselurus heterurus and furcatus of the Atlantic, Cypselurus simus of Hawaii and Cypselurus agoo in Japan. The very young of most of these species have a long barbel at the chin which is lost with age.

In the genus Exonautes the base of anal fin is long, as long as that of the dorsal. The species of this group, also strong in flight, are widely distributed. Most of the European flying-fishes, as Exonautes rondeleti, Exonautes speculiger, and Exonautes vinciguerræ, belong to this group, while those of Cypselurus mostly inhabit the Pacific. The large Australian species Exonautes unicolor, Fig. 226, Vol. I, belongs to this group. In the restricted genus Exocœtus the ventral fins are short and not used in flight. Exocœtus volitans (evolans) is a small flying-fish, with short ventral fins not used for flight. It is perhaps the most widely distributed of all, ranging through almost all warm seas. Parexocœtus brachypterus, still smaller, and with shorter, grasshopper-like wings, is also very widely distributed. An excellent account of the flying-fishes of the world has been given by Dr. C. F. Lütken (1876), the University of Copenhagen, which institution has received a remarkably fine series from trading-ships returning to that port. Later accounts have been given by Jordan and Meek, and by Jordan and Evermann.

Fig. 169.—Catalina Flying-fish, Cypselurus californicus (Cooper). Santa Barbara.

Very few fossil Exocœtidæ are found. Species of Scombresox and Hemirhamphus are found in the Tertiary, the earliest being Hemirhamphus edwardsi from the Eocene of Monte Bolca. No fossil flying-fishes are known, and the genera, Exocœtus, Exonautes, and Cypselurus are doubtless all of very recent origin.

CHAPTER XII
PERCESOCES AND RHEGNOPTERI

Suborder Percesoces.—In the line of direct ascending transition from the Haplomi and Synentognathi, the pike and flying-fish, towards the typical perch-like forms, we find a number of families, perch-like in essential regards but having the ventral fins abdominal.

These types, represented by the mullet, the silverside, and the barracuda, have been segregated by Cope as an order called Percesoces (Perca, perch; Esox, pike), a name which correctly describes their real affinities. In these typical forms, mullet, silverside, and barracuda, the affinities are plain, but in other transitional forms, as the threadfin and the stickleback, the relationships are less clear. Cope adds to the series of Percesoces the Ophiocephalidæ, which Gill leaves with the Anabantidæ among the spiny-rayed forms. Boulenger adds also the sand-lances (Ammodytidæ) and the threadfins (Polynemidæ), while Woodward places here the Crossognathidæ. In the present work we define the Percesoces so as to include all spiny-rayed fishes in which the ventral fins are naturally abdominal, excepting those having a reduced number of gill-bones, or of actinosts, or other peculiarities of the shoulder-girdle. The Ammodytidæ have no real affinities with the Percesoces. The Crossognathidæ and other families with abdominal ventrals and the dorsal spines wholly obsolete may belong with the Haplomi. Boulenger places the Chiasmodontidæ, the Stromateidæ, and the Tetragonuridæ among the Percesoces, an arrangement of very doubtful validity. In most of the Percesoces the scales are cycloid, the spinous dorsal forms a short separate fin, and in all the air-duct is wanting.

The Silversides: Atherinidæ.—The most primitive of living Percesoces constitute the large family of silversides (Atherinidæ), known as "fishes of the King," Pescados del Rey, Pesce Rey, or Peixe Re, wherever the Spanish or Portuguese languages are spoken. The species are, in general, small and slender fishes of dry and delicate flesh, feeding on small animals. The mouth is small, with feeble teeth. There is no lateral line, the color is translucent green, with usually a broad lateral band of silver. Sometimes this is wanting, and sometimes it is replaced by burnished black. Some of the species live in lakes or rivers, others in bays or arms of the sea, but never at a distance from the shore or in water of more than a few feet in depth. The larger species are much valued as food, the smaller ones, equally delicate, are fried in numbers as "whitebait," but the bones are firmer and more troublesome than in the smelts and young herring. The species of the genus Atherina, known as "friars," or "brit," are chiefly European, although some occur in almost all warm or temperate seas. These are small fishes, with the mouth relatively large and oblique and the scales rather large and firm. Atherina hepsetus and A. presbyter are common in Europe, Atherina stipes in the West Indies, Atherina bleekeri in Japan, and Atherina insularum and A. lacunosa in Polynesia. The genus Chirostoma contains larger species, with projecting lower jaw, abounding in the lakes of Mexico. Chirostoma humboldtianum is very abundant about Mexico City. Like all the other species of this genus it is remarkably excellent as food, the different species constituting the famous "Pescados Blancos" of the great lakes of Chapala and Patzcuaro of the western slope of Mexico. A very unusual circumstance is this: that numerous very closely related species occupy the same waters and are taken in the same nets. In zoology, generally, it is an almost universal rule that very closely related species occupy different geographical areas, their separation being due to barriers which prevent interbreeding. But in the lake of Chapala, near Guadalajara, Prof. John O. Snyder and the present writer, and subsequently Dr. S. E. Meek, found ten distinct species of Chirostoma, all living together, taken in the same nets and scarcely distinguishable except on careful examination. Most of these species are very abundant throughout the lake, and all reach a length of twelve to fifteen inches. These species are Chirostoma estor, Ch. lucius, Ch. sphyræna, Ch. ocotlane, Ch. lermæ, Ch. chapalæ, Ch. grandocule, Ch. labarcæ, Ch. promelas, and Ch. bartoni. A similar assemblage of species nearly all different from these was obtained by Dr. Seth E. Meek in the lake of Patzcuaro, farther south. In this lake were found Ch. attenuatum, Ch. patzcuaro, Ch. humboldtianum, Ch. grandocule, and Ch. estor. The lake of Zirahuen, near Chapala, contains Ch. estor and Ch. zirahuen.

Fig. 170.—Pescado blanco, Chirostoma humboldtianum (Val.). Lake Chalco, City of Mexico.

Fig. 171.—Silverside or Brit, Kirtlandia vagrans (Goode & Bean). Pensacola.

Still another species, Ch. jordani, is found about the city of Mexico, where it is sold baked in corn-husks. Along the coasts of Peru, Chile, and Argentina is found still another assemblage of fishes of the king, with very small scales, constituting the genera Basilichthys and Gastropterus (Pisciregia). Basilichthys microlepidotus is the common Pesca del Rey of Chile. The small silversides, or "brit," of our Atlantic coast belong to numerous species of Menidia, Menidia notata to the northward and Menidia menidia to the southward being most abundant. Kirtlandia laciniata, with ragged scales, is common along the Virginia coast, and K. vagrans farther south. Another small species, very slender and very graceful, is the brook silverside Labidesthes sicculus, which swarms in clear streams from Lake Ontario to Texas. This species, three to four inches long, has the snout produced and a very bright silvery stripe along the side. Large and small species of silversides occur in the sea along the California coast, where they are known familiarly as "blue smelt" or "Peixe Re." The most important of these and the largest member of the family, reaching a length of eighteen inches, is Atherinopsis californiensis, an important food-fish throughout California, everywhere wrongly known as smelt. Atherinops affinis is much like it, but has Y-shaped teeth. Iso flos-maris, called Nami-no-hana, or flower of the surf, is a shining little fish with belly shape like that of a herring. It lives in the surf on the coast of Japan. Melanotænia nigrans of Australia (family Melanotæniidæ) has the lateral band jet-black, as has also Melaniris balsanus of the rivers of southern Mexico. Atherinosoma vorax of Australia has strong teeth like those of a barracuda.

Fig. 172.—Blue Smelt or Pez del Rey, Atherinopsis californiensis Girard. San Diego.

Fig. 173.—Flower of the waves, Iso flos-maxis, Jordan & Starks. Enoshima, Japan.

Fossil species of Atherina occur in the Italian Eocene, the best known being Atherina macrocephala. Another species, Rhamphognathus paralepoides, allied to Menidia, occurs in the Eocene of Monte Bolca.

The Mullets: Mugilidæ.—The mullets (Mugilidæ) are more clumsy in form than the silversides, robust, with broad heads and stouter fin-spines. The ventral fins are abdominal but well forward, the pelvis barely touching the clavicle, a condition to be defined as "subabdominal." The small mouth is armed with very feeble teeth, often reduced to mere fringes. The stomach is muscular like the gizzard of a fowl and the species feed largely on the vegetation contained in mud. There are numerous species, mostly living in shallow bays and estuaries, but some of them are confined to fresh waters. All are valued as food and some of them under favorable conditions are especially excellent.

Most of the species belong to the genera Mugil, the mullet of all English-speaking people, although not at all related to the red mullet or surmullet of the ancient Romans, Mullus barbatus.

The mullets are stoutish fish from one to two feet long, with blunt heads, small mouths almost toothless, large scales, and a general bluish-silvery color often varied by faint blue stripes. The most important species is Mugil cephalus, the common striped mullet. This is found throughout southern Europe and from Cape Cod to Brazil, from Monterey, California, to Chile, and across the Pacific to Hawaii, Japan, and the Red Sea. Among specimens from all these regions we can detect no difference.

Professor Goode gives the following account of its habits:

"The large mullets begin to assemble along the Florida coast in schools in the height of summer, probably preparatory to spawning, and at this time the eggs commence to mature. In this season they swim at the surface, and are then pursued by enemies in the water and the air, and also fall an easy prey to the fishermen. They appear to prefer to swim against the wind, and school best with a northeast wind. They also run against the tide. In Florida the spawning season seems to extend from the middle of November to the middle of January. Some of the fishermen say that they go on the mud-flats and oyster-beds at the mouth of the river to deposit their eggs. What becomes of them after this no one seems to know, but it is probable that they spread themselves over the whole surface of water-covered country in such a manner as not to be perceptible to the fisherman, who makes no effort at this time to secure the spent, lean fish. Many of them probably find their way to the lakes and others remain wherever they find good feeding-ground, gathering flesh and recruiting strength for the great strain of the next spawning season."

Professor Goode informs us that the fishermen recognize "three distinct periods of schooling and separate runs of mullet. To what extent these are founded on tradition, or upon the necessity of change in the size of the mesh of their nets, it is impossible to say. The 'June mullet' average about five to the pound; the 'fat mullet,' which are taken from August 20 to October 1, weigh about two pounds; these have, the fishermen say, a 'roe of fat' on each side as thick as a man's thumb. The 'roe mullet' weigh about two and a half pounds and are caught in November and until Christmas. Between the seasons of 'fat mullet' and 'roe mullet' there is an intermission of two or three weeks in the fishing." Professor Goode hazards the suggestion that "the 'fat mullet' of September are the breeding fish of November, with roes in an immature state, the ova not having become fully differentiated."

The mullet feed on the bottom in quiet water, swimming head downward. The food is sifted over in the mouth, the mud rejected, and the plants, chiefly microscopic, retained. Mr. Silas Stearns compares a school of mullets to barnyard fowls feeding together. When a fish finds a rich spot the others flock about it as chickens do. The pharyngeals form a sort of filter, stopping the sand and mud, the coarse parts being ejected through the mouth. Dr. Günther thus describes this apparatus:

"The upper pharyngeals have a rather irregular form: they are slightly arched, the convexity being directed toward the pharyngeal cavity, tapering anteriorly and broad posteriorly. They are coated with a thick, soft membrane, which reaches far beyond the margin of the bone and is studded all over with minute horny cilia. Each branchial arch is provided with a series of long gill-rakers, which are laterally bent downward, each series closely fitting to the sides of the adjoining arch; they constitute together a sieve admirably adapted to permit a transit for the water, retaining at the same time every solid substance in the cavity of the pharynx."

The young mullet feed in schools and often swim with the head at the surface of the water.

Fig. 174.—Striped Mullet, Mugil cephalus (L.). Wood's Hole, Mass.

We are not able to distinguish from the common striped mullet of Europe and America the mullet of Hawaii, the famous Ama-ama, the most valued of Hawaiian fishes. This species is reared in mullet ponds, made by extending a stone wall across an arm of the sea. Through openings in the wall the young mullet enter, and in its protection they grow very fat on the abundant algæ and other vegetation. They thus become the most plentiful and most esteemed of the market fishes of Honolulu. The Awa (Chanos) and the Awa-awa (Elops) also enter these ponds and are reared with the mullet, being similarly but less valued. Unfortunately the kaku, or small barracuda (Sphyræna helleri), also enters with these helpless fishes and destroys many of the smaller individuals. Another striped species, also very similar to Mugil cephalus in appearance and value, in fact indistinguishable from the Hawaiian mullet, abounds in Japan and India.

The white or unstriped mullets are generally smaller, but otherwise differ little. Mugil curema is the white mullet of tropical America, ranging occasionally northward, and several other species occur in the West Indies and the Mediterranean. The genus Mugil has the eye covered by thick transparent tissue called the adipose eyelid. In Liza the adipose eyelid is wanting. Liza capito, the big-headed mullet of the Mediterranean, is a well-known species. Most of the mullets of the south seas belong to the genus Liza. Liza melinoptera and Liza cæruleomaculata are common in Samoa. The genus Querimana includes dwarf-mullets, two or three inches long, known as whirligig-mullets. These little fishes gather in small schools and swim round and round on the surface like the whirligig-beetles, or Gyrinidæ, their habits being like those of the young mullets; some young mullets having been, in fact, described as species of Querimana. The genus Agonostomus includes fresh-water mullets of the mountain rivers of the East and West Indies and Mexico, locally known as trucha, or trout. Agonostomus nasutus of Mexico is the best-known species.

Fig. 175.—Joturo or Bobo, Joturus pichardi Poey. Rio Bayano, Panama.

The Joturo, or Bobo, Joturus pichardi, is a very large robust and vigorous mullet which abounds at the foot of waterfalls in the mountain torrents of Cuba, eastern Mexico, and Central America. It is a good food-fish, frequently taken about Jalapa, Havana, and on the Isthmus of Panama. Its lips are very thick and its teeth are broad, serrated, loosely inserted incisors.

Fossil mullets are few. Mugil radobojanus is the earliest from the Miocene of Croatia.

The Barracudas: Sphyrænidæ.—The Sphyrænidæ, or barracudas, differ from the mullets in the presence of very strong teeth in the bones of the large mouth. The lateral line is also developed, there is no gizzard, and there are numerous minor modifications connected with the food and habits. The species are long, slender swift fishes, powerful in swimming and voracious to the last degree. Some of the species reach a length of six feet or more, and these are almost as dangerous to bathers as sharks would be. The long, knife-like teeth render them very destructive to nets. The numerous species are placed in the single genus Sphyræna, and some of them are found in all warm seas, where they feed freely on all smaller fishes, their habits in the sea being much like those of the pike in the lakes. The flesh is firm, delicate, and excellent in flavor. In the larger species, especially in the West Indies, it may be difficult of digestion and sometimes causes serious illness, or "ichthyosism."

Fig. 176.—Barracuda, Sphyræna barracuda Walbaum. Florida.

Sphyræna sphyræna is the spet, or sennet, a rather small barracuda common in southern Europe. Sphyræna borealis of our eastern coast is a similar but still feebler species rarely exceeding a foot in length. These and other small species are feeble folk as compared with the great barracuda (Sphyræna barracuda) of the West Indies, a robust savage fish, also known as picuda or becuna. Sphyræna commersoni of Polynesia is a similar large species, while numerous lesser ones occur through the tropical seas. On the California coast Sphyræna argentea is an excellent food-fish, slenderer than the great barracuda but reaching a length of five feet.

Several species of fossil barracuda occur in the Italian Eocene, Sphyræna bolcensis being the earliest.

Stephanoberycidæ.—We may append to the Percesoces, for want of a better place, a small family of the deep sea, its affinities at present unknown. The Stephanoberycidæ have the ventrals I, 5, subabdominal, a single dorsal without spine, and the scales cycloid, scarcely imbricated, each with one or two central spines. The mouth is large, with small teeth, the skull cavernous, as in the berycoids, from which group the normally formed ventrals abdominal in position would seem to exclude it. Stephanoberyx monæ and S. gilli are found at the depth of a mile and a half below the Gulf Stream. Boulenger first placed them with the Percesoces, but more recently suggests their relationship with the Haplomi. Perhaps, as supposed by Gill, they may prove to be degenerate berycoids in which the ventral fins have lost their normal connection.

Crossognathidæ.—A peculiar primitive group referred by Woodward to the Percesoces is the family of Crossognathidæ of the Cretaceous period. As in these fishes there are no fin-spines, they may be perhaps better placed with the Haplomi. The dorsal fin is long, without distinct spines, and the abdominal ventrals have six to eight rays. The mouth is small, with feeble teeth, and the body is elongate and compressed. Crossognathus sabandianum occurs in the Cretaceous of Switzerland and Germany, Syllæmus latifrons and other species in the Colorado Cretaceous, and Syllæmus anglicus in England. The Crossognathidæ have probably the lower pharyngeals separate, else they would be placed among the Synentognathi, a group attached by Woodward, not without reason, to the Percesoces.

Cobitopsidæ.—Near the Crossognathidæ may be placed the extinct Cobitopsidæ, Cobitopsis acuta being recorded from the Oligocene of Puy-de-Dôme in France. In this species there is a short dorsal fin of about seventeen rays, no teeth, and the well-developed ventral fins are not far in front of the anal. This little fish bears a strong resemblance to Ammodytes, but the affinities of the latter genus are certainly with the ophidioid fishes, while the real relationship of Cobitopsis is uncertain.

Fig. 177.—Cobitopsis acuta Gervais, restored. Oligocene of Puy-de-Dôme. (After Woodward.)

Suborder Rhegnopteri.—The threadfins (Polynemidæ) are allied to the mullets, but differ from them and from all other fishes in the structure of the pectoral fin and its basal bones, or actinosts.

Fig. 178.—Shoulder-girdle of a Threadfin, Polydactylus approximans (Lay & Bennett).

Fig. 179.—Threadfin, Polydactylus octonemus (Girard). Pensacola.

The pectoral fin is divided into two parts, the lower composed of free or separate rays very slender and thread-like, sometimes longer than the body. Two of the actinosts of the pectoral support the fin, one is slender and has no rays, while the fourth is plate-like and attached to the coracoids, supporting the pectoral filaments. The body is rather robust, covered with large scales, formed much as in the mullet. The lateral line extends on the caudal fin as in the Sciænidæ which group these fishes resemble in many ways. The mouth is large, inferior, with small teeth. The species are carnivorous fishes of excellent flesh, abounding on sandy shores in the warm seas. They are not very active and not at all voracious. The coloration is bluish and silvery, sometimes striped with black. Most of the species belong to the genus Polydactylus. Polydactylus virginicus, the barbudo, with seven filaments, is common in the West Indies and Florida. Polydactylus octonemus with eight filaments is more rare, but ranges further north. Polydactylus approximans, the raton of western Mexico, with six filaments, reaches San Diego. Polydactylus plebejus is common in Japan and other species range through Polynesia. In India isinglass is made from the large air-bladder of species of Polydactylus. The rare Polynemus quinquarius of the West Indies have five pectoral filaments, these being greatly elongate, much longer than the body.

No extinct Polynemidæ are recorded.

CHAPTER XIII
PHTHINOBRANCHII: HEMIBRANCHII, LOPHOBRANCHII,
AND HYPOSTOMIDES

Fig. 180.—Shoulder-girdle of a Stickleback, Gasterosteus aculeatus Linnæus. (After Parker.)

Fig. 181.—Shoulder-girdle of Fistularia petimba Lacépède, showing greatly extended interclavicle, the surface ossified.

Suborder Hemibranchii.—Still another transitional group, the Hemibranchii, is composed of spiny-rayed fishes with abdominal ventrals. In this suborder there are other points of divergence, though none of high importance. In these fishes the bones of the shoulder-girdle are somewhat distorted, the supraclavicle reduced or wanting, and the gill structures somewhat degenerate. The presence of bones called interclavicles or infraclavicles, below and behind the clavicle, has been supposed to characterize the order of Hemibranchii. But this character has very slight importance. In two families, Macrorhamphosidæ and Centriscidæ, the interclavicles are absent altogether. In the Fistulariidæ they are very large. According to the studies of Mr. Edwin C. Starks, the bone in question is not a true infraclavicle. It is not identical with the infraclavicle of the Ganoids, but it is only a backward extension of the hypocoracoid, there being no suture between the two bones. In those species which have bony plates instead of scales, this bone has a deposit of bony substance or ganoid enamel at the surface. This gives it an apparent prominence as compared with other bones of the skeleton, but it has no great taxonomic importance. Dr. Hay unites the suborders Hemibranchii, Lophobranchii, and Hypostomides to form the order Phthinobranchii (φθινάς, waning; βράγχος, gill), characterized by the reduction of the gill-arches. These forms are really nearly related, but their affinities with the Percesoces are so close that it may not be necessary to form a distinct order of the combined group. Boulenger unites the Hemibranchii with Lampris to form a group, Catosteomi, characterized by the development of infraclavicles; but we cannot see that Lampris bears any affinity to the sticklebacks, or that the presence of infraclavicle has any high significance, nor is it the supposed infraclavicle of Lampris homologous with that of the Hemibranchii. The dorsal fin in the Hemibranchii has more or less developed spines; spines are also present in the ventral fins. The lower pharyngeals are separated; there is no air-duct. The mouth is small and the bones of the snout are often much produced. The preopercle and symplectic are distinct. The group is doubtless derived from some transitional spiny-rayed type allied to the Percesoces. The Lophobranchs, another supposed order, represent simply a still further phase of degradation of gills and ventral fins. Dr. Gill separates these two groups as distinct orders and places them, as aberrant offshoots, near the end of his series of bony fishes. We prefer to leave them with the other transitional forms, not regarding their traits of divergence as of any great importance in the systematic arrangement of families.

The Sticklebacks: Gasterosteidæ.—The sticklebacks (Gasterosteidæ) are small, scaleless fishes, closely related to the Fistulariidæ so far as anatomy is concerned, but with very different appearance and habits. The body often mailed, the dorsal is preceded by free spines and the ventrals are each reduced to a sharp spine with a rudimentary ray. The jaws are short, bristling with sharp teeth, and these little creatures are among the most active, voracious, and persistent of all fishes. They attack the fins of larger fishes, biting off pieces, and at the same time they devour the eggs of all species accessible to them. In almost all fresh and brackish waters of the north temperate zone these little fishes abound. "It is scarcely to be conceived," Dr. Günther observes, "what damage these little fishes do, and how greatly detrimental they are to the increase of all the fishes among which they live, for it is with the utmost industry, sagacity, and greediness that they seek out and destroy all the young fry that come their way."

The sticklebacks inhabit brackish and fresh waters of the northern hemisphere, species essentially alike being found throughout northern Europe, Asia, and America. The same species is subject to great variation. The degree of development of spines and bony plates is greatest in individuals living in the sea and least in clear streams of the interior. Each of the mailed species has its series of half-mailed or even naked varieties found in the fresh waters. This is true in Europe, New England, California, and Japan. The farther the individuals are from the sea, the less perfect is their armature. Thus, Gasterosteus cataphractus, which in the sea has a full armature of bony plates on the side, about 30 in number, will have in river mouths from 6 to 20 plates and in strictly fresh water only 2 or 3 or even none at all.

The sticklebacks have been noted for their nest-building habits. The male performs this operation, and he is provided with a special gland for secretion of the necessary cement. Dr. Gill quotes from Dr. John A. Ryder an account of this process. The secretory gland is a "large vesicle filled with a clear secretion which coagulates into threads upon contact with water. It appears to open directly in front of the vent. As soon as it is ruptured, it loses its transparency, and whatever secretion escapes becomes whitish after being in contact with water for a short time. This has the same tough, elastic qualities as when spun by the animal itself, and is also composed of numerous fibers, as when a portion is taken that has been recently spun upon the nest. Thus provided, when the nuptial season has arrived the male stickleback prepares to build his nest, wherein his mate may deposit her eggs. How this nest is built, and the subsequent proceedings of the sticklebacks, have been told us in a graphic manner by Mr. John K. Lord, from observations on Gasterosteus cataphractus on Vancouver Island, although the source of his secretion was misunderstood:

"The site is generally amongst the stems of aquatic plants, where the water always flows but not too swiftly. He first begins by carrying small bits of green material which he nips off the stalks and tugs from out the bottom and sides of the bank; these he attaches by some glutinous material, that he clearly has the power of secreting, to the different stems destined as pillars for his building. During this operation he swims against the work already done, splashes about, and seems to test its durability and strength; rubs himself against the tiny kind of platform, scrapes the slimy mucus from his sides to mix with and act as mortar for his vegetable bricks. Then he thrusts his nose into the sand at the bottom, and, bringing a mouthful, scatters it over the foundation; this is repeated until enough has been thrown on to weight the slender fabric down and give it substance and stability. Then more twists, turns, and splashings to test the firm adherence of all the materials that are intended to constitute the foundation of the house that has yet to be erected on it. The nest, or nursery, when completed is a hollow, somewhat rounded, barrel-shaped structure worked together much in the same way as the platform fastened to the water-plants; the whole firmly glued together by the viscous secretion scraped from off the body. The inside is made as smooth as possible by a kind of plastering system; the little architect continually goes in, then, turning round and round, works the mucus from his body on to the inner sides of the nest, where it hardens like tough varnish. There are two apertures, smooth and symmetrical as the hole leading into a wren's nest, and not unlike it.

"All this laborious work is done entirely by the male fish, and when completed he goes a-wooing. Watch him as he swims towards a group of the fair sex enjoying themselves amidst the water-plants arrayed in his best and brightest livery, all smiles and amiability; steadily and in the most approved style of stickleback love-making this young and wealthy bachelor approaches the object of his affections, most likely tells her all about his house and its comforts, hints delicately at his readiness and ability to defend her children against every enemy, vows unfailing fidelity, and in lover fashion promises as much in a few minutes as would take a lifetime to fulfill. Of course she listens to his suit; personal beauty, indomitable courage, backed by the substantial recommendations of a house ready built and fitted for immediate occupation, are gifts not to be lightly regarded.

"Throwing herself on her side the captive lady shows her appreciation, and by sundry queer contortions declares herself his true and devoted spouse. Then the twain return to the nest, into which the female at once betakes herself and therein deposits her eggs, emerging, when the operation is completed, by the opposite hole. During the time she is in the nest (about six minutes) the male swims round and round, butts and rubs his nose against it, and altogether appears to be in a state of defiant excitement. On the female leaving, he immediately enters, deposits the milt on the eggs, taking his departure through the back door. So far his conduct is strictly pure; but I am afraid morality in stickleback society is of rather a lax order. No sooner has this lady, his first love, taken her departure, than he at once seeks another, introduces her as he did the first, and so on, wife after wife, until the nest is filled with eggs, layer upon layer, milt being carefully deposited betwixt each stratum of ova. As it is necessary there should be two holes, by which ingress and egress can be readily accomplished, so it is equally essential in another point of view. To fertilize fish-eggs, running water is the first necessity; and, as the holes are invariably placed in the direction of the current, a steady stream of water is thus directed over them."

To the genus Gasterosteus the largest species belong, those having three dorsal spines, and the body typically fully covered with bony plates. Gasterosteus aculeatus inhabits both shores of the Atlantic and the scarcely different Gasterosteus cataphractus swarms in the inlets from southern California to Alaska, Siberia, and northern Japan. Half-naked forms have been called by various names and one entirely naked in streams of southern California is named Gasterosteus williamsoni. Its traits are, however, clearly related to its life in fresh waters.

In Pygosteus pungitius, a type of almost equally wide range, there are nine or ten dorsal spines and the body is more slender. All kinds of waters of the north on both continents may yield this species or its allies and variations, mailed or naked. The naked, Apeltes quadracus, is found in the sea only, along the New England coast.

Fig. 182.—Three-spined Stickleback, Gasterosteus aculeatus L. Wood's Hole, Mass.

Fig. 183.—Four-spined Stickleback, Apeltes quadracus Mitchill. Wood's Hole, Mass.

Eucalia inconstans is the stickleback of the clear brook from New York to Indiana and Minnesota. The male is jet black in spring with the sheen of burnished copper and he is intensely active in his work of protecting the eggs of his own species and destroying the eggs and fry of others. Spinachia spinachia is a large sea stickleback of Europe with many dorsal spines.

No fossil Gasterosteidæ are recorded, and the family, while the least specialized in most regards, is certainly not the most primitive of the suborder.

The Aulorhynchidæ.—Closely related to the sticklebacks is the small family of Aulorhynchidæ, with four soft rays in the ventral fins. Aulorhynchus, like Spinachia, has many dorsal spines and an elongate snout approaching that of a trumpet-fish. Aulorhynchus flavidus lives on the coast of California and Aulichthys japonicus in Japan. The extinct family of Protosyngnathidæ is near Aulorhynchus, with the snout tubular, the ribs free, not anchylosed as in Aulorhynchus, and with the first vertebræ fused, forming one large one as in Aulostomus. Protosyngnathus sumatrensis occurs in Sumatra. Protaulopsis bolcensis of the Eocene of Italy has the ventral fins farther back, and is probably more primitive than the sticklebacks.

Cornet-fishes: Fistulariidæ.—Closely related to the sticklebacks so far as structure is concerned is a family of very different habit, the cornet-fishes, or cornetas (Fistulariidæ). In these fishes the body is very long and slender, like that of a garfish. The snout is produced into a very long tube, which bears the short jaws at the end. The teeth are very small. There are no scales, but bony plates are sunk in the skin. The ventrals are abdominal, each with a spine and four rays. The four anterior vertebræ are very much elongate. There are no spines in the dorsal and the back-bone extends through the forked caudal, ending in a long filament. The cornet-fishes are dull red or dull green in color. They reach a length of two or three feet, and the four or five known species are widely distributed through the warm seas, where they swim in shallow water near the surface. Fistularia tabaccaria, the tobacco-pipe fish, is common in the West Indies, Fistularia petimba, F. serrata, and others in the Pacific. A fossil cornet-fish of very small size, Fistularia longirostris, is known from the Eocene of Monte Bolca, near Verona. Fistularia kœnigi is recorded from the Oligocene of Glarus.

The Trumpet-fishes: Aulostomidæ.—The Aulostomidæ, or trumpet-fishes are in structure entirely similar to the Fistulariidæ, but the body is band-shaped, compressed, and scaly, the long snout bearing the feeble jaws at the end. There are numerous dorsal spines and no filament on the tail. Aulostomus chinensis (maculatus) is common in the West Indies, Aulostomus valentini abounds in Polynesia and Asia, where it is a food-fish of moderate importance. A species of Aulostomus (bolcensis) is found in the Italian Eocene. Allied to it is the extinct family Urosphenidæ, scaleless, but otherwise similar. Urosphen dubia occurs in the Eocene at Monte Bolca. Urosphen is perhaps the most primitive genus of the whole suborder of Hemibranchii.

Fig. 184.—Trumpet-fish, Aulostomus chinensis (L.) Virginia.

The Snipefishes: Macrorhamphosidæ.—Very remarkable fishes are the snipefishes, or Macrorhamphosidæ. In these forms the snout is still tubular, with the short jaws at the end. The body is short and deep, partly covered with bony plates. The dorsal has a very long serrated spine, besides several shorter ones, and the ventral fins have one spine and five rays.

Fig. 185.—Japanese Snipefish, Macrorhamphosus sagifue Jordan & Starks. Misaki, Japan.

The snipefish, or woodcock-fish, Macrorhamphosus scolopax, is rather common on the coasts of Europe, and a very similar species (M. sagifue) occurs in Japan. The Rhamphosidæ, represented by Rhamphosus, an extinct genus with the ventrals further forward, are found in the Eocene rocks of Monte Bolca. Rhamphosus vastrum has minute scales, short dorsal, and the snout greatly attenuate.

The Shrimp-fishes: Centriscidæ.—One of the most extraordinary types of fishes is the small family of Centriscidæ, found in the East Indies. The back is covered by a transparent bony cuirass which extends far beyond the short tail, on which the two dorsal fins are crowded. Anteriorly this cuirass is composed of plates which are soldered to the ribs. The small toothless mouth is at the end of a long snout.

Fig. 186.—Shrimp-fish, Æoliscus strigatus (Günther). Riu Kiu Islands, Japan.

These little fishes with the transparent carapace look very much like shrimps. Centriscus scutatus (Amphisile) with the terminal spine fixed is found in the East Indies, and Æoliscus strigatus with the terminal spine movable is found in southern Japan and southwards.

Fig. 187.—Æoliscus heinrichi Heckel. Eocene of Carpathia. Family Centriscidæ. (After Heckel.)

A fossil species, Æoliscus heinrichi, is found in the Oligocene of various parts of Europe, and Centriscus longirostris occurs in the Eocene of Monte Bolca.

In the Centriscidæ and Macrorhamphosidæ the expansions of the hypocoracoid called infraclavicles are not developed.

The Lophobranchs.—The suborder Lophobranchii (λοφός, tuft; βραγχός, gill) is certainly an offshoot from the Hemibranchii and belongs likewise among the forms transitional from soft to spiny-rayed fishes. At the same time it is a degenerate group, and in its modifications it turns directly away from the general line of specialization.

The chief characters are found in the reduction of the gills to small lobate tufts attached to rudimentary gill-arches. The so-called infraclavicles are present, as in most of the Hemibranchii. Bony plates united to form rings take the place of scales. The long tubular snout bears the short toothless jaws at the end. The preopercle is absent, and the ventrals are seven-rayed or wanting. The species known as pipefishes and sea-horses are all very small and none have any economic value. They are numerous in all warm seas, mostly living in shallow bays among seaweed and eel-grass. The muscular system is little developed and all the species have the curious habit of carrying the eggs until hatched in a pouch of skin under the belly or tail; this structure is usually found in the male.

The Solenostomidæ.—The Solenostomidæ of the East Indies are the most primitive of these fishes. They have the body rather short and provided with spinous dorsal, and ventral fins. The pretty species are occasionally swept northward to Japan in the Black Current. Solenostomus cyanopterus is a characteristic species. Solenorhynchus elegans, now extinct (with the trunk more elongate), preceded Solenostomus in the Eocene of Monte Bolca.

The Pipefishes: Syngnathidæ.—The Syngnathidæ are very long and slender fishes, with neither spinous dorsal, nor ventral fins, the body covered by bony rings. Of the pipefish, Syngnathus, there are very many species on all northern coasts. Syngnathus acus is common in Europe, Syngnathus fuscum along the New England coast, Syngnathus californiense in California, and Syngnathus schlegeli in Japan. Numerous other species of Syngnathus and other genera are found further south in the same regions. Corythroichthys is characteristic of coral reefs and Microphis of the streams of the islands of Polynesia. In general, the more northerly species have the greater number of vertebræ and of bony rings. Tiphle tiphle is a large pipefish of the Mediterranean. This species was preceded by Tiphle albyi (Siphonostoma) in the Miocene of Sicily. Other pipefishes, referred to as Syngnathus and Calamostoma, are found as fossils in Tertiary rocks.

The Sea-horses: Hippocampus.—Both fossil and recent forms constitute a direct line of connection from the pipefishes to the sea-horses. In the latter the head has the form of the head of a horse. It is bent at right angles to the body like the head of a knight at chess. There is no caudal fin, and the tail in typical species is coiled and can hardly be straightened out. Calamostoma of the Eocene, Gasterotokeus of Polynesia, and Acentronura of Japan are forms which connect the true sea-horses with the pipefish. Gasterotokeus has the long head and slender body of the pipefish, with the prehensile finless tail of a sea-horse. Most of the living species of the sea-horse belong to the genus Hippocampus. These little creatures have the egg-sac of the male under the abdomen. They range from two inches to a foot in length and some of the many species may be found in abundance in every warm sea. Some cling by the tails to floating seaweed and are swept to great distances; others cling to eel-grass and live very near the shore. The commonest European species is Hippocampus hippocampus. Most abundant on our Atlantic coast is Hippocampus hudsonius. Hippocampus coronatus is most common in Japan. The largest species are Hippocampus ingens of Lower California and Hippocampus kelloggi in Japan. Many species, especially of the smaller ones, have the spines of the bony plates of the body ending in fleshy flaps. These are sometimes so enlarged as to simulate leaves of seaweed, thus serving for the efficient protection of the species. These flaps are developed to an extreme degree in Phyllopteryx eques, a pipefish of the East Indies.

Fig. 188.—Solenostomus cyanopterus Bleeker. Misaki, Japan.

Fig. 189.—Sea-horse, Hippocampus hudsonius Dekay. Virginia.

No fossil sea-horses are known.

The following account of the breeding-habits of our smallest sea-horse (Hippocampus zosteræ) was prepared by the writer for a book of children's stories:

"He was a little bit of a sea-horse and his name was Hippocampus. He was not more than an inch long, and he had a red stripe on the fin on his back, and his head was made of bone and it had a shape just like a horse's head, but he ran out to a point at his tail, and his head and his tail were all covered with bone. He lived in the Grand Lagoon at Pensacola in Florida, where the water is shallow and warm and there are lots of seaweeds. So he wound his tail around a stem of seaweed and hung with his head down, waiting to see what would happen next, and then he saw another little sea-horse hanging on another seaweed. And the other sea-horse put out a lot of little eggs, and the little eggs all lay on the bottom of the sea at the foot of the seaweed. So Hippocampus crawled down from the seaweed where he was and gathered up all those little eggs, and down on the under side of his tail where the skin is soft he made a long slit for a pocket, and then he stuffed all the eggs into this pocket and fastened it together and stuck it with some slime. So he had all the other sea-horse's eggs in his own pocket.

"Then he went up on the seawrack again and twisted his tail around it, and hung there with his head down to see what would happen next. The sun shone down on him, and by and by all the little eggs began to hatch out, and each one of the eggs was a little sea-pony, shaped just like a sea-horse. And when he hung there with his head down he could feel all the little sea-ponies squirming inside his pocket, and by and by they squirmed so much that they pushed the pocket open, and then every one crawled away from him, and he couldn't get them back, and so he went along with them and watched to see that nothing should hurt them. And by and by they hung themselves all up on the seaweeds, and they are hanging there yet. And so he crawled back to his own piece of seaweed and twisted his tail around it, and waited to see what would happen next. And what happened next was just the same thing over again."

Suborder Hypostomides, the Sea-moths: Pegasidæ.—The small suborder of Hypostomides (ὑπό, below; στόμα, mouth) consists of the family of Pegasidæ. These "sea-moths" are fantastic little fishes, probably allied to the sticklebacks, but wholly unique in form. The slender body is covered with bony plates, the gill-covers are reduced to a single plate. The small mouth underneath a long snout has no teeth. The preopercle and the symplectic are both wanting. The ventrals are abdominal, formed of two rays, and the very large pectoral fin is placed horizontally like a great wing.

Fig 190.—Sea-moth, Zalises umitengu Jordan & Snyder. Misaki, Japan. (View from below.)

The species, few in number, known as sea-moths and sea-dragons, rarely exceed four inches in length. They are found in the East Indies and drift with the currents northward to Japan. The genera are Pegasus, Parapegasus, and Zalises. The best-known species are Zalises draconis and Pegasus volitans.

No fossil species of Pegasidæ are known.

CHAPTER XIV
SALMOPERCÆ AND OTHER TRANSITIONAL
GROUPS

Suborder Salmopercæ, the Trout-perches: Percopsidæ.—More ancient than the Hemibranchii, and still more distinctly in the line of transition from soft-rayed to spiny-rayed fishes, is the small suborder of Salmopercæ. This is characterized by the presence of the adipose fin of the salmon, in connection with the mouth, scales, and fin-spines of a perch. The premaxillary forms the entire edge of the upper jaw, the maxillary being without teeth. The air-bladder retains a rudimentary duct. The bones of the head are full of mucous cavities, as in the European perch called Gymnocephalus and Acerina. There are two spines in the dorsal and one or two in the anal, while the abdominal ventrals have each a spine and eight rays. Two species only are known among living fishes, these emphasizing more perfectly than any other known forms the close relation really existing between spinous and soft-rayed forms. The single family of Percopsidæ would seem to find its place in Cretaceous rocks rather than in the waters of to-day.

Fig. 191.—Sand-roller, Pecropsis guttatus Agassiz. Okoboji Lake, Ia.

Percopsis guttata, the trout-perch or sand-roller of the Great Lakes, is a pale translucent fish with dark spots, reaching a length of six inches. It abounds in the Great Lakes and their tributaries and is occasionally found in the Delaware, Ohio, Kansas, and other rivers and northwestward as far as Medicine Hat on the Saskatchewan. It is easily taken with a hook from the piers at Chicago.

Fig. 192.—Oregon Trout-perch, Columbia transmontana Eigenmann. Umatilla River, Oregon.

Columbia transmontana is another little fish of similar type, but rougher and more distinctly perch-like. It is found in sandy or weedy lagoons throughout the lower basin of the Columbia, where it was first noticed by Dr. Eigenmann in 1892. From the point of view of structure and classification, this left-over form is one of the most remarkable of American fishes.

Fig. 193.—Erismatopterus endlicheri Cope. Green River Eocene. (After Cope.)

Erismatopteridæ.—Here should perhaps be placed the family of Erismatopteridæ, represented by Erismatopterus levatus and other species of the Green River Eocene shales. In Erismatopterus the short dorsal has two or three spines, there are two or three spines in the anal, and the abdominal ventrals are opposite the dorsal. Allied to Erismatopterus is Amphiplaga of the same deposits.

We cannot, however, feel sure that these extinct fragments, however well preserved, belonged to fishes having an adipose fin. Among spiny-rayed fishes the Percopsidæ alone retain this character, and the real affinities of Erismatopterus may be with Aphredoderidæ and other percoid forms.

The relations of the extinct family of Asineopidæ are also still uncertain. This group comprises fresh-water fishes said to be allied to the Aphredoderidæ, but with the pelvic bones not forked. Asineops pauciradiata, squamifrons and viridensis are described from the Green River shales. With Erismatopterus all these fishes may belong to the suborder of Salmopercæ, but, as above stated, the possession of the adipose fin, the most characteristic trait of the Salmopercæ, cannot be verified in the fossil remains.

Fig. 194.—Shoulder-girdle of the Opah, Lampris guttatus (Brünnich), showing the enlarged infraclavicle. (After Boulenger.)

Suborder Selenichthyes, the Opahs: Lamprididæ.—We may bring together as constituting another suborder certain forms of uncertain relationship, but which seem to be transitional between deep-bodied extinct Ganoids and the forms allied to Platax, Zeus, and Antigonia. The name of Selenichthyes (σηλήνη, moon; ἰχθύς, fish) is suggested by Boulenger for the group of opahs, or moonfishes. These are characterized by the highly compressed body, the great development of a large hypocoracoid, and especially by the structure of the ventral fins, which are composed of about fifteen rays instead of the one spine and five rays characteristic of the specialized perch-like fishes. The living forms of this type are further characterized by the partial or total absence of the spinous dorsal, by the small oblique mouth, and the prominence of the ventral curve of the body. A thorough study of the osteology of these forms living and fossil will be necessary before the group can be properly defined. The large bone above mentioned was at first considered by Boulenger as the interclavicle or infraclavicle, the hypocoracoid being regarded by him as displaced, lying with the actinosts. But it is certain, from the studies of Mr. Starks, that this bone is the real hypocoracoid, which in this case is simply exaggerated in size, but placed as in ordinary fishes.

The single living family, Lamprididæ, contains but one species, Lampris guttatus, known as opah, moonfish, mariposa, cravo, Jerusalem haddock, or San Pedro fish. This species reaches a length of six feet and a weight of 500 to 600 pounds. Fig. 199 (Vol. I) is taken from a photograph of an example weighing 317½ pounds taken near Honolulu by Mr. E. L. Berndt. The body is almost as deep as long, plump and smooth, without scales or bony plates. The vertebræ are forty-five in number, and the large ventrals contain about fifteen rays. The dorsal is without spines, the small mouth without teeth. The color is a "rich brocade of silver and lilac, rosy on the belly, everywhere with round silvery spots." The head and back have ultramarine tints, the jaws and fins are vermilion. On a drawing of this fish made at Sable Island in 1856, Mr. James Farquhar wrote (to Dr. J. Bernard Gilpin): "Just imagine the body, a beautiful silver interspersed with spots of a lighter color about the size of sixpence, the eyes very large and brilliant, with a golden ring around them. You will then have some idea of the splendid appearance of the fish when fresh. If Caligula had seen them I might have realized a fortune."

The skeleton of the opah is very firm and heavy. The flesh is of varying shades of salmon-red, tender, oily, and of a rich, exquisite flavor scarcely surpassed by any other fish whatsoever.

The opah is a rare fish, swimming slowly near the surface and ranging very widely in all the warm seas. It was first noticed in Norway by Gunner, the good bishop of Throndhjem, about 1780. It was soon after recorded from Elsinore, Torbay, and Madeira, and is occasionally taken in various places in Europe. It is also recorded from Newfoundland, Sable Island, Cuba, Monterey, San Pedro Point (near San Francisco), Santa Catalina, Honolulu, and Japan.

The specimen studied by the writer came ashore at Monterey in an injured condition, having been worsted in a struggle with some better-armed fish.

Allied to Lampris is the imposing extinct species known as Semiophorus velifer from the Eocene of Monte Bolca near Verona, the type of the extinct family of Semiophoridæ. This is a deep compressed fish, with very high spinous dorsal and very long, many-rayed ventrals. Other related species are known also from the Eocene. There is no evidence of any close relation between these fishes with Caranx or Platax, with which Woodward associates Semiophorus.

The Semiophoridæ differ from the Lamprididæ chiefly in the development of the spinous dorsal fin, which is composed of many slender rays.

Suborder Zeoidea.—Not far from the Selenichthyes and the Berycoidei we may place the singular group of John Dories, or zeoid fishes. These have the ventral fins thoracic and many-rayed, the dorsal fin provided with spines, and the post-temporal, as in the Chætodontidæ, fused with the skull. Dr. Boulenger calls attention to the close relation of these fishes to the flounders, and suggests the possible derivation of both from a synthetic type, the Amphistiidæ, found in the European Eocene. The Amphistiidæ, Zeidæ, and flounders are united by him to form the group or suborder Zeorhombi, characterized by the thoracic ventrals, which have the rays not I, 5 in number, by the progressive degeneration of the fin-spines and the progressive twisting of the cranium, bringing the two eyes to the same side of the head. It is not certain that the flounders are really derived from Zeus-like fishes, but no other guess as to their origin has more elements of probability.

Fig. 195.—Semiophorus velifer Volta. Eocene. (After Agassiz, per Zittel.)

We may, however, regard the Zeoidea on the one hand and the Heterosomata on the other as distinct suborders. This is certain, that the flounders are descended from spiny-rayed forms and that they have no affinities with the codfishes.

Fig. 196.—Amphistium paradoxum Agassiz. Upper Eocene. (Supposed ancestor of the flounders). (After Boulenger.)

Amphistiidæ.—The Amphistiidæ, now extinct, are deep-bodied, compressed fishes, with long, continuous dorsal and anal fins in which a few of the anterior rays are simple, slender spines scarcely differentiated from the soft rays. The form of body and the structure of the fins are essentially as in the flounders, from which they differ chiefly by the symmetry of the head, the eyes being normally placed. Amphistium paradoxum is described by Agassiz from the upper Eocene. It occurs in Italy and France. In its dorsal and anal fins there are about twenty-two rays, the first three or four undivided. The teeth are minute or absent and there is a high supraoccipital crest.

The John Dories: Zeidæ.—The singular family of Zeidæ, or John Dories, agrees with Chætodonts in the single character of the fusion of the post-temporal with the skull. The species, however, diverge widely in other regards, and their ventral fins are essentially those of the Berycoids. In all the species there are seven to nine soft rays in the ventral fins, as in the Berycoid fishes. Probably the character of the fused post-temporal has been independently derived. The anterior vertebræ in Zeus, as in Chætodon, are closely crowded together. In the Zeidæ the spinous dorsal is well developed, the body naked or with very thin scales, and provided with bony warts at least around the bases of dorsal and anal fins. The species are mostly of small size, silvery in color, living in moderate depths in warm seas. The best-known genus is Zeus, which is a group of shore-fishes of the waters of Asia and Europe. The common John Dory (called in Germany Härings-König, or king of the herrings), Zeus faber, abounds in shallow bays on the coasts of Europe. It reaches a length of nearly a foot, and is a striking feature of the markets of southern Europe. The dorsal spines are high, the mouth large, and on the sides is a black ring, said by some to be the mark of the thumb of St. Peter, who is reported to have taken a coin from the mouth of this species. A black spot on several other species is associated with the same legend.

Fig. 197.—The John Dory, Zeus faber. Linnæus. Devon, England.

On the coasts of Japan abounds the Matao, or target-fish (Zeus japonicus), very similar to the European species and like it in form and color. Zenopsis nebulosa and Zen itea also occur on the coasts of Japan. The remaining Zeidæ (Cyttus, Zenopsis, Zenion, etc.) are all rare species occasionally dredged especially in the Australian region. Zeus priscus is recorded from the Tertiary, and Cyttoides glaronensis from the upper Eocene of Glavus.

Grammicolepidæ.—The Grammicolepidæ, represented by a single species, Grammicolepis brachiusculus, rarely taken off the coast of Cuba, is related to the Zeidæ. It has rough, ridged, parchment-like scales deeper than long. The ventrals are thoracic, with the rays in increased number, as in Zeus and Beryx, with each of which it suggests affinity.

CHAPTER XV
BERYCOIDEI

The Berycoid Fishes.—We may place in a separate order a group of fishes, mostly spiny-rayed, which appeared earlier in geological time than any other of the spinous forms, and which in several ways represent the transition from the isospondylous fishes to those of the type of the mackerel and perch. In the berycoid fishes the ventral fins are always thoracic, the number of rays almost always greater than I, 5, and in all cases an orbitosphenoid bone is developed in connection with the septum between the orbits above. This bone is found in the Isospondyli and other primitive fishes, but according to the investigations of Mr. E. C. Starks it is wanting in all percoid and scombroid forms, as well as in the Haplomi and in all the higher fishes. This trait may therefore, among thoracic fishes, be held to define the section or suborder of Berycoidei.

Fig. 198.—Skull of a Berycoid fish, Beryx splendens Cuv. & Val., showing the orbitosphenoid (OS), characteristic of all Berycoid fishes.

These fishes, most primitive of the thoracic types, were more abundant in Cretaceous and Eocene times than now. The possession of an increased number of soft rays in the ventral fins is archaic, although in one family, the Monocentridæ, the number is reduced to three. Most of the living Berycoidei retain through life the archaic duct to the air-bladder characteristic of most abdominal or soft-rayed fishes. In some however, the duct is lost. For the first time in the fish series the number of twenty-four vertebræ appears. In most spiny-rayed fishes of the tropics, of whatever family, this number is retained.

In every case spines are present in the dorsal fin, and in certain cases the development of the spinous dorsal surpasses that of the most extreme perch-like forms. In geological times the Berycoids preceded all other perch-like fishes. They are probably ancestral to all the latter. All the recent species, in spite of high specialization, retain some archaic characters.

The Alfonsinos: Berycidæ.—The typical family, Berycidæ, is composed of fishes of rather deep water, bright scarlet or black in color, with the body short and compressed, the scales varying in the different genera. The single dorsal fin has a few spines in front, and there are no barbels. The suborbitals are not greatly developed.

Fig. 199.—Beryx splendens Lowe. Gulf Stream.

The species of Beryx, called in Spanish Alfonsino, Beryx elegans and Beryx decadactylus, are widely distributed at moderate depths, the same species being recorded from Portugal, Madeira, Cuba, the Gulf Stream, and Japan. The colors are very handsome, being scarlet with streaks of white or golden. These fishes reach the length of a foot or more and are valued as food where sufficiently common.

Numerous species of Beryx and closely allied genera are found in all rocks since Cretaceous times; Beryx dalmaticus, from the Cretaceous of Dalmatia, is perhaps the earliest. Beryx insculptus is found in New Jersey, but no other Berycoids are yet known as fossils from North America. Sphenocephalus, with four anal spines, is found in the chalk, as are also species of Acrogaster and Pycnosterinx, these being the earliest of fishes with distinctly spiny fins.

Fig. 200.—Hoplopteryx lewesiensis (Mantell), restored. English Cretaceous Family Berycidæ. (After Woodward.)

The Trachichthyidæ are deep-sea fishes with short bodies, cavernous skulls, and rough scales. The dorsal is short, with a few spines in front. The suborbitals are very broad, often covering the cheeks, and the anal fin is shorter than the dorsal, a character which separates these fishes from the Berycidæ, in which group the anal fin is very long. The belly has often a serrated edge, and the coloration is red or black, the black species being softer in body and living in deeper water. Species of Hoplostethus, notably Hoplostethus mediterraneus, are found in most seas at a considerable depth. Trachichthys, a genus scarcely distinguishable from Hoplostethus, is found in various seas. The genus Paratrachichthys is remarkable for the anterior position of the vent, much as in Aphredoderus. Species occur in Japan and Australia. Gephyroberyx, with the dorsal fin notched, is known from Japan (G. japonicus) and Madeira (G. darwini).

We may also refer to the Trachichthyidæ certain species of still deeper waters, black in color and still softer in texture, with smaller scales which are often peculiar in form. These constitute the genera Caulolepis, Anoplogaster, Melamphaës, and Plectromus. In Caulolepis the jaws are armed with very strong canines.

Allied to the Trachichthyidæ are also the fossil genera Hoplopteryx and Homonotus. Hoplopteryx lewesiensis, from the English chalk, is one of the earliest of the spiny-rayed fishes.

Fig. 201.—Paratrachichthys prosthemius Jordan & Fowler, Misaki, Japan. Family Trachichthyidæ.

The Soldier-fishes: Holocentridæ.—The soldier-fishes (Holocentridæ), also known as squirrel-fishes, Welshmen, soldados, matajuelos, malau, alehi, etc., are shore fishes very characteristic of rocky banks in the tropical seas. In this family the flesh is firm and the large scales very hard and with very rough edges. There are eleven spines in the dorsal and four in the anal, the third being usually very long. The ventral fins have one spine and seven soft rays. The whole head and body are rough with prickles. The coloration is always brilliant, the ground hue being scarlet or crimson, often with lines or stripes of white, black, or golden. The fishes are valued as food, and they furnish a large part of the beauty of coloration so characteristic of the fishes of the coral reefs. The species are active, pugnacious, carnivorous, but not especially voracious, the mouth being usually small.

Fig. 202.—Soldier-fish, Holocentrus ascenscionis (Osbeck).

Fig. 203.—Soldier-fish, Holocentrus ittodai Jordan & Fowler. Riu Kiu Islands, Japan.

The genus Holocentrus is characterized by the presence of a large spine on the angle of the preopercle. Its species are especially numerous, Holocentrus ascenscionis, abundant in Cuba, ranges northward in the Gulf Stream. Holocentrus suborbitalis, the mojarra cardenal, is a small, relatively dull species swarming about the rocks of western Mexico. Holocentrus spinosissimus is a characteristic fish of Japan. Many other species abound throughout Polynesia and the East Indies, as well as in tropical America. Holocentrus ruber and Holocentrus diadema are common species of Polynesia and the East Indies. Other abundant species are H. spinifer, H. microstomus, and H. violascens.

Holocentrus marianus is the marian of the French West Indies. Holocentrus sammara, and related large-mouthed species occur in Polynesia.

Fig. 204.—Ostichthys japonicus (Cuv. & Val.). Giran, Formosa.

In Myripristis the preopercular spine is wanting and the air-bladder is divided into two parts, the anterior extending to the ear. Myripristis jacobus is the brilliantly colored candil, or "Frère Jacques," of the West Indies. Species of Myripristis are known in Hawaii as u-u. A curious method of catching Myripristis murdjan is pursued on the Island of Hawaii. A living fish is suspended by a cord in front of a reef inhabited by this species. It remains with scarlet fins spread and glistening red scales. Its presence is a challenge to other individuals, who rush out to attack it. These are then drawn out by a concealed scoop-net, and a fresh specimen is taken as a decoy. Myripristis pralinius, M. multiradiatus, and other species occur in Polynesia. Ostichthys is allied to Myripristis but with very large rough scales. Ostichthys japonicus is a large and showy fish of the waters of Japan. Ostichthys pillwaxi occurs at Honolulu. Holotrachys lima is a small, brick-red fish with small very rough scales found throughout Polynesia.

Fossil species of Holocentrus, Myripristis, and related extinct genera occur in the Eocene and Miocene. Holocentrus macrocephalus, from Monte Bolca Eocene, is one of the best known. Myricanthus leptacanthus from the same region, has very slender spines in the fins.

Fig. 205.—Pine-cone Fish, Monocentris japonicus (Houttuyn). Waka, Japan.

The Polymixiidæ.—The family of Polymixiidæ, or barbudos, is one of the most interesting in Ichthyology from its bewildering combination of characters belonging to different groups. With the general aspect of a Berycoid, the ventral rays I, 7, and the single dorsal fin with a few spines, Polymixia has the scales rather smooth and at the chin are two long barbels which look remarkably like those of the family of Mullidæ or Surmullets. As in the Mullidæ, there are but four branchiostegals. In other regards the two groups seem to have little in common. According to Starks, the specialized feelers at the chin are different in structure and must have been independently developed in the two groups. In Polymixia, each barbel is suspended from the hypohyal; three rudimentary branchiostegals forming its thickened base. In Mullus, each barbel is suspended from the trip of a slender projection of the ceratohyal, having no connection with the branchiostegals. Polymixia possesses the orbitosphenoid bone and is a true berycoid, while the Mullidæ are genuine percoid fishes.

Four species of Polymixia are recorded from rather deep water: Polymixia nobilis from Madeira, Polymixia lowei from the West Indies, Polymixia berndti from Hawaii, and Polymixia japonica from Japan. All are plainly colored, without red.

The Pine-cone Fishes: Monocentridæ.—Among the most extraordinary of all fishes is the little family of Monocentridæ, or pine-cone fishes. Monocentris japonicus, the best-known species, is common on the coasts of Japan. It reaches the length of five inches. The body is covered with a coat of mail, made of rough plates which look as though carelessly put together. The dorsal spines are very strong, and each ventral fin is replaced by a very strong rough spine. The animal fully justifies the remark of its discoverer, Houttuyn (1782), that it is "the most remarkable fish which exists." It is dull golden brown in color, and in movement as sluggish as a trunkfish. A similar species, called knightfish, Monocentris gloriæ-maris, is found in Australia. No fossils allied to Monocentris are known.

CHAPTER XVI
PERCOMORPHI

Suborder Percomorphi, the Mackerels and Perches.—We may place in a single suborder the various groups of fishes which cluster about the perches, and the mackerels. The group is not easily definable and may contain heterogeneous elements. We may, however, arrange in it, for our present purposes, those spiny-rayed fishes having the ventral fins thoracic, of one spine and five rays (the ventral fin occasionally wanting or defective, having a reduced number of rays), the lower pharyngeal bones separate, the suborbital chain without backward extension or bony stay, the post-temporal normally developed and separate from the cranium, the premaxillary and maxillary distinct, the cranium itself without orbitosphenoid bone, having a structure not greatly unlike that of perch or mackerel, and the back-bone primitively of twenty-four vertebræ, the number increased in arctic, pelagic, or fresh-water offshoots.

The species, comprising the great body of the spiny-rayed forms, group themselves chiefly about two central families, the Scombridæ, or mackerels, and the Serranidæ, the sea-bass, with their fresh-water allies, the Percidæ, or perch.

The Mackerel Tribe: Scombroidea.—The two groups of Percomorphi, the mackerel-like and the perch-like, admit of no exact definition, as the one fully grades into the other. The mackerel-like forms, or Scombroidea, as a whole are defined by their adaptation for swift movement. The profile is sharp anteriorly, the tail slender, with widely forked caudal; the scales are usually small, thin, and smooth, of such a character as not to produce friction in the water.

In general the external surface is smooth, the skeleton light and strong, the muscles firm, and the species are carnivorous and predaceous. But among the multitude of forms are many variations, and some of these will seem to be exceptions to any definition of mackerel-like fishes which could possibly be framed.

The mackerels, or Scombroidea, have usually the tail very slender, composed of very strong bones, with widely forked fin. In the perch and bass the tail is stout, composed largely of flesh, the supporting vertebræ relatively small and spread out fan-fashion behind. Neither mackerels nor perch nor any of their near allies ever have more than five soft rays in the ventral fins, and the persistence of this number throughout the Percomorphi, Squamipinnes, Pharyngognathi, and spiny fishes generally must be attributed to inheritance from the primitive perch-like or mackerel-like forms. In almost all the groups to be considered in this work, after the Berycoidea the ventral rays are I, 5, or else fewer through degeneration, never more. In the central or primitive members of most of these groups there are twenty-four vertebræ, the number increased in certain forms, probably through repetitive degeneration.

The True Mackerels: Scombridæ.—We may first consider the great central family of Scombridæ, or true mackerels, distinguished among related families by their swift forms, smooth scales, metallic coloration, and technically by the presence of a number of detached finlets behind the dorsal and anal fins. The cut of the mouth is peculiar, the spines in the fins are feeble, the muscular system is extremely strong, the flesh oily, and the air-bladder reduced in size or altogether wanting. As in most swift-swimming fishes and fishes of pelagic habit, the vertebræ are numerous and relatively small, an arrangement which promotes flexibility of body. It is not likely that this group is the most primitive of the scombroid fishes. In some respects the Stromateidæ stand nearer the primitive stock. The true mackerels, however, furnish the most convenient point of departure in reviewing the great group.

In the genus of true mackerels, Scomber, the dorsal fins are well separated, the first being rather short, and the scales of the shoulders are not modified to form a corselet. There are numerous species, two of them of general interest. The common mackerel, Scomber scombrus, is one of the best known of food-fishes. It is probably confined to the Atlantic, where on both shores it runs in vast schools, the movements varying greatly from season to season, the preference being for cool waters. The female mackerel produces about 500,000 eggs each year, according to Professor Goode. These are very minute and each is provided with an oil-globule, which causes it to float on the surface. About 400,000 barrels of mackerel are salted yearly by the mackerel fleet of Massachusetts. Single schools of mackerel, estimated to contain a million barrels, have been recorded. Captain Harding describes such a school as "a windrow of fish half a mile wide and twenty miles long."

Fig. 206.—Mackerel, Scomber scombrus L. New York.

Professor Goode writes:

"Upon the abundance of mackerel depends the welfare of many thousands of the citizens of Massachusetts and Maine. The success of the mackerel-fishery is much more uncertain than that of the cod-fishery, for instance, for the supply of cod is quite uniform from year to year. The prospects of each season are eagerly discussed from week to week in thousands of little circles along the coast, and are chronicled by the local press. The story of each successful trip is passed from mouth to mouth, and is a matter of general congratulation in each fishing community. A review of the results of the American mackerel-fishery, and of the movements of the fish in each part of the season, would be an important contribution to the literature of the American fisheries.

"The mackerel-fishery is peculiarly American, and its history is full of romance. There are no finer vessels afloat than the American mackerel-schooners—yachts of great speed and unsurpassed for seaworthiness. The modern instruments of capture are marvels of inventive skill, and require the highest degree of energy and intelligence on the part of the fishermen. The crews of the mackerel-schooners are still for the most part Americans of the old colonial stock, although the cod and halibut fisheries are to a great extent given up to foreigners.

"When the mackerel is caught, trout, bass, and sheepshead cannot vanquish him in a gastronomic tournament. In Holland, to be sure, the mackerel is not prized, and is accused of tasting like rancid fish-oil, and in England, even, they are usually lean and dry, like the wretched skeletons which are brought to market in April and May by the southern fleet, which goes forth in the early spring from Massachusetts to intercept the schools as they approach the coasts of Carolina and Virginia. They are not worthy of the name of mackerel. Scomber Scombrus is not properly in season until the spawning time is over, when the schools begin to feed at the surface in the Gulf of Maine and the 'North Bay.'

"Just from the water, fat enough to broil in its own drippings, or slightly corned in strong brine, caught at night and eaten in the morning, a mackerel or a bluefish is unsurpassable. A well-cured autumn mackerel is perhaps the finest of all salted fish, but in these days of wholesale capture by the purse-seine, hasty dressing and careless handling, it is very difficult to obtain a sweet and sound salt mackerel. Salt mackerel may be boiled as well as broiled, and a fresh mackerel may be cooked in the same manner. Americans will usually prefer to do without the sauce of fennel and gooseberry which transatlantic cooks recommend. Fresh and salt, fat and lean, new or stale, mackerel are consumed by Americans in immense quantities, as the statistics show, and whatever their state, always find ready sale."

Smaller, less important, less useful, but far more widely distributed is the chub-mackerel, or thimble-eyed mackerel, Scomber japonicus (Houttuyn, 1782), usually known by the later name of Scomber colias (Gmelin, 1788). In this species the air-bladder (absent in the common mackerel) is moderately developed. It very much resembles the true mackerel, but is of smaller size, less excellence as a food-fish, and keeps nearer to the shore. It may be usually distinguished by the presence of vague, dull-gray spots on the sides, where the true mackerel is lustrous silvery.

This fish is common in the Mediterranean, along our Atlantic coast, on the coast of California, and everywhere in Japan.

Scomber antarcticus is the familiar mackerel of Australia. Scomber loo, silvery, with round black spots, is the common mackerel of the South Seas, locally known as Ga.

Scomber priscus is a fossil mackerel from the Eocene.

Auxis thazard, the frigate mackerel, has the scales of the shoulders enlarged and somewhat coalescent, forming what is called a corselet. The species ranges widely through the seas of the world in great numbers, but very erratic, sometimes myriads reaching our Eastern coast, then none seen for years. It is more constant in its visits to Japan and Hawaii. Fossil species of Auxis are found in the Miocene.

The genus Gymnosarda has the corselet as in Auxis, but the first dorsal fin is long, extending backward to the base of the second. Its two species, Gymnosarda pelamis, the Oceanic bonito, and Gymnosarda alleterata, the little tunny, are found in all warm seas, being especially abundant in the Mediterranean, about Hawaii and Japan. These are plump fish of moderate size, with very red and very oily flesh.

Closely related to these is the great tunny, or Tuna (Thunnus thynnus) found in all warm seas and reaching at times a weight of 1500 pounds. These enormous fishes are much valued by anglers, a popular "Tuna Club" devoted to the sport of catching them with a hook having its headquarters at Avalon, on Santa Catalina Island, in California. They are good food, although the flesh of the large ones is very oily. The name horse-mackerel is often given to these monsters on the New England coast. In California, the Spanish name of tuna has become current among fisherman.

Very similar to the tuna, but much smaller, is the Albacore (Germo alalonga). This reaches a weight of fifteen to thirty pounds, and is known by its very long, almost ribbon-like pectoral fins. This species is common in the Mediterranean, and about the Santa Barbara Islands, where it runs in great schools in March. The flesh of the albacore is of little value, unless, as in Japan, it is eaten raw. The Japanese shibi (Germo germo) is another large albacore, having the finlets bright yellow. It is found also at Hawaii.

The bonito (Sarda sarda) wanders far throughout the Atlantic, abounding on our Atlantic coast as in the Mediterranean, coming inshore in summer to spawn or feed. Its flesh is red and not very delicate, though it may be reckoned as a fair food-fish. It is often served under the name of "Spanish mackerel" to the injury of the reputation of the better fish.

Fig. 207.—The Long-fin Albacore, Germo alalunga (Gmelin). Gulf Stream.

Professor Goode writes:

"One of these fishes is a marvel of beauty and strength. Every line in its contour is suggestive of swift motion. The head is shaped like a minie bullet, the jaws fit together so tightly that a knife-edge could scarcely pass between, the eyes are hard, smooth, their surfaces on a perfect level with the adjoining surfaces. The shoulders are heavy and strong, the contours of the powerful masses of muscle gently and evenly merging into the straighter lines in which the contour of the body slopes back to the tail. The dorsal fin is placed in a groove into which it is received, like the blade of a clasp-knife in its handle. The pectoral and ventral fins also fit into depressions in the sides of the fish. Above and below, on the posterior third of the body, are placed the little finlets, each a little rudder with independent motions of its own, by which the course of the fish may be readily steered. The tail itself is a crescent-shaped oar, without flesh, almost without scales, composed of bundles of rays flexible, yet almost as hard as ivory. A single sweep of this powerful oar doubtless suffices to propel the bonito a hundred yards, for the polished surfaces of its body can offer little resistance to the water. I have seen a common dolphin swimming round and round a steamship, advancing at the rate of twelve knots an hour, the effort being hardly perceptible. The wild duck is said to fly seventy miles in an hour. Who can calculate the speed of the bonito? It might be done by the aid of the electrical contrivances by which is calculated the initial velocity of a projectile. The bonitoes in our sounds to-day may have been passing Cape Colony or the Land of Fire day before yesterday."

Another bonito, Sarda chilensis, is common in California; in Chile, and in Japan. This species has fewer dorsal spines than the bonito of the Atlantic, but the same size, coloration, and flesh. Both are blue, with undulating black stripes along the side of the back.

The genus Scomberomorus includes mackerels slenderer in form, with larger teeth, no corselet, and the flesh comparatively pale and free from oil.

Fig. 208.—The Spanish Mackerel, Scomberomorus maculatus (Mitchill). New York.

Scomberomorus maculatus, the Spanish mackerel of the West Indies, is one of the noblest of food-fishes. Its biography was written by Mitchill almost a century ago in these words:

"A fine and beautiful fish; comes in July."

Goode thus writes of it:

"The Spanish mackerel is surely one of the most graceful of fishes. It appeals as scarcely any other can to our love of beauty, when we look upon it, as shown in Kilbourn's well-known painting, darting like an arrow just shot from the bow, its burnished sides, silver flecked with gold, thrown into bold relief by the cool green background of the rippled sea; the transparent grays, opalescent whites, and glossy blacks of its trembling fins enhance the metallic splendor of its body, until it seems to rival the most brilliant of tropical birds. Kilbourn made copies of his large painting on the pearly linings of seashells and produced some wonderful effects by allowing the natural luster of the mother-of-pearl to show through his transparent pigments and simulate the brilliancy of the life-inspired hues of the quivering, darting sea-sprite, whose charms even his potent brush could not properly depict.

"It is a lover of the sun, a fish of tropical nature, which comes to us only in midsummer, and which disappears with the approach of cold, to some region not yet explored by ichthyologists. It is doubtless very familiar in winter to the inhabitants of some region adjacent to the waters of the Caribbean or the tropical Atlantic, but until this place shall have been discovered it is more satisfactory to suppose that with the bluefish and the mackerel it inhabits that hypothetical winter resort to which we send the migratory fishes whose habits we do not understand—the middle strata of the ocean, the floating beds of Sargassum, which drift hither and thither under the alternate promptings of the Gulf-stream currents and the winter winds."

The Spanish mackerel swims at the surface in moderate schools and is caught in abundance from Cape May southward. Its white flesh is most delicious, when properly grilled, and Spanish mackerel, like pampano, should be cooked in no other way.

A very similar species, Scomberomorus sierra, occurs on the west coast of Mexico. For some reason it is little valued as food by the Mexicans. In California, the Monterey Spanish mackerel (Scomberomorus concolor) is equally excellent as a food-fish. This fish lacks the spots characteristic of most of its relatives. It was first found in the Bay of Monterey, especially at Santa Cruz and Soquel, in abundance in the autumn of 1879 and 1880. It has not, so far as is known, been seen since, nor is the species recorded from any other coast.

The true Spanish mackerel has round, bronze-black spots upon its sides. Almost exactly like it in appearance is the pintado, or sierra (Scomberomorus regalis), but in this species the spots are oblong in form. The pintado abounds in the West Indies. Its flesh is less delicate than that of the more true Spanish mackerel. The name sierra, saw, commonly applied to these fishes by Spanish-speaking people, has been corrupted into cero in some books on angling.

Still other Spanish mackerel of several species occur on the coasts of India, Chile, and Japan.

The great kingfish, or cavalla (Scomberomorus cavalla), is a huge Spanish mackerel of Cuba and the West Indies, reaching a weight of 100 pounds. It is dark iron-gray in color, one of the best of food-fishes, and is unspotted, and its firm, rich flesh resembles that of the barracuda.

Still larger is the great guahu, or peto, an immense sharp-nosed, swift-swimming mackerel found in the East and West Indies, as well as in Polynesia, reaching a length of six feet and a weight of more than a hundred pounds. Its large knife-like teeth are serrated on the edge and the color is almost black. Acanthocybium solandri is the species found in Hawaii and Japan. The American Acanthocybium petus, occasionally also taken in the Mediterranean, may be the same species.

Fossil Spanish mackerels, tunnies, and albacores, as well as representatives of related genera now extinct, abound in the Eocene and Miocene, especially in northern Italy. Among them are Scomber antiquus from the Miocene, Scombrinus macropomus from the Eocene London clays, much like Scomber, but with stronger teeth, Sphyrænodus priscus from the same deposits, the teeth still larger, Scombramphodon crossidens, from the same deposits, also with strong teeth, like those of Scomberomorus. Scomberomorus is the best represented of all the genera as fossil, Scomberomorus speciosus and numerous other species occurring in the Eocene. A fossil species of Germo, G. lanceolatus, occurs at Monte Bolca in Eocene rocks. Another tunny, with very small teeth is Eothynnus salmonens, from the lower Eocene near London. Several other tunny-like fishes occur in the lower Tertiary.

The Escolars: Gempylidæ.—More predaceous than the mackerels and tunnies are the pelagic mackerels, Gempylidæ, known as escolars ("scholars"), with the body almost band-shaped and the teeth very large and sharp. Some of these, from the ocean depths, are violet-black in color, those near the surface being silvery. Escolar violaceus lives in the abysses of the Gulf Stream. Ruvettus pretiosus, the black escolar, lives in more moderate depths and is often taken in Cuba, Madeira, Hawaii, and Japan. It is a very large fish, black, with very rough scales. The flesh is white, soft, and full of oil; sometimes rated very high, and at other times too rank to be edible. The name escolar means scholar in Spanish, but its root meaning, as applied to this fish, comes from a word meaning to scour, in allusion to the very rough scales.

Promethichthys prometheus, the rabbit-fish, or conejo, so-called from its wariness, is caught in the same regions, being especially common about Madeira and Hawaii. Gempylus serpens, the snake-mackerel, is a still slenderer and more voracious fish of the open seas. Thyrsites atun is the Australian "barracuda," a valued food-fish, voracious and predaceous.

Scabbard-and Cutlass-fishes: Lepidopidæ and Trichiuridæ.—The family of Lepidopidæ, or scabbard-fishes, includes degenerate mackerels, band-shaped, with continuous dorsal fin, and the long jaws armed with very small teeth. These are found in the open sea, Lepidopus candatus being the most common. This species reaches a length of five or six feet and comes to different coasts occasionally to deposit its spawn. It lives in warm water and is at once chilled by the least cold; hence the name of frostfish occasionally applied to it. Several species of Lepidopus are fossil in the later Tertiary. Lepidopus glarisianus occurs in the Swiss Oligocene, and with it Thyrsitocephalus alpinus, which approaches more nearly to the Gempylidæ.

Still more degenerate are the Trichiuridæ, or cutlass-fishes, in which the caudal fin is wanting, the tail ending in a hair-like filament. The species are bright silvery in color, very slender, and very voracious, reaching a length of three to five feet. Trichiurus lepturus is rather common on our Atlantic coast. The names hairfish and silver-eel, among others, are often given to it. Trichiurus japonicas, a very similar species, is common in Japan, and other species inhabit the tropical seas. Trichiurichthys, a fossil genus with well-developed scales, precedes Trichiurus in the Miocene.

Fig. 209.—Cutlass-fish, Trichiurus lepturus Linnæus. St. Augustine, Fla.

The Palæorhynchidæ.—The extinct family of Palæorhynchidæ is found from the Eocene to the Oligocene. It contains very long and slender fishes, with long jaws and small teeth, the dorsal fin long and continuous. The species resembles the Escolar on the one hand and the sailfishes on the other, and they may prove to be ancestral to the Istiophoridæ. Hemirhynchus deshayesi with the upper jaw twice as long as the lower, sword-like, occurs in the Eocene at Paris; Palæorhynchum glarisianum, with the jaws both elongate, the lower longest, is in the Oligocene of Glarus. Several other species of both genera are recorded.

Fig. 210.—Palæorhynchus glarisianus Blainville. Oligocene. (After Woodward.)

The Sailfishes: Istiophoridæ.—Remotely allied to the cutlass-fishes and still nearer to the Palæorhynchidæ is the family of sailfishes, Istiophoridæ, having the upper jaw prolonged into a sword made of consolidated bones. The teeth are very feeble and the ventral fins reduced to two or three rays. The species are few in number, of large size, and very brilliant metallic coloration, inhabiting the warm seas, moving northward in summer. They are excellent as food, similar to the swordfish in this as in many other respects. The species are not well known, being too large for museum purposes, and no one having critically studied them in the field. Istiophorus has the dorsal fin very high, like a great sail, and undivided; Istiophorus nigricans is rather common about the Florida Keys, where it reaches a length of six feet. Its great sail, blue with black spots, is a very striking object. Closely related to this is Istiophorus orientalis of Japan and other less known species of the East Indies.

Tetrapturus, the spearfish, has the dorsal fin low and divided into two parts. Its species are taken in most warm seas, Tetrapturus imperator throughout the Atlantic, Tetrapturus amplus in Cuba, Tetrapturus mitsukurii and Tetrapturus mazara in Japan. These much resemble swordfish in form and habits, and they have been known to strike boats in the same way.

Fossil Istiophoridæ are known only from fragments of the snout, in Europe and America, referred provisionally to Istiophorus. The genus Xiphiorhynchus, fossil swordfishes from the Eocene, known from the skull only, may be referred to this family, as minute teeth are present in the jaws. Xiphiorhynchus priscus is found in the London Eocene.

The Swordfishes: Xiphiidæ.—The family of swordfishes, Xiphiidæ, consists of a single species, Xiphias gladius, of worldwide distribution in the warm seas. The snout in the swordfish is still longer, more perfectly consolidated, and a still more effective weapon of attack. The teeth are wholly wanting, and there are no ventral fins, while the second of the two fins on the back is reduced to a slight finlet.

Fig. 211.—Young Swordfish, Xiphias gladius (Linnæus). (After Lütken.)

The swordfish follows the schools of mackerel to the New England coasts. "Where you see swordfish, you may know that mackerel are about," Goode quotes from an old fisherman. The swordfish swims near the surface, allowing its dorsal fin to appear, as also the upper lobe of the caudal. It often leaps out of the water, and none of all the fishes of the sea can swim more swiftly.

Fig. 212.—Swordfish, Xiphias gladius (Linnæus). (After Day.)

"The pointed head," says Goode, "the fins of the back and abdomen snugly fitting into grooves, the absence of ventrals, the long, lithe, muscular body, sloping slowly to the tail, fit it for the most rapid and forcible movement through the water. Prof. Richard Owen, testifying in an England court in regard to its power, said:

"'It strikes with the accumulated force of fifteen double-handed hammers. Its velocity is equal to that of a swivel-shot, and is as dangerous in its effects as a heavy artillery projectile.'

"Many very curious instances are on record of the encounters of this fish with other fishes, or of their attacks upon ships. What can be the inducement for it to attack objects so much larger than itself it is hard to surmise.

"It surely seems as if a temporary insanity sometimes takes possession of the fish. It is not strange that, when harpooned, it should retaliate by attacking its assailant. An old swordfish fisherman told Mr. Blackford that his vessel had been struck twenty times. There are, however, many instances of entirely unprovoked assault on vessels at sea. Many of these are recounted in a later portion of this memoir. Their movements when feeding are discussed below, as well as their alleged peculiarities of movement during the breeding season.

"It is the universal testimony of our fishermen that two are never seen swimming close together. Capt. Ashby says that they are always distant from each other at least thirty or forty feet.

"The pugnacity of the swordfish has become a byword. Without any special effort on my part numerous instances of their attacks upon vessels have in the last ten years found their way into the pigeon-hole labeled 'Swordfish.'"

Swordfishes are common on both shores of the Atlantic wherever mackerel run. They do not breed on our shores, but probably do so in the Mediterranean and other warm seas. They are rare off the California coast, but five records existing (Anacapa, Santa Barbara, Santa Catalina, San Diego, off Cerros Island). The writer has seen two large individuals in the market of Yokohama, but it is scarcely known in Japan. As a food-fish, the swordfish is one of the best, its dark-colored oily flesh, though a little coarse, making most excellent steaks. Its average weight on our coast is about 300 pounds, the maximum 625.

The swordfish undergoes great change in the process of development, the very young having the head armed with rough spines and in nowise resembling the adult.

Fossil swordfishes are unknown, or perhaps cannot be distinguished from remains of Istiophoridæ.

CHAPTER XVII
CAVALLAS AND PAMPANOS

The Pampanos: Carangidæ.—We next take up the great family of Pampanos, Carangidæ, distinguished from the Scombridæ as a whole by the shorter, deeper body, the fewer and larger vertebræ, and by the loss of the provision for swift movement in the open sea characteristic of the mackerels and their immediate allies. A simple mark of the Carangidæ is the presence of two separate spines in front of the anal fin. These spines are joined to the fin in the young. All of the species undergo considerable changes with age, and almost all are silvery in color with metallic blue on the back.

Most like the true mackerel are the "leather-jackets," or "runners," forming the genera Scomberoides and Oligoplites. Scomberoides of the Old World has the body scaly, long, slender, and fitted for swift motion; Scomberoides sancti-petri is a widely diffused species, and others are found in Polynesia. In the New World genus Oligoplites the scales are reduced to linear ridges imbedded in the skin at different angles. Oligoplites saurus is a common dry and bony fish abounding in the West Indies and ranging north in summer to Cape Cod.

Naucrates ductor, the pilot-fish, or romero, inhabits the open sea, being taken—everywhere rarely—in Europe, the West Indies, Hawaii, and Japan. It is marked by six black cross-bands. Its tail has a keel, and it reaches a length of about two feet. In its development it undergoes considerable change, its first dorsal fin being finally reduced to disconnected spines.

The amber-fishes, forming the genus Seriola, are rather robust fishes, with the anal fin much shorter than the soft dorsal. The sides of the tail have a low, smooth keel. From a yellow streak obliquely across the head in some species they receive their Spanish name of coronado. The species are numerous, found in all warm seas, of fair quality as food, and range in length from two to six feet.

Fig. 213.—Pilot-fish, Naucrates ductor (Linnæus). New Bedford, Mass.

Fig. 214.—Amber-fish, Seriola lalandi (Cuv. & Val.). Family Carangidæ. Wood's Hole.

Seriola dorsalis is the noted yellow-tail of California, valued by anglers for its game qualities. It comes to the Santa Barbara Islands in early summer. Seriola zonata is the rudder-fish, or shark's pilot, common on our New England coast. The banded young, abundant off Cape Cod, lose their marks with age. Seriola hippos is the "samson-fish" of Australia. Seriola lalandi is the great amber-fish of the West Indies, occasionally venturing farther northward, and Seriola dumerili the amber-jack, or coronado, of the Mediterranean. The deep-bodied medregal (Seriola fasciata) is also taken in the West Indies, as is also the high-finned Seriola rivoliana. Species very similar to these occur in Hawaii and Japan, where they are known as Ao, or bluefishes. Seriola lata is fossil in the mountains of Tuscany.

The runner, Elegatis bipinnulatus, differs from Seriola in having a finlet behind dorsal and anal. It is found in almost all warm seas, ranging north once in a while to Long Island.

The mackerel scads (Decapterus) have also a finlet, and on the posterior part of the body the lateral line is shielded with bony plates. In size and form these little fishes much resemble small mackerel, and they are much valued as food wherever abundant. Decapterus punclatus, known also as cigar-fish and round-robin, frequently visits our Atlantic coasts from the West Indies, where it is abundant. Decapterus russelli is the Maruaji, highly valued in Japan for its abundance, while Decapterus muroadsi is the Japanese muroaji.

Fig. 215.—The Saurel, Trachurus trachurus (Linnæus). Newport, R. I.

Megalaspis cordyla abounds in the East Indies and Polynesia. It has many finlets, and the bony plates on the lateral line are developed to an extraordinary degree.

In Trachurus the finlets are lost and the bony plates extend the whole length of the lateral line. The species known as saurel and wrongly called horse-mackerel are closely related and some of them very widely distributed.

Trachurus trachurus common in Europe, extends to Japan where it is the abundant maaji. Trachurus mediterraneus is common in southern Europe and Trachurus symmetricus in California. Trachurus picturatus of Madeira is much the same as the last named, and there is much question as to the right names and proper limits of all these species.

In Trachurops the bony plates are lacking on the anterior half of the body, and there is a peculiar nick and projection on the lower part of the anterior edge of the shoulder-girdle. Trachurops crumenophthalma, the goggler, or big-eyed scad, ranges widely in the open sea and at Hawaii, as the Akule, is the most highly valued because most abundant of the migratory fishes. At Samoa it is equally abundant, the name being here Atule. Trachurops torva is the meaji, or big-eyed scad, of the Japanese, always abundant.

Fig. 216.—Yellow Mackerel, Carangus chrysos (Mitchill). Wood's Hole.

To Caranx, Carangus, and a number of related genera, characterized by the bony armature on the narrow caudal peduncle, a host of species may be referred. These fishes, known as cavallas, hard-tails, jacks, etc., are broad-bodied, silvery or metallic black in color, and are found in all warm seas. They usually move from the tropics northward in the fall in search of food and are especially abundant on our Atlantic coast, in Polynesia, and in Japan. About the Oceanic Islands they are resident, these being their chosen spawning-grounds. In Hawaii and Samoa they form a large part of the food-supply, the ulua (Carangus forsteri) and the malauli (Carangus melampygus) being among the most valuable food-fishes, large in size and excellent in flesh, unsurpassed in fish chowders. Of the American species Carangus chrysos, called yellow mackerel, is the most abundant, ranging from Cape Cod southward. This is an elongate species of moderate size. The cavalla, or jiguagua, Carangus hippos, known by the black spot on the opercle, with another on the pectoral fin, is a widely distributed species and one of the largest of the tribe. Another important food-fish is the horse-eye-jack, or jurel, Carangus latus, which is very similar to the species called ulua in the Pacific. The black jack, or tiñosa, of Cuba, Carangus funebris, is said to be often poisonous. This is a very large species, black in color, the sale of which has been long forbidden in the markets of Havana. The young of different species of Carangus are often found taking refuge under the disk of jelly-fishes protected by the stinging feelers. The species of the genus Carangus have well-developed teeth. In the restricted genus of Caranx proper, the jaws are toothless. Caranx speciosus, golden with dark cross-bands, is a large food-fish of the Pacific. Citula armata is another widely distributed species, with some of the dorsal rays produced in long filaments.

In Alectis ciliaris, the cobbler-fish, or threadfish, the armature of the tail is very slight and each fin has some of its rays drawn out into long threads. In the young these are very much longer than the body, but with age they wear off and grow shorter, while the body becomes more elongate. In Vomer, Selene, and Chloroscombrus the bony armature of the tail, feeble in Alectis, by degrees entirely disappears.

Vomer setipinnis, the so-called moonfish, or jorobado, has the body greatly elevated, compressed, and distorted, while the fins, growing shorter with age, become finally very low. Selene vomer, the horse-head-fish, or look-down (see Fig. 113, Vol. I), is similarly but even more distorted. The fins, filamentous in the young, grow shorter with age, as in Vomer and Alectis. The skeleton in these fishes is essentially like that of Carangus, the only difference lying in the compression and distortion of the bones. Chloroscombrus contains the casabes, or bumpers, thin, dry, compressed fish, of little value as food, the bony armature of the tail being wholly lost.

To the genus Trachinotus belong the pampanos, broad-bodied, silvery fishes, toothless when adult, the bodies covered with small scales and with no bony plates.

The true pampano, Trachinotus carolinus, is one of the finest of all food-fishes, ranking with the Spanish mackerel and to be cooked in the same way, only by broiling. The flesh is white, firm, and flaky, with a moderate amount of delicate oil. It has no especial interest to the angler and it is not abundant enough to be of great commercial importance, yet few fish bring or deserve to bring higher prices in the markets of the epicures. The species is most common along our Gulf coast, ranging northward along the Carolinas as far as Cape Cod.

Fig. 217.—The Pampano, Trachinotus carolinus (Linnæus). Wood's Hole.

Pampano in Spanish means the leaf of the grape, from the broad body of the fish. The spelling "pompano" should therefore be discouraged.

The other pampanos, of which there are several in tropical America and Asia, are little esteemed, the flesh being dry and relatively flavorless. Trachinotus palometa, the gaff-topsail pampano, has very high fins and its sides have four black bands like the marks of a grill. The round pampano, Trachinotus falcatus, is common southward, as is also the great pampano, Trachinotus goodei, which reaches a length of three feet. Trachinotus ovatus, a large deep-bodied pampano, is common in Polynesia and the East Indies. No pampanos are found in Europe, but a related genus, Lichia, contains species which much resemble them, but in which the body is more elongate and the mouth larger.

Numerous fossils are referred to the Carangidæ with more or less certainty. Aipichthys pretiosus and other species occur in the Cretaceous. These are deep-bodied fishes resembling Seriola, having the falcate dorsal twice as long as the anal and the ventral ridge with thickened scales. Vomeropsis (longispina elongata, etc.), also from the Eocene, with rounded caudal, the anterior dorsal rays greatly elongate, and the supraoccipital crest highly developed, probably constitutes with it a distinct family, Vomeropsidæ. Several species referable to Carangus are found in the Miocene. Archæus glarisianus, resembling Carangus, but without scales so far as known, is found in the Oligocene of Glarus; Seriola prisca and other species of Seriola occur in the Eocene; Carangopsis brevis, etc., allied to Caranx, but with the lateral line unarmed, is recorded from the Eocene of France and Italy.

Ductor leptosomus from the Eocene of Monte Bolca resembles Naucrates; Trachinotus tenuiceps is recorded from Monte Bolca, and a species of uncertain relationship, called Pseudovomer minutus, with sixteen caudal vertebræ is taken from the Miocene of Licata.

The Papagallos: Nematistiidæ.—Very close to the Carangidæ, and especially to the genus Seriola, is the small family of Nematistiidæ, containing the papagallo, Nematistius pectoralis of the west coast of Mexico. This large and beautiful fish has the general appearance of an amber-fish, but the dorsal spines are produced in long filaments. The chief character of the family is found in the excessive division of the rays of the pectoral fins.

The Bluefishes: Cheilodipteridæ.—Allied to the Carangidæ is the family of bluefishes (Cheilodipteridæ, or Pomatomidæ). The single species Cheilodipterus saltatrix, or Pomatomus saltatrix, known as the bluefish, is a large, swift, extremely voracious fish, common throughout most of the warmer parts of the Atlantic, but very irregularly distributed on the various coasts. Its distribution is doubtless related to its food. It is more abundant on our Eastern coast than anywhere else, and its chief food here is the menhaden. The bluefish differs from the Carangidæ mainly in its larger scales, and in a slight serration of the bones of the head. Its flesh is tender and easily torn. As a food-fish, rich, juicy, and delicate, it has few superiors. Its maximum weight is from twelve to twenty pounds, but most of those taken are much smaller. It is one of the most voracious of all fish. Concerning this, Professor Baird observes:

Fig. 218.—Bluefish, Cheilodipterus saltatrix (L.). New York.

"There is no parallel in point of destructiveness to the bluefish among the marine species on our coast, whatever may be the case among some of the carnivorous fish of the South American waters. The bluefish has been well likened to an animated chopping-machine the business of which is to cut to pieces and otherwise destroy as many fish as possible in a given space of time. All writers are unanimous in regard to the destructiveness of the bluefish. Going in large schools in pursuit of fish not much inferior to themselves in size, they move along like a pack of hungry wolves, destroying everything before them. Their trail is marked by fragments of fish and by the stain of blood in the sea, as, where the fish is too large to be swallowed entire, the hinder portion will be bitten off and the anterior part allowed to float away or sink. It is even maintained with great earnestness that such is the gluttony of the fish, that when the stomach becomes full the contents are disgorged and then again filled. It is certain that it kills many more fish than it requires for its own support.

"The youngest fish, equally with the older, perform this function of destruction, and although they occasionally devour crabs, worms, etc., the bulk of their sustenance throughout the greater part of the year is derived from other fish. Nothing is more common than to find a small bluefish of six or eight inches in length under a school of minnows making continual dashes and captures among them. The stomachs of the bluefish of all sizes, with rare exceptions, are found loaded with the other fish, sometimes to the number of thirty or forty, either entire or in fragments.

"As already referred to, it must also be borne in mind that it is not merely the small fry that are thus devoured, and which it is expected will fall a prey to other animals, but that the food of the bluefish consists very largely of individuals which have already passed a large percentage of the chances against their reaching maturity, many of them, indeed, having arrived at the period of spawning. To make the case more clear, let us realize for a moment the number of bluefish that exist on our coast in the summer season. As far as I can ascertain by the statistics obtained at the fishing-stations on the New England coast, as also from the records of the New York markets, kindly furnished by Middleton & Carman, of the Fulton Market, the capture of bluefish from New Jersey to Monomoy during the season amounts to no less than one million individuals, averaging five or six pounds each. Those, however, who have seen the bluefish in his native waters and realized the immense numbers there existing will be quite willing to admit that probably not one fish in a thousand is ever taken by man. If, therefore, we have an actual capture of one million, we may allow one thousand millions as occurring in the extent of our coasts referred to, even neglecting the smaller ones, which, perhaps, should also be taken into account.

"An allowance of ten fish per day to each bluefish is not excessive, according to the testimony elicited from the fishermen and substantiated by the stomachs of those examined; this gives ten thousand millions of fish destroyed per day. And as the period of the stay of the bluefish on the New England coast is at least one hundred and twenty days, we have in round numbers twelve hundred million millions of fish devoured in the course of a season. Again, if each bluefish, averaging five pounds, devours or destroys even half its own weight of other fish per day (and I am not sure that the estimate of some witnesses of twice this weight is not more nearly correct), we will have, during the same period, a daily loss of twenty-five hundred million pounds, equal to three hundred thousand millions for the season.

"This estimate applies to three or four year old fish of at least three to five pounds in weight. We must, however, allow for those of smaller size, and a hundred-fold or more in number, all engaged simultaneously in the butchery referred to.

"We can scarcely conceive of a number so vast; and however much we may diminish, within reason, the estimate of the number of bluefish and the average of their capture, there still remains an appalling aggregate of destruction. While the smallest bluefish feed upon the diminutive fry, those of which we have taken account capture fish of large size, many of them, if not capable of reproduction, being within at least one or two years of that period.

"It is estimated by very good authority that of the spawn deposited by any fish at a given time not more than 30 per cent. are hatched, and that less than 10 per cent. attain an age when they are able to take care of themselves. As their age increases the chances of reaching maturity become greater and greater. It is among the small residuum of this class that the agency of the bluefish is exercised and whatever reasonable reduction may be made in our estimate, we cannot doubt that they exert a material influence.

"The rate of growth of the bluefish is also an evidence of the immense amount of food they must consume. The young fish which first appear along the shores of Vineyard Sound, about the middle of August, are about five inches in length. By the beginning of September, however, they have reached six or seven inches, and on their reappearance in the second year they measure about twelve or fifteen inches. After this they increase in a still more rapid ratio. A fish which passes eastward from Vineyard Sound in the spring weighing five pounds is represented, according to the general impression, by the ten to fifteen-pound fish of the autumn. If this be the fact, the fish of three or four pounds which pass along the coast of North Carolina in March return to it in October weighing ten to fifteen pounds.

"As already explained, the relationship of these fish to the other inhabitants of the sea is that of an unmitigated butcher; and it is able to contend successfully with any other species not superior to itself in size. It is not known whether an entire school ever unite in an attack upon a particular object of prey, as is said to be the case with the ferocious fishes of the South American rivers; should they do so, no animal, however large, could withstand their onslaught.

"They appear to eat anything that swims of suitable size—fish of all kinds, but perhaps more especially the menhaden, which they seem to follow along the coast, and which they attack with such ferocity as to drive them on the shore, where they are sometimes piled up in windrows to the depth of a foot or more."

The Sergeant-fishes: Rachycentridæ.—The Rachycentridæ, or sergeant-fishes, are large, strong, swift, voracious shore fishes, with large mouths and small teeth, ranging northward from the warm seas. The dorsal spines are short and stout, separate from the fin, and the body is almost cylindrical, somewhat like that of the pike.

Fig. 219.—Sergeant-fish, Rachycentron canadum (Linnæus). Virginia.

Rachycentron canadum, called cobia, crab-eater, snooks, or sergeant-fish, reaches a length of about five feet. The last name is supposed to allude to the black stripe along its side, like the stripe on a sergeant's trousers. It is rather common in summer along our Atlantic coast as far as Cape Cod, especially in Chesapeake Bay. Rachycentron pondicerrianum, equally voracious, extends its summer depredations as far as Japan. The more familiar name for these fishes, Elacate, is of later date than Rachycentron.

Mr. Prime thus speaks of the crab-eater as a game-fish:

"In shape he may be roughly likened to the great northern pike, with a similar head, flattened on the forehead. He is dark green on the back, growing lighter on the sides, but the distinguishing characteristic is a broad, dark collar over the neck, from which two black stripes or straps, parting on the shoulders, extend, one on each side, to the tail. He looks as if harnessed with a pair of traces, and his behavior on a fly-rod is that of a wild horse. The first one that I struck, in the brackish water of Hillsborough River at Tampa, gave me a hitherto unknown sensation. The tremendous rush was not unfamiliar, but when the fierce fellow took the top of the water and went along lashing it with his tail, swift as a bullet, then descended, and with a short, sharp, electric shock left the line to come home free, I was for an instant confounded. It was all over in ten seconds. Nearly every fish that I struck after this behaved in the same way, and after I had got 'the hang of them' I took a great many."

The Butter-fishes: Stromateidæ.—The butter-fishes (Stromateidæ) form a large group of small fishes with short, compressed bodies, smooth scales, feeble spines, the vertebræ in increased number and especially characterized by the presence of a series of tooth-like processes in the œsophagus behind the pharyngeals. The ventral fins present in the young are often lost in the process of development.

According to Mr. Regan, the pelvic bones are very loosely attached to the shoulder-girdle as in the extinct genera Platycormus and Homosoma. This is perhaps a primitive feature, indicating the line of descent of these fishes from berycoid forms.

We unite with the Stromateidæ the groups or families of Centrolophidæ and Nomeidæ, knowing no characters by which to separate them.

Stromateus fiatola, the fiatola of the Italian fishermen, is an excellent food-fish of the Mediterranean. Poronotus triacanthus, the harvest-fish, or dollar-fish, of our Atlantic coast, is a common little silvery fish six to ten inches, as bright and almost as round as a dollar. Its tender oily flesh has an excellent flavor. Very similar to it is the poppy-fish (Palometa simillima) of the sandy shores of California, miscalled the "California pampano," valued by the San Francisco epicure, who pays large prices for it supposing it to be pampano, although admitting that the pampano in New Orleans has firmer flesh and better flavor. The harvest-fish, Peprilus paru, frequently taken on our Atlantic coast, is known by its very high fins. Stromateoides argenteus, a much larger fish than any of these, is a very important species on the coasts of China.

Fig. 220.—Harvest-fish, Peprilus paru (Linnæus). Virginia.

Psenopsis anomala takes the place of our butter-fishes in Japan, and much resembles them in appearance as in flavor.

To the Stromateidæ we also refer the black ruff of Europe, Centrolophus niger, an interesting deep-sea fish rarely straying to our coast. Allied to it is the black rudder-fish, Palinurichthys perciformis, common on the Massachusetts coast, where it is of some value as a food-fish. A specimen in a live-box once drifted to the coast of Cornwall, where it was taken uninjured, though doubtless hungry. Other species of ruff-and rudder-fish are recorded from various coasts.

Allied to the Stromateidæ are numerous fossil forms. Omosoma sachelalmæ and other species occur in the Cretaceous at Mount Lebanon. Platycormus germanus, with ctenoid scales resembling a berycoid, but with the ventral rays I, 5, occurs in the Upper Cretaceous. Closely related to this is Berycopsis elegans, with smoother scales, from the English Chalk.

Fig. 221.—Portuguese Man-of-war Fish, Gobiomorus gronovii. Family Stromateidæ.

Gobiomorus gronovii (usually called Nomeus gronovii), the Portuguese man-of-war-fish, is a neat little fish about three inches long, common in the Gulf of Mexico and the Gulf Stream, where it hides from its enemies among the poisoned tentacles of the Portuguese man-of-war. Under the Portuguese man-of-war and also in or under large jelly-fishes several other species are found, notably Carangus medusicola and Peprilus paru. Many small species of Psenes, a related genus, also abound in the warm currents from tropical seas.

The Rag-fishes: Icosteidæ.—Allied to the butter-fishes are the deep-water Icosteidæ, fishes of soft, limp bodies as unresistant as a wet rag, Icosteus ænigmaticus of the California coast being known as ragfish. Schedophilus medusophagus feeds on medusæ and salpa, living on the surface in the deep seas. Mr. Ogilby thus speaks of a specimen taken in Ireland:

"It was the most delicate adult fish I ever handled; within twenty-four hours after its capture the skin of the belly and the intestines fell off when it was lifted, and it felt in the hand quite soft and boneless." A related species (S. heathi) has been lately taken by Dr. Charles H. Gilbert at Monterey in California.

The family of Acrotidæ contains a single species of large size. Acrotus willoughbyi, allied to Icosteus, but without ventral fins and with the vertebræ very numerous. The type, five and one-quarter feet long, was thrown by a storm on the coast of Washington, near the Quinnault agency.

The family of Zaproridæ contains also a single large species, Zaprora silenus, without ventrals, but scaly and firm in substance. One specimen 2½ feet long was taken at Nanaimo on Vancouver Island and a smaller one at Victoria.

The Pomfrets: Bramidæ.—The Bramidæ are broad-bodied fishes of the open seas, covered with firm adherent scales. The flesh is firm and the skeleton heavy, the hypercoracoid especially much dilated. Of the various species the pomfret, or black bream (Brama raii), is the best known and most widely diffused. It reaches a length of two to four feet and is sooty black in color. It is not rare in Europe and has been occasionally taken at Grand Bank off Newfoundland, at the Bermudas, off the coast of Washington, on Santa Catalina Island, and in Japan. It is an excellent food-fish, but is seldom seen unless driven ashore by storms.

Steinegeria rubescens of the Gulf of Mexico is a little-known deep-sea fish allied to Brama, but placed by Jordan and Evermann in a distinct family, Steinegeriidæ.

Closely related to the Bramidæ is the small family of Pteraclidæ, silvery fishes with large firm scales, living near the surface in the ocean currents. In these fishes the ventral fins are placed well forward, fairly to be called jugular, and the rays of the dorsal and anal, all inarticulate or spine-like, are excessively prolonged. The species, none of them well known, are referred to four genera—Pteraclis, Bentenia, Centropholis, and Velifer. They are occasionally taken in ocean currents, chiefly about Japan and Madeira.

Fossil forms more or less remotely allied to the Bramidæ are recorded from the Eocene and Miocene. Among these are Acanthonemus, and perhaps Pseudovomer.

The Dolphins: Coryphænidæ.—The dolphins, or dorados (Coryphænidæ), are large, swift sea-fishes, with elongate, compressed bodies, elevated heads, sharp like the cut-water of a boat, and with the caudal fin very strong. The long dorsal fin, elevated like a crest on the head, is without spines. The high forehead characteristic of the dolphin is developed only in the adult male. The flesh of the dolphin is valued as food. Its colors, golden-blue with deep-blue spots, fade rapidly at death, though the extent of this change has been much exaggerated. Similar changes of color occur at death in most bright-colored fishes, especially in those with thin scales. The common dolphin, or dorado (Coryphæna hippurus), is found in all warm seas swimming near the surface, as usual in predatory fishes, and reaches a length of about six feet. The small dolphin, Coryphæna equisetis, rarely exceeds 2½ feet, and is much more rare than the preceding, from which the smaller number of dorsal rays (53 instead of 60) best distinguishes it. Young dolphins of both species are elongate in form, the crest of the head not elevated, the physiognomy thus appearing very different from that of the adult. Goniognathus coryphænoides is an extinct dolphin of the Eocene.

Fig. 222.—Dolphin or Dorado, Coryphæna hippurus Linnæus. New York.

The name dolphin, belonging properly to a group of small whales or porpoises, the genus Delphinus, has been unfortunately used in connection with this very different animal, which bears no resemblance to the mammal of the same name.

Other mackerel-like families not closely related to these occur in the warm seas. The Leiognathidæ are small, silvery fishes of the East Indies. Leiognathus argentatus (Equula) is very common in the bays of Japan, a small silvery fish of moderate value as food. Gazza minuta, similar, with strong teeth, abounds farther south. Leiognathus fasciatum is common in Polynesia. A fossil species called Parequula albyi occurs in the Miocene of Licata.

The Kurtidæ are small, short-bodied fishes of the Indian seas, with some of the ribs immovably fixed between rings formed by the ossified cover of the air-bladder and with the hypocoracoid obsolete. Kurtus indicus is the principal species.

The Menidæ.—Near the Kurtidæ we may perhaps place the family of Menidæ, of one species, Mene maculata, the moonfish of the open seas of the East Indies and Japan. This is a small fish, about a foot long, with the body very closely compressed, the fins low and the belly, through the extension of the pelvic bone, a good deal more prominent than the back. The ventral fins have the usual number of one spine and five soft rays, a character which separates Mene widely from Lampris, which in some ways seems allied to it.

Fig. 223.—Mene maculata (Bloch & Schneider). Family Menidæ. Japan.

Another species of Menidæ is the extinct Gasteronemus rhombeus of the Eocene of Monte Bolca. It has much the same form, with long pubic bones. The very long ventral fins are, however, made of one spine and one or two rays. A second species, Gasteronemus oblongus, is recorded from the same rocks.

The Pempheridæ.—The Pempheridæ, "deep-water catalufas," or "magifi," are rather small deep-bodied fishes, reddish in color, with very short dorsal, containing a few graduated spines, and with a very long anal fin. These inhabit tropical seas at moderate depths. Pempheris bears a superficial resemblance to Beryx, but, according to Starks, this resemblance is not borne out by the anatomy. Pempheris mulleri and P. poeyi are found in the West Indies. Pempheris otaitensis and P. mangula range through Polynesia.

Fig. 224.—Gasteronemus rhombeus Agassiz. (After Woodward.) Menidæ.

Fig. 225.—Catalufa de lo Alto, Pempheris mulleri Poey. Havana.

Fig. 226.—Pempheris nyctereutes Jordan & Evermann. Giran, Formosa.

Fig. 227.—The Louvar, Luvarus imperialis Rafinesque. Family Luvaridæ. (After Day.)

Very close to the Pempheridæ is the small family of Bathyclupeidæ. These are herring-like fishes, much compressed and with a duct to the air-bladder. There are but one or two dorsal spines. The ventrals are of one spine and five rays as in perch-like fishes, but placed behind the pectoral fins. This feature, due to the shortening of the belly, is regarded by Alcock, the discoverer, as a result of degeneration, and the family was placed by him among the herrings. The persistent air-duct excludes it from the Percesoces, the normally formed ventrals from the Berycoidei. If we trust the indications of the skeleton, we must place the family with Pempheris, near the scombroid fishes.

Luvaridæ.—Another singular family is the group of Louvars, Luvaridæ. Luvaris imperialis. The single known species is a large, plump, voracious fish, with the dorsal and anal rays all unbranched, and the scales scurf-life over the smooth skin. It is frequently taken in the Mediterranean, and was found on the island of Santa Catalina, California, by Mr. C. F. Holden.

The Square-tails: Tetragonuridæ.—The Tetragonuridæ are long-bodied fishes of a plump or almost squarish form, covered with hard, firm, very adherent scales. Tetragonurus cuvieri, the single species, called square-tail, or escolar de natura, is a curious fish, looking as if whittled out of wood, covered with a compact armor of bony scales, and swimming very slowly in deep water. It is known from the open Atlantic and Mediterranean and has been once taken at Wood's Hole in Massachusetts. According to Mr. C. T. Regan the relations of this eccentric fish are with the Stromateidæ and Bramidæ, the skeleton being essentially that of Stromateus, and Boulenger places both Tetragonurus and Stromateus among the Percesoces.

The Crested Bandfishes: Lophotidæ.—The family of Lophotidæ consists of a few species of deep-sea fishes, band-shaped, naked, with the dorsal of flexible spines beginning as a high crest on the elevated occiput. The first spine is very strong. The ventrals are thoracic with the normal number, I, 5, of fin-rays. Lophotes cepedianus, the crested bandfish, is occasionally taken in the Mediterranean in rather deep water. Lophotes capellei is rarely taken in the deep waters of Japan.

It is thought that the Lophotidæ may be related to the ribbon-fishes, Tæniosomi, but on the whole they seem nearer to the highly modified Scombroidei, the Pteraclidæ for example.

In a natural arrangement, we should turn from the Bramidæ to the Antigoniidæ and the Ilarchidæ, then passing over the series which leads through Chætodontidæ and Teuthidæ to the Plectognaths. It is, however, necessary to include here, alongside the mackerels, though not closely related to them, the parallel series of perch-like fishes, which at the end become also hopelessly entangled, through aberrant forms, with other series of which the origin and relations are imperfectly understood. As the relations of forms cannot be expressed in a linear series, many pages must intervene before we can take up the supposed line of development from the Scombroid fishes to those called Squamipinnes.

CHAPTER XVIII
PERCOIDEA, OR PERCH-LIKE FISHES

Percoid Fishes.—We may now take up the long series of the Percoidea, the fishes built on the type of the perch or bass. This is a group of fishes of diverse habits and forms, but on the whole representing better than any other the typical Acanthopterygian fish. The group is incapable of concise definition, or, in general, of any definition at all; still, most of its members are definitely related to each other and bear in one way or another a resemblance to the typical form, the perch, or more strictly to its marine relatives, the sea-bass, or Serranidæ. The following analysis gives most of the common characters of the group:

Body usually oblong, covered with scales, which are typically ctenoid, not smooth nor spinous, and of moderate size. Lateral line typically present and concurrent with the back. Head usually compressed laterally and with the cheeks and opercles scaly. Mouth various, usually terminal and with lateral cleft; the teeth various, but typically pointed, arranged in bands on the jaws, and in several families on the vomer and palatine bones also, as well as on the pharyngeals; gill-rakers usually sharp, stoutish, armed with teeth, but sometimes short or feeble; lower pharyngeals almost always separate, usually armed with cardiform teeth; third upper pharyngeal moderately enlarged, elongate, not articulated to the cranium, the fourth typically present; gills four, a slit behind the fourth; gill membranes free from the isthmus, and usually not connected with each other; pseudobranchiæ typically well developed. Branchiostegals few, usually six or seven. No bony stay connecting the suborbital chain to the preopercle. Opercular bones all well developed, normal in position; the preopercle typically serrate. No cranial spines. Dorsal fin variously developed, but always with some spines in front, these typically stiff and pungent; anal fin typically short, usually with three spines, sometimes with a larger number, rarely with none; caudal fin various, usually lunate; pectoral fins well developed, inserted high; ventral fins always present, thoracic, separate, almost always with one spine and five rays, the Aphredoderidæ having more, a few Serranidæ having fewer. Air-bladder usually present, without air-duct in adult; simple and generally adherent to the walls of the abdomen. Stomach cæcal, with pyloric appendages, the intestines short in most species, long in the herbivorous forms. Vertebral column well developed, none of the vertebræ especially modified, the number 10 + 14 = 24, except in certain extratropical and fresh-water forms, which retain primitive higher numbers. Shoulder-girdle normally developed, the post-temporal bifurcate attached to the skull, but not coossified with it; none of the epipleural bones attached to the center of the vertebræ; coracoids normal, the hypercoracoid always with a median foramen, the basal bones of the pectoral (actinosts or pterygials) normally developed, three or four in number, hour-glass-shaped, longer than broad; premaxillary forming the border of the mouth usually protractile; bones of the mandible distinct. Orbitosphenoid wanting.

The most archaic of the perch-like types are apparently some of those of the fresh waters. Among these the process of evolution has been less rapid. In some groups, as the Percidæ, the great variability of species is doubtless due to the recent origin, the characters not being well fixed.

The Pirate-perches: Aphredoderidæ.—Among the most remarkable of the living percoid fishes and probably the most primitive of all, showing affinities with the Salmopercæ, is the pirate-perch, Aphredoderus sayanus, a little fish of the lowland streams of the Mississippi Valley. The family of Aphredoderidæ agrees with the berycoid fishes in scales and structure of the fins, and Boulenger places it with the Berycidæ. Starks has shown, however, that it lacks the orbitosphenoid, and the general osteology is that of the perch-like fishes. The dorsal and anal have a few spines. The thoracic ventrals have one spine and eight rays. There is no adipose fin and probably no duct to the air-bladder. A singular trait is found in the position of the vent. In the adult this is in front of the ventral fins, at the throat. In the young it is behind the ventral fins as in ordinary fishes. With age it moves forward by the prolongation of the horizontal part of the intestine or rectum. The same peculiar position of the vent is found in the berycoid genus Paratrachichthys.

Fig. 228.—Pirate Perch, Aphredoderus sayanus (Gilliams). Illinois River.

Fig. 229.—Everglade Pigmy Perch, Elassoma evergladei Jordan. Everglades of Florida.

In the family Aphredoderidæ but one species is known, Aphredoderus sayanus, the pirate-perch. It reaches a length of five inches and lives in sluggish lowland streams with muddy bottom from New Jersey and Minnesota to Louisiana. It is dull green in color and feeds on insects and worms. It has no economic value, although extremely interesting in its anatomy and relationship.

Whether the Asineopidæ, fresh-water fishes of the American Eocene, and the Erismatopteridæ, of the same deposits (see page 235) are related to Aphredoderus or to Percopsis is still uncertain.

Fig. 230.—Skull of the Rock Bass, Ambloplites rupestris.

The Pigmy Sunfishes: Elassomidæ.—One of the most primitive groups is that of Elassomidæ, or pigmy sunfishes. These are very small fishes, less than two inches long, living in the swamps of the South, resembling the sunfishes, but with the number of dorsal spines reduced to from three to five. Elassoma zonatum occurs from southern Illinois to Louisiana. Elassoma evergladei abounds in the Everglades of Florida. In both the body is oblong and compressed, the color is dull green crossed by black bars or blotches.

The Sunfishes: Centrarchidæ.—The large family of Centrarchidæ, or sunfishes, is especially characteristic of the rivers of the eastern United States, where the various species are inordinately abundant. The body is relatively short and deep, and the axis passes through the middle so that the back has much the same outline as the belly. The pseudobranchiæ are imperfect, as in many fresh-water fishes, and the head is feebly armed, the bones being usually without spines or serratures. The colors are often brilliant, the sexes alike, and all are carnivorous, voracious, and gamy, being excellent as food. The origin of the group is probably Asiatic, the fresh-water serranoid of Japan, Bryttosus, resembling in many ways an American sunfish, and the genus Kuhlia of the Pacific showing many homologies with the black bass, Micropterus.

Fig. 231.—Crappie, Pomoxis annularis Rafinesque. Ohio River.

Fig. 232.—Crappie, Pomoxis annularis (Raf.). (From life by Dr. R. W. Shufeldt.)

Fig. 233.—Rock Bass, Ambloplites rupestris (Rafinesque.) Ecorse, Mich.

Fig. 234.—Banded Sunfish, Mesogonistius chætodon (Baird). Delaware River.

Crappies and Rock Bass.—Pomoxis annularis, the crappie, and Pomoxis sparoides, the calico-bass, are handsome fishes, valued by the angler. These are perhaps the most primitive of the family, and in these species the anal fin is larger than the dorsal. The flier, or round bass, Centrarchus macropterus, with eight anal spines, is abundant in swamps and lowland ponds of the Southern States. It is a pretty fish, attractive in the aquarium. Acantharchus pomotis is the mud-bass of the Delaware, and Archoplites interruptus, the "perch" of the Sacramento. The latter is a large and gamy fish, valued as food and interesting as being the only fresh-water fish of the nature of perch or bass native to the west of the Rocky Mountains. The numbers of this species, according to Mr. Will S. Green of Colusa, California, have been greatly reduced by the introduction of the catfish (Ameiurus nebulosus) into the Sacramento. The perch eats the young catfish, and its stomach is torn by their sharp pectoral spines. Another species of this type is the warmouth (Chænobryttus gulosus) of the ponds of the South, and still more familiar rock-bass or redeye (Ambloplites rupestris) of the more northern lakes and rivers valued as a game-and food-fish. A very pretty aquarium fish is the black-banded sunfish, Mesogonistius chætodon, of the Delaware, as also the nine-spined sunfish, Enneacanthus gloriosus, of the coast streams southward. Apomotis cyanellus, the blue-green sunfish or little redeye, is very widely distributed from Ohio westward, living in every brook. The dissection of this species is given on page 26, Vol. I. To Lepomis belong numerous species having the opercle prolonged in a long flap which is always black in color, often with a border of scarlet or blue. The yellowbelly of the South (Lepomis auritus), ear-like the showily colored long-eared sunfish (Lepomis megalotis) of the southwest, figured on page 2, Vol. I, the bluegill (Lepomis pallidus), abundant everywhere south and west of New York, are members of this genus. The genus Eupomotis differs in its larger pharyngeals, which are armed with blunt teeth. The common sunfish, or pumpkinseed, Eupomotis gibbosus, is the most familiar representative of the family, abounding everywhere from Minnesota to New England, then south to Carolina on the east slope of the Alleghanies, breeding everywhere in ponds and in the eddies of the clear brooks.

Fig. 235.—Blue-Gill, Lepomis pallidus (Mitchill). Potomac River.

Fig. 236.—Long-eared Sunfish, Lepomis megalotis (Rafinesque). From Clear Creek, Bloomington, Indiana. Family Centrarchidæ.

Fig. 237.—Common Sunfish, Eupomotis gibbosus (Linnæus). Root River, Wis.

The Black Bass.—The black bass (Micropterus) belong to the same family as the sunfish, differing in the larger size, more elongate form, and more voracious habit. The two species are among the most important of American game-fishes, abounding in all clear waters east of the Alleghanies and resisting the evils of civilization far better than the trout.

The small-mouthed black bass, Micropterus dolomieu, is the most valuable of the species. Its mouth, although large, is relatively small, the cleft not extending beyond the eye. The green coloration is broken in the young by bronze cross-bands. The species frequents only running streams, preferring clear and cold waters, and it extends its range from Canada as far to the southward as such streams can be found. Dr. James A. Henshall, an accomplished angler, author of the "Book of the Black Bass," says: "The black bass is eminently an American fish; he has the faculty of asserting himself and of making himself completely at home wherever placed. He is plucky, game, brave, unyielding to the last when hooked. He has the arrowy rush and vigor of a trout, the untiring strength and bold leap of a salmon, while he has a system of fighting tactics peculiarly his own. I consider him inch for inch and pound for pound the gamest fish that swims."

In the same vein Charles Hallock writes: "No doubt the bass is the appointed successor of the trout; not through heritage, nor selection, nor by interloping, but by foreordination. Truly, it is sad to contemplate, in the not distant future, the extinction of a beautiful race of creatures, whose attributes have been sung by all the poets; but we regard the inevitable with the same calm philosophy with which the astronomer watches the burning out of a world, knowing that it will be succeeded by a new creation. As we mark the soft varitinted flush of the trout disappear in the eventide, behold the sparkle of the coming bass, as he leaps in the morning of his glory! We hardly know which to admire the most—the velvet livery and the charming graces of the departing courtier, or the flash of the armor-plates of the advancing warrior. The bass will unquestionably prove himself a worthy substitute for his predecessor and a candidate for a full legacy of honors.

"No doubt, when every one of the older states shall become as densely settled as Great Britain itself, and all the rural aspects of the crowded domain resemble the suburban surroundings of our Boston; when every feature of the pastoral landscape shall wear the finished appearance of European lands, and every verdant field be closely cropped by lawn-mowers and guarded by hedges, and every purling stream which meanders through it has its water-bailiff, we shall still have speckled trout from which the radiant spots have faded, and tasteless fish, to catch at a dollar a pound (as we already have on Long Island), and all the appurtenances and appointments of a genuine English trouting privilege and a genuine English 'outing.'

Fig. 238.—Small Mouth Black Bass, Micropterus dolomieu Lacépède.

"In those future days, not long hence to come, some venerable piscator, in whose memory still lingers the joy of fishing, the brawling stream which tumbled over the rocks in the tangled wildwood, and moistened the arbutus and the bunchberries which garnished its banks, will totter forth to the velvet edge of some peacefully flowing stream, and having seated himself on a convenient point in a revolving easy-chair, placed there by his careful attendant, cast right and left for the semblance of sport long dead.

"Hosts of liver-fed fish rush to the signal for their early morning meal, and from the center of the boil which follows the fall of the handfuls thrown in my piscator of the ancient days will hook a two-pound trout, and play him hither and yon, from surface to bottom, without disturbing the pampered gourmands which are gorging themselves upon the disgusting viands; and when he has leisurely brought him to land at last, and the gillie has scooped him with his landing-net, he will feel in his capacious pocket for his last trade dollar, and giving his friend the tip, shuffle back to his house, and lay aside his rod forever."

The black bass is now introduced into the streams of Europe and California. There is little danger that it will work injury to the trout, for the black bass prefers limestone streams, and the trout rarely does well in waters which do not flow over granite rock or else glacial gravel.

The large-mouth black bass (Micropterus salmoides) is very much like the other in appearance. The mouth is larger, in the adult cleft beyond the eye; the scales are larger, and in the young there is always a broad black stripe along the sides and no cross-bands. The two are found in the same region, but almost never in the same waters, for the large-mouth bass is a fish of the lakes, ponds, and bayous, always avoiding the swift currents. The young like to hide among weeds or beneath lily-pads. From its preference for sluggish waters, its range extends farther to the southward, as far as the Mexican State of Tamaulipas.

Plioplarchus is a genus of fossil sunfishes from the Eocene of South Dakota and Oregon. Plioplarchus sexspinosus, septemspinosus, and whitei are imperfectly known species.

The Saleles: Kuhliidæ.—Much like the sunfishes in anatomy, though more like the white perch in appearance and habit, are the members of the little family of Kuhliidæ. These are active silvery perches of the tropical seas, ponds, and river-mouths, especially abundant in Polynesia. Kuhlia malo is the aholehole of the Hawaiians, a silvery fish living in great numbers in brackish waters. Kuhlia rupestris, the salele of the Samoan rivers, is a large swift fish of the rock pools, in form, color, and habits remarkably like the black bass. It is silvery bronze in hue, everywhere mottled with olive-green. The sesele, Kuhlia marginata, lives with it in the rivers, but is less abundant. The saboti, Kuhlia tæniura, a large silvery fish with cross-bands on the caudal fin, lives about lava-rooks in Polynesia from the Galapagos to Samoa and the East Indies, never entering rivers. Still other species are found in the rock pools and streams of Japan and southward.

The skeleton in Kuhlia is essentially like that of the black bass, and Dr. Boulenger places the genus with the Centrarchidæ.

The True Perches: Percidæ.—The great family of Percidæ includes fresh-water fishes of the northern hemisphere, elongate in body, with the vertebræ in increased number and with only two spines in the anal fin. About ninety species are recorded, the vast majority being American. The dwarf perches, called darters (Etheostominæ), are especially characteristic of the clear streams to the eastward of the plains of the Missouri. These constitute one of the greatest attractions of our American river fauna. They differ from the perch and its European allies in their small size, bright colors, and large fins, and more technically in the rudimentary condition of the pseudobranchiæ and the air-bladder, both of which organs are almost inappreciable. The preopercle is unarmed, and the number of the branchiostegals is six. The anal papilla is likewise developed, as in the Gobiidæ, to which group the darters bear a considerable superficial resemblance, which, however, indicates no real affinity.

Fig. 239.—Large-mouthed Black Bass, Micropterus salmoides (Lac.). (From life by Dr. R. W. Shufeldt.)

Relations of Darters to Perches.—The colors of the Etheostominæ, or darters, are usually very brilliant, species of Etheostoma especially being among the most brilliantly colored fishes known; the sexual differences are often great, the females being, as a rule, dull in color and more speckled or barred than the males. Most of them prefer clear running water, where they lie on the bottom concealed under stones, darting, when frightened or hungry, with great velocity for a short distance, by a powerful movement of the fan-shaped pectorals, then stopping as suddenly. They rarely use the caudal fin in swimming, and they are seldom seen floating or moving freely in the water like most fishes. When at rest they support themselves on their expanded ventrals and anal fin. All of them can turn the head from side to side, and they frequently lie with the head in a curved position or partly on one side of the body. The species of Ammocrypta, and perhaps some of the others, prefer a sandy bottom, where, by a sudden plunge, the fish buries itself in the sand, and remains quiescent for hours at a time with only its eyes and snout visible. The others lurk in stony places, under rocks and weeds. Although more than usually tenacious of vitality, the darters, from their bottom life, are the first to be disturbed by impurities in the water. All the darters are carnivorous, feeding chiefly on the larvæ of Diptera, and in their way voracious. All are of small size; the largest (Percina rex) reaches a length of ten inches, while the smallest (Microperca punctulata) is, one of the smallest spiny-rayed fishes known, barely attaining the length of an inch and a half. In Europe no Etheostominæ are found, their place being filled by the genera Zingel and Aspro, which bear a strong resemblance to the American forms, a resemblance which may be a clue to the origin of the latter.

The Perches.—The European perch, Perca fluviatilis, is placed by Cuvier at the head of the fish series, as representing in a high degree the traits of a fish without sign of incomplete development on the one hand or of degradation on the other. Doubtless the increased number of the vertebræ is the chief character which would lead us to call in question this time-honored arrangement. Because, however, the perch has a relatively degenerate vertebral column, we have used an allied form, the striped bass, as a fairer type of the perfected spiny-rayed fish. Certainly the bass represents this type better than the perch.

But though we may regard the perch as nearest the typically perfect fish, it is far from being one of the most highly specialized, for, as we have seen in several cases, a high degree of specialization of a particular structure is a first step toward its degradation.

The perch of Europe is a common game-fish of the rivers. The yellow perch of America (Perca flavescens) is very much like it, a little brighter in color, olive and golden with dusky cross-bands. It frequents quiet streams and ponds from Minnesota eastward, then southward east of the Alleghanies. "As a still-pond fish," says Dr. Charles Conrad Abbott, "if there is a fair supply of spring-water, they thrive excellently; but the largest specimens come either from the river or from the inflowing creeks. Deep water of the temperature of ordinary spring-water, with some current and the bed of the stream at least partly covered with vegetation, best suits this fish." The perch is a food-fish of moderate quality. In spite of its beauty and gaminess, it is little sought for by our anglers, and is much less valued with us than is the European perch in England. But Dr. Goode ventures to prophesy that "before many years the perch will have as many followers as the black bass among those who fish for pleasure" in the region it inhabits. "A fish for the people it is, we will grant, and it is the anglers from among the people who have neither time nor patience for long trips nor complicated tackle who will prove its steadfast friends." The boy values it, according to Thoreau. When he returns from the mill-pond, he numbers his perch as "real fishes." "So many unquestionable fish he counts, and so many chubs, which he counts, then throws away."

Fig. 240.—Yellow Perch, Perca flavescens Mitchill. Potomac River.

In the perch, the oral valves, characteristic of all bony fishes, are well developed. These structures recently investigated by Evelyn G. Mitchill, form a fold of connective tissue just behind the premaxillary and before the vomer. They are used in respiration, preventing the forward flow of water as the mouth closes.

Several perch-like fishes are recorded as fossils from the Miocene.

Allied to the perch, but long, slender, big-mouthed, and voracious, is the group of pike perches, found in eastern America and Europe. The wall-eye, or glass-eye (Stizostedion vitreum), is the largest of this tribe, reaching a weight of ten to twenty pounds. It is found throughout the region east of the Missouri in the large streams and ponds, an excellent food-fish, with white, flaky flesh and in the north a game fish of high rank. The common names refer to the large glassy eye, concerning which Dr. Goode quotes from some "ardent admirer" these words: "Look at this beautiful fish, as symmetrical in form as the salmon. Not a fault in his make-up, not a scale disturbed, every fin perfect, tail clean-cut, and his great, big wall-eyes stand out with that life-like glare so characteristic of the fish."

Fig. 241.—Sauger, Stizostedion canadense (Smith). Ecorse, Mich.

Similar to the wall-eye, but much smaller and more translucent in color, is the sauger, or sand-pike, of the Great Lakes and Northern rivers, Stizostedion canadense. This fish rarely exceeds fifteen inches in length, and as a food-fish it is of correspondingly less importance.

Fig. 242.—The Aspron, Aspro asper (Linnæus). Rhone River. Family Percidæ. (After Seelye.)

The pike-perch, or zander, of central Europe, Centropomus (or Sandrus) lucioperca, is an excellent game-fish, similar to the sauger, but larger, characterized technically by having the ventral fins closer together. Another species, Centropomus volgensis, in Russia, looks more like a perch than the other species do. Sandroserrus, a fossil pike-perch, occurs in the Pliocene. Another European fish related to the perch is the river ruff, or pope, Acerina cernua, which is a small fish with the form of a perch and with conspicuous mucous cavities in the skull. It is common throughout the north of Europe and especially abundant at the confluence of rivers. Gymnocephalus schrætzer of the Danube has the head still more cavernous. Percarina demidoffi of southern Russia is another dainty little fish of the general type of the perch. A fossil genus of this type called Smerdis is numerously represented in the Miocene and later rocks. The aspron, Aspro asper, is a species like a darter found lying on the bottoms of swift rivers, especially the Rhone. The body is elongate, with the paired fins highly developed. Zingel zingel is found in the Danube, as is also a third species called Aspro streber. In form and coloration these species greatly resemble the American darters, and the genus Zingel is, perhaps, the ancestor of the entire group. Zingel differs from Percina mainly in having seven instead of six branchiostegals and the pseudobranchiæ better developed. The differences in these and other regards which distinguish the darters are features of degradation, and they are also no doubt of relatively recent acquisition. To this fact we may ascribe the difficulty in finding good generic characters within the group. Sharply defined genera occur where the intervening types are lost. The darter is one of the very latest products in the evolution of fishes.

Fig. 243.—The Zingel, Zingel zingel (Linnæus). Danube River. (After Seelye.)

The Darters: Etheostominæ.—Of the darters, or etheostomine perches, over fifty species are known, all confined to the streams of the region bounded by Quebec, Assiniboia, Colorado, and Nuevo Leon. All are small fishes and some of them minute, and some are the most brilliantly colored of all fresh-water fishes of any region, the most ornate belonging to the large genus called Etheostoma. The largest species, the most primitive because most like the perch, belong to the genus Percina.

First among the darters because largest in size, most perch-like in structure, and least degenerate, we place the king darter, Percina rex of the Roanoke River in Virginia. This species reaches a length of six inches, is handsomely colored, and looks like a young wall-eye.

Fig. 244.—Log-perch, Percina caprodes (Rafinesque). Licking Co., Ohio.

The log-perch, Percina caprodes, is near to this, but a little smaller, with the body surrounded by black rings alternately large and small. In this widely distributed species, large enough to take the hook, the air-bladder is present although small. In the smaller species it vanishes by degrees, and in proportion as in their habits they cling to the bottom of the stream. The air-bladder is least developed in those species which cling closest to the bottom of the stream.

Fig. 245.—Black-sided Darter, Hadropterus aspro (Cope & Jordan). Chickamauga River.

The genus Hadropterus includes many handsome species, most of them with a black lateral band widened at intervals. The black-sided darter, Hadropterus aspro, is the best-known species and one of the most elegant of all fishes, abounding in the clear gravelly streams of the Ohio basin and northwestward.

Hadropterus evides of the Ohio region is still more brilliant, with alternate bands of dark blue-green and orange-red, most exquisite in their arrangement. In the South, Hadropterus nigrofasciatus, the crawl-a-bottom of the Georgia rivers, is a heavily built darter, which Vaillant has considered the ancestral species of the group. Still more swift in movement and bright in color are the species of Hypohomus, which flash their showy hues in the sparkling brooks of the Ozark and the Great Smoky Mountains. Hypohomus aurantiacus is the best-known species.

Fig. 246.—Green-sided Darter, Diplesion blennioides Rafinesque. Clinch River. Family Percidæ.

Diplesion blennioides, the green-sided darter, is the type of numerous species with short heads, large fins, and coloration of speckled green and golden. It abounds in the streams of the Ohio Valley.

Fig. 247.—Tessellated Darter, Boleosoma olmstedi (Storer). Potomac River.

The tessellated darters, Boleosoma, are the most plainly colored of the group and among the smallest; yet in the delicacy, wariness, and quaintness of motion they are among the most interesting, especially in the aquarium. Boleosoma nigrum, the Johnny darter in the West, and Boleosoma olmstedi in the East are among the commonest species, found half hidden in the weeds of small brooks, and showing no bright colors, although the male in the spring has the head, and often the whole body, jet black.

Fig. 248.—Crystal Darter, Crystallaria asprella (Jordan). Wabash River.

Crystallaria asprella, a large species almost transparent, is occasionally taken in swift currents along the limestone banks of the Mississippi. Still more transparent is the small sand-darter, Ammocrypta pellucida, which lives in the clearest of waters, concealing itself by plunging into the sand. Its scales are scantily developed, as befits a fish that chooses this method of protection, and in the related Ammocrypta beani of the streams of the Louisiana pine-woods, the body is almost naked, as also in Ioa vitrea, the glassy darter of the pine-woods of North Carolina.

Fig. 249.—Sand-darter, Ammocrypta clara (Jordan & Meek). Des Moines River.

In the other darters the body is more compressed, the movements less active, the coloration even more brilliant in the males, which are far more showy than their dull olivaceous mates.

To Etheostoma nearly half of the species belong, and they form indeed a royal series of little fishes. Only a few can be noticed here, but all of them are described in detail and many are figured by Jordan and Evermann ("Fishes of North and Middle America," Vol. I).

Fig. 250.—Etheostoma jordani Gilbert. Chestnut Creek, Verbena, Ala.

Fig. 251.—Blue-breasted Darter, Etheostoma camurum (Cope), the most brilliantly colored of American river fishes. Cumberland Gap, Tenn.

Most beautiful of all fresh-water fishes is the blue-breasted darter, Etheostoma camurum, red-blue and olive, with red spots, like a trout. This species lives in clear streams of the Ohio valley, a region perhaps to be regarded as the center of abundance of these fishes.

Very similar is the trout-spotted darter, Etheostoma maculatum, dusky and red, with round crimson spots. Etheostoma rufilineatum of the French Broad is one of the most gaudy of fishes. Etheostoma australe of Chihuahua ranges farthest south of all the darters, and Etheostoma boreale of Quebec perhaps farthest north, though Etheostoma iowæ, found from Iowa to the Saskatchewan, may dispute this honor. Etheostoma cæruleum, the rainbow darter or soldier-fish, with alternate oblique bands of blue and scarlet, is doubtless the most familiar of the brilliantly colored species, as it is the most abundant throughout the Ohio valley.

Etheostoma flabellare, the fan-tailed darter, discovered by Rafinesque in Kentucky in 1817, was the first species of the series made known to science. It has no bright colors, but its movements in water are more active than any of the others, and it is the most hardy in the aquarium.

Psychromaster tuscumbia abounds in the great limestone springs of northern Alabama, while Copelandellus quiescens swarms in the black-water brooks which flow into the Dismal Swamp and thence southward to the Suwanee. It is a little fish not very active, its range going farther into the southern lowlands than any other. Finally, Microperca punctulata, the least darter, is the smallest of all, with fewest spines and dullest colors, most specialized in the sense of being least primitive, but at the same time the most degraded of all the darters.

No fossil forms nearly allied to the darters are on record. The nearest is perhaps Mioplosus labracoides from the Eocene at Green River, Wyoming. This elongate fish, a foot long, has the dorsal rays IX-1, 13, and the anal rays II, 13, its scales finely serrated, and the preopercle coarsely serrated on the lower limb only. This species, with its numerous congeners from the Rocky Mountain Eocene, is nearer the true perch than the darters. Several species related to Perca are also recorded from the Eocene of England and Germany. A species called Lucioperca skorpili, allied to Centropomus, is described from the Oligocene of Bulgaria, besides several other forms imperfectly preserved, of still more doubtful affinities.

CHAPTER XIX
THE BASS AND THEIR RELATIVES

The Cardinal-fishes. Apogonidæ.—The Apogonidæ or cardinal-fishes are perch-like fishes, mostly of small size, with two distinct short dorsal fins. They are found in the warm seas, and many of them enter rivers, some even inhabiting hot springs. Many of the shore species are bright red in color, usually with black stripes, bands, or spots. Still others, however, are olive or silvery, and a few in deeper water are violet-black.

Fig. 252.—Cardinal-fish, Apogon retrosella Gill. Mazatlan.

The species of Apogon are especially numerous, and in regions where they are abundant, as in Japan, they are much valued as food. Apogon imberbis, the "king of the mullet," is a common red species of southern Europe. Apogon maculatus is found in the West Indies. Apogon retrosella is the pretty "cardenal" of the west coast of Mexico. Apogon lineatus, semilineatus and other species abound in Japan, and many species occur about the islands of Polynesia. Epigonus telescopium is a deep-sea fish of the Mediterranean and Telescopias and Synagrops are genera of the depths of the Pacific. Paramia with strong canines is allied to Apogon, and similar in color and habit.

Allied to Apogon are several small groups often taken as distinct families. The species of Ambassis (Ambassidæ) are little fishes of the rivers and bays of India and Polynesia, resembling small silvery perch or bass. All these have three anal spines instead of two as in Apogon. Some of these enter rivers and several are recorded from hot springs. Scombrops boops, the mutsu of Japan, is a valued food-fish found in rather deep water. It is remarkable for its very strong teeth, although its flesh is feeble and easily torn. A still larger species in Cuba, Scombrops oculata, known as Escolar chino, resembles a barracuda. These fishes with fragile bodies and very strong teeth are placed by Gill in a separate family (Scombropidæ). Acropoma japonicum is a neat little fish of the Japanese coast, with the vent placed farther forward than in Apogon. It is the type of the Acropomidæ, a small family of the Pacific. Enoplosus armatus is an Australian fish with high back and fins, with a rather stately appearance, type of the Enoplosidæ. In his last catalogue of families of fishes Dr. Gill recognizes Scombropidæ and Acropomidæ as distinct families, but their relationships with Apogon are certainly very close. Many genera allied to Apogon and Ambassis occur in Australian rivers. Several fossils referred to Apogon (Apogon spinosus, etc.) occur in the Eocene of Italy and Germany.

The Anomalopidæ.—The family of Anomalopidæ is a small group of deep-sea fishes of uncertain relationship, but perhaps remotely related to Apogon. Anomalops palpebrata is found in Polynesia and has beneath the eye a large luminous organ unlike anything seen elsewhere among fishes.

The Asineopidæ.—Another family of doubtful relationship is that of Asineopidæ, elsewhere noticed. It is composed of extinct fresh-water fishes found in the Green River shales. In Asineops squamifrons the opercles are unarmed, the teeth villiform, and the dorsal fin undivided, composed of eight or nine spines and twelve to fourteen soft rays. The anal spines, as in Apogon, are two only, and the scales are cycloid.

Fig. 253.—Kuromutsu, Telescopias gilberti Jordan & Snyder. Misaki, Japan.

Fig. 254.—Apogon semilineatus Schlegel. Misaki, Japan.

Fig. 255.—Robalo, Oxylabrax undecimalis (Bloch). Florida.

The Robalos:[13] Oxylabracidæ.—The family of Robalos (Oxylabracidæ or Centropomidæ) is closely related to the Serranidæ, differing among other things in having the conspicuous lateral line extended on the caudal fin. These are silvery fishes with elongate bodies, large scales, a pike-like appearance, the first dorsal composed of strong spines and the second spine of the anal especially large. They are found in tropical America only, where they are highly valued as food, the flesh being like that of the striped bass, white, flaky, and of fine flavor. The common robalo, or snook, Oxylabrax (or Centropomus) undecimalis, reaches a weight of fifteen to twenty pounds. It ranges north as far as Texas. In this species the lateral line is black. The smaller species, of which several are described, are known as Robalito or Constantino.

13.  The European zander is the type of Lacépède's genus Centropomus. The name Centropomus has been wrongly transferred to the robalo by most authors.

The Sea-bass: Serranidæ.—The central family of the percoid fishes is that of the Serranidæ, or sea-bass. Of these about 400 species are recorded, carnivorous fishes found in all warm seas, a few ascending the fresh waters. In general, the species are characterized by the presence of twenty-four vertebræ and three anal spines, never more than three. The fresh-water species are all more or less archaic and show traits suggesting the Oxylabracidæ, Percidæ, or Centrarchidæ, all of which are doubtless derived from ancestors of Serranidæ. Among the connecting forms are the perch-like genera Percichthys and Percilia of the rivers of Chile. These species look much like perch, but have three anal spines, the number of vertebræ being thirty-five. Percichthys trucha is the common trucha, or trout, of Chilean waters.

Lateolabrax japonicus, the susuki, or bass, of Japan, is one of the most valued food-fishes of the Orient, similar in quality to the robalo, which it much resembles. This genus and the East Indian Centrogenys waigiensis approach Oxylabrax in appearance and structure. Niphon spinosus, the ara of Japan, is a very large sea-bass, also of this type. Close to these bass, marine and fresh water, are the Chinese genus Siniperca and the Korean genus Coreoperca, several species of which abound in Oriental rivers. In southern Japan is the rare Bryttosus kawamebari, a bass in structure, but very closely resembling the American sunfish, even to the presence of the bright-edged black ear-spot. There is reason to believe that from some such form the Centrarchidæ were derived.

Other bass-like fishes occur in Egypt (Lates), Australia (Percalates, etc.), and southern Africa. Oligorus macquariensis is the great cod of the Australian rivers and Ctenolates ambiguus is the yellow belly, while Percalates colonorum is everywhere the "perch" in Australian rivers. The most important member of these transitional types between perch and sea-bass is the striped bass, or rockfish (Roccus lineatus), of the Atlantic coast of the United States. This large fish, reaching in extreme cases a weight of 112 pounds, lives in shallow waters in the sea and ascends the rivers in spring to spawn. It is olivaceous in color, the sides golden silvery, with narrow black stripes. About 1880 it was introduced by the United States Fish Commission into the Sacramento, where it is now very abundant and a fish of large commercial importance. To the angler the striped bass is always "a gallant fish and a bold biter," and Genio Scott places it first among the game-fishes of America.

The white bass (Roccus chrysops) is very similar to it, but shorter and more compressed, reaching a smaller size. This fish is abundant in the Great Lakes and the upper Mississippi as far south as Arkansas.

The yellow bass (Morone interrupta), a coarser and more brassy fish, replaces it farther south. It is seldom seen above Cincinnati and St. Louis. The white perch (Morone americana) is a little fish of the Atlantic seaboard, entering the sea, but running up all the rivers, remaining contentedly landlocked in ponds. It is one of the most characteristic fishes of the coast from Nova Scotia to Virginia. It is a good pan fish, takes the hook vigorously, and in a modest way deserves the good-will of the angler who cannot stray far into the mountains. Very close to these American bass is the bass, bars, or robalo, of southern Europe, Dicentrarchus labrax, a large olive-colored fish, excellent as food, living in the sea about the mouths of rivers.

The Jewfishes.—In the warm seas are certain bass of immense size, reaching a length of six feet or more, and being robust in form, a weight of 500 or 600 pounds. These are dusky green in color, thick-headed, rough-scaled, with low fins, voracious disposition, and sluggish movements. In almost all parts of the world these great bass are called jewfish, but no reason for this name has ever been suggested. In habit and value the species are much alike, and the jewfish of California, Stereolepis gigas, the prize of the Santa Catalina anglers, may be taken as the type of them all. Closely related to this is the Japanese ishinagi, Megaperca ischinagi, the jewfish, or stone-bass, of Japan. Another Japanese jewfish is the Abura bodzu, or "fat priest," Ebisus sagamius. In the West Indies, as also on the west coast of Mexico, the jewfish, or guasa, is Promicrops itaiara. The black grouper, Garrupa nigrita, is the jewfish of Florida. The European jewfish, more often called wreckfish, or stone-bass, is Polyprion americanus, and the equally large Polyprion oxygeneios is found in Australia, as is also another jewfish, Glaucosoma hebraicum, the last belonging to the Lutianidæ. Largest of all these jewfishes is Promicrops lanceolata of the South Pacific. This huge bass, according to Dr. Boulenger, sometimes reaches a length of twelve feet.

Fig. 256.—White Perch, Morone americana Gmelin. (From life by Dr. R. W. Shufeldt; one half natural size.)

Fig. 257.—Florida Jewfish, Promicrops itaiara (Lichtenstein). St. John's River, Fla.

Related to the jewfishes are numerous smaller fishes. One of these, the Spanish-flag of Cuba, Gonioplectrus hispanus, is rose-colored, with golden bands like the flag of Spain itself. Other species referred to Acanthistius and Plectropoma have, like this, hooked spines on the lower border of the preopercle.

Fig. 258.—Epinephelus striatus (Bloch), Nassau Grouper: Cherna criolla. Family Serranidæ.

Fig. 259.—John Paw or Speckled Hind, Epinephelus drummond-hayi Goode Pensacola.

Fig. 260.—Epinephelus morio (Cuvier & Valenciennes), Red Grouper, or Mero. Family Serranidæ.

The Groupers.—In all warm seas abound species of Epinephelus and related genera, known as sea-bass, groupers, or merous. They are mostly large voracious fishes with small scales, pale flesh of fair quality, and from their abundance they are of large commercial importance. To English-speaking people these fishes are usually known as grouper, a corruption of the Portuguese name garrupa. In the West Indies and about Panama there are very many species, and still others abound in the Mediterranean, in southern Japan, and throughout Polynesia and the West Indies. They have very much in common, but differ in size and color, some being bright red, some gaudily spotted with red or blue, but most of them are merely mottled green or brown. In many cases individuals living near shore are olivaceous, and those of the same species in the depths are bright crimson or scarlet. We name below a few of the most prominent species. Even a bare list of all of them would take many pages. Cephalopholis cruentatus, the red hind of the Florida Keys, is one of the smallest and brightest of all of them. Cephalopholis fulvus, the blue-spotted guativere of the Cubans, is called negro-fish, butter-fish, yellow-fish, or redfish, according to its color, which varies with the depth. It is red, yellow, or olive, with many round blue spots. Epinephelus adscenscionis, the rock-hind, is spotted everywhere with orange. Epinephelus guaza is the merou, or giant-bass, of Europe, a large food-fish of value, rather dull in color. Epinephelus striatus is the Nassau grouper, or Cherna criolla, common in the West Indies. Epinephelus maculosus is the cabrilla of Cuba. Epinephelus drummond-hayi, the speckled hind, umber brown, spotted with lavender, is one of the handsomest of all the groupers. Epinephelus morio, the red grouper, is the commonest of all these fishes in the American markets. In Asia the species are equally numerous, Epinephelus quernus of Hawaii and the red Epinephelus fasciatus of Japan and southward being food-fishes of importance. Epinephelus merra, Epinephelus gilberti, and Epinephelus tauvina are among the more common species of Polynesia. Epinephelus corallicola, a species profusely spotted, abounds in the crevices of coral reefs, while Cepholopholis argus and C. leopardus are showy fishes of the deeper channels. Mycteroperca venenosa, the yellow-finned grouper, is a large and handsome fish of the coast of Cuba, the flesh sometimes poisonous; when red in deep water it is known as the bonaci cardenal. Mycteroperca bonaci; the bonaci arará sells in our markets as black grouper. Mycteroperca microlepis is commonest along our South Atlantic coast, not reaching the West Indies, and Mycteroperca rubra, which is never red, enters the Mediterranean. Mycteroperca falcata is known in the markets as scamp, and Mycteroperca venadorum is a giant species from the Venados Islands, near Mazatlan. Diploprion bifasciatus is a handsome grouper-like fish with two black cross-bands, found in Japan and India. Variola louti, red, with crimson spots and a forked caudal fin, is one of the most showy fishes of the equatorial Pacific.

Fig. 261.—Red Hind, Epinephelus adscensionis (Osbeck). Puerto Rico. (After Evermann.)

Fig. 262.—Yellow-fin Grouper, Mycteroperca venenosa (Linnæus). Havana.

The small fishes called Vaca in Cuba belong to the genus Hypoplectrus. Their extraordinary and unexplained variations in color have been noticed on page 235, Vol. I. The common species—blue, orange, green, plain, striated, checkered, or striped—bears the name of Hypoplectrus unicolor. (Fig. 264).

The Serranos.—In all the species known as jewfish and grouper, as also in the Oxylabracidæ and most Centrarchidæ, the maxillary bone is divided by a lengthwise suture which sets off a distinct supplemental maxillary. This bone is wanting in the remaining species of Serranidæ, as it is also in those forms already noticed which are familiarly known as bass. The species without the supplemental maxillary are in general smaller in size, the canines are on the sides of the jaws instead of in front, and there are none of the hinged depressible teeth which are conspicuous in the groupers. The species are abundant in the Atlantic, but scarcely any are found in Polynesia, and few in Japan or India.

Fig. 263.—Hypoplectrus unicolor nigricans (Poey). Tortugas, Fla.

Serranus cabrilla is the Cabrilla of the Mediterranean, a well-known and excellent food-fish, the original type of the family of Serranidæ. Serranellus scriba is the serran, a very pretty shore-fish of southern Europe, longer known than any other of the tribe. On the coast of southern California are also species called Cabrillas, fine, large, food-fish, bass-like in form, Paralabrax clathratus, and other less common species. The Cabrillas and their relatives are almost all American, a few straying across to Europe. One of the most important in the number is the black sea-bass, or black will, of our Atlantic coast, Centropristes striatus. This is a common food-and game-fish, dusky in color, gamy, and of fine flesh. The squirrel-fishes (Diplectrum) and the many serranos (Prionodes) of the tropics, small bright-colored fishes of the rocks and reefs, must be passed with a word, as also the small Paracentropristis of the Mediterranean and the fine red creole-fish of the West Indies, Paranthias furcifer. In one species, Anyperodon leucogrammicus of Polynesia, there are no teeth on the palatines.

The barber-fish (Anthias anthias) of southern Europe, bright red and with the lateral line running very high, is the type of a numerous group found at the lowest fishing level in all warm seas. All the species of this group are bright red, very handsome, and excellent as food. Hemianthias vivanus, known only from the spewings of the red snapper (Lutianus aya) at Pensacola, is one of the most brilliant species, red, with golden streaks. The genus Plesiops consists of small fishes almost black in color, with blue spots and other markings, abounding about the coral reefs. In this genus the lateral line is interrupted and there is some indication of affinity with the Opisthognathidæ.

Fig. 264.—Snowy Grouper, Epinephelus niveatus (Cuv. & Val.). Natural size: young. (Photograph by Dr. R. W. Shufeldt.)

Fig. 265.—Soapfish, Rypticus bistrispinus (Mitchill). Virginia.

In the soapfishes (Rypticus) the supplemental maxillary appears again, but in these forms the dorsal fin is reduced to two or three spines and there are none in the anal. Rypticus saponaceus, so called from the smooth or soapy scales, is the best known of the numerous species, which all belong to tropical America. Grammistes, with eight dorsal spines, is a related form in Polynesia, bright yellow, with numerous black stripes. Numerous species referred to the Serranidæ occur in the Eocene and Miocene rocks. Some are related to Epinephelus, others to Roccus and Lates. In the Tertiary lignite of Brazil is a species of Percichthys, Percichthys antiquus, with Properca beaumonti, which seem to be a primitive form of the bass, allied to Dicentrarchus. Prolates heberti of the Cretaceous, one of the earliest of the series, has the caudal rounded and is apparently allied to Lates, as is also the heavily armed Acanus regleysianus of the Oligocene. Smerdis minutus, a small fish from the Oligocene, is also related to Lates, which genus with Roccus and Dicentrarchus must represent the most primitive of existing members of this family. Of both Smerdis and Dicentrarchus (Labrax) numerous species are recorded, mostly from the Miocene of Europe.

Fig. 266.—Flasher, Lobotes surinamensis (Bloch). Virginia.

Fig. 267.—Catalufa, Priacanthus arenatus Cuv. & Val. Wood's Hole, Mass.

The Flashers: Lobotidæ.—The small family of Lobotidæ, flashers, or triple-tails, closely resembles the Serranidæ, but there are no teeth on vomer or palatines. The three species are robust fishes, of a large size, of a dark-green color, the front part of the head very short. They reach a length of about three feet and are good food-fishes. Lobotes surinamensis comes northward from the West Indies as far as Cape Cod. Lobotes pacificus is found about Panama. Lobotes erate, common in India, was taken by the writer at Misaki, Japan.

Fig. 268.—Bigeye, Pseudopriacanthus altus Gill. Young specimen. (From life by Dr. R. W. Shufeldt.)

The Bigeyes: Priacanthidæ.—The Catalufas or bigeyes (Priacanthidæ) are handsome fishes of the tropics, with short, flattened bodies, rough scales, large eyes, and bright-red coloration. The mouth is very oblique, and the anal fin about as large as the dorsal. The commonest species is Priacanthus cruentatus, widely diffused through the Pacific and also in the West Indies. This is the noted Aweoweo of the Hawaiians, which used to come into the bays in myriads at the period of death of royalty. It is still abundant, even after Hawaiian royalty has passed away.

Pseudopriacanthus altus is a short, very deep-bodied, and very rough fish, scarlet in color, occasionally taken along our coast, driven northward by the Gulf Stream. The young fishes are quite unlike the adult in appearance. Numerous other species of Priacanthus occur in the Indies and Polynesia.

The Pentacerotidæ.—Another family with strong spines and rough scales is the group of Pentacerotidæ. Histiopterus typus, the Matodai, is found in Japan, and is remarkable for its very deep body and very high spines. Equally remarkable is the Tengudai, Histiopterus acutirostris, also Japanese. Anoplus banjos is a third Japanese species, more common than the others, and largely taken in the Inland Sea. All these are eccentric variations from the perch-like type.

The Snappers: Lutianidæ.—Scarcely less numerous and varied than the sea-bass is the great family of Lutianidæ, known in America as snappers or pargos. In these fishes the maxillary slips along its edge into a sheath formed by the broad preorbital. In the Serranidæ there is no such sheath. In the Lutianidæ there is no supplemental maxillary, teeth are present on the vomer and palatines, and in the jaws there are distinct canines. These fishes of the warm seas are all carnivorous, voracious, gamy, excellent as food though seldom of fine grain, the flesh being white and not flaky. About 250 species are known, and in all warm seas they are abundant.

Fig. 269.—Gray Snapper, Lutianus griseus L. Puerto Rico. (After Evermann.)

To the great genus Lutianus most of the species belong. These are the snappers of our markets and the pargos of the Spanish-speaking fishermen. The shore species are green in color, mostly banded, spotted, or streaked. In deeper water bright-red species are found. One of these, Lutianus aya, the red snapper or pargo guachinango of the Gulf of Mexico, is, economically speaking, the most important of all these fishes in the United States. It is a large, rather coarse fish, bright red in color, and it is taken on long lines on rocky reefs chiefly about Pensacola and Tampa in Florida, although similar fisheries exist on the shores of Yucatan and Brazil.

Fig. 270.—Lutianus apodus (Walbaum), Schoolmaster or Cají. Family Lutianidæ.

Fig. 271.—Hoplopagrus guntheri Gill. Mazatlan.

Fig. 272.—Lane Snapper or Biajaiba, Lutianus synagris (Linnæus). Key West.

A related species is the Lutianus analis, the mutton snapper or pargo criollo of the West Indies. This is one of the staple fishes of the Havana market, always in demand for banquets and festivals, because its flesh is never unwholesome. The mangrove snapper, or gray-snapper, Lutianus griseus, called in Cuba, Caballerote, is the commonest species on our coasts. The common name arises from the fact that the young hide in the mangrove bushes of Florida and Cuba, whence they sally out in pursuit of sardines and other small fishes. It is a very wary fish, to be sought with care, hence the name "lawyer," sometimes heard in Florida. The cubero (Lutianus cyanopterus) is a very large snapper, often rejected as unwholesome, being said to cause the disease known as ciguatera. Certain snappers in Polynesia have a similar reputation. The large red mumea, Lutianus bohar, is regarded as always poisonous in Samoa—the most dangerous fish of the islands. L. leioglossus is also held under suspicion on Tutuila, though other fishes of this type are regarded as always safe. Other common snappers of Florida and Cuba are the dog snapper or jocu (Lutianus jocu), the schoolmaster or cají (Lutianus apodus), the black-fin snapper or sese de lo alto (Lutianus buccanella), the silk snapper or pargo de lo alto (Lutianus vivanus), the abundant lane snapper or biajaiba (Lutianus synagris), and the mahogany snapper or ojanco (Lutianus mahogani). Numerous other species occur on both coasts of tropical America, and a vastly larger assemblage is found in the East Indies, some of them ranging northward to Japan.

Fig. 273.—Yellow-tail Snapper, Ocyurus chrysurus (Linnæus). Key West.

Fig. 274.—Cachucho, Etelis oculatus (Linnæus). Havana.

Hoplopagrus guntheri is a large snapper of the west coast of Mexico, having very large molar teeth in its jaws besides slit-like nostrils and other notable peculiarities. From the standpoint of structure this species, with its eccentric characters—is especially interesting. The yellow-tail snapper or rabirubia (Ocyurus chrysurus) is a handsome and common fish of the West Indies, with long, deeply forked tail, which makes it a swifter fish than the others. Another red species is the diamond snapper or cagon de lo alto, Rhomboplites aurorubens. All these true snappers have the soft fins more or less scaly. In certain species that swim more freely in deep waters, these fins are naked. Among them is the Arnillo, Apsilus dentatus, a pretty brown fish of the West Indies, and its analogue in Hawaii, Apsilus brighami, red, with golden cross-bands. Aprion virescens, the Uku of Hawaii, is a large fish of a greenish color and elongate body, widely diffused throughout Polynesia and one of the best of food-fishes. A related species is the red voraz (Aprion macrophthalmus) of the West Indies.

Most beautiful of all the group are the species of Etelis, with the dorsal fin deeply divided and the head flattened above. These live in rather deep water about rocky reefs and are fiery red in color. Best known is the Cuban species, Etelis oculatus, the cachucho of the markets. Equally abundant and equally beautiful is Etelis carbunculus of Polynesia, Etelis evurus of Hawaii, and other species of the Pacific islands.

Fig. 275.—Xenocys jessiæ Jordan & Bollman. Family Lutianidæ. Galapagos Islands.

Verilus sordidus, the black escolar of Cuba, has the form of Etelis, but the flesh is very soft and the color violet-black, indicating its life in very deep water. Numerous small silvery snappers living near the shore along the coast of western Mexico belong to the genera called Xenichthys, Xenistius, and Xenocys. Xenistius californiensis is the commonest of these species, Xenocys jessiæ, the largest in size, with black lines like a striped bass. To the genus Dentex belongs a large snapper-like fish of the Mediterranean, Dentex dentex. Very many related species occur in the old world, the prettily colored Nemipterus virgatus, the Itoyori of Japan being one of the best known. Another interesting fish is Aphareus furcatus, a handsome, swift fish of the open seas occasionally taken in Japan and the East Indies. Glaucosoma burgeri is a large snapper of Japan, and a related species, Glaucosoma hebraicum, is one of the "jewfishes" of Australia. Numerous fossil forms referred to Dentex occur in the Eocene of Monte Bolca, as also a fish called Ctenodentex lackeniensis from the Eocene of Belgium.

Fig. 276.—Aphareus furcatus (Lacépède). Odawara, Japan. Family Lutianidæ.

Fig. 277.—Grunt, Hæmulon plumieri (Bloch). Charleston, S. C.

The Grunts: Hæmulidæ.—The large family of Hæmulidæ, known in America as grunters or roncos, is represented with the snappers in all tropical seas. The common names (Spanish, roncar, to grunt or snore) refer to the noise made either with their large pharyngeal teeth or with the complex air-bladder. These fishes differ from the Lutianidæ mainly in the feebler detention, there being no canines and no teeth on the vomer. Most of the American species belong to the genus Hæmulon or red-mouth grunts, so called from the dash of scarlet at the corner of the mouth. Hæmulon plumieri, the common grunt, or ronco arará, is the most abundant species, known by the narrow blue stripes across the head. In the yellow grunt, ronco amarillo (Hæmulon sciurus), these stripes cross the whole body. In the margate-fish, or Jallao (Hæmulon album), the largest of the grunts, there are no stripes at all. Another common grunt is the black spotted sailor's choice, Ronco prieto (Hæmulon parra), very abundant from Florida southward. Numerous other grunts and "Tom Tates" are found on both shores of Mexico, all the species of Hæmulon being confined to America. Anisotremus includes numerous deep-bodied species with smaller mouth, also all American. Anisotremus surinamensis, the pompon, abundant from Louisiana southward is the commonest species. Anisotremus virginicus, the porkfish or Catalineta, beautifully striped with black and golden, is very common in the West Indies. Plectorhynchus of Polynesia and the coasts of Asia contains numerous large species closely resembling Anisotremus, but lacking the groove at the chin characteristic of Anisotremus and Hæmulon. Some of these are striped or spotted with black in very gaudy fashion. Pomadasis, a genus equally abundant in Asia and America, contains silvery species of the sandy shores, with the body more elongate and the spines generally stronger. Pomadasis crocro is the commonest West Indian species, Pomadasis hasta the best known of the Asiatic forms. Gnathodentex aurolineatus with golden stripes is common in Polynesia.

Fig. 278.—Porkfish, Anisotremus virginicus (Linnæus). Key West.

The pigfishes, Orthopristis, have the spines feebler and the anal fin more elongate. Of the many species, American and Mediterranean, Orthopristis chrysopterus is most familiar, ranging northward to Long Island, and excellent as a pan fish. Parapristipoma trilineatum, the Isaki of Japan, is equally abundant and very similar to it. Many related species belong to the Asiatic genera, Terapon, Scolopsis, Cæsio, etc., sometimes placed in a distinct family as Teraponidæ. Terapon servus enters the streams of Polynesia, and is a very common fish of the river mouths, taken in Samoa by the boys. Terapon theraps is found throughout the East Indies. Terapon richardsoni is the Australian silver perch. Cæsio contains numerous small species, elongate and brightly colored, largely blue and golden. Scolopsis, having a spine on the preorbital, contains numerous species in the East Indies and Polynesia. These are often handsomely colored. Among them is the taiva, Scolopsis trilineatus of Samoa, gray with white streaks and markings of delicate pattern. A fossil species in the Italian Eocene related to Pomadasis is Pomadasis furcatus. Another, perhaps allied to Terapon, is called Pelates quindecimalis.

Fig. 279.—The Red Tai of Japan, Pagrus major Schlegel. Family Sparidæ. (After Kishinouye.)

The Porgies: Sparidæ.—The great family of Sparidæ or porgies is also closely related to the Hæmulidæ. The most tangible difference rests in the teeth, which are stronger, and some of those along the side of the jaw are transformed into large blunt molars, fitted for grinding small crabs and shells. The name porgy, in Spanish pargo, comes from the Latin Pagrus and Greek πάγρος, the name from time immemorial of the red porgy of the Mediterranean, Pagrus pagrus. In this species the front teeth are canine-like, the side teeth molar. It is a fine food-fish, very handsome, being crimson with blue spots, and in the Mediterranean it is much esteemed. It also breeds sparingly on our south Atlantic and Gulf coasts.

Fig. 280.—Ebisu, the Fish-god of Japan, bearing a Red Tai. (Sketch by Kako Morita.)

Fig. 281.—Scup, Stenotomus chrysops (Linnæus). Wood's Hole, Mass.

Fig. 282.—Calamus bajonado (Bloch & Schneider), Jolt-head Porgy. Pez de Pluma. Family Sparidæ.

Fig. 283.—Little-head Porgy, Calamus proridens Jordan & Gilbert. Key West.

Very similar to the porgy is the famous red tai or akadai of Japan (Pagrus major), a fish so highly esteemed as to be, with the rising sun and the chrysanthemum, a sort of national emblem. In all prints and images the fish-god Ebisu (Fig. 280), beloved of the Japanese people, appears with a red tai under his arm. This species, everywhere abundant, is crimson in color, and the flesh is always tender and excellent. A similar species is the well-known and abundant "schnapper" of Australia, Pagrus unicolor. Another but smaller tai or porgy, crimson, sprinkled with blue spots, Pagrus cardinalis, occurs in Japan in great abundance, as also two species similar in character but without red, known as Kurodai or black tai. These are Sparus latus and Sparus berda. The gilt-head of the Mediterranean, Sparus aurata, is very similar to these Japanese species. Sparus sarba in Australia is the tarwhine, and Sparus australis the black bream. The numerous species of Pagellus abound in the Mediterranean. These are smaller in size than the species of Pagrus, red in color and with feebler teeth. Monotaxis grandoculis, known as the "mu," is a widely diffused and valuable food-fish of the Pacific islands, greenish in color, with pale cross-bands. Very closely related is also the American scup or fair maid (Stenotomus chrysops), one of our commonest pan fishes. In this genus and in Calamus the second interhæmal spine is very greatly enlarged, its concave end formed like a quill-pen and including the posterior end of the large air-bladder. This arrangement presumably assists in hearing. Of the penfishes, or pez de pluma, numerous species abound in tropical America, where they are valued as food. Of these the bajonado or jolt-head porgy (Calamus bajonado) is largest, most common and dullest in color. Calamus calamus is the saucer-eye porgy, and Calamus proridens, the little-head porgy. Calamus leucosteus is called white-bone porgy, and the small Calamus arctifrons the grass-porgy.

The Chopa spina, or pinfish, Lagodon rhomboides, is a little porgy with notched incisors, exceedingly common on our South Atlantic coast.

In some of the porgies the front teeth instead of being canine-like are compressed and truncate, almost exactly like human incisors. These species are known as sheepshead, or sargos.

Fig. 284.—Diplodus holbrooki Bean. Pensacola.

Diplodus sargus and Diplodus annularis are common sargos of the Mediterranean, silvery, with a black blotch on the back of the tail. Diplodus argenteus of the West Indies and Diplodus holbrooki of the Carolina coast are very close to these.

The sheepshead, Archosargus probatocephalus, is much the most valuable fish of this group. The broad body is crossed by about seven black cross-bands. It is common from Cape Cod to Texas in sandy bays, reaching rarely a weight of fifteen pounds. Its flesh is most excellent, rich and tender. The sheepshead is a quiet bottom-fish, but takes the hook readily and with some spirit. Close to the sheepshead is a smaller species known as Salema (Archosargus unimaculatus), with blue and golden stripes and a black spot at the shoulder. It abounds in the West Indies.

Fig. 285.—Archosargus unimaculatus (Bloch), Salema, Striped Sheepshead. Family Sparidæ.

On the coast of Japan and throughout Polynesia are numerous species of Lethrinus and related genera, formed and colored like snappers, but with molar teeth and the cheek without scales. A common species in Japan is Lethrinus richardsoni.

Fossil species of Diplodus, Sparus, Pagrus, and Pagellus occur in the Italian Eocene, as also certain extinct genera, Sparnodus and Trigonodon, of similar type. Sparnodus macrophthalmus is abundant in the Eocene of Monte Bolca.

The Picarels: Mænidæ.—The Mænidæ, or Picarels, are elongate, gracefully formed fishes, remarkable for the extreme protractility of the upper jaw. Spicara smaris and several other small species are found in the Mediterranean. Emmelichthys contains species of larger size occurring in the West Indies and various parts of the Pacific, chiefly red and very graceful in form and color. Emmelichthys vittatus, the boga, is occasionally taken in Cuba, Erythrichthys schlegeli is found in Japan and Hawaii.

Fig. 286.—Mojarra, Xystæma cinereum (Walbaum). Key West.

The Mojarras: Gerridæ.—The Gerridæ, or Mojarras, have the mouth equally protractile, but the form of the body is different, being broad, compressed, and covered with large silvery scales. In some species the dorsal spines and the third anal spine are very strong, and in some the second interhæmal is quill-shaped, including the end of the air-bladder, as in Calamus. Most of the species, including all the peculiar ones, are American. The smallest, Eucinostomus, have the quill-shaped interhæmal and the dorsal and anal spines are very weak. The commonest species is the silver jenny, or mojarra de Ley, Eucinostomus gula, which ranges from Cape Cod to Rio Janeiro, in the surf along sandy shores. Equally common is Eucinostomus californiensis of the Pacific Coast of Mexico, while Eucinostomus harengulus of the West Indies is also very abundant. Ulæma lefroyi has but two anal spines and the interhæmal very small. It is common through the West Indies. Xystæma, with the interhæmal spear-shaped and normally formed, is found in Asia and Polynesia more abundantly than in America, although one species, Xystæma cinereum, the broad shad, or Mojarra blanca, is common on both shores of tropical America. Xystæma gigas is found in Polynesia, X. oyena in Japan, and X. filamentosum in Formosa and India. Xystæma massalongoi is also fossil in the Miocene of Austria. The species of Gerres have very strong dorsal and anal spines and the back much elevated. Gerres plumieri, the striped mojarra, Gerres brasiliensis, the patao, Gerres olisthostomus, the Irish pampano, and Gerres rhombeus are some of the numerous species found on the Florida coast and in the West Indies. The family of Leiognathidæ, already noticed (page 287), should stand next to the Gerridæ.

Fig. 287.—Irish Pampano, Gerres olisthostomus Goode & Bean. Indian River, Fla.

The Rudder-fishes: Kyphosidæ.—The Kyphosidæ, called rudder-fishes, have no molars, the front of the jaws being occupied by incisors, which are often serrated, loosely attached, and movable. The numerous species are found in the warm seas and are chiefly herbivorous.

Fig. 288.—Chopa or Rudder-fish, Kyphosus sectatrix (Linnæus). Wood's Hole, Mass.

Boops boops and Boops salpa, known as boga and salpa, are elongate fishes common in the Mediterranean. Other Mediterranean forms are Spondyliosoma cantharus, Oblata melanura, etc. Girella nigricans is the greenfish of California, everywhere abundant about rocks to the south of San Francisco, and of considerable value as food. Almost exactly like it is the Mejinadai (Girella punctata) of Japan. The best-known members of this group belong to the genus Kyphosus. Kyphosus sectatrix is the rudder-fish, or Chopa blanca, common in the West Indies and following ships to the northward even as far as Cape Cod, once even taken at Palermo. It is supposed that it is enticed by the waste thrown overboard. Kyphosus elegans is found on the west coast of Mexico, Kyphosus tahmel in the East Indies and Polynesia, and numerous other species occur in tropical America and along the coasts of southern Asia. Sectator ocyurus is a more elongate form of rudder-fish, striped with bright blue and yellow, found in the Pacific. Medialuna californiensis is the half-moon fish, or medialuna, of southern California, an excellent food-fish frequently taken on rocky shores. Numerous related species occur in the Indian seas.

Fig. 288a.—Blue-green Sunfish, Apomotis cyanellus (Rafinesque). Kansas River. (After Kellogg.)

Fossil fragments in Europe have been referred to Boops, Spondyliosoma, and other genera.

CHAPTER XX
THE SURMULLETS, THE CROAKERS AND THEIR
RELATIVES

Fig. 289.—Red Goatfish, or Salmonete, Pseudupeneus maculatus Bloch. Family Mullidæ (Surmullets.)

The Surmullets, or Goatfishes: Mullidæ.—The Mullidæ (Surmullets) are shore-fishes of the warm seas, of moderate size, with small mouth, large scales, and possessing the notable character of two long, unbranched barbels of firm substance at the chin. The dorsal fins are short, well separated, the first of six to eight firm spines. There are two anal spines and the ventral fins, thoracic, are formed of one spine and five rays. The flesh is white and tender, often of very superior flavor. The species are carnivorous, feeding chiefly on small animals. They are not voracious, and predaceous fishes feed freely on them. The coloration is generally bright, largely red or golden, in nearly all cases with an under layer, below the scales, of red, which appears when the fish is scaled or placed in alcohol. The barbels are often bright yellow, and when the fish swims along the bottom these are carried in advance, feeling the way. Testing the bottom with their feelers, these fishes creep over the floor of shallow waters, seeking their food.

The numerous species are all very much alike in form, and the current genera are separated by details of the arrangement of the teeth. But few are found outside the tropics.

The surmullet or red mullet of Europe, Mullus barbatus, is the most famous species, placed by the Romans above all other fishes unless it be the scarus, Sparisoma cretense. From the satirical poets we learn that "enormous prices were paid for a fine fish, and it was the fashion to bring the fish into the dining-room and exhibit it alive before the assembled guests, so that they might gloat over the brilliant and changing colors during the death-agonies." It is red in life, and when the scales are removed, the color is much brighter.

It is an excellent fish, tender and rich, but nowhere so extravagantly valued to-day as was formerly the case in Rome. Mullus surmuletus is a second European species, scarcely different from Mullus barbatus.

Fig. 290.—Golden Surmullet, Mullus auratus Jordan & Gilbert. Wood's Hole, Mass.

Equally excellent as food and larger in size are two Polynesian species known as kumu and munu (Pseudupeneus porphyreus and Pseudupeneus bifasciatus). Mullus auratus is a small surmullet occasionally taken off our Atlantic coast, but in deeper water than that frequented by the European species. Pseudupeneus maculatus is the red goatfish or salmonete, common from Florida to Brazil, as is also the yellow goatfish, Pseudupeneus martinicus, equally valued. Many other species are found in tropical America, Polynesia, and the Indies and Japan. Perhaps the most notable are Upeneus vittatus, striped with yellow and with the caudal fin cross-barred and the belly sulphur-yellow, and Upeneus arge, similar, the belly white. The common red and black-banded "moana" or goatfish of Hawaii is Pseudupeneus multifasciatus.

No fossil Mullidæ are recorded, so far as known to us.

The Croakers: Sciænidæ.—The family of Sciænidæ (croakers, roncadors) is another of the great groups of food-fishes. The species are found on every sandy shore in warm regions and all of them are large enough to have value as food, while many have flesh of superior quality. None are brightly colored, most of the species being nearly plain silvery.

Fig. 291.—Spotted Weakfish, Cynoscion nebulosus. Virginia.

Special characters are the cavernous structure of the bones of the head, which are full of mucous tracts, the specialization (and occasional absence) of the air-bladder, and the presence of never more than two anal spines, one of these being sometimes very large. Most of the species are marine, all are carnivorous; none inhabit rocky places and none descend to depths in the sea. At the least specialized extreme of the family, the mouth is large with strong canines and the species are slender, swift, and predaceous.

The weakfish or squeteague (Cynoscion regalis) is a type of a multitude of species, large, swift, voracious, but with tender flesh, which is easily torn. The common weakfish, abundant on our Atlantic coast, suffers much at the hands of its enemy and associate, the bluefish. It is one of the best of all our food-fishes. Farther south the spotted weakfish (Cynoscion nebulosus), very incorrectly known as sea-trout, takes its place, and about New Orleans is especially and justly prized.

The California "bluefish," Cynoscion parvipinnis, is very similar to these Atlantic species, and there are many other species of Cynoscion on both coasts of tropical America, forming a large part of the best fish-supply of the various markets of the mainland. On the rocky islands, as Cuba, and about coral reefs, Sciænidæ are practically unknown. In the Gulf of California, the totuava, Cynoscion macdonaldi, reaches a weight of 172 pounds, and the stateliest of all, the great "white sea-bass" of California, Cynoscion nobilis, reaches 100 pounds. In these large species the flesh is much more firm than in the weakfish and thus bears shipment better. Cynoscion has canines in the upper jaw only and its species are all American. In the East Indies the genus Otolithes has strong canines in both jaws. Its numerous species are very similar in form, habits, and value to those of Cynoscion. The queenfish, Seriphus politus, of the California coast, is much like the others of this series, but smaller and with no canines at all. It is a very choice fish, as are also the species of Macrodon (Ancylodon) known as pescadillo del red, voracious fishes of both shores of South America.

Plagioscion squamosissimus and numerous species of Plagioscion and other genera live in the rivers of South America. A single species, the river-drum, gaspergou, river sheepshead, or thunder-pumper (Aplodinotus grunniens), is found in streams in North America. This is a large fish reaching a length of nearly three feet. It is very widely distributed, from the Great Lakes to Rio Usumacinta in Guatemala, whence it has been lately received by Dr. Evermann. This species abounds in lakes and sluggish rivers. The flesh is coarse, and in the Great Lakes it is rarely eaten, having a rank odor. In Louisiana and Texas it is, however, regarded as a good food-fish. In this species the lower pharyngeals are very large and firmly united, while, as in all other Sciænidæ, except the genus Pogonias, these bones are separated. In all members of the family the ear-bones or otoliths are largely developed, often finely sculptured. The otoliths of the river-drum are known to Wisconsin boys as "lucky-stones," each having a rude impress of the letter L. The names roncador, drum, thunder-pumper, croaker, and the like refer to the grunting noise made by most Sciænidæ in the water, a noise at least connected with the large and divided air-bladder.

Fig. 292.—Mademoiselle, Bairdiella chrysura (Linnæus). Virginia.

Numerous silvery species belong to Larimus, Corvula, Odontoscion, and especially to Bairdiella, a genus in which the second anal spine is unusually strong. The mademoiselle, Bairdiella chrysura is a pretty fish of our Atlantic coast, excellent as a pan fish. In Bairdiella ensifera of Panama the second anal spine is enormously large, much as in a robalo (Oxylabrax).

In Stellifer and Nebris, the head is soft and spongy. Stellifer lanceolatus is occasionally taken off South Carolina, and numerous other species of this and related genera are found farther South.

Sciænops ocellata is the red-drum or channel bass of our South Atlantic coast, a most important food-fish reaching a weight of seventy-five pounds. It is well marked by a black ocellus on the base of the tail. On the coast of Texas, this species, locally called redfish, exceeds in economic value all other species found in that State.

Pseudosciæna aquila, the maigre of southern Europe, is another large fish, similar in value to the red drum. Pseudosciæna antarctica is the kingfish of Australia. To Sciæna belong many species, largely Asiatic, with the mouth inferior, without barbels, the teeth small, and the convex snout marked with mucous pores. Sciæna umbra, the ombre, is the common European species, Sciæna saturna, the black roncador of California, is much like it. Sciæna deliciosa is one of the most valued food-fishes of Peru, and Sciæna argentata is valued in Japan. Species of Sciæna are especially numerous on the coasts of India.

Fig. 293.—Red Drum, Sciænops ocellata Linnæus. Texas.

Roncador stearnsi, the California roncador, is a large fish with a black ocellus at the base of the pectoral. It has some importance in the Los Angeles market. The goody, spot, or lafayette (Leiostomus xanthurus) is a small, finely flavored species abundant from Cape Cod to Texas. Similar to it but inferior is the little roncador (Genyonemus lineatus) of California. The common croaker, Micropogon undulatus, is very abundant on our Eastern coast, and other species known as verrugatos or white-mouthed drummers replace it farther South.

In Umbrina the chin has a short thick barbel. The species abound in the tropics, Umbrina cirrosa in the Mediterranean; Umbrina coroides in California, and the handsome Umbrina roncador, the yellow-tailed roncador, in southern California. The kingfish, Menticirrhus, differs in lacking the air-bladder, and lying on the bottom in shallow water the lower fins are enlarged much as in the darters or gobies. All the species are American. All are dull-colored and all excellent as food. Menticirrhus saxatilis is the common kingfish or sea-mink, abundant from Cape Ann southward, Menticirrhus americanus is the equally common sand-whiting of Carolina, and Menticirrhus littoralis the surf-whiting. The California whiting or sand-sucker is Menticirrhus undulatus.

Fig. 294.—Yellow-fin Roncador, Umbrina sinaloæ Scofield. Mazatlan.

Fig. 295.—Kingfish, Menticirrhus americanus (Linnæus). Pensacola.

Pogonias chromis, the sea-drum, has barbels on the chin and the lower pharyngeals are enlarged and united as in the river-drum, Aplodinotus. It is a coarse fish common on our Atlantic coasts, a large specimen taken at St. Augustine weighing 146 pounds. Other species of this family, belonging to the genus Eques, are marked with ribbon-like stripes of black. Eques lanceolatus, known in Cuba as serrana, is the most ornate of these species, looking like a butterfly-fish or Chætodon.

Several fossil fragments have been doubtfully referred to Sciæna, Umbrina, Pogonias, and other genera. Otoliths or ear-bones not clearly identifiable are found from the Miocene on. These structures are more highly specialized in this group than in any other.

Fig. 296.—Drum, Pogonias chromis (Linnæus). Matanzas, Fla.

The Sillaginidæ, etc.—Allied to the Sciænidæ is the small family of Kisugos, Sillaginidæ, of the coasts of Asia. These are slender, cylindrical fishes, silvery in color, with a general resemblance to small Sciænas.

Sillago japonicas, the kisugo of Japan, is a very abundant species, valued as food. Sillago sihama ranges from Japan to Abyssinia.

A number of small families, mostly Asiatic, may be appended to the percoid series, with which they agree in general characters, especially in the normal structure of the shoulder-girdle and in the insertion of the pectoral and ventral fins.

The Lactariidæ constitute a small family of the East Indies, allied to the Sciænidæ, but with three anal spines. The mouth is armed with strong teeth. Lactarius lactarius is a food-fish of India.

The Nandidæ are small spiny-rayed fishes of the East Indian streams, without pseudobranchiæ.

The Polycentridæ are small fresh-water perch-like fishes of the streams of South America, without lateral line and with many anal spines.

The Jawfishes: Opisthognathidæ, etc.—The Pseudochromipidæ are marine-fishes of the tropics with the lateral line interrupted, and with a single dorsal. They bear some resemblance to Plesiops and other aberrant Serranidæ.

Fig. 297.—Gnathypops evermanni Jordan & Snyder. Misaki, Japan.

Fig. 298.—Jawfish, Opisthognathus macrognathus Poey. Tortugas, Fla.

Very close to these are the Opisthognathidæ or jawfishes with a single lateral line and the mouth very large. In certain species of Opisthognathus, the maxillary, long and curved, extends far behind the head. The few species are found in warm seas, but always very sparingly. Some of them are handsomely colored.

The Stone-wall Perch: Oplegnathidæ.—A singular group evidently allied to the Hæmulidæ is the family of Oplegnathidæ. In these fishes the teeth are grown together to form a bony beak like the jaw of a turtle. Except for this character, the species are very similar to ordinary grunts. While the mouth resembles that of the parrot-fish, it is structurally different and must have been independently developed. Oplegnathus punctatus, the "stonewall perch" (ishigakidai), is common in Japan, as is also the banded Oplegnathus fasciatus. Other species are found in Australia and Chile.

Fig. 299.—Opisthognathus nigromarginatus. India. (After Day.)

The Swallowers: Chiasmodontidæ.—The family of swallowers Chiasmodontidæ, is made up of a few deep-sea fishes of soft flesh and feeble spines, the opercular apparatus much reduced. The ventrals are post-thoracic, the rays I, 5, facts which point to some affinity with the Opisthognathidæ, although Boulenger places these fishes among the Percesoces. Chiasmodon niger, the black swallower of the mid-Atlantic, has exceedingly long teeth and the whole body so distensible that it can swallow fishes of many times its own size. According to Gill:

Fig. 300.—Black Swallower, Chiasmodon niger Johnson, containing a fish larger than itself. Le Have Bank.

"It espies a fish many times larger than itself, but which, nevertheless, may be managed; it darts upon it, seizes it by the tail and gradually climbs over it with its jaws, first using one and then the other; as the captive is taken in the stomach and integuments stretch out, and at last the entire fish is passed through the mouth and into the stomach, and the distended belly appears as a great bag, projecting out far backwards and forwards, over which is the swallower with the ventrals dislocated and far away from their normal place. The walls of the stomach and belly have been so stretched that they are transparent, and the species of the fish can be discerned within. But such rapacity is more than the captor itself can stand. At length decomposition sets in, the swallower is forced belly upwards, and the imprisoned gas, as in a balloon, takes it upwards from the depths to the surface of the ocean, and there, perchance, it may be found and picked up, to be taken home for a wonder, as it is really. Thus have at least three specimens found their way into museums—one being in the United States National Museum—and in each the fish in the stomach has been about twice as long, and stouter in proportion, than the swallower—six to twelve times bulkier! Its true habitat seems to be at a depth of about 1,500 fathoms."

Allied to this family is the little group of Champsodontidæ of Japan and the East Indies. Champsodon vorax looks like a young Uranoscopus. The body is covered with numerous lateral lines and cross-lines.

The Malacanthidæ.—The Malacanthidæ are elongate fishes, rather handsomely colored, with a strong canine on the premaxillary behind. Malacanthus plumieri, the matajuelo blanco, a slender fish of a creamy-brown color, is common in the West Indies. Other species are found in Polynesia, the most notable being Malacanthus (or Oceanops) lativittatus, a large fish of a brilliant sky-blue, with a jet-black lateral band. In Samoa this species is called gatasami, the "eye of the sea."

The Blanquillos: Latilidæ.—The Latilidæ, or blanquillos, have also an enlarged posterior canine, but the body is deeper and the flesh more firm. The species reach a considerable size and are valued as food. Lopholotilus chamæleonticeps is the famous tilefish dredged in the depths under the Gulf Stream. It is a fish of remarkable beauty, red and golden. This species, Professor Gill writes, "was unknown until 1879, when specimens were brought by fishermen to Boston from a previously unexplored bank about eighty miles southeast of No Man's Land, Mass. In the fall of 1880 it was found to be extremely abundant everywhere off the coast of southern New England at a depth of from seventy-five to two hundred and fifty fathoms. The form of the species is more compressed, and higher, than in most of the family, and what especially distinguishes it is the development of a compressed, 'fleshy, fin-like appendage over the back part of the head and nape, reminding one of the adipose fin of the salmonids and catfishes.' It is especially notable, too, for the brilliancy of its colors, as well as for its size, being by far larger than any other member of its family. A weight of fifty pounds or more is, or rather, one might say, was frequently attained by it, although such was very far above the average, that being little over ten pounds. In the reach of water referred to, it could once be found abundantly at any time, and caught by hook and line. After a severe gale in March, 1882, millions of tilefish could be seen, or calculated for, on the surface of the water for a distance of about three hundred miles from north to south, and fifty miles from east to west. It has been calculated by Capt. Collins that as many as one thousand four hundred and thirty-eight millions were scattered over the surface. This would have allowed about two hundred and twenty-eight pounds to every man, woman and child of the fifty million inhabitants of the United States! On trying at their former habitat the next fall, as well as all successive years to the present time, not a single specimen could be found where formerly it was so numerous. We have thus a case of a catastrophe which, as far as has been observed, caused complete annihilation of an abundant animal in a very limited period. Whether the grounds it formerly held will be reoccupied subsequently by the progeny of a protected colony remains to be seen, but it is scarcely probable that the entire species has been exterminated." It is now certain that the species is not extinct.

Caulolatilus princeps is the blanquillo or "whitefish" of southern California, a large handsome fish formed like a dolphin, of purplish, olivaceous color and excellent flesh. Other species of Caulolatilus are found in the West Indies. Latilus japonicus is the amadai or sweet perch of Japan, an excellent food-fish of a bright crimson color.

The Pinguipedidæ of Chile resemble the Latilidæ, having also the enlarged premaxillary tooth. The ventrals are, however, thickened and placed farther forward.

The Bandfishes: Cepolidæ.—The small family of Cepolidæ, or bandfishes, resemble the Latilidæ somewhat and are probably related to them. The head is normally formed, the ventral fins are thoracic, with a spine and five rays, but the body is drawn out into a long eel-like form, the many-rayed dorsal and anal fins meeting around the tail. The few species are crimson in color with small scales. They are used as food, but the flesh is dry and the bones are stiff and numerous. Cepola tænia is common in the Mediterranean, and Acanthocepola krusensterni abounds in the bays of southern Japan.

The Cirrhitidæ.—The species of the family Cirrhitidæ strongly resemble the smaller Serranidæ and even Serranus itself, but the lower rays of the pectoral fins are enlarged and are undivided, as in the sea-scorpions and some sculpins. In these fishes, however, the bony stay, which characterizes Scorpænidæ and Cottidæ, is wholly absent. It is, however, considered possible that this interesting family represents the point of separation at which the mail-cheeked fishes become differentiated from the typical perch-like forms. Goniistius zonatus, the takanohadai, is a valuable food-fish of Japan, marked by black cross-bands. Paracirrhites forsteri and other species of Cirrhitus and Paracirrhites are very pretty fishes of the coral reefs, abundant in the markets of Honolulu, the spotted Cirrhitus marmoratus being the most widely diffused of these. Only one species of this family, Cirrhitus rivulatus, a large fish, green, with blue markings, is found in American waters. It frequents the rocky shores of the west coast of Mexico.

Allied to the Cirrhitidæ is the small family of Latrididæ, with a long dorsal fin deeply divided, and the lower rays of the pectoral similarly modified. Latris hecateia is called the "trumpeter" in Australian waters. It is one of the best food-fishes of Australia, reaching a weight of sixty to eighty pounds.

Another small family showing the same peculiar structure of the pectoral fin is that of the Aplodactylidæ. The species of Aplodactylus live on the coasts of Chile and Australia. They are herbivorous fishes, with flat, tricuspid teeth, and except for their pectoral fins are very similar to the Kyphosidæ.

Fig. 301.—Cirrhitus rivulatus Valenciennes. Mazatlan.

The Sandfishes: Trichodontidæ.—In the neighborhood of the Latrididæ, Dr. Boulenger places the Trichodontidæ or sandfishes, small, scaleless, silvery fishes of the northern Pacific. These are much compressed in body, with very oblique mouths, with fringed lips and, as befits their northern habitat, with a much increased number of vertebræ. They bury themselves in sand under the surf, and the two species, Trichodon trichodon and Arctoscopus japonicus, range very widely in the regions washed by the Japan current. These species bear a strong resemblance to the star-gazers (Uranoscopus), but this likeness seems to be superficial only.

Fig. 302.—Sandfish, Trichodon trichodon (Tilesius). Shumagin Islands, Alaska.

CHAPTER XXI
LABYRINTHICI AND HOLCONOTI

The Labyrinthine Fishes.—An offshoot of the Percomorphi is the group of Labyrinthici, composed of perch-like fishes which have a very peculiar structure to the pharyngeal bones and respiratory apparatus. This feature is thus described by Dr. Gill:

"The upper elements of one of the pairs of gill-bearing arches are peculiarly modified. The elements in question (called branchihyal) of each side, instead of being straight and solid, as in most fishes, are excessively developed and provided with several thin plates or folds, erect from the surface of the bones and the roof of the skull, to which the bones are attached. These plates, by their intersection, form chambers, and are lined with a vascular membrane, which is supplied with large blood-vessels. It was formerly supposed that the chambers referred to had the office of receiving and retaining supplies of water which should trickle down and keep the gills moist; such was supposed to be an adaptation for the sustentation of life out of the water. The experiments of Surgeon Day, however, throw doubt upon this alleged function, and tend to show: (1) that these fishes died when deprived of access to atmospheric air, not from any deleterious properties either in the water or in the apparatus used, but from being unable to subsist on air obtained solely from the water, aerial respiration being indispensable; (2) that they can live in moisture out of the water for lengthened periods, and for a short, but variable period in water only; and (3) that the cavity or receptacle does not contain water, but has a moist secreting surface, in which air is retained for the purpose of respiration. It seems probable that the air, after having been supplied for aerial respiration, is ejected by the mouth, and not swallowed to be discharged per anum. In fine, the two respiratory factors of the branchial apparatus have independent functions: (1) the labyrinthiform, or branchihyal portion, being a special modification for the respiration of atmospheric air, and (2) the gill filaments discharging their normal function. If, however, the fish is kept in water and prevented from coming to the surface to swallow the atmospheric air, the labyrinthiform apparatus becomes filled with water which cannot be discharged, owing to its almost non-contractile powers. There is thus no means of emptying it, and the water probably becomes carbonized and unfit for oxygenizing the blood, so that the whole of the respiration is thus thrown on the branchiæ. This will account for the fact that when the fish is in a state of quiescence, it lives much longer than when excited, whilst the sluggishness sometimes evinced may be due to poisoned or carbonized blood."

Four families of labyrinth-gilled fishes are recognized by Professor Gill; and to these we may append a fifth, which, however, lacks the elaborate structures mentioned above and which shows other evidences of degeneration.

The Climbing-perches: Anabantidæ.—The family of Anabantidæ, according to Gill, "includes those species which have the mouth of moderate size and teeth on the palate (either on the vomer alone, or on both the vomer and palatine bones). To the family belongs the celebrated climbing-fish.

Fig. 303.—The Climbing Perch, Anabas scandens Linnæus. Opercle cut away to show the gill-labyrinth.

"The climbing-fish (Anabas scandens) is especially noteworthy for the movability of the suboperculum. The operculum is serrated. The color is reddish olive, with a blackish spot at the base of the caudal fin; the head, below the level of the eye, grayish, but relieved by an olive band running from the angle of the mouth to the angle of the preoperculum, and with a black spot on the membrane behind the hindermost spines of the operculum.

"The climbing-fish was first made known in a memoir, printed in 1797, by Daldorf, a lieutenant in the service of the Danish East India Company at Tranquebar. Daldorf called it Perca scandens, and affirmed that he himself had taken one of these fishes, clinging by the spine of its operculum in a slit in the bark of a palm (Borassus flabelliformis) which grew near a pond. He also described its mode of progression; and his observations were substantially repeated by the Rev. Mr. John, a missionary resident in the same country. His positive evidence was, however, called into question by those who doubted on account of hypothetical considerations. Even in popular works not generally prone to even a judicious skepticism, the accounts were stigmatized as unworthy of belief. We have, however, in answer to such doubts, too specific information to longer distrust the reliability of the previous reports.

"Mr. Rungasawmy Moodeliar, a native assistant of Capt. Jesse Mitchell of the Madras Government Central Museum, communicated to his superior the statement that 'this fish inhabits tanks or pools of water, and is called Panai feri, i.e., the fish that climbs palmyra-trees. When there are palmyra-trees growing by the side of a tank or pool, when heavy rain falls and the water runs profusely down their trunks, this fish, by means of its opercula, which move unlike those of other fishes, crawls up the tree sideways (i.e., inclining to the sides considerably from the vertical) to a height of from five to seven feet, and then drops down. Should this fish be thrown upon the ground, it runs or proceeds rapidly along in the same manner (sideways) as long as the mucus on it remains.'

"These movements are effected by the opercula, which, it will be remembered, are unusually mobile in this species; they can, according to Captain Mitchell (and I have verified the statement), be raised or turned outwards to nearly a right angle with the body, and when in that position, the suboperculum distends a little, and it appears that it is chiefly by the spines of this latter piece that the fish takes a purchase on the tree or ground. 'I have,' says Captain Mitchell, 'ascertained by experiment that the mere closing of the operculum, when the spines are in contact with any surface, even common glass, pulls an ordinary-sized fish forwards about half an inch,' but it is probable that additional force is supplied by the caudal and anal fins, both of which, it is said, are put in use when climbing or advancing on the ground; the motion, in fact, is described as a wriggling one.

"The climbing-fish seems to manifest an inclination to ascend streams against the current, and we can now understand how, during rain, the water will flow down the trunk of a tree, and the climbing-fish, taking advantage of this, will ascend against the down-flow by means of the mechanism already described, and by which it is enabled to reach a considerable distance up the trunk." (Gill.)

The Gouramis: Osphromenidæ.—"The Osphromenidæ are fishes with a mouth of small size, and destitute of teeth on the palate. To this family belongs the gourami, whose praises have been so often sung, and which has been the subject of many efforts for acclimatization in France and elsewhere by the French.

"The gourami (Osphromenus goramy) has an oblong, oval form, and, when mature, the color is nearly uniform, but in the young there are black bands across the body, and also a blackish spot at the base of the pectoral fin. The gourami, if we can credit reports, occasionally reaches a gigantic size, for it is claimed that it sometimes attains a length of 6 feet, and weighs 150 pounds, but if this is true, the size is at least exceptional, and one of 20 pounds is a very large fish; indeed, they are considered very large if they weigh as much as 12 or 14 pounds, in which case they measure about 2 feet in length.

"The countries in which the gourami is most at home lie in the intertropical belt. The fish is assiduous in the care of its young, and prepares a nest for the reception of eggs. The bottom selected is muddy, the depth variable within a narrow area, that is, in one place about a yard, and near by several yards deep.

"They prefer to use, for the nests, tufts of a peculiar grass (Panicum jumentorum) which grows on the surface of the water, and whose floating roots, rising and falling with the movements of the water, form natural galleries, under which the fish can conceal themselves. In one of the corners of the pond, among the plants which grow there, the gouramis attach their nest, which is of a nearly spherical form, and composed of plants and mud, and considerably resembles in form those of some birds.

"The gourami is omnivorous, taking at times flesh, fish, frogs, insects, worms, and many kinds of vegetables; and on account of its omnivorous habit, it has been called by the French colonists of Mauritius porc des rivières, or 'water-pig.' It is, however, essentially a vegetarian, and its adaptation for this diet is indicated by the extremely elongated intestinal canal, which is many times folded upon itself. It is said to be especially fond of the leaves of several araceous plants. Its flesh is, according to several authors, of a light-yellow straw-color, firm and easy of digestion. They vary in quality with the nature of the waters inhabited, those taken from a rocky river being much superior to those from muddy ponds; but those dwelling at the mouth of rivers, where the water is to some extent brackish, are the best of all. Again, they vary with age; and the large, overgrown fishes are much less esteemed than the small ones. They are in their prime when three years old. Dr. Vinson says the flavor is somewhat like that of carp; and, if this is so, we may entertain some skepticism as to its superiority; but the unanimous testimony in favor of its excellence naturally leads to the belief that the comparison is unfair to the gourami.

"Numerous attempts have been made by the French to introduce the gourami into their country, as well as into several of their provinces; and for a number of years consignments of the eggs, or the young, or adult fish, were made. Although at least partially successful, the fish has never been domiciliated in the Republic, and, indeed, it could not be reasonably expected that it would be, knowing, as we do, its sensitiveness to cold and the climates under which it thrives.

"The fish of paradise (Macropodus viridi-auratus) is a species remarkable for its beauty and the extension of its fins, and especially of the ventrals, which has obtained for it the generic name Macropodus. To some extent this species has also been made the subject of fish-culture, but with reference to its beauty and exhibition in aquaria and ponds, like the goldfish, rather than for its food qualities.

"The only other fish of the family that needs mention is the fighting-fish (Betta pugnax). It is cultivated by the natives of Siam, and a special race seems to have been the result of such cultivation. The fishes are kept in glasses of water and fed, among other things, with the larvæ of mosquitoes or other aquatic insects. 'The Siamese are as infatuated with the combats of these fishes as the Malays are with their cock-fights, and stake on the issue considerable sums, and sometimes their own persons and families. The license to exhibit fish-fights is farmed, and brings a considerable annual revenue to the king of Siam. The species abounds in the rivulets at the foot of the hills of Penang. The inhabitants name it 'pla-kat,' or the 'fighting-fish.'"

The Helostomidæ are herbivorous, with movable teeth on the lips and with long intestines. Helostoma temmincki lives in the rivers of Java, Borneo, and Sumatra.

The Luciocephalidæ of East Indian rivers have the suprabranchial organ small, formed of two gill-arches dilated by a membrane. In these species there are no spines in the dorsal and anal, while in the Anabantidæ and Osphromenidæ numerous spines are developed both in the dorsal and anal. Luciocephalus pulcher indicates a transition toward the Ophicephalidæ.

The Snake-head Mullets: Ophicephalidæ.—The family of Ophicephalidæ, snake-head mullets, or China-fishes, placed among the Percesoces by Cope and Boulenger, seems to us nearer the Labyrinthine fishes, of which it is perhaps a degenerate descendant. The body is long, cylindrical, covered with firm scales which on the head are often larger and shield-like. The mouth is large, the head pike-like, and the habit carnivorous and voracious. There are no spines in any of the fins, but the thoracic position of the ventrals indicates affinity with perch-like forms and the absence of ventral spines seems rather a feature of degradation, the more so as in one genus (Channa) the ventrals are wanting altogether. The numerous species are found in the rivers of southern China and India, crossing to Formosa and to Africa. They are extremely tenacious of life, and are carried alive by the Chinese to San Francisco and to Hawaii, where they are now naturalized, being known as "China-fishes."

Fig. 304.—Channa formosana Jordan & Evermann. Streams of Formosa.

Fig. 305.—Snake-headed China-fish, Ophicephalus barca. India. (After Day.)

These fishes have no special organ for holding water on the gills, but the gill space may be partly closed by a membrane. According to Dr. Günther, these fishes are "able to survive drought living in semi-fluid mud or lying in a torpid state below the hard-baked crusts of the bottom of a tank from which every drop of water has disappeared. Respiration is probably entirely suspended during the state of torpidity, but whilst the mud is still soft enough to allow them to come to the surface, they rise at intervals to take in a quantity of air, by means of which their blood is oxygenized. This habit has been observed in some species to continue also to the period of the year in which the fish lives in normal water, and individuals which are kept in a basin and prevented from coming to the surface and renewing the air for respiratory purposes are suffocated. The particular manner in which the accessory branchial cavity participates in respiratory functions is not known. It is a simple cavity, without an accessory branchial organ, the opening of which is partly closed by a fold of the mucous membrane."

Ophicephalus striatus is the most widely diffused species in China, India, and the Philippines, living in grassy swamps and biting at any bait from a live frog to an artificial salmon-fly. It has been introduced into Hawaii. Ophicephalus marulius is another very common species, as is also Channa orientalis, known by the absence of ventral fins.

Suborder Holconoti, the Surf-fishes.—Another offshoot from the perch-like forms is the small suborder of Holconoti (ὅλκος, furrow; νῶτος, back). It contains fishes percoid in appearance, with much in common with the Gerridæ and Sparidæ, but with certain striking characteristics not possessed by any perch or bass. All the species are viviparous, bringing forth their young alive, these being in small number and born at an advanced stage of development. The lower pharyngeals are solidly united, as in the Labridæ, a group which these fishes resemble in scarcely any other respects. The soft dorsal and anal are formed of many fine rays, the anal being peculiarly modified in the male sex. The nostrils, ventral fins, and shoulder-girdle have the structure normal among perch-like fishes, and the dorsal furrow, which suggested to Agassiz the name of Holconoti, is also found among various perch-like forms.

Fig. 306.—White Surf-fish, viviparous, with young, Cymatogaster aggregatus Gibbons. San Francisco.

Fig. 307.—Fresh-water Viviparous Perch, Hysterocarpus traski Gibbons. Sacramento River.

Fig. 308.—Hypsurus caryi (Agassiz). Monterey.

The Embiotocidæ.—The group contains a single family, the Embiotocidæ, or surf-fishes. All but two of the species are confined to California, these two living in Japan. The species are relatively small fishes, from five inches to eighteen inches in length, with rather large, usually silvery scales, small mouths and small teeth. They feed mainly on crustaceans, two or three species being herbivorous. With two exceptions, they inhabit the shallow waters on sandy beaches, where they bring forth their young. They can be readily taken in nets in the surf. As food-fishes they are rather inferior, the flesh being somewhat watery and with little flavor. Many are dried by the Chinese. The two exceptions in distribution are Hysterocarpus traski, which lives exclusively in fresh waters, being confined to the lowlands of the Sacramento Basin, and Zalembius rosaceus, which descends to considerable depths in the sea. In Hysterocarpus the spinous dorsal is very greatly developed, seventeen stout spines being present, the others having but eight to eleven and these very slender.

Fig. 309.—White Surf-fish, Damalichthys argyrosomus (Girard). British Columbia.

Fig. 310.—Thick-lipped Surf-fish, Rhacochilus toxotes Agassiz. Monterey, Cal.

Fig. 311.—Silver Surf-fish (viviparous), Hypocritichthys analis (Agassiz). Monterey.

The details of structure vary greatly among the different species, for which reason almost every species has been properly made the type of a distinct genus. The two species found in Japan are Ditrema temmincki and Neoditrema ransonneti. In the latter species the female is always toothless. Close to Ditrema is the blue surf-fish of California, Embiotoca jacksoni, the first discovered and perhaps the commonest species. Tæniotoca lateralis is remarkable for its bright coloration, greenish, with orange stripes. Hypsurus caryi, still brighter in color, orange, green and black, has the abdominal region very long. Phanerodon furcatus and P. atripes are dull silvery in color, as in Damalichthys argyrosomus, the white surf-fish, which ranges northward to Vancouver Island, and is remarkable for the extraordinary size of its lower pharyngeals. Holconotus rhodoterus is a large, rosy species, and Amphistichus argenteus a large species with dull yellowish cross-bands. Rhachochilus toxotes is the largest species in the family and the one most valued as food. It is notable for its thick, drooping, ragged lips. Hyperprosopon arcuatus, the wall-eye surf-fish, is brilliantly silvery, with very large eyes. H. agassizi closely resembles it, as does also the dwarf species, Hypocritichthys analis, to which the Japanese Neoditrema ransonneti is very nearly related. The other species are all small. Abeona minima and A. aurora feed on seaweed. Brachyistius frenatus is the smallest of all, orange-red in color, while its relative, Zalembius rosaceus, is handsomest of all, rose-red with a black lateral spot. Cymatogaster aggregatus, the surf-shiner, is a little fish, excessively common along the California coast, and from its abundance it has been selected by Dr. Eigenmann as the basis of his studies of these fishes. In this species the male shows golden and black markings, which are wanting in the silvery female, and the anterior rays of the anal are thickened or otherwise modified.

No fossil embiotocoids are recorded.

The viviparity of the Embiotocidæ was first made known by Dr. A. C. Jackson in 1863 in a letter to Professor Agassiz. From this letter we make the following extracts:

"A few days, perhaps a week, after the four trials, and on the 7th of June, I rose early in the morning for the purpose of taking a mess of fish for breakfast, pulled to the usual place, baited with crabs, and commenced fishing, the wind blowing too strong for profitable angling; nevertheless on the first and second casts I fastened the two fishes, male and female, that I write about, and such were their liveliness and strength that they endangered my slight trout rod. I, however, succeeded in bagging both, though in half an hour's subsequent work I got not even a nibble from either this or any other species of fish. I determined to change the bait, to put upon my hook a portion of the fish already caught, and cut for that purpose into the larger of the two fish caught. I intended to take a piece from the thin part of the belly, when what was my surprise to see coming from the opening thus made a small live fish. This I at first supposed to be prey which this fish had swallowed, but on further opening the fish I was vastly astonished to find next to the back of the fish and slightly attached to it a long very light violet bag, so clear and so transparent that I could already distinguish through it the shape, color, and formation of a multitude of small fish (all facsimiles of each other), with which it was well filled. I took it on board (we were occupying a small vessel which we had purchased for surveying purposes). When I opened the bag, I took therefrom eighteen more of the young fish, precisely like in size, shape, and color the first I had accidentally extracted. The mother was very large round her center and of a very dark-brown color, approaching about the back and on the fins a black color, and a remarkably vigorous fish. The young which I took from her were in shape, save as to rotundity, perfect miniatures of the mother, formed like her, and of the same general proportions, except that the old one was (probably owing to her pregnancy) much broader and wider between the top of the dorsal and the ventral fins in proportion to her length than the young were. As to color, they were in all respects like the mother, though the shades were many degrees lighter. Indeed, they were in all respects like their mother and like each other, the same peculiar mouth, the same position and shape of the fins, and the same eyes and gills, and there cannot remain in the mind of any one who sees the fish in the same state that I did a single doubt that these young were the offspring of the fish from whose body I took them, and that this species of fish gives birth to her young alive and perfectly formed, and adapted to seeking its own livelihood in the water. The number of young in the bag was nineteen (I fear I misstated the number in my former letter), and every one as brisk and lively and as much at home in a bucket of salt water as if they had been for months accustomed to the water. The male fish that was caught was not quite as large as the female, either in length or circumference, and altogether a more slim fish. I think we may reasonably expect to receive the specimens by the first of December. But I can hardly hope to get satisfactory specimens of the fish as I found it, with young well grown, before the return of the same season, viz., June. By that time I trust the facts will be fully decided, and the results, as important as they may be, fully appreciated."

Dr. Jackson's specimens came from Sausalito Bay, near San Francisco. Soon after the publication of this letter a similar discovery was made independently by Dr. William P. Gibbons, of Alameda. Still other specimens were made known in 1854 by Dr. Charles Girard, these having been collected in connection with the United States Pacific Railroad Surveys. The species first examined by Dr. Jackson was named by Agassiz Embiotoca jacksoni.

In Professor Agassiz's comments on Dr. Jackson's discovery he makes the following observations (Amer. Jour. Science and Arts, 1854):

"The female genital apparatus in the state of pregnancy consists of a large bag the appearance of which in the living animal has been described by Mr. Jackson. Upon the surface of it large vascular ramifications are seen, and it is subdivided internally into a number of distinct pouches, opening by wide slits into the lower part of the sac. This sac seems to be nothing but the widened lower end of the ovary, and the pouches within it to be formed by the folds of the ovary itself. In each of these pouches a young is wrapped up as in a sheet, and all are packed in the most economical manner as far as saving space is concerned, some having their head turned forwards and others backwards. This is, therefore, a normal ovarian gestation. The external genital opening is situated behind the anus, upon the summit and in the center of a conical protuberance formed by a powerful sphincter, kept in its place by two strong transverse muscles attached to the abdominal walls. The number of young contained in this sac seems to vary. Mr. Jackson counted nineteen; I have seen only eight or nine in the specimens sent by Mr. Cary, but since these were open when received it is possible that some had been taken out. However, their size is most remarkable in proportion to the mother. In a specimen of Emb. jacksoni 10½ inches long and 4½ high the young were nearly 3 inches long and 1 inch high; and in an Emb. caryi 8 inches long and 3¼ high the young were 2¾ inches long and ⅞ of an inch high. Judging from their size, I suspected for some time that the young could move in and out of this sac like young opossums, but on carefully examining the position of the young in the pouches, and also the contracted condition of the sphincter at the external orifice of the sexual organs, I remained satisfied that this could not be the case, and that the young which Mr. Jackson found so lively after putting them in a bucket of salt water had then for the first time come into free contact with the element in which they were soon to live; but at the same time it can hardly be doubted that the water penetrates into the marsupial sac, since these young have fully developed gills. The size of the young compared with that of the mother is very remarkable, being full one-third its length in the one, and nearly so in the other species. Indeed these young Embiotocæ, not yet hatched, are three or four times larger than the young of a Pomotis (of the same size) a full year old. In this respect these fishes differ from all the other viviparous species known to us. There is another feature about them of considerable interest, that while the two adults differ markedly in coloration, the young have the same dress, light yellowish olive with deeper and brighter transverse bands, something like the young trout and salmon in their parr dress."

Fig. 312.—Viviparous Perch (male), Hysterocarpus traski Gibbons. Battle Creek, Sacramento River. (Photograph by Cloudsley Rutter.)

CHAPTER XXII
CHROMIDES AND PHARYNGOGNATHI

Suborder Chromides.—The suborder Chromides contains spiny-rayed fishes similar to the perch-like forms in most regards, but strikingly distinguished by the complete union of the lower pharyngeal bones, as in the Holconoti and Pharyngognathi, and still more remarkably by the presence of but one nasal opening on each side. In all the perch-like fishes and in nearly all others there are two nasal openings or nostrils on each side, these two entering into the same nasal sac. In all the Chromides the lateral line is incomplete or interrupted, and the scales are usually large and ctenoid.

The Cichlidæ.—The suborder Chromides includes two families, Cichlidæ, and Pomacentridæ. The Cichlidæ are fresh-water fishes of the tropics, characterized by the presence of three to ten spines in the anal fin. In size, color, appearance, habits, and food value they bear a striking resemblance to the fresh-water sunfishes, or Centrarchidæ, of the eastern United States. This resemblance is one of analogy only, for in structure the Cichlidæ have no more in common with the Centrarchidæ than with other families of perch or bass. The numerous species of Cichlidæ are confined to tropical America and to corresponding districts in Africa and western Asia. Tilapia nilotica abounds in the Nile. Tilapia galilæa is found in the river Jordan and the Lake of Galilee. This species is supposed to form part of the great draught of fishes recorded in the Gospels, and a black spot on the side is held to commemorate the touch of Simon Peter. Numerous other species of Cichlidæ, large and small, abound in central Africa, even in the salt ditches of the Sahara.

The species of Cichla, especially Cichla ocellaris, of the rivers of South America, elongate and large-mouthed, bear a strong analogy to the black bass of farther north. A vast number of species belonging to Heros, Acara, Cichlasoma, Geophagus, Chætobranchus, and related genera swarm in the Amazon region. Each of the large rivers of Mexico has one or more species; one of these, Heros cyanoguttatus, occurs in the Rio Grande and the rivers of southern Texas, its range corresponding with that of Tetragonopterus argentatus, just as the range of the whole family of Cichlidæ corresponds with that of the Characinidæ. No other species of either family enters the United States. A similar species, Heros tetracanthus, abounds in the rivers of Cuba, and another, Heros beani, called the mojarra verde, in the streams of Sinaloa. In the lakes and swamps of Central America Cichlidæ and Characinidæ are very abundant. One fossil genus is known, called Priscacara by Cope. Priscacara clivosa and other species occur in the Eocene of Green River and the Great Basin of Utah. In this genus vomerine teeth are said to be present, and there are three anal spines. None of the living Cichlidæ have vomerine teeth.

Fig. 313.—Garibaldi (scarlet in color), Hypsypops rubicunda (Girard). La Jolla, San Diego, Cal.

Fig. 314.—Pomacentrus leucostictus (Müller & Troschel), Damsel-fish. Family Pomacentridæ.

The Damsel-fishes: Pomacentridæ.—The Pomacentridæ, called rock-pilots or damsel-fishes, are exclusively marine and have in all cases but two anal spines. The species are often very brilliantly colored, lustrous metallic blue and orange or scarlet being the prevailing shades among the bright-colored species. Their habits in the reef pools correspond very closely with those of the Chætodontidæ. With the rock-pilots, as with the butterfly-fishes, the exceeding alertness and quickness of movement make up for lack of protective colors. With both groups the choice of rocky basins, crevices in the coral, and holes in coral reefs preserves them from attacks of enemies large enough to destroy them. In Samoa the interstices in masses of living coral are often filled with these gorgeous little fishes. The Pomacentridæ are chiefly confined to the coral reefs, few ranging to the northward of the Tropic of Cancer. Sometimes the young are colored differently from the adult, having sky-blue spots and often ocelli on the fins, which disappear with age. But one species Chromis chromis, is found in the Mediterranean. Chromis punctipinnis, the blacksmith, is found in southern California, and Chromis notatus is the common dogoro of Japan. One of the largest species, reaching the length of a foot, is the Garibaldi, Hypsypops rubicundus, of the rocky shores of southern California. This fish, when full grown, is of a pure bright scarlet. The young are greenish, marked with blue spots. Species of Pomacentrus, locally known as pescado azul, abound in the West Indies and on the west coast of Mexico. Pomacentrus fuscus is the commonest West Indian species, and Pomacentrus rectifrenum the most abundant on the west coast of Mexico, the young, of an exquisite sky-blue, crowding the rock pools. Pomacentrus of many species, blue, scarlet, black, and golden, abound in Polynesia, and no rock pool in the East Indies is without several forms of this type. The type reaches its greatest development in the south seas. About forty different species of Pomacentrus and Glyphisodon occur in the corals of the harbor of Apia in Samoa.

Fig. 315.—Cockeye Pilot, Glyphisodon marginatus (Bloch). Cuba.

Almost equally abundant are the species of Glyphisodon. The "cockeye pilot," or jaqueta, Glyphisodon marginatus, green with black bands, swarms in the West Indies, occasionally ranging northward, and is equally common on the west coast of Mexico. Glyphisodon abdominalis replaces it in Hawaii, and the Asiatic Glyphisodon saxatilis is perhaps the parent of both. Glyphisodon sordidus banded with pale and with a black ocellus below the soft dorsal is very common from Hawaii to the Red Sea, and is a food-fish of some importance. Glyphisodon cœlestinus blue, with black bands, abounds in the south seas.

The many species of Amphiprion are always brilliant, red or orange, usually marked by one or two cross-bands of creamy blue. Amphiprion melanopus abounds in the south seas. Azurina hirundo is a slender species of lower California of a brilliant metallic blue. All these species are carnivorous, feeding on shrimps, worms, and the like.

Fig. 316.—Indigo Damsel fish, Microspathodon dorsalis (Gill). Mazatlan, Mex.

Microspathodon is herbivorous, the serrated incisors being loosely implanted in the jaws. Microspathodon dorsalis, of the west coast of Mexico, is of a deep indigo-blue color, with streamer-like fins. Microspathodon chrysurus, of the West Indian coral reefs, black with round blue spots and the tail yellow. This family is probably of recent origin, as few fossils are referred to it. Odonteus pygmæus of the Eocene perhaps belongs to it.

Suborder Pharyngognathi.—The wrasses and parrot-fishes, constituting the group called Pharyngognathi (φαρύγξ, gullet; γνάθος, jaw), by Johannes Müller, have the lower pharyngeal bones much enlarged and solidly united, their teeth being either rounded or else flat and paved. The nostrils, ventral fins, pectoral fins and shoulder-girdle are of the ordinary perch-like type. The teeth are, however, highly specialized, usually large and canine-like, developed in the jaws only, and the gills are reduced in number, 3½ instead of 4, with no slit behind the last half gill. The scales are always cycloid and are usually large. In the tropical forms the vertebræ are always twenty-four in number (10 + 14), but in northern forms the number is largely increased with a proportionate increase in the number and strength of the dorsal spines. All the species are strictly marine, and the coloration is often the most highly specialized and brilliant known among fishes, the predominant shade being blue.

Fig. 317.—Tautog, Tautoga onitis (L.). Wood's Hole, Mass.

All are carnivorous, feeding mainly on crustaceans and snails, which they crush with their strong teeth, there being often a strong canine at the posterior end of the premaxillary, which holds the snail while the lower jaw acts upon it. The species are very numerous and form the most conspicuous feature in the fish markets of every tropical port. They abound especially in the pools and openings in the coral reefs. All are good for food, though all are relatively flavorless, the flesh being rather soft and not oily.

The Wrasse Fishes: Labridæ.—The principal family is that of the Labridæ, characterized by the presence of separate teeth in the front of the jaws. Numerous fossil species are known from the Eocene and Miocene. Most of these are known only from the lower pharyngeal bones. Labrodon is the most widely diffused genus, probably allied to Labrus, but with a pile of successional teeth beneath each functional tooth. The species are mostly from the Miocene.

Fig. 318.—Tautog, Tautoga onitis (L.). (From life by Dr. R. W. Shufeldt.)

The northern forms of Labridæ are known as wrasse on the coasts of England. Among these are Labrus bergylta, the ballan wrasse; Labrus viridis, the green wrasse; Labrus ossiphagus, the red wrasse; and Labrus merula, the black wrasse. Acantholabrus palloni and Centrolabrus exoletus have more than three anal spines. The latter species, known as rock cook, is abundant in western Norway, as far north as Throndhjem, its range extending to the northward beyond that of any other Labroid. Allied to these, on the American coast, is the tautog or blackfish, Tautoga onitis, a common food-fish, dusky in color with excellent white flesh, especially abundant on the coast of New England. With this, and still more abundant, is the cunner or chogset, Tautogolabrus adspersus, greenish-blue in color, the flesh being also more or less blue. This fish is too small to have much value as food, but it readily takes the hook set for better fishes.

Fig. 319.—Capitaine or Hogfish, Lachnolaimus falcatus. Florida.

In the Mediterranean are found many species of Crenilabrus, gaily colored, each species having its own peculiar pattern and its own arrangement of inky spots. Among these are Crenilabrus mediterraneus, Crenilabrus pavo, and Crenilabrus griseus. With these are the small species called Ctenolabrus rupestris, the goldsinny, much like the American cunner, and the long-nosed Symphodus scina.

Of the many West Indian species we may notice the Capitaine or hogfish, Lachnolaimus maximus, a great fish, crimson in color, with its fin spines ending in long streamers; Bodianus rufus, the Spanish ladyfish or pudiano, half crimson, half golden. Halichæres radiatus, the pudding-wife (a mysterious word derived from "oldwife" and the Portuguese name, pudiano), a blue fish handsomely mottled and streaked. Of the smaller species, Clepticus parræ, the janissary, with very small teeth, Halichœres bivittatus, the slippery-dick, ranging northward to Cape Hatteras, and Doratonotus megalepis, of an intense grass-green color, are among the most notable. The razor-fish, Xyrichthys psittacus, red, with the forehead compressed to a sharp edge, is found in the Mediterranean as well as throughout the West Indies, where several other species of razor-fish also occur.

Fig. 320.—Razor-fish, Xyrichthys psittacus (Linnæus). Tortugas, Fla.

Fig. 321.—Redfish (male), Pimelometopon pulcher (Ayres). San Diego.

Fig. 322.—Lepidaplois perditio (Quoy & Gaimard). Wakanoura, Japan.

Scarcely less numerous are the species of the Pacific Coast of America. Pimelometopon pulcher, the redfish or fathead of southern California, reaches a length of two feet or more. It abounds in the broad band of giant kelp which lines the California coast and is a food-fish of much importance. The female is dull crimson. In the male the head and tail are black and on the top of the head is developed with age a great adipose hump. A similar hump is found on the adult of several other large labroids. Similar species on the coast of South America, differing in color and size of scales, are Pimelometopon darwini, Trochocopus opercularis, and Bodianus diplotænia. The señorita, Oxyjulis californica, is a dainty cream-colored little fish of the California coast, Halichœres semicinctus, the kelpfish, light olive, the male with a blue shoulder bar, is found in southern California. On the west coast of Mexico are numerous species of Thalassoma, Halichœres, Pseudojulis, Xyrichthys and Iniistius, all different from the corresponding species in the West Indies, and equally different from the much greater variety found in Hawaii and in Samoa. About the Polynesian and West Indian islands abound a marvelous wealth of forms of every shade and pattern of bright colors—blue, green, golden, scarlet, crimson, purple—as if painted on with lavish hand and often in the most gaudy pattern, although at times laid on with the greatest delicacy. The most brilliant species belong to Thalassoma and Julis, the most delicately colored to Stethojulis and Cirrhilabrus. In Gomphosus the snout is prolonged on a long slender tube. In Cheilio the whole body is elongate. In Iniistius the first two dorsal spines form a separate fin, the forehead being sharp as in Xyrichthys. Other widely distributed genera are Anampses, Lepidaplois, Semicossyphus, Duymæria, Platyglossus, Pseudolabrus, Hologymnosus, Macropharyngodon, Coris, Julis, Hemipteronotus, Novaculichthys, Cheilinus, Hemigymnus, and Cymolutes. Halichœres is as abundant in the East Indies as in the West, one of its species Halichœres pæcilopterus being common as far north as Hakodate in Japan. In this species as in a few others the sexes are very different in color, although in most species no external sexual differences of any sort appear. In the East Indian genus, Pseudocheilinus, the eye is very greatly modified. The cornea is thickened, forming two additional lens-like structures.

The small family of Odacidæ differs from the Labridæ in having in each jaw a sharp cutting edge without distinct teeth anteriorly, the pharyngeal teeth being pavement-like. The scales are small, very much smaller than in the Scaridæ, the body more elongate, and the structure of the teeth different. The species are mostly Australian, Odax balteatus being the most abundant. It is locally known as kelpfish.

In the Siphonognathidæ the teeth are much as in the Odacidæ, but the body is very elongate, the snout produced as in the cornet-fishes (Fistularia), and the upper jaw ends in a long skinny appendage. Siphonognathus argyrophanes, from Australia, reaches a length of sixteen inches.

The Parrot-fishes: Scaridæ.—The parrot-fishes, or Scaridæ, are very similar to the Labridæ in form, color, and scales, but differ in the more or less complete fusion of the teeth, a character which varies in the different genera.

Of these the most primitive is Calotomus, confined to the East Indies and Polynesia. In this genus the teeth are united at base, their tips free and imbricated over the surface of the jaw.

The species are dull in color, reddish or greenish. Calotomus japonicus is the Budai or Igami of Japan. Calotomus sandwichensis and Calotomus irradians are found in Hawaii, and Calotomus xenodon on the off-shore islands of Mexico. In Calotomus the dorsal spines are slender. In Scaridea (balia) of the Hawaiian Islands the first dorsal is formed of pungent spines as in Sparisoma.

Fig. 323.—Pharyngeals of Italian Parrot-fish, Sparisoma cretense (L.). a, upper; b, lower.

Fig. 324.—Jaws of a Parrot-fish, Calotomus xenodon Gilbert.

Fig. 325.—Cryptotomus beryllinus Jordan & Swain. Key West, Florida.

Cryptotomus of the Atlantic is also a transitional group having the general characters of Sparisoma, but the anterior teeth more separate. The several species are all small and characteristic of the West Indian fauna, one species, Cryptotomus beryllinus, ranging northward to Long Island.

Fig. 326.—Sparisoma hoplomystax (Cope). Key West.

In the large genus Sparisoma the teeth are more completely joined. In this group, which is found only in the tropical Atlantic, the lower pharyngeals are broader than long and hexagonal. The teeth of the jaws are not completely united, the dorsal spines are pungent, the lateral line not interrupted, and the gill membranes broadly united to the isthmus.

Fig. 327.—Sparisoma abildgaardi (Bloch), Red Parrot-fish. Loro, Colorado. Family Scaridæ.

Of the numerous species the dull-colored Sparisoma flavescens is most abundant in the West Indies and ranges farther north than any other. Sparisoma cretense, the Scarus of the ancients, is found in the Mediterranean, being the only member of the family known in Europe and the only Sparisoma known from outside the West Indian fauna.

Other West Indian species are the red parrot-fish, Sparisoma abildgaardi, Sparisoma xystrodon, Sparisoma hoplomystax, the last two being small species about the Florida Keys, and the handsome Sparisoma viride from the West Indies.

Fig. 328.—Jaws of Blue Parrot-fish, Scarus cæruleus (Bloch).

Scarus is the great central genus of parrot-fishes. Its members are especially abundant in Polynesia and the East Indies, the center of distribution of the group, although some extend their range to western Mexico, Japan, the Red Sea, and Australia, and a large number are found in the West Indies. Most of them are fishes of large size, but a few, as the West Indian Scarus croicensis, reach the length of less than a foot, and other still smaller species (Scarus evermanni, Scarus bollmani) are found only in water of considerable depth (200 fathoms).

Fig. 329.—Upper pharyngeals of an Indian Parrot-fish, Scarus strongylocephalus.

Fig. 330.—Lower pharyngeals of a Parrot-fish, Scarus strongylocephalus (Bleeker).

Fig. 331.—Scarus emblematicus Jordan & Rutter. Jamaica.

Fig. 332.—Scarus cœruleus (Bloch). Blue Parrot-fish. Loro, Azul. Family Scaridæ.

The genus Scarus is characterized by not only the almost complete fusion of its teeth, but by numerous other characters. Its lower pharyngeals are oblong and spoon-shaped, the teeth appearing as a mosaic on the concave surface. The gill-membranes are scarcely united to the narrow isthmus, the lateral line is interrupted, the dorsal spines are flexible, and there are but few scales on the head. These, as well as the scales of the body, are always large. The most highly specialized of its species have the teeth deep blue in color, a character which marks the genus or subgenus Pseudoscarus. Of the species of this type, the loro, Pseudoscarus cœlestinus, and the more abundant guacamaia, Pseudoscarus guacamaia (fig. 215 vol. I) of the West Indies, are characteristic forms. The perrico, Pseudoscarus perrico of the west coast of Mexico, and the great blue parrot-fish, or galo, of Hawaii and Samoa, Pseudoscarus jordani, belong to this type. Pseudoscarus jordani was formerly tabu to the king in Hawaii, and its brilliant colors and toothsome flesh (when eaten raw) made it the most highly valued fish at the royal banquets of old Hawaii. It still sells readily at a dollar or more per pound. To this type belong also the blue parrot-fish, Pseudoscarus ovifrons, of Japan. In the restricted genus Scarus proper the teeth are pale. The great blue parrot-fish, of the West Indies, Scarus cœruleus, belongs to this group. This species, deep blue in color, reaches a large size, and the adult has a large fleshy hump on the forehead. Lesser parrot-fish with pale teeth and with showy coloration are the West Indian species Scarus tæniopterus, Scarus vetula, Scarus croicensis, etc.

Fig. 333.—Scarus vetula Bloch & Schneider, Parrot-fish. Family Scaridæ.

Fig. 334.—Slippery-dick or Doncella, Halichœres bivittatus (Bloch), a fish of the coral reefs. Key West. Family Labridæ.

Very many species of both Scarus and Pseudoscarus, green, blue, red-brown, or variegated, abound about the coral reefs of Polynesia. About twenty-five species occur in Samoa. Pseudoscarus latax and P. ultramarinus being large and showy species, chiefly blue. Pseudoscarus prasiognathus is deep red with the jaws bright blue.

Fossil species referred to Scarus but belonging rather to Sparisoma are found in the later Tertiary. The genera Phyllodus, Egertonia, and Paraphyllodus of the Eocene perhaps form a transition from Labridæ to Scaridæ. In Paraphyllodus medius the three median teeth of the lower pharyngeals are greatly widened, extending across the surface of the bone.

CHAPTER XXIII
THE SQUAMIPINNES

Fig. 335.—Monodactylus argenteus (Linnæus). From Apia, Samoa. Family Scorpididæ.

The Squamipinnes.—Very closely allied to the Percomorphi is the great group called Squamipinnes (squama, scale; pinna, fin) by Cuvier and Epelasmia by Cope. With a general agreement with the Percomorphi, it is distinguished by the more or less complete soldering of the post-temporal with the cranium. In the more specialized forms we find also a soldering of the elements of the upper jaw, and a progressive reduction in the size of the gill-opening. The ventral fin retains its thoracic insertion, and, as in the perch mackerel-like forms, it has one spine and five rays, never any more. The ventral fins are occasionally lost in the adult, as in the Stromateidæ, or they may lose part of their rays. The name Squamipinnes refers to the scaly fins, the typical species having the soft rays of dorsal, anal, and caudal, and sometimes of other fins densely covered with small scales. In various aberrant forms these scales are absent. The name Epelasmia (ἔπι, above; ἐλάσμος, plate) refers to the thin upper pharyngeals characteristic of certain forms. The transition from this group to the Sclerodermi is very clear and very gradual. The Squamipinnes, Sclerodermi, Ostracodermi, and Gymnodontes form a continuous degenerating series. On the other hand the less specialized Squamipinnes approach very closely to forms already considered. The Antigoniidæ are of uncertain affinities, possibly derived from such forms as Histiopteridæ, while Platax show considerable resemblance to scaly-finned fishes like the Kyphosidæ and Stromateidæ. The Scorpididæ seem intermediate between Stromateidæ and Platacidæ. In such offshoots from Scombroidei or Percoidei the group doubtless had its origin.

We may begin the series with some forms which are of doubtful affinity and more or less intermediate between the Squamipinnes and the more primitive Percomorphi.

The Scorpididæ.—This family has the general appearance of Platax and Ilarches, but the teeth are not brush-like, and the post-temporal is free from the skull as in perch-like fishes. The species inhabit the Pacific. Scorpis georgianus is a food-fish of Australia, with the body oblong. Monodactylus argenteus, the toto of Samoa, is almost orbicular in form, while Psettus sebæ is twice as deep as long, the deepest-bodied of all fishes in proportion to its length.

The Boarfishes: Antigoniidæ.—The boarfishes (Antigoniidæ) are characterized by a very deep body covered with rough scales, the post-temporal, as in the Chætodontidæ and the Zeidæ, being adnate to the skull.

Fig. 336.—Psettus sebæ Cuv. & Val. East Indies.

These fishes bear some resemblance to Zeus, but there is no evidence of close affinity nor is it clear that they are related to the Chætodontidæ. Capros aper, the boarfish, is common in southern Europe, reaching a length of less than a foot, the protractile mouth suggesting that of a pig. The diamond-fishes, Antigonia, are deeper than long and strongly compressed, the body being covered with roughish scales. The color is salmon-red and the species live just below the depths ordinarily explored by fishermen. Antigonia capros is found at Madeira and in the West Indies, Antigonia steindachneri about Hawaii and in Japan, while the smaller Antigonia rubescens is abundant in the Japanese bays at a depth reached by the dredge. An extinct genus, Proantigonia from the Miocene is said to connect Antigonia with Capros.

The Arches: Toxotidæ.—The archers, Toxotidæ, have the body compressed, the snout produced, and the dorsal fin with but five spines. The skeleton differs widely from that of Chætodon and the family should perhaps rather find its place among the percoids. Toxotes jaculatrix is found in the East Indies. The name alludes to its supposed habit of catching insects by shooting drops of water at them through its long mouth.

The Ephippidæ.—With the typical Squamipinnes, the teeth become very slender, crowded in brush-like bands. The least specialized family is that of Ephippidæ, characterized by the presence of four anal spines and a recumbent spine before the dorsal. The principal genus, Ephippus (Scatophagus), is represented by Ephippus argus, a small, bass-like fish, spotted with black, found in the Indian seas, and ranging northward to Formosa. Species referred to Ephippus (Scatophagus) are recorded from the Italian Eocene of Monte Bolca, where a species of Toxotes has been also found.

The Spadefishes: Ilarchidæ.—In the Ilarchidæ the dorsal is divided into two fins, the spinous part being free from scales. In various regards the species are intermediate between ordinary perch-like forms and the chætodonts. In these fishes the body is very deep and, with the soft fins, closely covered with roughish scales. In Ilarches (Ephippus), represented by Ilarches orbis of the Indian seas, these scales are relatively large. This species is a common food-fish from India to Formosa.

In the American genus, Chætodipterus, the scales are quite small. The spadefish (Chætodipterus faber), sometimes called also moonfish or angel-fish, is a large, deep-bodied fish, reaching a length of two feet. It is rather common from Cape Cod to Cuba, and is an excellent pan fish, with finely flavored white flesh. The young are marked by black cross-bands which disappear with age, and in the adult the supraoccipital crest is greatly thickened and the skull otherwise modified. A very similar species, Chætodipterus zonatus, occurs on the west coast of Mexico. Species allied to Chætodipterus are fossil in the Italian Eocene. The Drepanidæ of the East Indies are close to the Ilarchidæ. Drepane punctata is a large, deep-bodied fish resembling the spadefish but with larger scales.

Fig. 337.—Spadefish, Chætodipterus faber (L.). Virginia.

The Platacidæ.—Closely related to the Ilarchidæ is also the East Indian family of Platacidæ, remarkable for the very great depth and compression of the body, which is much deeper than long, and the highly elevated dorsal and anal still further emphasize this peculiarity of form. In this group the few dorsal spines are closely attached to the soft rays and the general color is dusky. In the young the body is deeper than in the adult and the ventral fins much more produced. The best-known species is the tsuzume or batfish (Platax orbicularis), which ranges from India through the warm current to northern Japan. Platax teira, farther south, is very similar. Platax altissimus, with a very high dorsal, is a fossil in the Eocene of Monte Bolca.

Fig. 338.—Butterfly-fish, Chætodon capistratus Linnæus. Jamaica.

The Butterfly-fishes: Chætodontidæ.—The central family of Squamipinnes is that of the butterfly-fishes or Chætodontidæ. In this group the teeth are distinctly brush-like, the mouth small, the dorsal fin continuous and closely scaly, and the ventral fins with one spine and five rays. The species are mostly of small size and brilliant and varied coloration, yellow and black being the leading colors. They vary considerably with age, the young having the posterior free edges of the bones of the head produced, forming a sort of collar. These forms have received the name of Tholichthys, but that supposed genus is merely the young of Chætodon. The species of Chætodontidæ abound in rock pools and about coral reefs in clear water. They are among the most characteristic forms of these waters and their excessive quickness of movement compensates for their conspicuous coloration. In these confined localities they have, however, few enemies. The broad bodies and spinous fins make them rather difficult for a large fish to swallow. They feed on small crustaceans, worms, and the like. The analogy to the butterfly is a striking one, giving rise to the English name, butterfly-fish, the Spanish mariposa, and the Japanese chochouwo, all having the same meaning. Fossil chætodonts are rather few, Chætodon pseudorhombus of the Pliocene of France, Holocanthus microcephalus and Pomacanthus subarcuatus of the Eocene, being the only species recorded by Zittel.

Fig. 339.—Black Angel-fish, Pomacanthus arcuatus (Linnæus). Barnegat, New Jersey.

In the principal genus, Chætodon, the colors are especially bright. There is almost always a black bar across the eye, and often black ocelli adorn the fins. This genus is wanting in Europe. Chætodon capistratus, striatus, and numerous other species are found in the West Indies; Chætodon humeralis and nigrirostris are common on the coast of Mexico. The center of their distribution is in Polynesia and the East Indian Archipelago. Chætodon reticulatus, lineolatus, ulietensis, ornatissimus, ephippion, setifer, and auriga are among the most showy species. Numerous closely related genera are described. In some of these the snout is prolonged into a long tube, bearing the jaws at its end. Of this type are Chelmo in India, Forcipiger in Polynesia, and Prognathodes in the West Indies. Heniochus (macrolepidotus) has one dorsal spine greatly elongated. Microcanthus strigatus, one of the most widely distributed species, is known by its small scales. Megaprotodon (triangularis) has four anal spines instead of three as in the others.

Fig. 340.—Angel-fish or Isabelita, Holacanthus ciliaris (Linnæus). Jamaica. Family Chætodontidæ.

The species of Holacanthus, known as angel-fishes, are larger in size, and their colors are still more showy, being often scarlet or blue. In this genus the preopercle is armed with a strong spine, and there are fourteen or more strong spines in the dorsal. This genus has also its center of distribution in the East Indies, whence two species (septentrionalis and ronin) with concentric stripes of blue range northward to Japan. Holacanthus tibicen, jet-black with one yellow cross-band, is found from the Riu Kiu Islands southward. The angel-fish or isabelita (Holacanthus ciliaris), orange-red, sky-blue, and golden, as though gaudily painted, is the best-known species. The vaqueta de dos colores or rock beauty (Holacanthus bicolor), half jet-black, half golden, is scarcely less remarkable. Both are excellent food-fishes of the West Indies. Holacanthus passer is a showy inhabitant of the west coast of Mexico. Holacanthus diacanthus, orange, barred with blue, is one of the gaudiest inhabitants of the coral reefs of Polynesia. Holacanthus flavissimus, golden with some deep-blue markings, and Holacanthus nicobariensis, blackish with white circles, are found with other species in the same waters.

The genus Pomacanthus (Pomacanthodes) includes American species only, still larger in size and differing from Holacanthus in having nine to eleven spines only in the dorsal fin. The young of Pomacanthus are blackish, crossed by many curved yellow cross-bands, which disappear entirely with age. Three species are known, Pomacanthus arcuatus, the black angel, chirivita or portugais, Pomacanthus paru, the Indian-fish or paru of the West Indies, and Pomacanthus zonipectus, "Mojarra de las Piedras," of the west coast of Mexico. All are good food-fishes, but lacking the brilliant colors of Holacanthus and the fine pattern usual in Chætodon.

Fig. 341.—Rock Beauty, Holacanthus tricolor (L.). Puerto Rico.

The Pygæidæ.—Between the Chætodontidæ and the Acanthuridæ we would place the extinct family of Pygæidæ, of the Eocene. In Pygæus gigas and other species the dorsal spines are strong and numerous; there are 5 to 8 species in the anal fin, the scales are shagreen-like, and the teeth seem coarser than in the Chætodontidæ. The tail is apparently unarmed, and the soft dorsal, as in Chætodon, is much shorter than the spinous. To this family the Eocene genera, Aulorhamphus (bolceusis), with produced snout, and Apostasis (croaticus), with long spinous dorsal, probably belong.

Fig. 342.—The Moorish Idol, Zanclus canescens (Linnæus). From Hawaii. Family Zanclidæ. (Painting by Mrs. E. G. Norris.)

The Moorish Idols: Zanclidæ.—The family of Zanclidæ includes a single species, the Moorish idol or kihi kihi, Zanclus canescens. In this family the scales are reduced to a fine shagreen, and in the adult two bony horns grow out over the eye. The dorsal spines are prolonged in filaments and the color is yellow crossed by bars of black. Zanclus canescens is a very handsome fish with the general appearance and habit of a Chætodon, but the form is more exaggerated. It is found throughout Polynesia, from Japan to the off-shore islands of Mexico, and is generally common, though rarely entering rock pools.

Zanclus eocænus is recorded from the Italian Eocene.

The Tangs: Acanthuridæ.—In the next family, Acanthuridæ, the surgeon-fishes or tangs, the scales remain small and shagreen-like, the body is more elongate, the gill-openings still more restricted, and the teeth are flattened and incisor-like. The pubic bone is more elongate, and in all the species some sort of armature is developed on the side of the tail. The spinous dorsal in all is less developed than the soft dorsal. The species abound in the warm seas, especially about the tide pools, and are used as food. They undergo considerable changes with age, the caudal armature being developed by degrees. Nearly all are dull brown in color, but in some a vivid ornamentation is added. Fossil forms are found from the Eocene and later. Most of these are referable to Teuthis and Acanthurus.

Fig. 343.—Teuthis cœruleus (Bloch & Schneider), Blue Tang. Mexico. Family Teuthididæ.

The principal genus is Teuthis, characterized by the presence on each side of the tail of a sharp, knife-like, movable spine with the point turned forwards and dropping into a sheath. This spine gives these fishes their name of surgeon-fish, doctor-fish, lancet-fish, tang, barbero, etc., and it forms a very effective weapon against fish or man who would seize one of these creatures by the tail. The species have the center of distribution in the East Indies and have not reached Europe. Three species are found in the West Indies. The blue tang (Teuthis cœruleus) is chiefly bright blue. The common tang, Teuthis chirurgus, is brown with bluish streaks, while a third species, Teuthis bahianus, has a forked caudal fin. Very close to this species is Teuthis crestonis, of the west coast of Mexico, and both are closely related to Teuthis matoides, found from India to Hawaii.

Fig. 344.—Brown Tang, Teuthis bahianus (Ranzani). Tortugas, Fla.

Teuthis triostegus, of Japan and Polynesia and the East Indies, is covered with cross-bands alternately black and pale. In Hawaii this is replaced by the very similar Teuthis sandwichensis. Many species are found about Hawaii and the other Polynesian Islands. Teuthis achilles has a large blotch of brilliant scarlet on the tail, and Teuthis olivaceus a bright-colored mark on the shoulder. Teuthis lineatus, yellow with blue stripes, a showily colored fish of the coral reefs, is often poisonous, its flesh producing ciguatera.

Zebrasoma differs from Teuthis in having but 4 or 5 dorsal spines instead of 10 or 11. In this genus the soft dorsal fin is very high. Zebrasoma flavescens, sometimes brown, sometimes bright yellow, is common in Polynesia; Zebrasoma veliferum, cross-barred with black, is also common.

Ctenochætus (strigosus), unlike the others, is herbivorous and has its teeth loosely implanted in the gums. This species, black with dull orange streaks, was once tabu to the king of Hawaii, who ate it raw, and common people who appropriated it were put to death.

In Xesurus the caudal lancelet is replaced by three or four bony tubercles which have no sharp edge. Xesurus scalprum is common in Japan, and there are three species or more on the west coast of Mexico, Xesurus punctatus and Xesurus laticlavius being most abundant.

In Prionurus (microlepidotus) of the tropical Pacific the armature is still more degraded, about six small plates being developed.

In Acanthurus (Monoceros, Naseus), the unicorn-fish and its relatives, the ventral fins are reduced, having but three soft rays, the caudal spines are very large, blunt, immovable, one placed in front of the other. In most of the species of Acanthurus a long, bony horn grows forward from the cranium above the eye. This is wanting in the young and has various degrees of development in the different species, in some of which it is wholly wanting. The species of Acanthurus reach a large size, and in some the caudal spines are bright scarlet, in others blue. Acanthurus unicornis, the unicorn-fish, is the commonest species and the one with the longest horn. It is abundant in Japan, in Hawaii, and in the East Indies.

Axinurus thynnoides of the East Indies has a long, slim body, with slender tail like a mackerel.

Suborder Amphacanthi, the Siganidæ.—The Amphacanthi (ἄμφϊ, everywhere; ἄκανθα, spine) are spiny-rayed fishes certainly related to the Teuthididæ, but differing from all other fishes in having the last ray of the ventrals spinous as well as the first, the formula being I. 4, I. The anal fin has also six or seven spines; and the maxillary is soldered to the premaxillary. The skeleton is essentially like that of the Acanthuridæ.

The single family, Siganidæ, contains fishes of moderate size, valued as food, and abounding about rocks in shallow water from the Red Sea to Tahiti. The coloration is rather plain olive or brown, sometimes with white spots, sometimes with bluish lines. The species are very much alike and all belong to the single genus Siganus. One species, Siganus fuscescens, dusky with small, pale dots, is a common food-fish of Japan. Others, as Siganus oramin and Siganus vermiculatus, occur in India, and Siganus punctatus, known as lo, abounds about the coral reefs of Samoa. Siganus vulpinus differs from the others in the elongate snout.

A fossil genus, Archoteuthis (glaronensis), is found in the Tertiary of Glarus. It differs from Siganus in the deeper body and in the presence of six instead of seven spines in the anal fin.

The real relationship of the Siganidæ is still uncertain, but the family is probably most nearly allied to the Acanthuridæ, with which the species were first combined by Linnæus, who included both in his genus Teuthis. In the structure of the vertical fins the Siganidæ resemble the extinct genus Pygæus.

CHAPTER XXIV
SERIES PLECTOGNATHI

The Plectognaths.—Derived directly from the Acanthuridæ, from which they differ by progressive steps of degeneration, are the three suborders of Sclerodermi, Ostracodermi, and Gymnodontes, forming together the series or suborder of Plectognathi. As the members of this group differ from one another more widely than the highest or most generalized forms differ from the Acanthuridæ, we do not regard it as a distinct order. The forms included in it differ from the Acanthuridæ much as the swordfishes differ from ordinary mackerel. The Plectognathi (πλεϡτός, woven together; γνάθος, jaw) agree in the union of the maxillary and premaxillary, in the union of the post-temporal with the skull, in the great reduction of the gill-opening, and in the elongation of the pelvic bones. All these characters in less degree are shown in the Squamipinnes. We have also the reduction and final entire loss of ventral fins, the reduction and loss of the spinous dorsal, the compression and final partial or total fusion of the teeth of the upper jaw, the specialization of the scales, which change from bony scutes into a solid coat of mail on the one hand, and on the other are reduced to thorns or prickles and are finally altogether lost. The number of vertebræ is also progressively reduced until in the extreme forms the caudal fin seems attached to the head, the body being apparently wanting. Throughout the group poisonous alkaloids are developed in the flesh. These may produce the violent disease known as ciguatera, directly attacking the nervous system. See p. 182, vol. I.

The three suborders of plectognathous are easily recognized by external characters. In the Sclerodermi (σκλερός, hard; δέρμα, skin) the spinous dorsal is present and the body is more or less distinctly scaly. The teeth are separate and incisor-like and the form is compressed. In the Ostracodermi (ὀστράκος, a box; δέρμα, skin) there is no spinous dorsal, the teeth are slender, and the body is inclosed in an immovable, bony box. In the Gymnodontes (γυμνός, naked; ὀδούς, tooth) the teeth are fused into a beak like that of a turtle, either continuous or divided by a median suture in each jaw, the spinous dorsal is lost, and the body is covered with thorns or prickles or else is naked.

The Scleroderms.—The Sclerodermi include three recent and one extinct families. Of the recent forms, Triacanthidæ is the most primitive, having the ventral fins each represented by a stout spine and the skin covered with small, rough scales. The dorsal has from four to six stiff spines.

Triacanthodes anomalus is found in Japan, Hollardia hollardi in Cuba. Triacanthus brevirostris, with the first spine very large, is the common hornfish of the East Indies ranging northward to Japan.

Fig. 345.—The Trigger-fish, Balistes carolinensis Gmelin. New York.

The Trigger-fishes: Balistidæ.—The Balistidæ, or trigger-fishes, have the body covered with large rough scales regularly arranged. The first dorsal fin is composed of a short stout rough spine, with a smaller one behind it and usually a third so placed that by touching it the first spine may be set or released. This peculiarity gives the name of trigger-fish as well as the older name of Balistes, or cross-bow shooter. There are no ventral fins, the long pelvis ending in a single blunt spine. The numerous species of trigger-fishes are large coarse fishes of the tropical seas occasionally ranging northward. The center of distribution is in the East Indies, where many of the species are most fantastically marked. Balistes carolinensis, the leather-jacket, or cucuyo, is found in the Mediterranean as also on the American coast. Balistes vetula, the oldwife, oldwench, or cochino, marked with blue, is common in the West Indies, as are several other species, as Canthidermis sufflamen, the sobaco, and the jet-black Melichthys piceus, the black oldwife, or galafata. Several species occur on the Pacific Coast of Mexico, the Pez Puerco, Balistes verres, being commonest. Still others are abundant about the Hawaiian Islands and Japan. The genus Balistapus, having spinous plates on the tail, contains the largest number of species, these being at the same time the smallest in size and the most oddly colored. Balistapus aculeatus and Balistapus undulatus are common through Polynesia to Japan. Most of the tropical species of Balistidæ are more or less poisonous, causing ciguatera, the offensive alkaloids becoming weaker in the northern species. Melichthys radula abounds in Polynesia. In this species great changes take place at death, the colors changing from blue and mottled golden green to jet black. Other abundant Polynesian species are Xanthichthys lineopunctatus, Balistes vidua, Balistes bursa, and Balistes flavomarginatus.

Fig. 346.—File-fish, Osbeckia lævis (scripta). Wood's Hole, Mass.

Fig. 347.—The Needle-bearing File-fish, Amanses scopas of Samoa.

The File-fishes: Monacanthidæ.—Closely related to the Balistidæ are the Monacanthidæ, known as filefishes, or foolfishes. In these the body is very lean and meager, the scales being reduced to shagreen-like prickles. The ventral fins are replaced by a single movable or immovable spine, which is often absent, and the first dorsal fin is reduced to a single spine with sometimes a rudiment behind it. The species are in general smaller than the Balistidæ and usually but not always dull in color. They have no economic value and are rarely used as food, the dry flesh being bitter and offensive. The species are numerous in tropical and temperate seas, although none are found in Europe. On our Atlantic coast, Stephanolepis hispidus and Ceratacanthus schœpfi are common species. In the West Indies are numerous others, Osbeckia lævis and Alutera güntheriana, largest in size, among the commonest. Both of these are large fishes without ventral spine. Monacanthus chinensis, with a great, drooping dewlap of skin behind the ventral spine, is found on the coast of China. Of the numerous Japanese species, the most abundant and largest is Pseudomonacanthus modestus, with deep-blue fins and the ventral spine immovable. Another is Stephanolepis cirrhifer, known as Kawamuki, or skin-peeler. Alutera monoceros, and Osbeckia scripta, the unicorn fish, abound in the East Indies, with numerous others of less size and note. In the male of the Polynesian Amanses scopas (Fig. 347) the tail is armed with a brush of extraordinarily long needle-like spines.

In Stephanolepis spilosomus the caudal fin is of a brilliant scarlet color, contrasting with the usual dull colors of these fishes. In Oxymonacanthus longirostris the body is blue with orange checker-like spots and the snout is produced in a long tube. About the islands of Polynesia, filefishes are relatively few, but some of them are very curious in form or color.

Fig. 348.—Common File fish, Stephanolepis hispidus (Linnæus). Virginia.

The Spinacanthidæ.—In the extinct family Spinacanthidæ the body is elongate, high in front and tapering behind. The first dorsal has six or seven spines, and there are rough spines in the pectoral. The teeth are bluntly conical. Spinacanthus blennioides and S. imperalis are found in the Eocene of Monte Bolca. These are probably the nearest to the original ancestor among known scleroderms.

The Trunkfishes: Ostraciidæ.—The group Ostracodermi contains the single family of Ostraciidæ, the trunkfishes or cuckolds. In this group, the body is enveloped in a bony box, made of six-sided scutes connected by sutures, leaving only the jaws, fins and tail free. The spinous dorsal fin is wholly wanting. There are no ventral fins, and the outer fins are short and small. The trunkfishes live in shallow water in the tropical seas. They are slow of motion, though often brightly colored.

Fig. 349.—Horned Trunkfish, Cowfish, or Cuckold, Lactophrys tricornis (Linnæus). Charleston, S. C.

Fig. 350.—Horned Trunkfish, Ostracion cornutum (Linnæus). East Indies. (After Bleeker.)

Fig. 351.—Spotted Trunkfish, Lactophrys bicaudalis (Linnæus). Cozumel Island, Yucatan.

Fig. 352.—Spotted Trunkfish (face view), Lactophrys bicaudalis (Linnæus).

Fig. 353.—Spineless Trunkfish, Lactophrys triqueter (Linnæus). Tortugas.

Against most of their enemies they are protected by the bony case. The species range from four inches to a foot in length, so far as known. They are not poisonous, and are often baked in the shell. Three genera are recognized: Lactophrys with the carapace, three-angled; Ostracion with four angles; and Aracana, resembling Ostracion, but with the carapace not closed behind the anal fin. In each of these genera there is considerable minor variation due to the presence or absence of spines on the bony shell. In some species, called cuckolds, or cowfishes, long horns are developed over the eye. Others have spines on some other part of the shield and some have no spines at all. No species are found in Europe, and none on the Pacific coast of America. The three-angled species, called Lactophrys, are native chiefly to the West Indies, sometimes carried by currents to Guinea, and one is described from Australia. Lactophrys tricornis of the West Indies has long horns over the eye; Lactophrys trigonus has spines on the lower parts only. Lactophrys triqueter is without spines, and the fourth American species, Lactophrys bicaudalis, is marked by large black spots. The species of Ostracion radiate from the East Indies. One of them, Ostracion gibbosum, has a turret-like spine on the middle of the back, causing the carapace to appear five-angled; Ostracion diaphanum has short horns over the eye, and Ostracion cornutum very long ones; Ostracion immaculatus, the common species of Japan, is without spines; Ostracion sebæ of Hawaii and Samoa is deep, rich blue with spots of golden. Aracana is also of East Indian origin; Aracana aculeata, with numerous species, is common in Japan. A fossil species of Ostracion (O. micrurum) is known from the Eocene of Monte Bolca.

Fig. 354.—Hornless Trunkfish, Lactophrys trigonus (Linnæus). Tortugas, Fla.

The Gymnodontes.—The group of Gymnodontes, having the teeth united in a turtle-like beak, carry still further the degeneration of scales and fins. There is no trace of spinous dorsal, or ventral. The scales are reduced to thorns or prickles, or are lost altogether. All the species have the habit of inflating themselves with air when disturbed, thus floating, belly upward, on the surface of the water. Very few, and these only northern species, are used as food, the flesh of the tropical forms being generally poisonous, and that often in a higher degree than any other fishes whatever.

Fig. 355.—Skeleton of the Cowfish, Lactophrys tricornis (Linnæus).

The Triodontidæ.—The most generalized family is that of the Triodontidæ. These fishes approach the Balistidæ in several regards, having the body compressed and covered with rough scales. The teeth form a single plate in the lower jaw, but are divided on the median line above. The compressed, fan-like, ventral flap is greatly distensible. Triodon bursarius, of the East Indies and northward to Japan, is the sole species of the family.

Fig. 356.—Silvery Puffer, Lagocephalus lævigatus (Linnæus). Virginia.

The Globefishes: Tetraodontidæ.—In the Tetraodontidæ (globefishes, or puffers), each jaw is divided by a median suture. The dorsal and anal are short, and the ventrals are reduced in number, usually fifteen to twenty (7 + 13 to 7 + 9). The walls of the belly are capable of extraordinary distension, so that when inflated, the fish appears like a globe with a beak and a short tail attached. The principal genus Spheroides contains a great variety of forms, forming a closely intergrading series. In some of these the body is smooth, in others more or less covered with prickles, usually three-rooted. In some the form is elongate, the color silvery, and the side of the belly with a conspicuous fold of skin. In these species, the caudal is lunate and the other fins falcate, and with numerous rays. But these forms (called Lagocephalus) pass by degrees into the short-bodied forms with small rounded fins, and no clear line has yet been drawn separating the group into genera. In these species each nostril has a double opening. Lagocephalus lagocephalus, large and silvery, is found in Europe. Lagocephalus lævigatus replaces it on the Atlantic Coast of North America. In Japan are numerous forms of this type, the venomous Lagocephalus sceleratus being one of the best known. Numerous other Japanese species, Spheroides xanthopterus, rubripes, pardalis, ocellatus, vermiculatus, chrysops, etc., mark the transition to typical Spheroides. Spheroides maculatus is common on our Atlantic coast, the puffer, or swell-toad of the coastwise boys who tease it to cause it to swell. Spheroides spengleri and S. testudineus abound in the West Indies. Spheroides politus on the west coast of Mexico.

Fig. 357.—Puffer, inflated, Spheroides spengleri (Bloch). Wood's Hole, Mass.

Fig. 358.—Puffer, Spheroides maculatus (Schneider). Noank, Conn.

In Tetraodon the nasal tentacle is without distinct opening, its tip being merely spongy. The species of this genus are even more inflatable and are often strikingly colored, the young sometimes having the belly marked by concentric stripes of black which disappear with age. Tetraodon hispidus abounds in estuaries and shallow bays from Hawaii to India. In Hawaii, it is regarded as the most poisonous of all fishes (muki-muki) and it is said that its gall was once used to poison arrows. Tetraodon fahaka is a related species, the first known of the family. It is found in the Nile. Tetraodon lacrymatus, black with white spots, is common in Polynesia. Tetraodon aërostaticus, with black spots, is frequently taken in Japan, and Tetraodon setosus is frequent on the west coast of Mexico. This species is subject to peculiar changes of color. Normally dark brown, with paler spots, it is sometimes deep blue, sometimes lemon-yellow and sometimes of mixed shades. Specimens showing these traits were obtained about Clarion Island of the Revillagigedos. No Tetraodon occurs in the West Indies. Colomesus psittacus, a river fish of the northern part of South America, resembles Spheroides, but shows considerable difference in the skull.

Fig. 359.—Tetraodon meleagris (Lacépède). Riu Kiu Islands.

But few fossil Tetraodontidæ have been recognized. These are referred to Tetraodon. The earliest is Tetraodon pygmæus from Monte Bolca.

The Chonerhinidæ of the East Indies are globefishes having the dorsal and anal fins very long, the vertebræ more numerous (12 + 17), twenty-nine in number. Chonerhinus naritus inhabits the rivers of Sumatra and Java.

The little family of Tropidichthyidæ is composed of small globefishes, with a sharply-keeled back, and the nostrils almost, or quite, wanting. The teeth are as in the Tetraodontidæ. The skeleton differs considerably from that of Spheroides, apparently justifying their separation as a family. The species are all very small, three to six inches in length, and prettily colored. In the West Indies Tropidichthys rostratus is found. Tropidichthys solandri abounds in the South Seas, dull orange with blue spots. Tropidichthys rivulatus is common in Japan and several ether species are found in Hawaii.

Fig. 360.—Bristly Globefish, Tetraodon setosus Rosa Smith. Clarion Island, Mex.

Other species occur on the west coast of Mexico, in Polynesia, and in the East Indies.

Fig. 361.—Porcupine-fish, Diodon hystrix (Linnæus). Tortugas Islands.

The Porcupine-fishes: Diodontidæ.—In the remaining families of Gymnodontes, there is no suture in either jaw, the teeth forming an undivided beak. The Diodontidæ, or porcupine-fishes, have the body spherical or squarish, and armed with sharp thorns, the bases of which are so broad as to form a continuous coat of mail. In some of them, part of the spines are movable, these being usually two-rooted; in others, all are immovable and three-rooted. All are reputed poisonous, especially in the equatorial seas.

In Diodon the spines are very long, the anterior ones, at least, movable. The common porcupine-fish, Diodon hystrix, is found in all seas, and often in abundance. It is a sluggish fish, olive and spotted with black. It reaches a length of two feet or more, and by its long spines it is thoroughly protected from all enemies. A second species, equally common, is the lesser porcupine-fish, Diodon holacanthus. In this species, the frontal spines are longer than those behind the pectoral, instead of the reverse, as in Diodon hystrix. Many species of Diodon are recorded from the Eocene, besides numerous species from later deposits. One of these, as Heptadiodon heptadiodon from the Eocene of Italy, with the teeth subdivided, possibly represents a distinct family. Diodon erinaceus is found in the Eocene of Monte Bolca and Progymnodon hilgendorfi in the Eocene of Egypt.

Fig. 362.—Rabbit-fish, Chilomycterus schœpfi (Walbaum). Noank, Conn.

In the rabbit-fishes (Chilomycterus) the body is box-shaped, covered with triangular spines, much shorter and broader at base than those of Diodon. Numerous species are known.

Chilomycterus schœpfi is the common rabbit-fish, or swell-toad of our Atlantic coast, light green, prettily varied with black lines. The larger, Chilomycterus affinis, with the pectoral fin spotted with black, is widely diffused through the Pacific. It is rather common in Japan, where it is the torabuku, or tiger puffer. It is found also in Hawaii, and it is once recorded by Dr. Eigenmann from San Pedro, California, and once by Snodgrass and Heller, from the Galapagos.

The Head-fishes: Molidæ.—The headfishes, or Molidæ, also called sunfishes, have the body abbreviated behind so that the dorsal, anal, and caudal fins seem to be attached to the posterior outline of the head. This feature, constituting the so-called gephyrocercal tail is a trait of specialized degradation.

Fig. 363.—Headfish (adult), Mola mola (Linnæus). Virginia.

Mola mola, the common head-fish or sunfish, is found occasionally in all tropical and temperate seas. Its form is almost circular, having been compared by Linnæus to a mill-wheel (mola), and its surface is covered with a rough, leathery skin. It swims very lazily at the surface of the water, its high dorsal often rising above the surface. It is rarely used as food, though not known to be poisonous. The largest example known to the writer was taken at Redondo Beach, California, by Mr. Thomas Shooter, of Los Angeles. This specimen was 8 feet 2 inches in length, and weighed 1200 pounds. Another, almost as large, was taken at San Diego, in April, 1904. No difference has been noticed among specimens from California, Cape Cod, Japan, and the Mediterranean. The young, however, differ considerably from the adult, as might be expected in a fish of such great size and extraordinary form. (See Figs. 109 and 110, Vol. I.)

Fragments named Chelonopsis, and doubtfully referred to Mola, are found in the Pliocene of Belgium. Certain jaws of cretaceous age, attributed to Mola, probably belong, according to Woodward, to a turtle.

Fig. 364.—The King of the Mackerel, Ranzania makua Jenkins, from Honolulu. (After Jenkins.)

In the genus Ranzania, the body is more elongate, twice as long as deep, but as in Mola, the body appears as if bitten off and then provided with a fringe of tail. The species are rarely taken. Ranzania truncata is found in the Mediterranean and once at Madeira. Ranzania makua, known as the king of the mackerels about Hawaii, is beautifully colored brown and silvery. This species has been taken once in Japan.

In Hawaii it is believed that all the Scombroid fishes are subject to the rule of the makua and that they will disappear if this fish be killed. By a similar superstition, Regalecus glesne is "king of the herrings" in Norway and about Cape Flattery, Trachypterus rex salmonorum is "king of the salmon."

CHAPTER XXV
PAREIOPLITÆ, OR MAILED-CHEEK FISHES

The Mailed-cheek Fishes.—The vast group of Pareioplitæ (Loricati) or mailed-cheek fishes is characterized by the presence of a "bony stay" or backward-directed process from the third suborbital. This extends backward across the cheek toward the preopercle. In the most generalized forms this bony stay is small and hidden under the skin. In more specialized forms it grows larger, articulates with the preopercle, and becomes rough or spinous at its surface. Finally, it joins the other bones to form a coat of mail which covers the whole head. In degenerate forms it is again reduced in size, finally becoming insignificant.

The more primitive Pareioplitæ (παρεία, cheek; ὁπλιτής, armed) closely resemble the Percomorphi, having the same fins, the same type of shoulder-girdle, and the same insertion of the ventral fins. In the more specialized forms the ventral fins remain thoracic, but almost all other parts of the anatomy are greatly distorted. In all cases, so far as known to the writer, the hypercoracoid is perforate as in the Percomorphi. There are numerous points of resemblance between the Cirrhitidæ and the Scorpænidæ, and it is probable that the Scorpænidæ with all the other Pareioplitæ sprang from some perciform stock allied to Cirrhitidæ and Latrididæ.

Fossil mailed-cheek fishes are extremely few and throw little light on the origin of the group. Those belong chiefly to the Cottidæ. Lepidocottus, recorded from the Miocene and Oligocene, seems to be the earliest genus.

Fig. 365.—Rosefish, Sebastes marinus Linnæus. Cape Cod.

Fig. 366.—Skull of Scorpænichthys marmoratus Girard, showing the suborbital stay (a).

The Scorpion-fishes: Scorpænidæ.—The vast family of Scorpænidæ, or scorpion-fishes, comprises such a variety of forms as almost to defy diagnosis. The more primitive types are percoid in almost all respects, save in the presence of the subocular stay. Their scales are ctenoid and well developed. The dorsal spines are numerous and strong. The ventral fins are complete and normally attached; the anal has three strong spines. The cranium shows only a trace of spiny ridges, and the five spines on the preoperculum are not very different from those seen in some species of bass. The gill-arches are, however, different, there being but 3½ gills and no slit behind the last. Otherwise the mouth and pharanx show no unusual characters. In the extremes of the group, however, great changes take place, the head becomes greatly distorted with ridges and grooves, the anal spines are lost, and the dorsal spines variously modified. The scales may be lost or replaced by warts or prickles and the ventral fins may be greatly reduced. Still the changes are very gradual, and it is not easy to divide the group into smaller families.

The most primitive existing genus is doubtless Sebastes. The familiar rosefish, Sebastes marinus, is found on both shores of the north Atlantic. It is bright red in color and is valued as food. As befits a northern fish, it has an increased number of vertebræ (31) and the dorsal spines number 15. From its large haddock-like eye it has been called the Norway haddock. It is an important food-fish in New England as well as in northern Europe.

Fig. 367.—Sebastolobus altivelis Gilbert. Alaska.

In the north Pacific Sebastes gives place to Sebastolobus, with three species (macrochir, altivelis, and alascanus), all bright-red fishes of soft substance and living in rather deep water. Sebastolobus is characterized by its two-lobed pectoral fin, the lower rays being enlarged.

The genus Sebastodes, with its rougher-headed ally Sebastichthys, with 13 dorsal spines and the vertebræ 27, ranges farther south than Sebastes and forms one of the most characteristic features of the fauna of California and Japan, 50 species occurring about California and 25 being already known from Japan. One species (Sebastichthys capensis) is recorded from the Cape of Good Hope, and two, Sebastichthys oculatus and S. darwini, from the coast of Chile.

Within the limits of Sebastodes and Sebastichthys is a very large range of form and color, far more than should exist within the range of a natural genus. On the other hand, all attempts at generic subdivision have failed because the species form a number of almost perfectly continuous series. At one extreme are species with large mouths, small scales, relatively smooth cranium, and long gill-rakers. At the other extreme are robust species, with the head very rough, the mouth moderate, the scales larger, and the gill-rakers short and thick. Still other species have slender cranial spines and spots of bright pink in certain specialized localities. These approach the genus Helicolenus as other species approach Scorpæna.

Fig. 368.—Priest-fish, Sebastodes mystinus Jordan & Gilbert. Monterey, Cal.

The various species are known in California as rockfish, or rock-cod, in Japan as Soi and Mebaru. In both regions they form a large part of the bulk of food-fishes, the flesh being rather coarse and of moderate flavor. All the species so far as known are ovoviviparous, the young being brought forth in summer in very great number, born at the length of about ¼ of an inch. The species living close to shore are brown, black, or green. Those living in deeper waters are bright red, and in still deeper waters often creamy or gray, with the lining of the mouth and the peritoneum black. The largest species reach a length of two or three feet, the smallest eight or ten inches. None are found between Lower California and Peru and none south of Nagasaki in Japan. Of the California species the following are of most note: Sebastodes paucispinis, the Bocaccio of the fishermen, from its large mouth, is an elongate fish, dull red in color, and reaching a very large size. In deeper waters are Sebastodes jordani and Sebastodes goodei, the former elongate and red, the latter more robust and of a very bright crimson color. Sebastodes ovalis, the viuva, and Sebastodes entomelas are grayish in hue, and the related Sebastodes proriger is red. The green rockfish Sebastodes flavidus is common along the shore, as also the black rockfish, known as pêche prêtre or priestfish, Sebastodes mystinus. Less common is Sebastodes melanops. Similar to this but more orange in color is the large Sebastodes miniatus. Somewhat rougher-headed is the small grass rockfish, Sebastodes atrovirens. On the large red rockfish, Sebastichthys ruberrimus, the spinous ridges are all large and rough serrate. On the equally large Sebastichthys levis these ridges are smooth. Both these species are bright red in color. Sebastichthys rubrovinctus, called the Spanish-flag, is covered with broad alternating bands of deep crimson and creamy pink. It is the most handsomely colored of our marine fishes and is often taken in southern California. Sebastichthys elongatus is a red species with very large mouth. Several other species small in size are red, with three or four spots of bright pink. The commonest of these is the corsair, Sebastichthys rosaceus, plain red and golden. Another species is the green and red flyfish, Sebastichthys rhodochloris. Sebastichthys constellatus is spotted with pink and Sebastichthys chlorostictus with green. To this group with pink spots the South American and African species belong, but none of the Japanese. Sebastodes aleutianus is a large red species common in Alaska and Sebastodes ciliatus a green one. About the wharves in California and northward the brown species called Sebastichthys auriculatus is abundant. In the remaining species the spinous ridges are progressively higher, though not so sharp as in some of those already named. Sebastichthys maliger has very high dorsal spines and a golden blotch on the back. In Sebastichthys caurinus and especially Sebastichthys vexillaris the spines are very high, but the coloration is different, being reddish brown. Sebastichthys nebulosus is blue-black with golden spots. Sebastichthys chrysomelas is mottled black and yellow. Sebastichthys carnatus is flesh-color and green. Sebastichthys rastrelliger is a small, blackish-green species looking like Sebastodes atrovirens, but with short gill-rakers. Sebastichthys hopkinsi and Sebastichthys gilberti are small species allied to it. The treefish, Sebastichthys serriceps, has very high spines on the head, and the olive body is crowned by broad black bands. Still more striking is the black-banded rockfish, Sebastichthys nigrofasciatus, with very rough head and bright red body with broad cross-bands of black.

Fig. 369.—Sebastichthys serriceps Jordan & Gilbert. Monterey, Cal.

Of the Japanese species the commonest, Sebastodes inermis, the Mebaru, much resembles Sebastodes flavidus. Sebastodes fuscescens looks like Sebastodes melanops, as does also Sebastodes taczanowskii. Sebastodes matsubaræ and S. flammeus and S. iracundus, bright-red off-shore species, run close to Sebastodes aleutianus. Sebastichthys pachycephalus suggests Sebastichthys chrysomelas. Sebastodes steindachneri and S. itinus are brighter-colored allies of Sebastodes ovalis and Sebastodes scythropus and Sebastodes joyneri represent Sebastodes proriger. Sebastichthys trivittatus, green, striped with bright golden, bears some resemblance to Sebastichthys maliger. Sebastichthys elegans, Sebastichthys oblongus, and Sebastichthys mitsukurii, dwarf species, profusely spotted, have no analogues among the American forms. Sebastodes glaucus of the Kurile Islands has 14 dorsal spines and is not closely related to any other. Fourteen dorsal spines are occasionally present in Sebastichthys elegans. All the other species show constantly 13.

Fig. 370.—Banded Rockfish, Sebastichthys nigrocinctus (Ayres). Straits of Fuca.

The genus Sebastiscus has the general appearance of Sebastodes, and like the latter possesses a large air-bladder. It however agrees with Scorpæna in the possession of but 12 dorsal spines and 24 vertebræ. The two known species are common in Japan. Sebastiscus marmoratus, mottled brown, is everywhere abundant along the coast, and the pretty Sebastiscus albofasciatus, pink, violet, and golden, represents it in equal abundance in deeper water.

The genus Sebastopsis differs from Sebastodes only in having no teeth on the palatines. The species, all of small size and red or varied coloration, are confined to the Pacific. Sebastopsis xyris occurs in lower California and Sebastopsis guamensis and S. scaber in Polynesia. Species of this genus are often found dried in Chinese insect boxes.

Helicolenus differs from Sebastiscus only in the total absence of air-bladder. The species are all bright crimson in color, very handsome, and live in deep water. Helicolenus dactylopterus is rather common in the Mediterranean, and is sometimes taken in the Gulf Stream, and also in Japan, where two or three other species occur.

Neosebastes is much like Sebastodes, but the suborbital stay bears strong spines and the dorsal is very high. Neosebastes panda is found in Australia, and N. entaxis in Japan. Setarches is distinguished by the cavernous bones of its head. Species are found in both the Atlantic and Pacific in deep water. Several other peculiar or transitional genera are found in different parts of the Pacific.

Fig. 371.—Florida Lion fish, Scorpæna grandicornis Cuv. & Val. Key West.

In Scorpæna the head is more uneven in outline than in Sebastodes and Sebastichthys, skinny flaps are often present on head and body, the air-bladder is wanting, there are 12 dorsal spines and 24 vertebræ, and on each dorsal spine is a small venom-secreting gland. The species are very numerous, highly varied in color, and found in all warm seas, being known as scorpion-fishes or Rascacios. Two species, Scorpæna scrofa and Scorpæna porcus, are common in the Mediterranean, being regarded as good food-fishes, though disliked by the fishermen.

Of the numerous West Indian species, Scorpæna plumieri, Scorpæna grandicornis, and Scorpæna brasiliensis are best known. Scorpæna guttata is common in southern California and is an excellent food-fish. Scorpæna mystes is found on the west coast of Mexico. Scorpæna onaria and S. izensis are found in Japan. Fossil remains referred to Scorpæna are recorded from the Tertiary rocks.

In the islands of the Pacific are numerous dwarf species less than three inches long, which have been set apart as a separate genus, Sebastapistes. The longest known of these is Sebastapistes strongensis, named from Strong Island, abundant in crevices in the corals throughout Polynesia, and much disliked by fishermen.

Fig. 372.—Sea-scorpion, Scorpæna mystes Jordan. Mazatlan.

The genus Scorpænopsis differs from Scorpæna in the absence of palatine teeth. It is still more fantastic in form and color. Scorpænopsis cirrhosa, Scorpænopsis fimbriata, and other species are widely distributed through the East Indies and Polynesia.

The lion-fishes (Pterois) of the tropical Pacific are remarkable for their long pectoral fins, elongate dorsal spines, and zebra-like coloration. The numerous species are fantastic and handsomely colored, but their poisoned, needle-like spines are dreaded by fishermen. They lurk in crevices in the coral reefs, some of them reaching a foot in length.

Inimicus japonicus, common in Japan, has a depressed and monstrous head and a generally bizarre appearance. It is usually black in color but is largely bright red when found among red algæ. A related species, Inimicus aurantiacus, is blackish when near shore, but lemon-yellow in deep water. (See frontispiece.) A related species in the East Indies is Pelor filamentosum, called Nohu or Gofu in Polynesia.

Fig. 373.—Lion-fish or Sausolele (the dorsal spines envenomed), Pterois volitans (Linnæus). Family Scorpænidæ. (From a specimen from Samoa.)

Still more monstrous are the species of Synanceia, short, thick-set, irregularly formed fishes, in which the poisoned spines reach a high degree of venom. The flesh in all these species is wholesome, and when the dorsal spines are cut off the fishes sell readily in the markets. These fishes lie hidden in cavities of the reefs, being scarcely distinguishable from the rock itself. (See Fig. 168, Vol. I.)

The black Emmydrichthys vulcanus of Tahiti lies in crevices of lava, and could scarcely be distinguished from an irregular lump of lava-rock.

Fig. 374.—Black Nohu, or Poison-fish, Emmydrichthys vulcanus Jordan. A species with stinging spines, showing resemblance to lumps of lava among which it lives. Family Scorpænidæ. From Tahiti.

A related form, Erosa erosa, the daruma-okose of Japan, is monstrous in form but often beautifully colored with crimson and gray.

In Congiopus the very strong dorsal spines begin in the head, and the mouth is very small. Dr. Gill makes this genus the type of a distinct family, Congiopodidæ.

Besides these, very many genera and species of small poison-fishes, called okose in Japan, abound in the sandy bays from Tokio to Hindostan and the Red Sea. Some of these are handsomely colored, others are fantastically formed. Paracentropogon rubripinnis and Minous adamsi are the commonest species in Japan. Trachicephalus uranoscopus abounds in the bays of hina. Snyderina yamanokami occurs in Southern Japan.

Fig. 375.—Snyderina yamanokami Jordan & Starks. Family Scorpænidæ. Satsuma, Japan.

But few fossil Scorpænidæ are recorded. Scorpænopterus siluridens, a mailed fish from the Vienna Miocene, with a warty head, seems to belong to this group, and Ampheristus toliapicus, with a broad, depressed head, is found in the London Eocene, and various Miocene species have been referred to Scorpæna. Sebastodes rosæ is based on a fragment, probably Pleistocene, from Port Harford, California.

Fig. 376.—Trachicephalus uranoscopus. Family Scorpænidæ. From Swatow, China.

The small family of the Caracanthidæ consists of little fishes of the coral reefs of the Pacific. These are compressed in form, and the skin is rough with small prickles, the head being feebly armed. The species are rare and little known, brown in color with pale spots.

Fig. 377.—Skilfish, Anoplopoma fimbria (Pallas). California.

The Skilfishes: Anoplopomidæ.—The small family of skilfishes or Anoplopomidæ consists of two species found on the coast of California and northward. These resemble the Scorpænidæ, having the usual form of nostrils, and the suborbital stay well developed. The skull is, however, free from spines, the scales are small and close-set, and the sleek, dark-colored body has suggested resemblance to the mackerel or hake. Anoplopoma fimbria, known as skilfish, beshow, or coalfish, is rather common from Unalaska to Monterey, reaching a length of two feet or more. In the north it becomes very fat and is much valued as food. About San Francisco it is dry and tasteless.

The Greenlings: Hexagrammidæ.—The curious family of greenlings, Hexagrammidæ, is confined to the two shores of the North Pacific. The species vary much in form, but agree in the unarmed cranium and in the presence of but a single nostril on each side, the posterior opening being reduced to a minute pore. The vertebræ are numerous, the scales small, and the coloration often brilliant. The species are carnivorous and usually valued as food. They live in the kelp and about rocks in California and Japan and along the shores of Siberia and Alaska. The atka-fish (Pleurogrammus monopterygius) is one of the finest of food-fishes. This species reaches a length of eighteen inches. It is yellow in color, banded with black, and the flesh is white and tender, somewhat like that of the Lake whitefish (Coregonus clupeiformis), and is especially fine when salted. This fish is found about the Aleutian Islands, especially the island of Atka, from which it takes its name. It is commercially known as Atka mackerel.

Fig. 378.—Atka-fish, Pleurogrammus monopterygius (Pallas). Atka Island.

In this genus there are numerous lateral lines, and the dorsal fin is continuous. In Hexagrammos, the principal genus of the family, the dorsal is divided into two fins, and there are about five lateral lines on each side.

Hexagrammos decagrammus is common on the coast of California, where it is known by the incorrect name of rock-trout. It is a well-known food-fish, reaching a length of eighteen inches. The sexes are quite unlike in color, the males anteriorly with blue spots, the females speckled with red or brown.

Fig. 379.—Greenling, Hexagrammos decagrammus (Pallas). Sitka.

Fig. 380.—Cultus Cod, Ophiodon elongatus (Girard). Sitka, Alaska.

Hexagrammos octogrammus, the common greenfish of Alaska, and the greenling Hexagrammos stelleri, are also well-known species. Close to the latter species is the Abura ainame, or fat cod, Hexagrammos otakii, common throughout Japan. The red rock-trout, Hexagrammos superciliosus, is beautifully variegated with red, the color being extremely variable. Other species are found in Japan and Kamchatka. Agrammus agrammus of Japan differs in the possession of but one lateral line. Ophiodon elongatus, the blue cod, cultus cod, or Buffalo cod of California, is a large fish of moderate value as food, much resembling a codfish, but with larger mouth and longer teeth. The flesh and bones are deeply tinged with bluish green. Cultus is the Chinook name for worthless. Zaniolepis latipinnis is a singular-looking fish, very rough, dry, and bony, occasionally taken on the California coast. Oxylebius pictus is a small, handsome, and very active little fish, whitish with black bands, common among rocks and algæ on the California coast. It is, however, rarely brought into the markets, as it shows great skill in escaping the nets.

No fossil Hexagrammidæ are known.

The Flatheads or Kochi: Platycephalidæ.—The family of Platycephalidæ consists of spindle-shaped fishes, with flattened, rough heads and the body covered with small, rough scales. About fifty species occur in the East Indian region, where the larger ones are much valued as food. The most abundant species and usually the largest in size is Platycephalus insidiator, the kochi of the Japanese. The genus Insidiator contains smaller species with larger scales. In all these the head is very much depressed, a feature which separates them from all the Scorpænidæ. Hoplichthys langsdorfi, the nezupo or rat-tail of Japan, is the type of a separate family, Hoplichthyidæ, characterized by a bony armature of rough plates. Bembras japonicas, another little Japanese fish, with the ventrals advanced in position and the skin with rough plates, is the type of the family of Bembradidæ.

The Sculpins: Cottidæ.—The great family of Cottidæ or sculpins is one especially characteristic of the northern seas, where a great variety of species is found. These differ in general from the Scorpænidæ, from which they are perhaps derived, in the greater number of vertebræ and in the relative feebleness or degeneration of the spinous dorsal, the ventrals, and the scales. In all these regards great variation exists. In the most primitive genus, Jordania, the body is well scaled, the spinous dorsal well developed, and the ventral rays I, 5. In Hemitripterus a large number of dorsal spines remains, but the structure in other regards is highly modified. In the most degraded types, Cottunculus, Psychrolutes, Gilbertidia, which are also among the most specialized, there is little trace of spinous dorsal, the scales are wholly lost, and the ventral fin is incomplete. Most of the species of Cottidæ live on the bottom in shallow seas. Some are found in deep water and a few swarm in the rivers. All are arctic or subarctic, none being found to the south of Italy, Virginia, California, and Japan. None are valued as food, being coarse and tough. Scarcely any are found fossil.

Of the multitude of genera of Cottidæ we notice a few of the most prominent. Jordania zonope, a pretty little fish of Puget Sound, is the most primitive in its characters, being closely allied to the Hexagrammidæ.

Fig. 381.—Jordania zonope Starks. Puget Sound.

Scorpænichthys marmoratus, the great sculpin, or cabezon, of California reaches a length of 2½ feet. It has the ventral rays I, 5, although almost in all the other sculpins the rays are reduced to I, 3 or I, 4. The flesh has the livid blue color seen in the cultus cod Ophiodon elongatus.

Fig. 382.—Astrolytes notospilotus (Girard). Puget Sound.

Fig. 383.—Irish Lord, Hemilepidotus jordani Bean. Unalaska.

Fig. 384.—Triglops pingeli Kröyer. Chebucto, Canada.

Fig. 335.—Buffalo Sculpin, Enophrys bison (Girard). Puget Sound.

To Icelinus, Artedius, Hemilepidotus, Astrolytes, and related genera belong many species with the body partly scaled. These are characteristic of the North Pacific, in which they drop to a considerable depth. Icelus, Triglops, and Artediellus are found also in the North Atlantic, the Arctic fauna of which is derived almost entirely from Pacific sources. The genus Hemilepidotus contains coarse species, with bands of scales. The "Irish lord," Hemilepidotus jordani, a familiar and fantastic inhabitant of Bering Sea, is much valued by the Aleuts as a food-fish, although the flesh is rather tough and without much flavor. Almost equally common in Bering Sea is the red sculpin, Hemilepidotus hemilepidotus, and the still rougher Ceratocottus diceraus. The stone-sculpin, or buffalo-sculpin, Enophrys bison, with bony plates on the side and rough horns on the preopercle, is found about Puget Sound and southward. In all these large rough species from the North Pacific the preopercle is armed with long spines which are erected when the fish is disturbed. This makes it almost impossible for any larger fish to swallow them.

Fig. 386.—Ceratocottus diceraus (Cuv. & Val.). Tolstoi Bay, Alaska.

Fig. 387.—Elanura forficata Gilbert. Bering Sea.

Fig. 388.—Yellowstone Miller's Thumb, Cottus punctulatus (Gill). Yellowstone River.

The genera Cottus and Uranidea include the miller's thumbs, also called in America, blob and muffle-jaws, of the Northern rivers. These little fishes are found in Europe, Asia, and America wherever trout are found. They lurk under weeds and stones, moving with the greatest swiftness when disturbed. They are found in every cold stream of the region north of Virginia, and they vie with the sticklebacks in their destruction of the eggs and fry of salmon and trout. Cottus gobio is the commonest species of Europe. Cottus ictalops is the most abundant of the several species of the eastern United States, and Cottus asper in streams of the Pacific Coast, though very many other species exist in each of these regions. The genus Uranidea is found in America. It is composed of smaller species with fewer teeth and fin-rays, the ventrals I, 3. Uranidea gracilis is the commonest of these, the miller's thumb of New England. Rheopresbe fujiyamæ is a large river sculpin in Japan.

Fig. 389.—Miller's Thumb, Uranidea tenuis Evermann & Meek. Klamath Falls.

Fig. 390.—Cottus evermanni Gilbert. Lost River, Oregon.

Trachidermus ansatus is another river species, the "mountain-witch" (yamanokami) of Japan, remarkable for a scarlet brand on its cheek, conspicuous in life.

The chief genus of Atlantic sculpins is Myoxocephalus, containing large marine species, in structure much like the species of Cottus. Myoxocephalus bubalis is the European fatherlasher, or proach; the European sculpin is Myoxocephalus scorpius. The very similar daddy sculpin of New England is Myoxocephalus grœnlandicus. This species swarms everywhere from Cape Cod northward.

Fig. 391.—California Miller's Thumb, Cottus gulosus Girard. McCloud River, Cal. (Photograph by Cloudsley Rutter.)

According to Fabricius, Myoxocephalus grœnlandicus is "abundant in all the bays and inlets of Greenland, but prefers a stony coast clothed with seaweed. It approaches the shore in spring and departs in winter. It is very voracious, preying on everything that comes in its way and pursuing incessantly the smaller fish, not sparing the young of its own species, and devouring crustacea and worms. It is very active and bold, but does not come to the surface unless it be led thither in pursuit of other fish. It spawns in December and January and deposits its red-colored roe on the seaweed. It is easily taken with a bait, and constitutes the daily food of the Greenlanders, who are very fond of it. They eat the roe raw."

Fig. 392.—Pribilof Sculpin, Myoxocephalus niger (Bean). St. Paul Island, Bering Sea.

The little sculpin, or grubby, of the New England coast is Myoxocephalus æneus, and the larger eighteen-spined sculpin is Myoxocephalus octodecimspinosus. Still more numerous and varied are the sculpins of the North Pacific, Myoxocephalus polyacanthocephalus being the best known and most widely diffused. Oncocottus quadricornis is the long-horned sculpin of the Arctic Europe, entering the lakes of Russia and British America. Triglopsis thompsoni of the depths in our own Great Lakes seems to be a dwarfed and degenerate descendant of Oncocottus.

Fig. 393.—18-spined Sculpin, Myoxocephalus octodecimspinosus (Mitchill). Beasley Point, N. J.

Fig. 394.—Oncocottus quadricornis (L.). St. Michael, Alaska.

The genus Zesticelus contains small soft-bodied sculpins from the depths of the North Pacific. Zesticelus profundorum was taken in 664 fathoms off Bogoslof Island and Zesticelus bathybius off Japan. In this genus the body is very soft and the skeleton feeble, the result of deep-sea life. Another deep-water genus less degraded is Cottunculus, from which by gradual loss of fins the still more degraded Psychrolutes (paradoxus) and Gilbertidia (sigolutes) are perhaps descended. In sculpins of this type the liparids, or sea-snails, may have had their origin. Among the remaining genera Gymnocanthus (tricuspis, etc.) has no vomerine teeth. Leptocottus (armatus) and Clinocottus (analis) abound on the coast of California, and Pseudoblennius (percoides) is found everywhere along the shores of Japan. Vellitor centropomus of Japan is remarkable among sculpins for its compressed body and long snout. Dialarchus snyderi of the California rock-pools is perhaps the smallest species of sculpin, Blepsias (cirrhosus), Nautichthys (oculofasciatus), and Hemitripterus (americanus), the sea-raven, among the most fantastic. In the last-named genus the spinous dorsal is many-rayed, as in Scorpænidæ, a fact which has led to its separation by Dr. Gill as a distinct family. But the dorsal spines are equally numerous in Jordania, which stands at the opposite extreme of the cottoid series.

Fig. 395.—Blepsias cirrhosus Pallas. Straits of Fuca.

Fig. 396.—Sea raven, Hemitripterus americanus (Gmelin). Halifax, Nova Scotia.

Fig. 397.—Oligocottus maculosus Girard. Sitka.

In Ascelichthys (rhodorus), a pretty sculpin of the rock-pools of the Oregon region, the ventral fins are wholly lost. Ereunias grallator, a deep-water sculpin from Japan, without ventrals and with free rays below its pectorals, should perhaps represent a distinct family, Ereuniidæ.

The degeneration of the spinous dorsal in Psychrolutes and Gilbertidia of the North Pacific has been already noticed. These genera seem to lead directly from Cottunculus to Liparis.

Fossil Cottidæ are few. Eocottus veronensis, from the Eocene of Monte Bolca, is completely scaled, with the ventral rays I, 5. It is apparently related to Jordania, but is still more primitive. Lepidocottus (aries and numerous other species, mostly from the Miocene) is covered with scales, but apparently has less than five soft rays in the ventrals. Remains of Oncocottus, Icelus, and Cottus are found in Arctic Pleistocene rocks. The family as a whole is evidently of recent date.

The Rhamphocottidæ consist of a single little sculpin with a large bony and singularly formed head, found on the Pacific Coast from Sitka to Monterey. The species is called Rhamphocottus richardsoni.

The Sea-poachers: Agonidæ.—The sea-poachers or alligator-fishes, Agonidæ, are sculpins inclosed in a coat of mail made by a series of overlying plates, much like those of the sea-horses or the catfishes of the family Loricariidæ. So far as structure goes, these singular fishes are essentially like the Cottidæ, but with a different and more perfect armature. The many species belong chiefly to the North Pacific, a few in the Atlantic and on the coast of Patagonia. Some are found in considerable depth of water. All are too small to have value as food and some have most fantastic forms. Only a few of the most prominent need be noticed. The largest and most peculiar species is Percis japonicus of the Kurile Islands. Still more fantastic is the Japanese Draciscus sachi with sail-like dorsal and anal. Agonus cataphractus, the sea-poacher, is the only European species. Podothecus acipenserinus, the alligator-fish, is the commonest species of the North Pacific. Pallasina barbata is as slender as a pipefish, with a short beard at the chin. Aspidophoroides monopterygius of the Atlantic and other similar species of the Pacific lack the spinous dorsal fin.

Fig. 398.—Ereunias grallator Jordan & Snyder. Misaki, Japan.

Fig. 399.—Sleek Sculpin, Psychrolutes paradoxus (Günther). Puget Sound.

Fig. 400.—Gilbertidia sigolutes (Jordan). Puget Sound.

Fig. 401.—Richardson's Sculpin, Rhamphocottus richardsoni (Günther). Puget Sound.

Fig. 402.—Stelgis vulsus (Jordan & Gilbert). Point Reyes, Cal.

Fig. 403.—Draciscus sachi Jordan & Snyder. Family Agonidæ. Aomori, Japan.

Fig. 404.—Agonoid-fish, Pallasina barbata (Steindachner). Port Mulgrave, Alaska.

Fig. 405.—Aspidophoroides monopterygius (Bloch). Halifax.

No fossil Agonidæ are known.

The Lump-suckers: Cyclopteridæ.—The lump-suckers, Cyclopteridæ, are structurally very similar to the Cottidæ, but of very different habit, the body being clumsy and the movements very slow. The ventral fins are united to form a sucking disk by which these sluggish fishes hold fast to rocks. The skeleton is feebly ossified, the spinous dorsal fin wholly or partly lost, the skin smooth or covered with bony warts. The slender suborbital stay indicates the relation of these fishes with the Cottidæ. The species are chiefly Arctic, the common lumpfish or "cock and hen paddle," Cyclopterus lumpus, abounding on both shores of the North Atlantic. It reaches a length of twenty inches, spawning in eel-grass where the male is left to watch the eggs. Cyclopterichthys ventricosus is a large species with smooth skin from the North Pacific.

Fig. 406.—Lumpfish, Cyclopterus lumpus (Linnæus). Eastport, Me.

Fig. 407.—Liparid, Crystallias matsushimæ, (Jordan and Snyder). Family Liparididæ. Matsushima Bay, Japan.

The Sea-snails: Liparididæ.—The sea-snails, Liparididæ are closely related to the lumpfishes, but the body is more elongate, tadpole shaped, covered with very lax skin, like the "wrinkled skin on scalded milk." In structure the liparids are still more degenerate than the lumpfishes. Even the characteristic ventral disk is lost in some species (Paraliparis; Amitra) and in numerous others the tail is drawn out into a point (leptocercal), a character almost always a result of degradation. The dorsal spines are wanting or imbedded in the loose skin, and all trace of spines on the head is lost, but the characteristic suborbital stay is well developed. The numerous species are all small, three to twelve inches in length. They live in Arctic waters, often descending to great depths, in which case the body is very soft. One genus, Enantioliparis, is found in the Antarctic. In the principal genus, Liparis, the ventral disk is well developed, and the spinous dorsal obsolete. Liparis liparis is found on both shores of the North Atlantic, and is subject to large variations in color. Liparis agassizi is abundant in Japan and northward, and Liparis pulchellus in California. In the most primitive genus, Neoliparis, a notch in the fin indicates the separation of the spinous dorsal. Neoliparis montagui is common in Europe, replaced in New England by Neoliparis atlanticus. Careproctus, with numerous elongate species, inhabits depths of the North Pacific. In Paraliparis (or Hilgendorfia) ulochir, the ventral disk is gone and the lowest stage of degradation of the Loricate or Scorpæna-Cottus type of fishes is reached. No fossil lump-suckers or liparids are recorded, although remains of Cyclopterus lumpus are found in nodules of glacial clay in Canada.

Fig. 408.—Snailfish, Neoliparis mucosus (Ayres). San Francisco.

The Baikal Cods: Comephoridæ.—The family of Comephoridæ includes Comephorus baikalensis, a large fresh-water fish of Lake Baikal in Siberia, having no near affinities with any other existing fish, but now known to be a mail-cheek fish related to the Cottidæ. The body is elongate, naked, with soft flesh and feeble skeleton. The mouth is large, with small teeth, and the skull has a cavernous structure. There are no ventral fins. The spinous dorsal is short and low, the second dorsal and anal many-rayed, and the pectoral fins are excessively long, almost wing-like; the vertebræ number 8 + 35 = 43, and unlike most fresh-water fishes, the species has no air-bladder. Little is known of the habits of this singular fish. Another genus is recently described under the name of Cottocomephorus.

Suborder Craniomi: the Gurnards, Triglidæ.—A remarkable offshoot from the Pareioplitæ is the suborder of gurnards, known as Craniomi (κράνιον, skull; ὤμος, shoulder). In these fishes the suborbital stay is highly developed, much as in the Agonidæ, bony externally and covering the cheeks. The shoulder-girdle is distorted, the post-temporal being solidly united to the cranium, while the postero-temporal is crowded out of place by the side of the proscapula. In other regards these fishes resemble the other mail-cheek forms, their affinities being perhaps closest with the Agonidæ or certain aberrant Cottidæ as Ereunias.

In the true gurnards or Triglidæ the head is rough and bony, the body covered with rough scales and below the pectoral fin are three free rays used as feelers by the fish as it creeps along the bottom. These free rays are used in turning over stones, exploring shells and otherwise searching for food. The numerous species are found in the warm seas. In Europe, the genus Trigla, without palatine teeth and with the lateral line armed, is represented by numerous well-known species. Trigla cuculus is a common form of the Mediterranean. Chelidonichthys, similar to Trigla but larger and less fully armed, is found in Asia as well as in Europe. Several species occur in the Mediterranean. Chelidonichthys kumu is a common species in Japan, a large fish with pectorals of a very brilliant variegated blue, like the wings of certain butterflies.

Fig. 409.—Sea-robin, Prionotus evolans (L.). Wood's Hole, Mass.

Lepidotrigla, with larger scales, has many species on the coasts of Europe as well as in China and Japan. Lepidotrigla alata, a red fish with a peculiar bony, forked snout, is common in Japan. The American species of gurnards, having teeth on the palatine, belong to the genus Prionotus. Northward these fishes, known as sea-robins, live along the shores in shallow water. In the tropics they descend to deeper water, assuming a red color. Prionotus carolinus is the commonest species in New England. Prionotus strigatus, the striped sea-robin, and Prionotus tribulus, the rough-headed sea-robin, are common species along the Carolina coast. None have much value as food, being dry and bony. Numerous fossil species referred to Trigla are found in the Miocene. Podopteryx, from the Italian Miocene, with small pectorals and very large ventrals, perhaps belongs also to this family, but its real affinities are unknown.

Fig. 410.—Flying Gurnard, Cephalacanthus volitans (L.). Virginia.

Fig. 411.—Peristedion miniatum Goode & Bean. Depths of the Gulf Stream.

The Peristediidæ.—The Peristediidæ are deep-water sea-robins, much depressed, with flat heads, a bony coat of mail, and two free feelers on the pectoral fin instead of three. The species of Peristedion are occasionally taken with the dredge. Peristedion cataphractum is rather common in Europe. The extinct Peristedion urcianense is described from the Pliocene of Orciano, Tuscany.

The Flying Gurnards: Cephalacanthidæ.—The flying gurnards, Cephalacanthidæ, differ in numerous respects and are among the most fantastic inhabitants of the sea. The head is short and bony, the body covered with firm scales, and the very long, wing-like pectoral fin is divided into two parts, the posterior and larger almost as long as the rest of the body. This fin is beautifully colored with blue and brownish red. The first spine of the dorsal fin is free from the others and more or less prolonged. The few species of flying gurnard are much alike, ranging widely in the tropical seas, and having a slight power of flight. The flying robin, or batfish, called in Spanish volador or murcielago, Cephalacanthus volitans, is common on both coasts of the Atlantic, reaching a length of eighteen inches. Cephalacanthus peterseni is found in Japan and Cephalacanthus orientalis in the East Indies, Japan, and Hawaii. The immature fishes have the pectoral fins much shorter than in the adult, and differ in other regards. Cephalacanthus pliocenicus occurs in the Lower Pliocene of Orciano, Tuscany.

Petalopteryx syriacus, an extinct flying gurnard found in the Cretaceous of Mount Lebanon, is an ally of Cephalacanthus. The body is covered with four-angled bony plates, and the first (free) spine of the dorsal is enlarged.

CHAPTER XXVI
GOBIOIDEI, DISCOCEPHALI, AND TÆNIOSOMI

Suborder Gobioidei, the Gobies: Gobiidæ.—The great family of Gobiidæ, having no near relations among the spiny-rayed fishes, may be here treated as forming a distinct suborder.

The chief characteristics of the family are the following: The ventral fins are thoracic in position, each having one spine and five soft rays, in some cases reduced to four, but never wanting. The ventral fins are inserted very close together, the inner rays the longest, and in most cases the two fins are completely joined, forming a single roundish fin, which may be used as a sucking-disk in clinging to rocks. The shoulder-girdle is essentially perch-like in form, the cranium is usually depressed, the bones being without serrature. There is no lateral line, the gill-openings are restricted to the sides, and the spinous dorsal is always small, of feeble spines, and is sometimes altogether wanting. There is no bony stay to the preopercle. The small pharyngeals are separate, and the vertebræ usually in normal number, 10 + 14 = 24.

The species are excessively numerous in the tropics and temperate zones, being found in lakes, brooks, swamps, and bays, never far out in the sea, and usually in shallow water. Many of them burrow in the mud between or below tide-marks. Others live in swift waters like the darters, which they much resemble. A few reach a length of a foot or two, but most of the species rarely exceed three inches, and some of them are mature at half an inch.

The largest species, Philypnus dormitor, the guavina de rio, is found in the rivers of Mexico and the West Indies. It reaches a length of nearly two feet and is valued as food. Unlike most of the others, in this species there are teeth on the vomer. Other related forms of the subfamily of Eleotrinæ, having the ventral fins separate, are Eleotris pisonis, a common river-fish everywhere in tropical America; Eleotris fusca, a river-fish abounding from Tahiti and Samoa to Hindostan; Dormitator maculatus, the stout-bodied guavina-mapo of the West Indian regions, with the form of a small carp. Guavina guavina of Cuba is another species of this type, and numerous other species having separate ventrals are found in the East Indies, the West Indies, and in the islands of Polynesia. Some species, as Valenciennesia strigata of the East Indies and Vireosa hanæ of Japan, are very gracefully colored. One genus, Eviota, is composed of numerous species, all minute, less than an inch in length. These abound in the crevices in coral-heads. Eviota epiphanes is found in Hawaii, the others farther south. Hypseleotris guntheri, of the rivers and springs of Polynesia, swims freely in the water, like a minnow, never hugging the bottom as usual among gobies.

Fig. 412.—Guavina de Rio, Philypnus dormitor (Bloch & Schneider). Puerto Rico.

Fig. 413.—Dormeur, Eleotris pisonis Gmelin. Tortugas, Fla.

Fig. 414.—Guavina mapo, Dormitator maculatus (Schneider). Puerto Rico.

Fig. 415.—Vireosa hanæ Jordan & Snyder. Misaki, Japan.

Fig. 416.—Esmeralda de Mar, Gobionellus oceanicus (Pallas). Puerto Rico.

Of the typical gobies having the ventrals united we can mention but a few of the myriad forms, different species being abundant alike in fresh and salt waters in all warm regions. In Europe Gobius jozo, Gobius ophiocephalus, and many others are common species. The typical genus Gobius is known by its united ventrals, and by the presence of silken free rays on the upper part of the pectoral fin. Mapo soporator swarms about coral reefs in both Indies. Gobionellus oceanicus, the esmeralda or emerald-fish, is notable for its slender body and the green spot over its tongue. Gobiosoma alepidotum and other species are scaleless. Barbulifer ceuthœcus lives in the cavities of sponges. Coryphopterus similis, a small goby, swarms in almost every brook of Japan. The species of Pterogobius are beautifully colored, banded with white or black, or striped with red or blue. Pterogobius virgo and Pterogobius daimio of Japan are the most attractive species. Species of Cryptocentrus are also very prettily colored.

Fig. 417.—Pterogobius daimio Jordan & Snyder. Misaki, Japan.

Fig. 418.—Darter Goby, Aboma etheostoma Jordan. Mazatlan, Mex.

Of the species burrowing in mud the most interesting is the long-jawed goby, Gillichthys mirabilis. In this species the upper jaw is greatly prolonged, longer than the head, as in Opisthognathus and Neoclinus. In the "American Naturalist" for August, 1877, Mr. W. N. Lockington says of the long-jawed goby:

"I call it the long-jawed goby, as its chief peculiarity consists in its tremendous length of jaw. A garpike has a long jaw, and so has an alligator, and it is not unlikely that the title will call up in the minds of some who read this the idea of a terrible mouth, armed with a bristling row of teeth. This would be a great mistake, for our little fish has no teeth worth bragging about, and does not open his mouth any wider than a well-behaved fish should do. The great difference between his long jaws and those of a garpike is that the latter's project forward, while those of our goby are prolonged backward immensely.

"The long-jawed goby was discovered by Dr. J. G. Cooper in the Bay of San Diego, among seaweed growing on small stones at the wharf, and in such position that it must have been out of the water from three to six hours daily, though kept moist by the seaweed.

Fig. 419.—Long-jawed Goby. Gillichthys mirabilis Cooper. Santa Barbara.

"On a recent occasion a single Gillichthys, much larger than any of the original types, was presented by a gentleman who said that the fish, which was new to him, was abundant upon his ranch in Richardson's Bay, in the northern part of the Bay of San Francisco; that the Chinamen dug them up and ate them, and that he had had about eleven specimens cooked, and found them good, tasting, he thought, something like eels. The twelfth specimen he had preserved in alcohol, in the interest of natural science. This gentleman had the opportunity of observing something of the mode of life of these fishes, and informed us that their holes, excavated in the muddy banks of tidal creeks, increase in size as they go downward, so that the lower portion is below the water-level, or at least sufficiently low to be kept wet by the percolation from the surrounding mud.

"When the various specimens now acquired were placed side by side, the difference in the relative length of their jaws was very conspicuous, for while in the smallest it was about one-fifth of the total length, in the largest it exceeded one-third.

"As the fish had now been found in two places in the bay, I thought I would try to find it also, and to this end sallied out one morning, armed with a spade, and commenced prospecting in a marsh at Berkeley, not far from the State University. For a long time I was unsuccessful, as I did not know by what outward signs their habitations could be distinguished, and the extent of mud-bank left bare by the retreating tide was, as compared with my powers of delving, practically limitless.

"At last, toward evening, while digging in the bend of a small creek, in a stratum of soft, bluish mud, and at a depth of about a foot below a small puddle, I found five small fishes, which at first I believed to belong to an undescribed species, so little did they resemble the typical G. mirabilis, but which proved, upon a closer examination, to be the young of that species. There was the depressed, broad head, the funnel-shaped ventral 'disk' formed by the union of the two ventral fins, and the compressed tail of the long-jawed goby, but where were the long jaws? The jaws were, of course, in their usual place, but their prolongations had only just begun to grow along the sides of the head, and were not noticeable unless looked for. A comparison of the various specimens proved conclusively that the strange-looking appendage is developed during the growth of the fish, as will be seen by the following measurements of four individuals:

"In the smallest specimen the maxillary expansion extends beyond the orbit for a distance about equal to that which intervenes between the anterior margin of the orbit and the tip of the snout; in No. 2 it reaches to the posterior margin of the preoperculum; in No. 3 it ends level with the gill-opening; while in the largest individual it passes the origin of the pectoral and ventral fins.

"What can be the use of this long fold of skin and cartilage, which is not attached to the head except where it joins the mouth, and which, from its gradual development and ultimate large dimensions, must certainly serve some useful purpose?

"Do not understand that I mean that every part of a creature is of use to it in its present mode of life, for, as all naturalists know, there are in structural anatomy, just as in social life, cases of survival; remains of organs which were at some former time more developed, parallel in their nature to such survivals in costume as the two buttons on the back of a man's coat, once useful for the attachment of a sword-belt. But in this fish we have no case of survival, but one of unusual development; the family (Gobiidæ) to which it belongs presents no similar case, although its members have somewhat similar habits, and the conviction grows upon us, as we consider the subject, that the long jaws serve some useful purpose in the economy of the creature. In view of the half-terrestrial life led by this fish, I am inclined to suspect that the expansion of the upper jaw may serve for the retention of a small quantity of water, which, slowly trickling downward into the mouth and gills, keeps the latter moist when, from an unusually low tide or a dry season, the waters of its native creek fail, perhaps for several hours, to reach the holes in which the fishes dwell. It may be objected to this view that, were such an appendage necessary or even useful, other species of Gobiidæ, whose habits are similar, would show traces of a similar adaptation. This, however, by no means follows. Nature has many ways of working out the same end; and it must be remembered that every real species, when thoroughly known, differs somewhat in habits from its congeners, or at least from its family friends. To take an illustration from the mammalia. The chimpanzee and the spider-monkey are both quadrumanous and both arboreal, yet the end which is attained in the former by its more perfect hands is reached in the latter by its prehensile tail.

"Why may not the extremely long channel formed by the jaw of this rather abnormal member of the goby family be another mode of provision for the requirements of respiration?"

Of the Asiatic genera, Periophthalmus and Boleophthalmus are especially notable. In these mud-skippers the eyes are raised on a short stalk, the fins are strong, and the animal has the power of skipping along over the wet sands and mud, even skimming with great speed over the surface of the water. It chases its insect prey among rocks, leaves, and weeds, and out of the water is as agile as a lizard. Several species of these mud-skippers are known on the coasts of Asia and Polynesia, Periophthalmus barbarus and Boleophthalmus chinensis being the best known. Awaous crassilabris is the common oopu, or river goby, of the Hawaiian streams, and Lentipes stimpsoni is the mountain oopu, capable of clinging to the rocks in the rush of torrents. Paragobiodon echinocephalus is a short thick-set goby with very large head, found in crevices of coral reefs of Polynesia.

Fig. 420.—Pond-skipper, Boleophthalmus chinensis (Osbeck). Bay of Tokyo, Japan. (Eye-stalks sunken in preservation.)

Fig. 421.—Mud-skippy, Periophthalmus oarbarus (L.). Mouth of Vaisigono River, Apia, Samoa.

In numerous interesting species the first dorsal fin is wanting or much reduced. The crystal goby, Crystallogobius nilssoni, of Europe is one of this type, with the body translucent. Equally translucent is the little Japanese shiro-uwo, or whitefish, Leucopsarion petersi. Mistichthys luzonius of the Philippine Islands, another diaphanous goby, is said to be the smallest of all vertebrates, being mature at half an inch in length. This minute fish is so very abundant as to become an important article of food in Luzon. The rank of "smallest-known vertebrate" has been claimed in turn for the lancelet (Asymmetron lucayanum), the top minnow, Heterandria formosa, and the dwarf sunfish (Elassoma zonatum). Mistichthys luzonius is smaller than any of these, but the diminutive gobies, called Eviota, found in interstices of coral rocks are equally small, and there are several brilliant but minute forms in the reefs of Samoa. The snake-like Eutæniichthys gilli of Japanese rivers is scarcely larger, though over an inch long. Typhlogobius californiensis, "the blindfish of Point Loma," is a small goby, colorless and blind, found clinging in dark crevices of rock about Point Loma and Dead Man's Island in southern California.

Fig. 422.—Eutæniichthys gillii Jordan & Snyder. Tokyo, Japan.

Its eyes are represented by mere rudiments, their loss being evidently associated with the peculiar habit of the species, which clings to the under side of stones in relative darkness, though in very shallow water. The flesh is also colorless, the animal appearing pink in life.

In the Japanese species Luciogobus guttatus, common under stones and along the coast, the spinous dorsal, weak in numerous other species, finally vanishes altogether. Other gobies are band-shaped or eel-shaped, the dorsal spines being continuous with the soft rays. Among these are the barreto of Cuba, Gobioides broussoneti, and in Japan Tænioides lacepedei and Trypauchen wakæ, the latter species remarkable for its strong canines. Fossil gobies are practically unknown. A few fragments, otoliths, and partial skeletons in southern Europe have been referred to Gobius, but no other genus is represented.

The family of Oxudercidæ contains one species, Oxuderces dentatus, a small goby-like fish from China. It is an elongate fish, without ventral fins, and with very short dorsal and anal.

Suborder Discocephali, the Shark-suckers: Echeneididæ.—Next to the gobies, for want of a better place, we may mention the singular group of Discocephali (δίσκος, disk; κεφαλή, head). In this group the first dorsal fin is transformed into a peculiar laminated sucking-disk, which covers the whole top of the head and the nape. In other respects the structure does not diverge very widely from the percoid type, there being a remarkable resemblance in external characters to the Scombroid genus Rachycentron. But the skeleton shows no special affinity to Rachycentron or to any perciform fish. The basis of the cranium is simple, and in the depression of the head with associated modifications the Discocephali approach the gobies and blennies rather than the mackerel-like forms.

Fig. 423.—Sucking-fish, or Pegador, Leptecheneis naucrates (Linnæus). Virginia.

The Discocephali comprise the single family of shark-suckers or remoras, the Echeneididæ. All the species of this group are pelagic fishes, widely diffused in the warm seas. All cling by their cephalic disks to sharks, barracudas, and other free-swimming fishes, and are carried about the seas by these. They do not harm the shark except by slightly impeding its movement. They are carnivorous fishes, feeding on sardines, young herring, and the like. When a shark, taken on the hook, is drawn out of the water the sucking-fish leaves it instantly, and is capable of much speed in swimming on its own account. These fishes are all dusky in color, the belly as dark as the back, so as to form little contrast to the color of the shark.

The commonest species, Leptecheneis naucrates, called pegapega or pegador in Cuba, reaches a length of about two feet and is almost cosmopolitan in its range, being found exclusively on the larger sharks, notably on Carcharias lamia. It has 20 to 22 plates in its disk, and the sides are marked by a dusky lateral band.

Almost equally widely distributed is the smaller remora, or shark-sucker (Echeneis remora), with a stouter body and about 18 plates in the cephalic disk. This species is found in Europe, on the coast of New York, in the West Indies, in California, and in Japan, but is nowhere abundant. Another widely distributed species is Remorina albescens with 13 plates in its disk. Remoropsis brachyptera, with 15 plates and a long soft dorsal, is also occasionally taken. Rhombochirus osteochir is a rare species of the Atlantic with 18 plates, having the pectoral rays all enlarged and stiff. The louse-fish (Phtheirichthys lineatus) is a small and slender remora having but 10 plates in its disk. It is found attached, not to sharks, but to barracudas and spearfishes.

Fig. 424.—Rhombochirus osteochir (Cuv. & Val.). Wood's Hole, Mass.

A fossil remora is described from the Oligocene shales in Glarus, Switzerland, under the name of Opisthomyzon glaronensis. It is characterized by the small disk posteriorly inserted. Its vertebræ are 10 + 13 = 24 only. Dr. Storms gives the following account of this species:

"A careful comparison of the proportion of all the parts of the skeleton of the fossil Echeneis with those of the living forms, such as Echeneis naucrates or Echeneis remora, shows that the fossil differs nearly equally from both, and that it was a more normally shaped fish than either of these forms. The head was narrower and less flattened, the preoperculum wider, but its two jaws had nearly the same length. The ribs, as also the neural and hæmal spines, were longer, the tail more forked, and the soft dorsal fin much longer. In fact it was a more compressed type, probably a far better swimmer than its living congeners, as might be expected if the smallness of the adhesive disk is taken into account."

Concerning the relations of the Discocephali Dr. Gill has the following pertinent remarks:

"The family of Scomberoides was constituted by Cuvier for certain forms of known organization, among which were fishes evidently related to Caranx, but which had free dorsal spines. Dr. Günther conceived the idea of disintegrating this family because, inter alias, the typical Scomberoides (family Scombridæ) have more than 24 vertebræ and others (family Carangidæ) had just 24. The assumption of Cuvier as to the relationship of Elacate (Rachycentron) was repeated, but inasmuch as it had 'more than 24 vertebræ' (it had 25 = 12 + 13) it was severed from the free-spined Carangidæ and associated with the Scombridæ. Elacate has an elongated body, flattened head, and a longitudinal lateral band; therefore Echeneis was considered to be next allied to Elacate and to belong to the same family. The very numerous differences in structure between the two were entirely ignored, and the reference of the Echeneis to the Scombridæ is simply due to assumption piled on assumption. The collocation need not, therefore, longer detain us. The possession by Echeneis of the anterior oval cephalic disk in place of a spinous dorsal fin would alone necessitate the isolation of the genus as a peculiar family. But that difference is associated with almost innumerable other peculiarities of the skeleton and other parts, and in a logical system it must be removed far from the Scombridæ, and probably be endowed with subordinal distinction. In all essential respects it departs greatly from the type of structure manifested in the Scombridæ and rather approximates—but very distantly—the Gobioidea and Blennioidea. In those types we have in some a tendency to flattening of the head, of anterior development of the dorsal fin, a simple basis cranii, etc. Nevertheless there is no close affinity, nor even tendency to the extreme modification of the spinous dorsal exhibited by Echeneis. In view of all these facts Echeneis, with its subdivisions, may be regarded as constituting not only a family but a suborder.... Who can consistently object to the proposition to segregate the Echeneididæ as a suborder of teleocephalous fishes? Not those who consider that the development of three or four inarticulate rays (or even less) in the front of the dorsal fin is sufficient to ordinarily differentiate a given form from another with only one or two such. Certainly the difference between the constituents of a disk and any rays or spines is much greater than the mere development or atrophy of articulations. Not those who consider that the manner of depression of spines, whether directly over the following, or to the right or left alternately, are of cardinal importance; for such differences, again, are manifestly of less morphological significance than the factors of a suctorial disk. Nevertheless there are doubtless many who will passively resist the proposition because of a conservative spirit, and who will vaguely refer to the development of the disk as being a 'teleological modification,' and as if it were not an actual fact and a development correlated with radical modifications of all parts of the skeleton at least. But whatever may be the closest relations of Echeneis, or the systematic value of its peculiarities, it is certain that it is not allied to Elacate any more than to hosts of scombroid, percoid, and kindred fishes, and that it differs in toto from it notwithstanding the claims that have been made otherwise. It is true that there is a striking resemblance, especially between the young—almost as great, for example, as that between the placental mouse and the marsupial Antechinomys—but the likeness is entirely superficial, and the scientific ichthyologist should be no more misled than would be the scientific therologist by the likeness of the marsupial and placental mammals."

Suborder Tæniosomi, the Ribbon-fishes.—The suborder Tæniosomi (ταινία, ribbon; σῶμα, body), or ribbon-fishes, is made up of strange inhabitants of the open seas, perhaps aberrant derivatives of the mackerel stock. The body is greatly elongate, much compressed, extremely fragile, covered with shining silvery skin. The ribbon-fishes live in the open sea, probably at no very great depth, but are almost never taken by collectors except when thrown on shore in storms or when attacked by other fishes and dragged above or below their depth. When found they are usually reported as sea-serpents, and although perfectly harmless, they are usually at once destroyed by their ignorant captors. The whole body is exceedingly fragile; the bones are porous, thin, and light, containing scarcely any calcareous matter. In the Tæniosomi the ventral fins are thoracic, formed of one or a few soft rays. More remarkable is the character of the caudal fin, which is always distorted and usually not in line with the rest of the body. The teeth are small. The general structure is not very different from that of the cutlass-fishes, Trichiuridæ, and other degraded offshoots from the scombroid group. The species are few and, from the nature of things, very imperfectly known. Scarcely any specimens are perfectly preserved. When dried the body almost disappears, both flesh and bones being composed chiefly of water.

The Oarfishes: Regalecidæ.—The Regalecidæ, or oarfishes, have the caudal fin obsolete and the ventrals reduced to long filaments, thickened at the tip. The species reach a length of twenty or thirty feet, and from their great size, slender forms, and sinuous motion have been almost everywhere regarded as sea-serpents. The very long anterior spines of the dorsal fin are tipped with red, and the fish is often and not untruthfully described as a sea-serpent "having a horse's head with a flaming red mane."

The great oarfish, Regalecus glesne (see Fig. 237, Vol. I) was long known to the common people of Norway as king of the herrings, it being thought that to harm it would be to drive the herring to some other coast. The name "king of the herrings" went into science as Regalecus, from rex, king, and halec, herring. The Japanese fancy, which runs in a different line, calls the creature "Dugunonuatatori," which means the "cock of the palace under the sea."

The Atlantic oarfish is named Regalecus glesne, from the Norwegian farm of Glesnæs, where the first recorded specimen, described by Ascanius, was taken 130 years ago. Since then the species has been many times found on the shores of Great Britain and Norway, and once at Bermuda.

In this species the body is half-transparent, almost jelly-like, light blue in color, with some darker cross-stripes, and the head has a long jaw and a high forehead, suggesting the head of a horse. The dorsal fin begins on the head, and the first few spines are very long, each having a red tuft on the end. When the animal is alive these spines stand up like a red mane.

The creature is harmless, weak in muscle as well as feeble in mind. It lives in the deep seas, all over the world. After great storms it sometimes comes ashore. Perhaps this is because for some reason it has risen above its depth and so lost control of itself. When a deep-water fish rises to the surface the change of pressure greatly affects it. Reduction of pressure bursts its blood-vessels, its swim-bladder swells, if it has one, and turns its stomach inside out. If a deep-water fish gets above its depth it is lost, just as surely as a surface fish is when it gets sunk to the depth of half a mile.

Sometimes, again, these deep-sea fishes rush to the shore to escape from parasites, crustaceans that torture their soft flesh, or sharks that would tear it.

Numerous specimens have been found in the Pacific, and to these several names have been given, but the species are not at all clearly made out. The oldest name is that of Regalecus russelli, for the naturalist Patrick Russell, who took a specimen at Vizagapatam in 1788. I have seen two large examples of Regalecus in the museum at Tokio, and several young ones have recently been stranded on the Island of Santa Catalina in southern California. A specimen twenty-two feet long lately came ashore at Newport in Orange County, California. The story of its capture is thus told by Mr. Horatio J. Forgy, of Santa Ana, California:

"On the 22d of February, 1901, a Mexican Indian reported at Newport Beach that about one mile up the coast he had landed a sea-serpent, and as proof showed four tentacles and a strip of flesh about six feet long. A crowd went up to see it, and they said it was about twenty feet long and like a fish in some respects and like a snake in others. Mr. Remsberg and I, on the following day, went up to see it, and in a short time we gathered a crowd and with the assistance of Mr. Peabody prepared the fish and took the picture you have received.

"It measured twenty-one feet and some inches in length, and weighed about 500 or 600 pounds.

"The Indian, when he reported his discovery, said it was alive and in the shallow water, and that he had landed it himself.

"This I very much doubt, but when it was first landed it was in a fine state of preservation and could have easily been shipped to you, but he had cut it to such an extent that shipment or preservation seemed out of the question when we first saw it.

"At the time it came ashore an unusual number of peculiar fishes and sharks were found. Among others, I found a small oarfish about three feet long in a bad state of preservation in a piece of kelp. One side of it was nearly torn off and the other side was decayed."

Mr. C. F. Holder gives this account of the capture of oarfishes in southern California:

"From a zoological point of view the island of Santa Catalina, which lies eighteen miles off the coast of Los Angeles County, southern California, is very interesting, many rare animals being found there. Every winter the dwellers of the island find numbers of argonaut-shells, and several living specimens have been secured, one for a time living in the aquarium which is maintained here for the benefit of students and the entertainment of visitors. A number of rare and interesting fishes wander inshore from time to time. Several years ago I found various Scopeloid fishes, which up to that time had been considered rare, and during the past few years I have seen one oarfish (Regalecus russelli) alive, while another was brought to me dead. From reports I judge that a number of these very rare fishes have been observed here. The first was of small size, not over two feet in length, and was discovered swimming in shallow water along the beach of Avalon Bay. I had an opportunity to observe the radiant creature before it died. Its 'topknot'—it can be compared to nothing else—was a vivid red or scarlet mass of seeming plumes—the dorsal fins, which merged into a long dorsal fin, extending to the tail. The color of the body was a brilliant silver sheen splashed with equally vivid black zebra-like stripes, which gave the fish a most striking appearance.

"The fish was a fragile and delicate creature, a very ghost of a fish, which swam along where the water gently lapped the sands with an undulatory motion, looking like one of its names—the ribbon-fish. The fortunate finder of this specimen could not be persuaded to give it up or sell it, and it was its fate to be pasted upon a piece of board, dried in the sun as a 'curio,' where, as if in retaliation at the desecration of so rare a specimen, it soon disappeared.

"This apparently was the first oarfish ever seen in the United States, so at least Dr. G. Brown Goode wrote me at the time that it had not been reported. In 1899 another oarfish was brought to me, evidently having been washed in after a storm and found within a few yards of the former at Avalon. The discoverer of this specimen also refused to allow it to be properly preserved, or to donate or sell it to any one who would have sent it to some museum, but, believing it valuable as a 'curio,' also impaled it, the delicate creature evaporating under the strong heat of the semitropic sun.

"This, as stated, was the second fish discovered, and during the past winter (1900) a fine large specimen came in at Newport Beach, being reported by H. J. Forgy, of Santa Ana. The newspapers announced that a Mexican had found a young sea-serpent at Newport, and investigation showed that, as in hundreds of similar instances, the man had found a valuable prize without being aware of it. According to the account, the discoverer first saw the fish alive in the surf and hauled it ashore. Being ignorant of its value, he cut it up, bringing in a part of the scarlet fins and a slice of the flesh. This he showed to some men, and led the way to where lay the mutilated remains of one of the finest oar-or ribbon-fishes ever seen. The specimen was twenty-one feet in length, and its weight estimated at five hundred pounds. The finder had so mutilated it that the fish was ruined for almost any purpose. If he had packed it in salt, the specimen would have returned him the equivalent of several months' labor. Apparently the man had cut it up in wanton amusement.

"This recalls a similar incident. I was on one occasion excavating at San Clemente Island, and had remarked that it was a singular fact that all the fine stone ollas were broken. 'Nothing strange about that,' said a half-breed, one of the party. 'I used to herd sheep here, and we smashed mortars and ollas to pass away time.'"

Fig. 425.—Oarfish, Regalecus russelli, on the beach at Newport, Orange Co., Cal. (Photograph by C. P. Remsberg.)

The Dealfishes: Trachypteridæ.—The family of Trachypteridæ comprises the dealfishes, creatures of fantastic form and silvery coloration, smaller than the oarfishes and more common, but of similar habit.

Just as in Norway the fantastic oarfish was believed to be the king of the herrings and cherished as such, so among the Indians of Puget Sound another freak fish is held sacred as the king of the salmon. The people about Cape Flattery believe that if one does any harm to this fish the salmon will at once leave the shores. This fable led the naturalists who first discovered this fish to give it its name of Trachypterus rex-salmonorum.

In Europe a similar species (Trachypterus atlanticus) has long been known by the name of dealfish, or vogmar, neither of these names having any evident propriety.

The dealfish is one of the most singular of all the strange creatures of the sea. It reaches a length of three or four feet. Its body is thin as a knife and would be transparent were it not covered over with a shining white pigment which gives to the animal the luster of burnished silver. On this white surface is a large black blotch or two, but no other colors. The head is something like that of the oarfish, to which animal the dealfish bears a close relationship. Both have small teeth and neither could bite if it would, and neither wants to, for they are creatures of the most inoffensive sort. On the head of the dealfish, where the oarfish has its mane, is a long, streamer-like fin. At the end of the tail, instead of the ordinary caudal fin, is a long, slim fin which projects directly upwards at right angles to the direction of the back-bone. No other fish shows this strange peculiarity.

The dealfish swims in the open sea close to the surface of the water. It does not often come near shore, but it is occasionally blown on the beach by storms. Trachypterus rex-salmonorum has been recorded two or three times from Puget Sound and twice from California. The finest specimen known, the one from which our figure is taken, was secured off the Farallones in 1895 by a fisherman named W. C. Knox, and by him sent to Stanford University. The specimen is perfect in all its parts, a condition rare with these fragile creatures, and its picture gives a good idea of the mysterious king of the salmon.

Fig. 426.—Dealfish, or King of the Salmon, Trachypterus rex-salmonorum Jordan & Gilbert. Family Trachypteridæ. (From a specimen taken off the Farallones.)

Four of these fishes have been obtained on the coast of Japan, and have been described and figured by the present writer in the annals of the Imperial University of Tokyo. These are different from the California species and are named Trachypterus ishikawæ, but they show the same bright silver color and the same streamers on the head and tail. Probably they, too, in Japan are kings of something or other, or perhaps silver swans from the submarine palace, for along such lines the Japanese fancy is more likely to run.

The young of the dealfish has the caudal symmetrical, and the dorsal spines and ventral rays produced in very long streamers.

According to Goode and Bean, the dealfishes are "true deep-sea fishes, which live at very great depths, and are only found when floating dead on the surface or washed ashore by the waves. Almost nothing is known of their habits except through Nilsson's observations in the far north. This naturalist, as well as Olafson, appears to have had the opportunity of observing them in life. They say that they approach the shore at flood-tide on sandy, shelving bottoms, and are often left by the retreating waves. Nilsson's opinion is that its habits resemble those of the flatfishes, and that they move with one side turned obliquely upward, the other toward the ground; and he says that they have been seen on the bottom in two or three fathoms of water, where the fishermen hook them up with the implements employed to raise dead seals, and that they are slow swimmers. This is not necessarily the case, however, for the removal of pressure and the rough treatment by which they were probably washed ashore would be demoralizing, to say the least. Trichiurus, a fish similar in form, is a very strong, swift swimmer, and so is Regalecus. Whether or not the habits of Trachypterus arcticus, on which these observations were made, are a safe guide in regard to the other forms is a matter of some doubt, but it is certain that they live far from the surface, except near the Arctic Circle, and that they only come ashore accidentally. They have never been taken by the deep-sea dredge or trawl-net, and indeed perfect specimens are very rare, the bodies being very soft and brittle, the bones and fin-rays exceedingly fragile. A considerable number of species have been described, but in most instances each was based on one or two specimens. It is probable that future studies may be as fruitful as that of Emery, who, by means of a series of twenty-three specimens, succeeded in uniting at least three of the Mediterranean species which for half a century or more had been regarded as distinct. The common species of the eastern Atlantic, Trachypterus atlanticus, is not rare, one or more specimens, according to Günther, being secured along the coast of northern Europe after almost every severe gale. We desire to quote the recommendation of Dr. Günther, and to strongly urge upon any one who may be so fortunate as to secure one of these fishes that no attempt should be made to keep it entire, but that it should be cut into short lengths and preserved in the strongest spirits, each piece wrapped separately in muslin."

The family of Stylephoridæ is known from a single specimen of the species, Stylephorus chordatus, taken off Cuba in 1790. In this form the tail ends in a long, whip-like appendage, twice as long as the head.

No fossil dealfishes or oarfishes are known.

CHAPTER XXVII
SUBORDER HETEROSOMATA

The Flatfishes.—Perhaps the most remarkable offshoot from the order of spiny-rayed fishes is the great group of flounders and soles, called by Bonaparte Heterosomata (ἔτερός, differing; σῶμα, body). The essential character of this group is found in the twisting of the anterior part of the cranium, an arrangement which brings both eyes on the same side of the head. This is accompanied by a great compression of the body, as a result of which the flounders swim horizontally or lie flat on the sand. On the side which is uppermost both eyes are placed, this side being colored, brown or gray or mottled. The lower side is usually plain white. In certain genera the right side is uppermost, in others the left. In a very few, confined to the coast of California, the eyes are on the right or left side indifferently.

The process of the twisting of the head has been already described (see p. 174, Vol. I). The very young have the body translucent and symmetrical, standing upright in the water. Soon the tendency to rest on the bottom sets in, the body leans to left or right, and the lower eye gradually traverses the front of the head to the other side. This movement is best seen in the species of Platophrys, in which the final arrangement of the eyes is a highly specialized one.

In some or all of the soles it is perhaps true that the eye turns over and pierces the cranium instead of passing across it. This opinion needs verification, and the process should be studied in detail in as many species as possible. The present writer has seen it in species of Platophrys only, the same genus in which it was carefully studied by Dr. Carlo F. Emery of Bologna. In the halibut, and in the more primitive flounders generally, the process takes place at an earlier stage than in Platophrys.

Optic Nerves of Flounders.—In the Bulletin of the Museum of Comparative Zoology (Vol. XL, No. 5) Professor George H. Parker discusses the relations of the optic nerves in the group of flounders or flatfishes.

In the bony fishes the optic nerves pass to the optic lobes of the brain, the one passing to the lobes of the opposite side simply lying over the other, without intermingling of fibers, such as takes place in the higher vertebrates and in the more primitive fishes.

According to Parker's observations, in ordinary bony fishes the right nerve may be indifferently above or below the other. In 1000 specimens of ten common species, 486 have the left nerve uppermost and 514 the right nerve. In most individual species the numbers are practically equal. Thus, in the haddock, 48 have the left nerve uppermost and 52 the right nerve.

In the unsymmetrical teleosts or flounders, and soles, this condition no longer obtains. In those species of flounder with the eyes on the right side 236 individuals, representing sixteen species, had the left nerve uppermost in all cases.

Of flounders with the eyes on the left side, 131 individuals, representing nine species, all have the right nerve uppermost.

Fig. 427.—Young Flounder, just hatched, with symmetrical eyes. (After S. R. Williams.)

There are a few species of flounders in which reversed examples are so common that the species may be described as having the eyes on the right or left side indifferently. In all these species, however, whether dextral or sinistral, the relation of the nerves conforms to the type and is not influenced by the individual deviation. Thus the starry flounder (Platichthys) belongs to the dextral group. In 50 normal specimens, the eyes on the right have the left nerve dorsal, while the left nerve is also uppermost in 50 reversed examples with eyes on the left. In 15 examples of the California bastard halibut (Paralichthys californicus), normally sinistral, the right eye is always uppermost. It is uppermost in 11 reversed examples.

Among the soles this uniformity or monomorphism no longer obtains. In 49 individuals of four species of dextral soles, the left nerve is uppermost in 24, the right nerve in 25. Among sinistral soles, or tongue-fishes, in 18 individuals of two species, the left nerve is uppermost in 13, the right nerve in 5.

Professor Parker concludes from this evidence that soles are not degenerate flounders, but rather descended from primitive flounders which still retain the dimorphic condition as to the position of the optic nerves, a condition prevalent in all bony fishes except the flounders.

The lack of symmetry among the flounders lies, therefore, deeper than the matter of the migration of the eye. The asymmetry of the mouth is an independent trait, but, like the migration of the eye, is an adaptation to swimming on the side. Each of the various traits of asymmetry may appear independently of the others.

Fig. 428.—Larval Flounder, Pseudopleuronectes americanus. (After S. R. Williams.)

The development of the monomorphic arrangement in flounders Professor Parker thinks can be accounted for by the principle of natural selection. In a side-swimming fish the fixity of this trait has a mechanical advantage. The unmetamorphosed young of the flounder are not strictly symmetrical, for they possess the monomorphic position of the optic nerve. The reversed examples of various species of flounders (these, by the way, chiefly confined to the California fauna) afford "striking examples of discontinuous variation."

A very curious feature among the flounders is the possession in nine of the California-Alaskan species of an accessory half-lateral line. This is found in two different groups, while near relatives in other waters lack the character. One species in Japan has this trait, which is not found in any Atlantic species, or in any other flounders outside the fauna of northern California, Oregon, and Alaska.

Ancestry of Flounders.—The ancestry of the flounders is wholly uncertain. Because, like the codfishes, the flounders lack all fin-spines, they have been placed by some authors after the Anacanthini, or codfishes, and a common descent has been assumed. Some writers declare that the flounder is only a codfish with distorted cranium.

Fig. 429.

Figs. 429 and 430.—Larval stages of Platophrys podas, a flounder of the Mediterranean, showing the migration of the eye. (After Emery.)

A little study of the osteology of the flounder shows that this supposition is without foundation. The flounders have thoracic ventrals, not jugular as in the cod. The tail is homocercal, ending in a large hypural plate, never isocercal, except in degraded soles, in which it is rather leptocercal. The shoulder-girdle, with its perforate hypercoracoid, has the normal perch-like form. The ventral fins have about six rays, as in the perch, although the first ray is never spinous. Pseudobranchiæ are developed, these structures being obsolete in the codfishes. The gills and pharyngeals are essentially as in the perch.

It is fairly certain that the Heterosomata have diverged from the early spiny-rayed forms, Zeoidei, Berycoidei, or Scombroidei of the Jurassic or Cretaceous, and that their origin is prior to the development of the great perch stock.

If one were to guess at the nearest relationships of the group, it would be to regard them as allies of the deep-bodied mackerel-like forms, as the Stromateidæ, or perhaps with extinct Berycoid forms, as Platycormus, having the ventral fins wider than in the mackerel. Still more plausible is the recent suggestion of Dr. Boulenger that the extinct genus Amphistium resembles the primitive flounder. But there is little direct proof of such relation, and the resemblance of larval flounders to the ribbon-fishes may have equal significance. But the ribbon-fishes themselves may be degenerate Scombroids. In any case both ribbon-fishes and flounders find their nearest living relatives among the Berycoidei or Zeoidei, and have no affinity whatever with the isocercal codfish or with other members of the group called Anacanthini.

Fig. 431.—Platophrys lunatus (Linnæus), the Peacock Flounder. Family Pleuronectidæ. Cuba. (From nature by Mrs. H. C. Nash.)

The Heterosomata are found in all seas, always close to the bottom and swimming with a swift, undulatory motion. They are usually placed in a single family, but the degraded types known as soles may be regarded as forming a second family.

The Flounders: Pleuronectidæ.—In the flounders, or Pleuronectidæ, the membrane-bones of the head are distinct, the eyes large and well separated, the mouth not greatly contracted, and the jaws always provided with teeth. Among the 500 species of flounders is found the greatest variation in size, ranging in weight from an ounce to 500 pounds. The species found in arctic regions are most degenerate and these have the largest number of vertebræ and of fin-rays. The halibut has 50 vertebræ (16 + 34), the craig-flounder 58, while in Etropus and other tropical forms the number is but 34 (10 + 24). The common flounders of intermediate geographical range (Paralichthys dentatus, etc.) show intermediate numbers as 40 (10 + 30). The apparent significance of this peculiar series of fact is given on page 212, Vol. I. It is, perhaps, related to the greater pressure of natural selection in the tropics, showing itself in the better differentiation of the bones and consequently smaller number of the vertebræ.

Fig. 432.—Heterocercal tail of young Trout, Salmo fario Linnæus. (After Parker & Haswell.)

Fig. 433.—Homocercal tail of a Flounder, Paralichthys californicus.]

Fossil flounders are very few and give no clue as to the origin of the group. In the Eocene and Miocene are remains which have been referred to Bothus (Rhombus). Bothus minimus is the oldest species known, described by Agassiz from the Eocene of Monte Bolca. In the Miocene are numerous other species of Bothus, as also tubercles referable to Scophthalmus.

On the testimony of fossils alone the genus Bothus, or one of its allies, would be the most primitive of the group. If it be so, the simpler structure of the halibut and its relatives is due to degeneration, which is probable, although their structure has the suggestion of primitive simplicity, especially in the greater approach to symmetry in the head and the symmetry in the insertion of the ventral fins.

Fig. 434.—Window-pane, Lophopsetta maculata. Virginia.

Soles have been found in the later Tertiary rocks. Solea kirchbergiana of the Miocene is not very different from species now extant in southern Europe. No remains referable to allies of the halibut or plaice are found in Tertiary rocks, and these relatively simple types must be regarded as of recent origin.

The Turbot Tribe: Bothinæ.—The turbot tribe have the mouth large, the eyes and color on the left side, and the ventral fins unlike, that of the left side being extended along the ridge of the abdomen. The species are found in the warm seas only. They are deeper in body than the halibut and plaice, and some of them are the smallest of all flounders. It is probable that these approach most nearly of existing flounders to the original ancestors of the group.

Perhaps the most primitive genus is Bothus, species of which genus are found in Italian Miocene. The European brill, Bothus rhombus, is a common fish of southern Europe, deep-bodied and covered with smooth scales.

Fig. 435.—Wide-eyed Flounder, Syacium papillosum Linnæus. Pensacola, Fla.

Very similar but much smaller in size is the half translucent speckled flounder of our Atlantic coast (Lophopsetta maculata), popularly known as window-pane. This species is too small to have much value as food. Another species, similar to the brill in technical characters but very different in appearance, is the turbot, Scophthalmus maximus, of Europe. This large flounder has a very broad body, scaleless but covered with warty tubercles. It reaches a weight of seventy pounds and has a high value as a food-fish. There is but one species of turbot and it is found in Europe only, on sandy bottoms from Norway to Italy. In a turbot of twenty-three pounds weight Buckland found a roe of five pounds nine ounces, with 14,311,260 eggs. The young retains its symmetrical condition for a relatively long period. No true turbot is found in America and none in the Pacific. Other European flounders allied to the turbot and brill are Zeugopterus punctatus; the European whiff, Lepidorhombus whiff-jagonis; the topknot, Phrynorhombus regius; the lantern-flounder, Arnoglossus laterna, and the tongue-fish, Eucitharus linguatula, the last two of small size and feeble flesh.

In the wide-eyed or peacock flounders, Platophrys podas in Europe, Platophrys lunatus, etc., in America, Platophrys mancus in Polynesia, the eyes in the old males are very far apart, and the changes due to age and sex are greater than in any other genera. The species of this group are highly variegated and lie on the sand in the tropical seas. Numerous small species allied to these abound in the West Indies, known in a general way as whiffs. The most widely distributed of these are Citharichthys spilopterus of the West Indies, Citharichthys gilberti and Azevia panamensis of Panama, Orthopsetta sordida of California, and especially the common small-mouthed Etropus crossotus found throughout tropical America. Numerous other genera and species of the turbot tribe are found on the coasts of tropical Asia and Africa, most of them of small size and weak structure.

Fig. 436.—Etropus crossotus Jordan & Gilbert. Cedar Keys, Fla.

Samaris cristatus of Asia is the type of another tribe of flounders and the peculiar hook-jawed Oncopterus darwini of Patagonia represents still another tribe.

The Halibut Tribe: Hippoglossinæ.—In the great halibut tribe the mouth is large and the ventral fins symmetrical. The arctic and subarctic species have the eyes and color on the right. Those of the warmer regions (bastard halibut) have the eyes and color on the left. These grow progressively smaller in size to the southward, the mouth being smaller and more feebly armed in southern species.

The largest of the family, and the one commercially of far greatest importance, is the halibut (Hippoglossus hippoglossus). This species is found on both shores of both oceans, north of about the latitude of Paris, Boston, Cape Mendocino, and Matsushima Bay in Japan. Its preference is for off-shore banks of no great depth, and in very many localities it exists in great abundance, reaching a length of 6 to 8 feet and a weight of 600 pounds. It sometimes ranges well out to sea and enters deeper waters than the cod. The flesh is firm, white, and of good quality, although none of the flatfishes have much flavor, the muscles being mostly destitute of oil. Small halibut, called "chicken halibut," are highly esteemed.

Dr. Goode states that the "history of the halibut fishery has been a peculiar one. At the beginning of the present century these fishes were exceedingly abundant on George's Banks; since 1850 they have partially disappeared from this region, and the fishermen have since been following them to other banks, and since 1874 out into deeper and deeper water, and the fisheries are now carried on almost exclusively in the gullies between the off-shore banks and on the outer edges of the banks, in water 100 to 350 fathoms in depth.

"The halibut with its large mouth is naturally a voracious fish, and probably would disdain few objects in the way of fresh meat it would come across. It is said, however, to feed more especially upon crabs and mollusks in addition to fish. These fish 'they waylay lying upon the bottom, invisible by reason of their flat bodies, colored to correspond to the general color of the sand or mud upon which they rest. When in pursuit of their prey they are active and often come quite to the surface, especially when in summer they follow the capelin to the shoal water near the land. They feed upon skates, cod, haddock, menhaden, mackerel, herring, lobsters, flounders, sculpins, grenadiers, turbot, Norway haddock, bank-clams, and anything else that is eatable and can be found in the same waters.' Frequently halibut may be seen chasing flatfish over the bottom of the water. About Cape Sable their favorite food seems to be haddock and cusk. A very singular mode of attacking a cod has been recorded by Captain Collins, an experienced fisherman and good observer. They often kill their prey by blows of the tail, a fact which is quite novel and interesting. He has described an instance which occurred on a voyage home from Sable Island in 1877: 'The man at the wheel sang out that he saw a halibut flapping its tail about a quarter of a mile off our starboard quarter. I looked through the spy-glass and his statement was soon verified by the second appearance of the tail. We hove out a dory, and two men went with her, taking with them a pair of gaff-hooks. They soon returned, bringing not only the halibut, which was a fine one of about seventy pounds weight, but a small codfish which it had been trying to kill by striking it with its tail. The codfish was quite exhausted by the repeated blows and did not attempt to escape after its enemy had been captured. The halibut was so completely engaged in the pursuit of the codfish that it paid no attention to the dory and was easily captured.'

"The females become heavy with roe near the middle of the year, and about July and August are ready to spawn, although 'some fishermen say that they spawn at Christmas' or 'in the month of January, when they are on the shoals.' The roe of a large halibut which weighed 356 pounds weighed 44 pounds, and indeed the 'ovaries of a large fish are too heavy to be lifted by a man without considerable exertion, being often 2 feet or more in length.' A portion of the roe 'representing a fair average of the eggs, was weighed and found to contain 2185 eggs,' and the entire number would be 2,182,773."

Closely allied to the halibut are numerous smaller forms with more elongate body. The Greenland halibut, Reinhardtius hippoglossoides, and the closely related species in Japan, Reinhardtius matsuuræ, differ from the halibut most obviously in the straight lateral line. The arrow-toothed halibut, Atheresthes stomias, lives in deeper waters in the North Pacific. Its flesh is soft, the mouth very large, armed with arrow-shaped teeth. The head in this species is less distorted than in any of the others, the upper eye being on the edge of the disk in front of the dorsal fin. For this reason it has been supposed to be the most primitive of the living species, but these traits are doubtless elusive and a result of degeneration.

Eopsetta jordani is a smaller halibut-like fish, common on the coast of California, an excellent food-fish, with firm white flesh, sold in San Francisco restaurants under the very erroneous name of "English sole." Large numbers are dried by the Chinese for export to China. A similar species, Hippoglossoides platessoides, known as the "sand-dab," is common on both shores of the North Atlantic, and several related species are found in the North Pacific. Verasper variegatus of Japan is notable for its bright coloration, the lower side being largely orange-red.

In the bastard halibuts, Paralichthys, the eyes and color are on the left side. These much resemble the true halibut, but are smaller and inferior as food, besides differing in details of structure. The Monterey halibut (Paralichthys californicus) is the largest of these, reaching a weight of sixty pounds. This species and one other from California (Xystreurys liolepis), normally left-sided, differ from all the other flounders in having the eyes almost as often on the right side as on the left side, as usual or normal in their type. The summer flounder (Paralichthys dentatus) replaces the Monterey halibut on the Atlantic Coast, where it is a common food-fish. Farther south it gives way to the Southern flounder (Paralichthys lethostigma) and the Gulf flounder, Paralichthys albigutta. In Japan Paralichthys olivaceus is equally common, and in western Mexico Paralichthys sinaloæ. The four-spotted flounder of New England, Paralichthys oblongus, belongs to this group. Similar species constituting the genus Pseudorhombus abound in India and Japan.

Fig. 437.—Halibut, Hippoglossus hippoglossus Linnæus. Marmot I., Alaska.

The Plaice Tribe: Pleuronectinæ.—The plaice tribe pass gradually into the halibut tribe, from which they differ in the small mouth, in which the blunt teeth are mostly on the blind side. The eyes are on the right side, the vertebræ are numerous, and the species live only in the cold seas, none being found in the tropics. In most of the Pacific species the lateral line has an accessory branch along the dorsal fin. The genus Pleuronichthys, or frog-flounders, has the teeth in bands. Pleuronichthys cornutus is common in Japan and three species, Pleuronichthys cœnosus being the most abundant, are found on the coast of California. Closely related to these is the diamond-flounder, Hypsopsetta guttulata of California. Parophrys vetulus is a small flounder of California, so abundant as to have considerable economic value. Lepidopsetta bilineata, larger and rougher, is almost equally common. It is similar to the mud-dab (Limanda limanda) of northern Europe and the rusty-dab (Limanda ferruginea) of New England.

Fig. 438.—Wide mouthed Flounder, Paralichthys dentatus (L.). St. George I., Md.

The plaice, Pleuronectes platessa, is the best known of the European species of this type, being common in most parts of Europe and valued as food. Closely related to the plaice is a second species of southern Europe also of small size, Flesus flesus, to which the name flounder is in England especially applied. The common winter flounder of New England, Pseudopleuronectes americanus, is also very much like the plaice, but with more uniform scales. It is an important food-fish, the most abundant of the family about Cape Cod. The eel-back flounder, Liopsetta putnami, also of New England, is frequently seen in the markets. The males of this species have scattered rough scales, while the females are smooth. The great starry flounder of Alaska, Platichthys stellatus, is the largest of the small-mouthed flounders and in its region the most abundant. On the Pacific coast from Monterey to Alaska and across to northern Japan it constitutes half the catch of flounders. The body is covered with rough scattered scales, the fins are barred with black. It reaches a weight of twenty pounds. Living in shallow waters, it ascends all the larger rivers.

An allied species in Japan is Kareius bicoloratus, with scattered scales. Clidoderma asperrimum, also of northern Japan, has the body covered with series of warts.

Fig. 439.—Eel-back Flounder, Liopsetta putnami (Gill). Salem, Mass.

In deeper water are found the elongate forms known as smear-dab and flukes. The smear-dab of Europe (Microstomus kitt) is rather common in deep water. Its skin is very slimy, but the flesh is excellent. The same is true of the slippery sole, Microstomus pacificus, of California and Alaska, and of other species found in Japan. Glyptocephalus cynoglossus, the craig-fluke, or pole-flounder, of the North Atlantic, is taken in great numbers in rather deep water on both coasts. Its flesh is much like that of the sole. A similar species (Glyptocephalus zachirus) with a very long pectoral on the right scale is found in California, and Microstomus kitaharæ in Japan.

The Soles: Soleidæ.—The soles (Soleidæ) are degraded flounders, the typical forms bearing a close relation to the plaice tribe, from which they may be derived. There are three very different groups or tribes of soles, and some writers have thought that these are independently derived from different groups of flounders. This fact has been urged as an argument against the recognition of the Soleidæ as a family separate from the flounders. If clearly proved, the soles should either be joined with the flounders in one family or else they should be divided into two or three, according to their supposed origin.

The soles as a whole differ from the flounders in having the bones of the head obscurely outlined, their edges covered by scales. The gill-openings are much reduced, the eyes small and close together, the ventral fins often much reduced, and sometimes the pectoral or caudal also. The mouth is very small, much twisted, and with few teeth.

Fig. 440.—Starry Flounder, Platichthys stellatus (Pallas). Alaska.

The species of sole, about 150 in number, abound on sandy bottoms in the warm seas along the continents, very few being found about the Oceanic Islands. The three subfamilies, or tribes, may be designated as broad soles, true soles, and tongue-fishes.

The Broad Soles: Achirinæ.—The American soles (Achirinæ), or broad soles, resemble the smaller members of the turbot tribe of flounders, having the ventral fin of the eyed side extended along the ridge of the abdomen. The eyes and color are, however, on the right side. The eyes are separated by a narrow interorbital ridge. In most of these forms the body is broad and covered with rough scales. The species are mostly less than six inches long, and nearly all are confined to the warmer parts of America, many of them ascending the rivers. A very few (Aseraggodes, Pardachirus) are found in Japan and China. Some are scaleless and some have but a single small gill-opening on the blind side. The principal genus is Achirus. Achirus fasciatus, the common American sole, or hog-choker, is abundant from Boston to Galveston. Achirus lineatus and other species are found in the West Indies and on the west coast of Mexico. Almost all the species of Achirus are banded with black and the pectorals are very small or wanting altogether. All these species are practically useless as food from their very small size.

Fig. 441.—Hog-choker Sole, Achirus lineatus (L.). Potomac River.

The European Soles (Soleinæ).—The European soles are more elongate in form, with the ventral fins narrow and not extended along the ridge of the abdomen. The eyes are on the right side with no bony ridge between them. No species of this type is certainly known from American waters, although numerous in Europe and Asia. The species have much in common with the plaice tribe of flounders and may be derived from the same stock. One species, as above noted, is found in the Miocene.

The common sole of Europe, Solea solea, is one of the best of food-fishes, reaching a length, according to Dr. Gill, of twenty-six inches and a weight of nine pounds. As usually seen in the markets it rarely exceeds a pound. It is found from Norway to Italy, and when properly cooked is very tender and delicate, superior to any of the flounders. According to Dr. Francis Day, it appears to prefer sandy or gravelly shores, but is rather uncertain in its migrations, for, although mostly appearing at certain spots almost at a given time, and usually decreasing in numbers by degrees, in other seasons they disappear at once, as suddenly as they arrive. Along the British seacoast they retire to the deep as frosts set in, revisiting the shallows about May if the weather is warm, their migrations being influenced by temperature. The food of the sole is to a considerable extent molluscous, but it is also said to eat the eggs and fry of other fishes and sea-urchins.

The spawning season is late in the year and during the spring months. The ova are in moderate number; a sole of one pound weight has, according to Buckland, about 134,000 eggs. The newly hatched, according to Dr. Day, do not appear to be commonly found so far out at sea as some other species. They enter into shallow water at the edge of the tide and are very numerous in favorable localities.

As is well known, the sole is one of the most esteemed of European fishes. In the words of Dr. Day, "the flesh of this fish is white, firm, and of excellent flavor, those from the deepest waters being generally preferred. Those on the west coast and to the south are larger, as a rule, than those towards the north of the British islands. In addition to its use as food, it is available for another purpose. The skin is used for fining coffee, being a good substitute for isinglass, and also as a material for artificial baits.

"The markets are generally supplied by the trawl. The principal English trawling-ground lies from Dover to Devonshire. They may be taken by spillers, but are not commonly captured with hooks; it is suggested that one reason may be that spillers are mostly used by day, whereas the sole is a night feeder. They are sometimes angled for with the hook, baited with crabs, worms, or mollusks; the most favorable time for fishing is at night, after a blow, when the water is thick, while a land breeze answers better than a sea breeze."

Several smaller species of sole are found in Europe. In Japan Zebrias zebra, black-banded, and Usinosita japonica, known as Usinóshita, or cow's tongue, are common. Farther south are numerous species of Synaptura and other genera peculiar to the Indian and Australian regions.

The Tongue-fishes: Cynoglossinæ.—The tongue-fishes are soles having the eyes on the left side not separated by a bony ridge, the two being very small and apparently in the same socket. The body is lanceolate, covered usually with rough scales, and as often with two or three lateral lines as with one. The species are mostly Asiatic. Cynoglossus robustus and other species are found in Japan, and in India are many others belonging to Cynoglossus and related genera. The larger species are valued as food. The single European species Symphurus nigrescens, common in the Mediterranean, is too small to have any value. Symphurus plagiusa, the tongue-fish of our coast, is common on our sandy shores from Cape Hatteras southward. Symphurus plagusia, scarcely different, replaces it in the West Indies. Symphurus atricandus is found in San Diego Bay, and numerous other species of no economic importance find their place farther south.

Fig. 442.—Symphurus plagiusa (L.). Beaufort, N. C.

CHAPTER XXVIII
SUBORDER JUGULARES

The Jugular-fishes.—In all the families of spiny-rayed fishes, as ranged in order in the present work, from the Berycidæ to the Soleidæ, the ventrals are thoracic in position, the pelvis, if present, being joined to the shoulder-girdle behind the symphysis of the clavicles so that the ventral fin falls below or behind the pectoral fin. To this arrangement the families of Bembradidæ and Pinguipedidæ offer perhaps the only exceptions.

In all the families which precede the Berycidæ in the linear series adopted in this work, the ventral fins when present are abdominal, the pelvis lying behind the clavicles and free from them as in the sharks, the reptiles, and all higher vertebrates.

In all the families remaining for discussion, the ventrals are brought still farther forward to a point distinctly before the pectorals. This position is called jugular (Lat. jugulum, throat).

The fishes with jugular ventrals we here divide into six groups, orders, and suborders: Jugulares, Haplodoci, Xenopterygii, Anacanthini, Opisthomi, and Pediculati. The last two groups, and perhaps the Anacanthini also, may well be considered as distinct orders, being more aberrant than the others.

For the most primitive and at the same time most obscurely defined of these groups we may retain the term applied by Linnæus to all of them, the name Jugulares. This group includes those jugular-fishes in which the position of the gills, the structure of the skull, and the form of the tail are essentially as in ordinary fishes. It is an extremely diversified and perhaps unnatural group, some of its members resembling Opisthognathidæ and Malacanthidæ, others suggesting the mailed-cheek fishes, and still others more degenerate. The fishes having the fins thus placed were long ago set apart by Linnæus, under the name of "Jugulares," Callionymus being the genus first placed by him in this group. Besides their anterior insertion, the ventrals in the Jugulares are more or less reduced in size, the rays being usually but not always less than I, 5 in number and more often reduced to one or two, or even wholly lost.

In general, the jugular fishes are degenerate as compared with the perch-like forms, but in certain regards they are often highly specialized. The groups showing this character are probably related one to another, but in some cases this fact is not clearly shown. In most of the jugular-fishes the shoulder-girdle shows some change or distortion. The usual foramen in the hypercoracoid is often wanting or relegated to the interspace between the coracoids, and the arrangement of the actinosts often deviates from that seen in the perciform fishes.

The Weevers: Trachinidæ.—Of the various families the group of weevers, Trachinidæ, most approaches the type of ordinary fishes. In the words of Dr. Gill, these fishes are known by "an elongated body attenuated backward from the head, compressed, oblong head, with the snout very short, a deeply cleft, oblique mouth, and a long spine projecting backward from each operculum and strengthened by extension on the surface of the operculum, as a keel. The dorsal fins are distinct, the first composed of strong, pungent spines radiating from a short base and about six or seven in number. The second dorsal and anal are very long. The pectorals have the lower rays unbranched, and the ventrals are in advance of the pectorals, and have each a spine and five rays. The species of this family are mostly found along the European and western African coast; but singularly enough a species closely related to the Old World form is found on the coast of Chile. None have been obtained from the intermediate regions or from the American coast. Two species are found in England, and are known under the name of the greater weever (Trachinus draco), about twelve inches long, and the lesser weever (Trachinus vipera), about six inches long. They are perhaps the most dreaded of the smaller English fishes. The formidable opercular spines are weapons of defense, and when seized by the fisherman the fish is apt to throw its head in the direction of the hand and lance a spine into it. The pungent dorsal spines are also defensive. Although without a poison gland, such as some fishes distantly related have at the base of the spines, they cause very severe wounds, and death may occur from tetanus. They are therefore divested of both opercular and dorsal spines before being exposed for sale. The various popular names which the weevers enjoy, in addition to their general designation, mostly refer to the armature of the spines, or are the result of the armature; such are adder-fish, stingfish, and sting-bull."

No species of Trachinidæ is known from North America or from Asia. In these fishes, as Dr. Boulenger has lately shown, the hypercoracoid is without foramen, the usual perforation lying between this bone and the hypercoracoid. A similar condition exists in the Anacanthini, or codfishes, but it seems to have been developed independently in the two groups. In the relatives of the Trachinidæ the position of this foramen changes gradually, moving by degrees from its usual place to the lower margin of the hypercoracoid. Species referred to Trachinus are recorded from the Miocene as well as Trachinus.

The extinct group of Callipterygidæ found in the Eocene of Monte Bolca seems allied to the Trachinidæ. It has the dorsal fin continuous, the spines small, the soft rays high; the scales are very small or wanting. Callipteryx speciosus and C. recticandus are the known species.

The Nototheniidæ.—In the family of Nototheniidæ the foramen is also wanting or confluent with the suture between the coracoids. To this family belong many species of the Antarctic region. These are elongate fishes with ctenoid scales and a general resemblance to small Hexagrammidæ. In most of the genera there is more than one lateral line. These species are the antipodes of the Cottidæ and Hexagrammidæ; although lacking the bony stay of the latter, they show several analogical resemblances and have very similar habits.

The Harpagiferidæ, naked, with the opercle armed with spines, and resemble sculpins even more closely than do the Nototheniidæ. Harpagifer is found in Antarctic seas, and the three species of Draconetta in the deeper waters of the North Atlantic and Pacific. These little fishes resemble Callionymus, but the opercle, instead of the preopercle, bears spines. The Bovichthyidæ of New Zealand are also sculpin-like and perhaps belong to the same family. Dr. Boulenger places all these Antarctic forms with the foramen outside the hypercoracoid in one family, Nototheniidæ. Several deep-sea fishes of this type have been lately described by Dr. Louis Dollo and others from the Patagonian region. One of these forms, Macrias amissus, lately named by Gill and Townsend, is five feet long, perhaps the largest deep-sea fish known. The family of Percophidæ, from Chile, is also closely allied to these forms, the single species differing in slight respects of osteology.

Fig. 443.—Pteropsaron evolans Jordan & Snyder. Sagami Bay, Japan.

Closely related to the family of Nototheniidæ and perhaps scarcely distinct from it is the small family of Pteropsaridæ, which differs in having but one lateral line and the foramen just above the lower edge of the hypercoracoid. The numerous species inhabit the middle Pacific, and are prettily colored fishes, looking like gobies. Pteropsaron is a Japanese genus, with high dorsal and anal fins; Parapercis is more widely diffused. Osurus schauinslandi is one of the neatest of the small fishes of Hawaii. Several species of Parapercis and Neopercis occur in Japan and numerous others in the waters of Polynesia. Pseudeleginus majori of the Italian Miocene must belong near Parapercis.

The Bathymasteridæ, or ronquils, are perhaps allied to the Nototheniidæ; they resemble the Opisthognathidæ, but the jaws are shorter and they have a large number of vertebræ as befits their northern distribution. Ronquilus jordani is found in Puget Sound and Bathymaster signatus in Alaska. The ventral rays are I, 5, and the many-rayed dorsal has a few slender spines in front.

Fig. 444.—Bathymaster signatus Cope. Shumagin Is., Alaska.

The Leptoscopidæ.—The Leptoscopidæ of New Zealand resemble the weevers and star-gazers, but the head is unarmed, covered by thin skin.

The Star-gazers: Uranoscopidæ.—The Uranoscopidæ, or star-gazers, have the head cuboid, mostly bony above, the mouth almost vertical, the lips usually fringed, and the eyes on the flat upper surface of the head. The spinous dorsal is short and may be wanting. The hypercoracoid has a foramen, and the body is naked or covered with small scales. The appearance is eccentric, like that of some of the Scorpænidæ, but the anatomy differs in several ways from that of the mailed-cheek fishes.

The species inhabit warm seas, and the larger ones are food-fishes of some importance. One species, Uranoscopus scaber, abounds in the Mediterranean. Uranoscopus japonicus and other species are found in Japan. Astroscopus y-græcum is the commonest species on our Atlantic coast. The bare spaces on the top of the head in this species yield vigorous electric shocks. Another American species is Astroscopus guttatus. In Japan and the East Indies the forms are more numerous and varied. Ichthyscopus lebeck, with a single dorsal, is a fantastic inhabitant of the seas of Japan, and Anema monopterygium in New Zealand.

Uranoscopus peruzzii, an extinct star-gazer, has been described from the Pliocene of Tuscany.

Fig. 445.—A Star-gazer Ariscopus iburius Jordan & Snyder. Iburi, Japan.

The Dragonets: Callionymidæ.—Remotely allied to the Uranoscopidæ is the interesting family of dragonets, or Callionymidæ. These are small scaleless fishes with flat heads, the preopercle armed with a strong spine, the body bearing a general resemblance to the smaller and smoother Cottidæ. The gill-openings are very small, the ventral fins wide apart. The colors are highly variegated, the fins are high, often filamentous, and the sexes differ much in coloration and in the development of the fins. The species are especially numerous on the shores of Japan, where Callionymus valenciennesi, Callionymus beniteguri, and Calliurichthys japonicus are food-fishes of some slight importance. Others are found in the East Indies, and several large and handsome forms are taken in the Mediterranean. Callionymus draco, the dragonet, or "sculpin," reaches the coast of England. In America but three species have been taken. These are dredged in deep water in the East Indies. In other parts of the world these fantastic little creatures are shore-fishes, creeping about in the shallow bays. Species of Synchiropus, colored like the coral sands, abound in the Polynesian coral reefs.

A fossil species of Callionymus (C. macrocephalus) are found in the Miocene of Croatia.

The family of Rhyacichthyidæ is a small group of Asiatic fishes allied to the Callionymidæ, but less elongate and differing in minor details. They are found not in the sea, but in mountain streams. Rhyacichthys (formerly called by the preoccupied name Platyptera) is the principal genus.

Fig. 446.—Star-gazer, Astroscopus guttatus Abbott. (From life by Dr. R. W. Shufeldt.)

The Trichonontidæ, with wide gill-openings and cycloid scales, are also related to the Callionymidæ. The species are few, small, and confined to the Indian and Australian seas. Another small family closely related to this is the group of Hemerocœtidæ of the same region.

The Dactyloscopidæ.—In this and the preceding families of jugular fishes the ventral rays remain I, 5, as in the typical thoracic forms. In most of the families yet to be described the number is I, 3, a character which separates the little fishes of the family of Dactyloscopidæ from the Uranoscopidæ and Leptoscopidæ. Dactyloscopus tridigitatus is a small fish of the coral sands of Cuba. The other species of this family are found mostly in the West Indies and on the west coast of Mexico. Several genera, Myxodagnus, Gillellus, Dactylagnus, etc., are recognized. In the structure of the shoulder-girdle these species diverge from the star-gazers, approaching the blennies, and their position is intermediate between Trachinidæ and Blenniidæ.

CHAPTER XXIX
THE BLENNIES: BLENNIIDÆ

Fig. 447.—Sarcastic Blenny, Neoclinus satiricus Girard. Monterey.

The great family of blennies, Blenniidæ, contains a vast number of species with elongate body, numerous dorsal spines, without suborbital stay or sucking-disk, and the ventrals jugular, where present, and of one spine and less than five soft rays. Most of them are of small size, living about rocks on the sea-shores of all regions. In general they are active fishes, of handsome but dark coloration, and in the different parts of the group is found great variety of structure. The tropical forms differ from those of arctic regions in the much shorter bodies and fewer vertebræ. These forms are most like ordinary fishes in appearance and structure and are doubtless the most primitive. Of the five hundred known species of blennies, we can note only a few of the most prominent. To Clinus and related genera belong many species of the warm seas, scaly and ovoviviparous, at least for the most part. The largest of these is the great kelpfish of the coast of California, Heterostichus rostratus, a food-fish of importance, reaching the length of two feet. Others of this type scarcely exceed two inches. Neoclinus satiricus, also of California, is remarkable for the great length of the upper jaw, which is formed as in Opisthognathus. Its membranes are brightly colored, being edged with bright yellow. Gibbonsia elegans is the pretty "señorita" of the coralline-lined rock-pools of California. Lepisoma nuchipinne, with a fringe of filaments at the nape, is very abundant in rock-pools of the West Indies. The species of Auchenopterus abound in the rock-pools of tropical America. These are very small neatly colored fishes with but one soft ray in the long dorsal fin. Species of Tripterygion, Myxodes, Cristiceps, and other genera abound in the South Pacific.

Fig. 448.—Kelp Blenny, Gibbonsia evides Jordan & Gilbert. San Diego.

Fig. 449.—Blennius cristatus L. Florida.

In Blennius and its relatives the body is scaleless and the slender teeth are arranged like the teeth of a comb. In most species long, fang-like posterior canines are developed in the jaws. Blennius is represented in Europe by many species, Blennius galerita, ocellaris, and basiliscus being among the most common. Certain species inhabit Italian lakes, having assumed a fresh-water habit. The numerous American species mostly belong to other related genera, Chasmodes bosquianus being most common. Blennius yatabei abounds in Japan. In Petroscirtes and its allies the gill-openings are much restricted. The species are mainly Asiatic and Polynesian and are very prettily colored. Petroscirtes elegans and P. trossulus adorn the Japanese rock-pools and others, often deep blue in color, abound in the coral reefs of Polynesia.

Fig. 450.—Rock-skipper, Alticus atlanticus. San Cristobal, Lower Cal.

Fig. 451.—Lizard-skipper, Alticus saliens (Forster). A blenny which lies out of water on lava rocks, leaping from one to another with great agility. From nature; specimen from Point Distress, Tutuila Island, Samoa. (About one-half size.)

Fig. 452.—Emblemaria atlantica Jordan. Pensacola, Fla.

The rock-skippers (Salarias, Alticus, etc.) are herbivorous, with serrated teeth set loosely in the jaws. These live in the rock-pools of the tropics and leap from rock to rock when disturbed with the agility of lizards. They are dusky or gray in color with handsome markings. One of them, Erpichthys or Alticus saliens in Samoa, lives about lava rocks between tide-marks, and at low tide remains on the rocks, over which it runs with the greatest ease and with much speed, its movements being precisely like those of Periophthalmus. As in the species of the latter genus, otherwise wholly different, this Alticus has short ventral fins padded with muscle.

Fig. 453.—Scartichthys enosimæ Jordan & Snyder, a fish of the rock-pools of the sacred island of Enoshima, Japan. Family Blenniidæ.

Erpichthys atlanticus is found in abundance on both coasts of tropical America. Many species abound in Polynesia and in both Indies. Salarias enosimæ lives in the clefts of lava rocks on the shores of Japan. Ophioblennius (webbi) is remarkable for its strong teeth, Emblemaria (nivipes, Atlantica) for its very high dorsal. Many other genera allied to Blennius, Clinus, and Salarias abound in the warm seas.

Fig. 454.—Zacalles bryope Jordan & Snyder. Misaki, Japan.

Fig. 455.—Bryostemma tarsodes Jordan & Snyder. Unalaska.

Fig. 456.—Exerpes asper Jenkins & Evermann. Guaymas, Mexico. Family Blenniidæ.

The Northern Blennies: Xiphidiinæ, Stichæiniæ, etc.—The blennies of the north temperate and arctic zones have the dorsal fin more elongate, the dorsal fin usually but not always composed entirely of spines. The scales are small and the ventral fins generally reduced in size. These are divided by Dr. Gill into several distinct families, but the groups recognized by him are subject to intergradations.

Fig. 457.—Gunnel, Pholis gunnellus (L.). Gloucester, Mass.

Fig. 458.—Xiphistes chirus Jordan & Gilbert. Amchitka I., Alaska.

Chirolophis (ascanii) of north Europe is remarkable for the tufted filaments on the head. These are still more developed in Bryostemma of the North Pacific, Bryostemma polyactocephalum and several other species being common from Puget Sound to Japan. Apodichthys (flavidus) of California is remarkable for a large quill-shaped anal spine and for the great variation in color, the hue being yellow, grass-green, or crimson, according to the color of the algæ about it. There is no evidence, however, that the individual fish can change its color, and these color forms seem to be distinct races within the species. Xererpes fucorum of California lies quiescent in the seaweed (Fucus) after the tide recedes, its form, color, and substance seeming to correspond exactly with those of the stems of algæ. Pholis gunnellus is the common gunnel (gunwale), or butter-fish, of both shores of the North Atlantic, with numerous allies in the North Pacific. Of these, Enedrias nebulosus, the ginpo, or silver-tail, is especially common in Japan. Xiphidion and Xiphistes of the California coast, and Dictyosoma of Japan, among others, are remarkable for the great number of lateral lines, these extending crosswise as well as lengthwise. Cebedichthys violaceus, a large blenny of California, has the posterior half of the dorsal made of soft rays. Opisthocentrus of Siberia and north Japan has the dorsal spines flexible, only the posterior ones being short and stiff. The snake-blennies (Lumpenus), numerous in the far North, are extremely slender, with well-developed pectorals and ventrals. Lumpenus lampetræformis is found on both shores of the Atlantic. In Stichæus a lateral line is present. There is none in Lumpenus, and in Ernogrammus and Ozorthe there are three. All these are elongate fishes, of some value as food and especially characteristic of the Northern seas. Fossil blennies are almost unknown. Pterygocephalus paradoxus of the Eocene resembles the living Cristiceps, a genus which differs from Clinus in having the first few dorsal spines detached, inserted on the head. The first spine alone in Pterygocephalus is detached and is very strong. A species called Clinus gracilis is described from the Miocene near Vienna, Blennius fossilis from the Miocene of Croatia, and an uncertain Oncolepis isseli from Monte Bolca. The family is certainly one of the most recent in geologic times. The family of Blenniidæ, as here recognized, includes a very great variety of forms and should perhaps be subdivided into several families, as Dr. Gill has suggested. At present there is, however, no satisfactory basis of division known.

Fig. 459.—Ozorthe dictyogramma (Hertzenstein), a Japanese blenny from Hakodate: showing increased number of lateral lines, a trait characteristic of many fishes of the north Pacific.

Fig. 460.—Stichæus punctatus Fabricius. St. Michael, Alaska.

The Quillfishes: Ptilichthyidæ.—The Ptilichthyidæ, or quillfishes, are small and slender blennies of the North Pacific, with very numerous fin-rays. Ptilichthys goodei has 90 dorsal spines and 145 soft rays. Another group of very slender naked blennies is the small family of Xiphasiidæ from the South Pacific. The jaws have excessively long canines; there are no ventral fins. The dorsal fin is very high and the caudal ends in a long thread.

Fig. 461.—Bryostemma otohime Jordan & Snyder. Hakodate, Japan. Family Blenniidæ.

Fig. 462.—Quillfish, Ptilichthys goodei Bean. Unalaska.

Fig. 463.—Blochius longirostris Volta, restored. Upper Eocene of Monte Bolca. (After Woodward.)

The Blochiidæ.—Of doubtful relationship is the extinct family of Blochiidæ. In this group the body is elongate, covered with keeled plates imbricated like shingles. The dorsal is composed of many slender spines, and the vertebræ much elongate. In Blochius longirostris (Monte Bolca Eocene) has very long jaws, lined with small teeth. Zittel regards the family as allied to the Belonorhynchidæ, but the prolongation of the jaws may be a character of analogy merely. Woodward places it next to the Blenniidæ, supposing it to have small and jugular ventral fins. But as the presence of ventral fins is uncertain, the position of the family cannot be ascertained and it may really belong in the neighborhood of Ammodytes. The dorsal rays are figured by Woodward as simple.

Fig. 464.—Xiphasia setifera Swainson. India. (After Day.)

The Patæcidæ etc.—The Patæcidæ are blenny-like fishes of Australia, having the form of Congriopus, the spinous dorsal being very high and inserted before the eyes, forming a crest. Patæcus fronto is not rare in South Australia. The Gnathanacanthidæ is another small group of peculiar blennies from the Pacific. The Acanthoclinidæ are small blennies of New Zealand with numerous spines in the anal fin. Acanthoclinus littoreus is the only known species.

The Gadopsidæ, etc.—The family of Gadopsidæ of the rivers of New Zealand and southern Australia consists of a single species, Gadopsis marmoratus, resembling the scaly blennies called Clinus, but with long ventrals of a single ray, and three spines in the anal fin besides other peculiarities. The species is locally very common and with various other fishes in regions where true trout are unknown, it is called "trout."

The Cerdalidæ are small band-shaped blennies of the Pacific coast of Panama. The slender dorsal spines pass gradually into soft rays. Three species are known.

Fig. 465.—Wrymouth, Cryptacanthodes maculatus. New York.

The wrymouths, or Cryptacanthodidæ, are large blennies of the northern seas, with the mouth almost vertical and the head cuboid. The wrymouth or ghostfish, Cryptacanthodes maculatus, is frequently taken from Long Island northward. It is usually dusky in color, but sometimes pure white. Other genera are found in the north Pacific.

The Wolf-fishes: Anarhichadidæ.—The wolf-fishes (Anarhichadidæ) are large blennies of the northern seas, remarkable for their strong teeth. Those in front are conical canines. Those behind are coarse molars. The dorsal is high, of flexible spines. The species are large, powerful, voracious fishes, known as wolf-fishes. Anarhichas lupus is the common wolf-fish of the north Atlantic, reaching a length of four to six feet, the body marked by dark cross-bands. Other similar species are found both in the north Pacific and north Atlantic. Anarhichas lepturus, plain brown in color, is common about the Aleutian Islands.

Fig. 466.—Wolf-fish, Anarhichas lupus (L.). Georges Bank.

Fig. 467.—Skull of Anarrhichthys ocellatus Ayres.

In the wolf-eel (Anarrhichthys ocellatus) of the coast of California, the head is formed as in Anarhichas but the body is band-shaped, being drawn out into a very long and tapering tail. This species, which is often supposed to be a "sea-serpent," sometimes reaches a length of eight feet. It is used for food. It feeds on sea-urchins and sand-dollars (Echinarachinius) which it readily crushes with its tremendous teeth.

The skull of a fossil genus, Laparus (alticeps), with a resemblance to Anarhichas, is recorded from the Eocene of England.

The Eel-pouts: Zoarcidæ.—The remaining blenny-like forms lack fin spines, agreeing in this respect with the codfishes and their allies. In all of the latter, however, the hypercoracoid is imperforate, the pseudobranchiæ are obsolete, and the tail isocercal. The forms allied to Zoarces and Ophidion, and which we may regard as degraded blennies, have homocercal (rarely leptocercal) tails, generally but not always well-developed pseudobranchiæ and the usual foramen in the hypercoracoid.

Fig. 463.—Eel-pout, Zoarces anguillaris Peck. Eastport, Me.

The Zoarcidæ, or eel-pouts, have the body elongate, naked, or covered with small scales, the dorsal and anal of many soft rays and the gill-openings confined to the side. Most of the species live in rather deep water in the Arctic and Antarctic regions. Zoarces viviparus, the "mother of eels," is a common fish of the coasts of northern Europe. In the genus Zoarces, the last rays of the dorsal are short and stiff, like spines. The species are viviparous; the young being eel-like in form, the name "mother of eels" has naturally arisen in popular language. The American eel-pout, sometimes called mutton-fish, Zoarces anguillaris, is rather common north of Cape Cod, and a similar species, Zoarces elongatus, is found in northern Japan. Lycodopsis pacifica, without spines in the dorsal, replaces Zoarces in California. The species of Lycodes, without spines in the dorsal, and with teeth on the vomer and palatines, are very abundant in the northern seas, extending into deep waters farther south. Lycodes reticulatus is the most abundant of these fishes, which are valued chiefly by the Esquimaux and other Arctic races of people. Numerous related genera are recorded from deep-sea explorations, and several others occur about Tierra del Fuego. Gymnelis, small, naked species brightly colored, is represented by Gymnelis viridis in the Arctic and by Gymnelis pictus about Cape Horn.

Fig. 469.—Eel-pout, Lycodes reticulatus Reinhardt. Banquereau.

Fig. 470.—Lycenchelys verrilli (Goode & Bean). Chebucto, Nova Scotia.

Fig. 471.—Scytalina cerdale Jordan & Gilbert. Straits of Fuca.

The family of Scytalinidæ contains a single species, Scytalina cerdale, a small snake-shaped fish which lives in wet gravel between tide-marks, on Waada Island near Cape Flattery in Washington, not having yet been found elsewhere. It dives among the wet stones with great celerity, and can only be taken by active digging.

To the family of Congrogadidæ belong several species of eel-shaped blennies with soft rays only, found on the coasts of Asia. Another small family, Derepodichthyidæ, is represented by one species, a scaleless little fish from the shores of British Columbia.

The Xenocephalidæ consist of a single peculiar species, Xenocephalus armatus, from the island of New Ireland. The head is very large, helmeted with bony plates and armed with spines. The body is short and slender, the ventrals with five rays, the dorsal and anal short.

The Cusk-eels: Ophidiidæ.—The more important family of Ophidiidæ, or cusk-eels, is characterized by the extremely anterior position of the ventral fins, which are inserted at the throat, each one appearing as a long forked barbel. The tail is leptocercal, attenuate, the dorsal and anal confluent around it. Ophidion barbatum and Rissola rochei are common in southern Europe. Rissola marginata is the commonest species on our Atlantic coast, and Chilara taylori in California. Other species are found farther south, and still others in deep water. Genypterus contains numerous species of the south Pacific, some of which reach the length of five feet, forming a commercial substitute for cod. Genypterus capensis is the klipvisch of the Cape of Good Hope, and Genypterus australis the "Cloudy Bay cod" or "rock ling" of New England. Another large species, Genypterus maculatus, occurs in Chile. A few fragments doubtfully referred to Ophidion and Fierasfer occur in the Eocene and later rocks. The Lycodapodidæ contain a few small, scaleless fishes (Lycodapus) dredged in the north Pacific.

Fig. 472.—Cusk-eel, Rissola marginata (De Kay). Virginia.

Fig. 473.—Lycodapus dermatinus Gilbert. Lower California.

Sand-lances: Ammodytidæ.—Near the Ophidiidæ are placed the small family of sand-lances (Ammodytidæ). This family comprises small, slender, silvery fishes, of both Arctic and tropical seas, living along shore and having the habit of burying themselves in the sand under the surf in shallow water. The jaws are toothless, the body scarcely scaly and crossed by many cross-folds of skin, the many-rayed dorsal fin is without spines, and the ventral fins when present are jugular. The species of the family are very much alike. From their great abundance they have sometimes much value as food, more perhaps as bait, still more as food for salmon and other fishes, from which they escape by plunging into the sand. Sometimes a falling tide leaves a sandy beach fairly covered with living "lants" looking like a moving foam of silver. Ammodytes tobianus is the sand-lance or lant of northern Europe. Ammodytes americanus, scarcely distinguishable, replaces it in America; and Ammodytes personatus in California, Alaska, and Japan. This is a most excellent pan fish, and the Japanese, who regard little things, value it highly.

Fig. 474.—Sand-lance, Ammodytes americanus De Kay. Nantucket.

Fig. 475.—Embolichthys mitsukurii (Jordan & Evermann). Formosa.

In the genus Hyperoplus there is a large tooth on the vomer. In the tropical genera there is a much smaller number of vertebræ and the body is covered with ordinary scales instead of delicate, oblique cross-folds of skin. These tropical species must probably be detached from the Ammodytidæ to form a distinct family, Bleekeriidæ. Bleekeria kallolepis is found in India, Bleekeria gilli is from an unknown locality, and the most primitive species of sand-lance, Embolichthys mitsukurii, occurs in Formosa. In this species, alone of the sand-lances, the ventral fins are retained. These are jugular in position, as in the Zoarcidæ, and the rays are I, 3. The discovery of this species makes it necessary to separate the Ammodytidæ and Bleekeriidæ widely from the Percesoces, and especially from the extinct families of Crossognathidæ and Cobitopsidæ with which its structure in other regards has led Woodward, Boulenger, and the present writer to associate it.

Although an alleged sand-lance, Rhynchias septipinnis, with ventral fins abdominal, was described a century ago by Pallas, no one has since seen it, and it may not exist, or, if it exists, it may belong among the Percesoces. The relation of Ammodytes to Embolichthys is too close to doubt their close relationship. According to Dr. Gill the Ammodytidæ belong near the Hemerocœtidæ.

Fig. 476.—Pearlfish, Fierasfer dubius Putnam, embedded in a layer of mother-of-pearl. La Paz, Lower California. (Photograph by Capt. M. Castro.)

The Pearlfishes: Fierasferidæ.—In the little group of pearlfishes, called Fierasferidæ or Carapidæ, the body is eel-shaped with a rather large head, and the vent is at the throat. Numerous species of Fierasfer (Carapus) are found in the warm seas. These little fishes enter the cavities of sea-cucumbers (Holothurians) and other animals which offer shelter, being frequently taken from the pearl-oyster. In the Museum of Comparative Zoology, according to Professor Putnam, is "one valve of a pearl-oyster in which a specimen of Fierasfer dubius is beautifully inclosed in a pearly covering deposited on it by the oyster." A photograph of a similar specimen is given above. The species found in Holothurians are transparent in texture, with a bright pearly luster. Species living among lava rocks, as Jordanicus umbratilis of the south seas, are mottled black. Since this was written a specimen of this black species has been obtained from a Holothurian in Hilo, Hawaii, by Mr. H. W. Henshaw.

Fig. 477.—Pearlfish, Fierasfer acus (Linnæus), issuing from a Holothurian. Coast of Italy. (After Emery.)

The Brotulidæ.—The Brotulidæ constitute a large family of fishes, resembling codfishes, but differing in the character of the hypercoracoid, as well as in the form of the tail. The resemblance between the two groups is largely superficial. We may look upon the Brotulidæ as degraded blennies, but the Gadidæ have an earlier and different origin which has not yet been clearly made out. Most of the Brotulidæ live in deep water and are without common name or economic relations. Two species have been landlocked in cave streams in Cuba, where they have, like other cavefishes, lost their sight, a phenomenon which richly deserves careful study, and which has been recently investigated by Dr. C. H. Eigenmann. These blind Brotulids, called Pez Ciego in Cuba, are found in different caves in the county of San Antonio, where they reach a length of about five inches. As in other blindfishes, the body is translucent and colorless. These species are known as Lucifuga subterranea and Stygicola dentata. They are descended from allies of the genera called Brotula and Dinematichthys. Brotula barbata is a cusk-like fish, occasionally found in the markets of Havana. Similar species, Brotula multibarbata and Sirembo inermis, are common in Japan, and Brosmophycis marginatus, beautifully red in color, is occasionally seen on the coast of California. Many other genera and species abound in the depths of the sea and in crevices of coral reefs, showing much variety in form and structure.

Fig. 478.—Brotula barbata Schneider. Cuba.

Fig. 479.—Blind Brotula. Lucifuga subterranea (Poey), showing viviparous habit. Joignan Cave, Pinar del Rio, Cuba. (Photograph by Dr. Eigenmann.)

The Bregmacerotidæ are small fishes, closely related to the Brotulids, having the hypercoracoid perforate, but with several minor peculiarities, the first ray of the dorsal being free and much elongate. They live near the surface in the open sea. Bregmaceros macclellandi is widely diffused in the Pacific.

Ateleopodidæ.—The small family of Ateleopodidæ includes long-bodied, deep-water fishes of the Pacific, resembling Macrourus, but with smooth scales. The group has the coracoids as in Brotulidæ, and the actinosts are united in an undivided plate. Ateleopus japonicus is the species taken in Japan.

Suborder Haplodoci.—We may here place the peculiar family of Batrachoididæ, or toadfishes. It constitutes the suborder of Haplodoci (ἁπλόος, simple; δόκος, shaft) from the simple form of the post-temporal. This order is characterized by the undivided post-temporal bone and by the reduction of the gill-arches to three. A second bone behind the post-temporal connects the shoulder-girdle above to the vertebral column. The coracoid bones are more or less elongate, suggesting the arm seen in pediculate fishes.

The single family has the general form of the Cottidæ, the body robust, with large head, large mouth, strong teeth, and short spinous dorsal fin. The shoulder-girdle and its structures differ little from the blennioid type. There are no pseudobranchiæ and the tail is homocercal. The species are relatively few, chiefly confined to the warm seas and mostly American, none being found in Europe or Asia. Some of them ascend rivers, and all are carnivorous and voracious. None are valued as food, being coarse-grained in flesh. The group is probably nearest allied to the Trachinidæ or Uranoscopidæ.

Fig. 480.—Leopard Toadfish, Opsanus pardus (Goode & Bean). Pensacola.

Opsanus tau, the common toadfish, or oyster-fish, of our Atlantic coast, is very common in rocky places, the young clinging to stones by a sucking-disk on the belly, a structure which is early lost. It reaches a length of about fifteen inches. Opsanus pardus, the leopard toadfish, or sapo, of the Gulf coast, lives in deeper water and is prettily marked with dark-brown spots on a light yellowish ground.

In Opsanus the body is naked and there is a large foramen, or mucous pore, in the axil of the pectoral. In the Marcgravia cryptocentra, a large Brazilian toadfish, this foramen is absent. In Batrachoides, a South American genus, the body is covered with cycloid scales. Batrachoides surinamensis is a common species of the West Indies. Batrachoides pacifici occurs at Panama. The genus Porichthys is remarkable for the development of series of mucous pores and luminous spots in several different lateral lines which cover the body. These luminous spots are quite unlike those found in the lantern-fishes (Myctophidæ) and other Iniomi. Their structure has been worked out in detail by Dr. Charles Wilson Greene, a summary of whose conclusions are given on page 191, Vol. I.

The common midshipman, or singing fish, of the coast of California is Porichthys notatus. This species, named midshipman from its rows of shining spots like brass buttons, is found among rocks and kelp and makes a peculiar quivering or humming noise with its large air-bladder.

Porichthys porosissimus, the bagre sapo, is common on all coasts of the Gulf of Mexico and the Caribbean Sea. Porichthys margaritatus is found about Panama and Porichthys porosus in Chile.

Fig. 481.—Singing Fish or Bagre Sapo, Porichthys porosissimus (Cuv. & Val.). Galveston.

The species of Thalassophryne and Thalassothia, the poison toadfishes, are found along the coasts of South America, where they sometimes ascend the rivers. In these species there is an elaborate series of venom glands connected with the hollow spines of the opercle and the dorsal spines. Dr. Günther gives the following account of this structure as shown in Thalassophryne reticulata, a species from Panama:

"In this species I first observed and closely examined the poison organ with which the fishes of this genus are provided. Its structure is as follows: (1) The opercular part: The operculum is very narrow, vertically styliform and very mobile; it is armed behind with a spine, eight lines long in a specimen of 10½ inches, and of the same form as the venom fang of a snake; it is, however, somewhat less curved, being only slightly bent upward. It has a longish slit at the outer side of its extremity which leads into a canal perfectly closed and running along the whole length of its interior; a bristle introduced into the canal reappears through another opening at the base of the spine, entering into a sac situated on the opercle and along the basal half of the spine; the sac is of an oblong-ovate shape and about double the size of an oat grain. Though the specimen had been preserved in spirits for about nine months it still contained a whitish substance of the consistency of thick cream, which on the slightest pressure freely flowed from the opening in the extremity of the spine. On the other hand, the sac could be easily filled with air or fluid from the foramen of the spine. No gland could be discovered in the immediate neighborhood of the sac; but on a more careful inspection I found a minute tube floating free in the sac, whilst on the left-hand side there is only a small opening instead of the tube. The attempts to introduce a bristle into this opening for any distance failed, as it appears to lead into the interior of the basal portion of the operculum, to which the sac firmly adheres at this spot. (2) The dorsal part is composed of the two dorsal spines, each of which is ten lines long. The whole arrangement is the same as in the opercular spines; their slit is at the front side of the point; each has a separate sac, which occupies the front of the basal portion; the contents were the same as in the opercular sacs, but in somewhat greater quantity. A strong branch of the lateral line ascends to the immediate neighborhood of their base. Thus we have four poison spines, each with a sac at its base; the walls of the sacs are thin, composed of a fibrous membrane, the interior of which is coated over with mucus. There are no secretory glands embedded between these membranes, and these sacs are probably merely the reservoirs in which the fluid secreted accumulates. The absence of a secretory organ in the immediate neighborhood of the reservoirs (an organ the size of which would be in accordance with the quantity of fluid secreted), the diversity of the osseous spines which have been modified into poison organs, and the actual communication indicated by the foramen in the sac lead me to the opinion that the organ of secretion is either that system of muciferous channels which is found in nearly the whole class of fishes, and the secretion of which has poisonous qualities in a few of them, or at least an independent portion of it. This description was made from the first example; through the kindness of Captain Dow I received two other specimens, and in the hope of proving the connection of the poison bags with the lateral-line system, I asked Dr. Pettigrew, of the Royal College of Surgeons, a gentleman whose great skill has enriched that collection with a series of the most admirable anatomical preparations, to lend me his assistance in injecting the canals. The injection of the bags through the opening of the spine was easily accomplished; but we failed to drive the fluid beyond the bag or to fill with it any other part of the system of muciferous channels. This, however, does not disprove the connection of the poison bags with that system, inasmuch as it became apparent that if there be minute openings they are so contracted by the action of the spirit in which the specimens were preserved as to be impassable to the fluid of injection. A great part of the lateral-line system consists of open canals; however, on some parts of the body, these canals are entirely covered by the skin; thus, for instance, the open lateral line ceases apparently in the suprascapular region, being continued in the parietal region. We could not discover any trace of an opening by which the open canal leads to below the skin; yet we could distinctly trace the existence of the continuation of the canal by a depressed line, so that it is quite evident that such openings do exist, although they may be passable only in fresh specimens. Thus likewise the existence of openings in the bags, as I believed to have found in the first specimen dissected, may be proved by examination of fresh examples. The sacs are without an external muscular layer and situated immediately below the loose thick skin which envelops their spines to their extremity. The injection of the poison into a living animal, therefore, can only be effected by the pressure to which the sac is subjected the moment the spine enters another body. Nobody will suppose that a complicated apparatus like the one described can be intended for conveying an innocuous substance, and therefore I have not hesitated to designate it as poisonous; and, Captain Dow informs me in a letter lately received, 'the natives of Panama seemed quite familiar with the existence of the spines and of the emission from them of a poison which, when introduced into a wound, caused fever, an effect somewhat similar to that produced by the sting of a scorpion; but in no case was a wound caused by one of them known to result seriously. The slightest pressure of the finger at the base of the spine caused the poison to jet a foot or more from the opening of the spine.' The greatest importance must be attached to this fact, inasmuch as it assists us in our inquiries into the nature of the functions of the muciferous system, the idea of its being a secretory organ having lately been superseded by the notion that it serves merely as a stratum for the distribution of peripheric nerves. Also the objection that the sting-rays and many Siluroid fishes are not poisonous because they have no poison organ cannot be maintained, although the organs conveying their poison are neither so well adapted for this purpose nor in such a perfect connection with the secretory mucous system as in Thalassophryne. The poison organ serves merely as a weapon of defense. All the Batrachoids with obtuse teeth on the palate and in the lower jaw feed on Mollusca and Crustaceans."

No fossil Batrachoididæ are known.

Suborder Xenopterygii.—The clingfishes, forming the suborder Xenopterygii (ξενός, strange; πτερύξ, fin), are, perhaps, allied to the toadfishes. The ventral fins are jugular, the rays I, 4 or I, 5, and between them is developed an elaborate sucking-disk, not derived from modified fins, but from folds of the skin and underlying muscles.

The structure of this disk in Gobiesox sanguineus is thus described by Dr. Günther:

"The whole disk is exceedingly large, subcircular, longer than broad, its length being (often) one-third of the whole length of the fish. The central portion is formed merely by skin, which is separated from the pelvic or pubic bones by several layers of muscles. The peripheric portion is divided into an anterior and posterior part by a deep notch behind the ventrals. The anterior peripheric portion is formed by the ventral rays, the membrane between them and a broad fringe which extends anteriorly from one ventral to the other. This fringe is a fold of the skin, containing on one side the rudimentary ventral spine, but no cartilage. The posterior peripheric portion is suspended on each side on the coracoid, the upper bone of which is exceedingly broad, becoming a free, movable plate behind the pectoral. The lower bone of the coracoid is of a triangular form, and supports a very broad fold of the skin, extending from one side to the other, and containing a cartilage which runs through the whole of that fold. Fine processes of the cartilage are continued into the soft striated margin, in which the disk terminates posteriorly. The face of the disk is coated with a thick epidermis, like the sole of the foot in higher animals. The epidermis is divided into many polygonal plates. There are no such plates between the roots of the ventral fins."

Fig. 482.—Aspasma ciconiæ Jordan & Snyder. Wakanoura, Japan.

The body is formed much as in the toadfishes. The skin is naked and there is no spinous dorsal fin. The skeleton shows several peculiarities; there is no suborbital ring, the palatine arcade is reduced, as are the gill-arches, the opercle is reduced to a spine-like projection, and the vertebræ are numerous. The species are found in tide-pools in the warm seas, where they cling tightly to the rocks with their large ventral disks.

Several species of Lepadogaster and Mirbelia are found in the Mediterranean. Lepadogaster gouani is the best-known European species. Aspasma ciconiæ and minima occur about the rocks in the bays of Japan.

Fig. 483.—Clingfish, Caularchus mæandricus (Girard). Monterey, Cal.

Most of the West Indian species belong to Gobiesox, with entire teeth, and to Arbaciosa, with serrated teeth. Some of these species are deep crimson in color, but most of them are dull olive. Gobiesox virgatulus is common on the Gulf Coast. Caularchus mæandricus, a very large species, reaching a length of six inches, abounds along the coast of California. Other genera are found at the Cape of Good Hope, especially about New Zealand. Chorisochismus dentex, from the Cape of Good Hope, reaches the length of a foot.

CHAPTER XXX
OPISTHOMI AND ANACANTHINI

Order Opisthomi.—The order Opisthomi (ὄπισθη, behind; ὤμος, shoulder) is characterized by the general traits of the blennies and other elongate, spiny-rayed fishes, but the shoulder-girdle, as in the Apodes and the Heteromi, is inserted on the vertebral column well behind the skull.

The single family, Mastacembelidæ, is composed of eel-shaped fishes with a large mouth and projecting lower jaw, inhabiting the waters of India, Africa, and the East Indies. They are small in size and of no economic importance. The dorsal is long, with free spines in front and there are no ventral fins. Were these fins developed, they should in theory be jugular in position. There is no air-duct in Mastacembelus and it seems to be a true spiny-rayed fish, having no special relation to either Notacanthus or to the eels. Except for the separation of the shoulder-girdle from the skull, there seems to be no reason for separating them far from the Blennioid forms, and the resemblance to Notacanthus seems wholly fallacious.

Fig. 484.—Mastacembelus ellipsifer Boulenger. Congo River. (After Boulenger.)

Mastacembelus armatus is a common species of India and China. In Rhynchobdella the nasal appendage or proboscis, conspicuous in Mastacembelus, is still more developed. Rhynchobdella aculeata is common in India.

Order Anacanthini.—We may separate from the other jugular fishes the great group of codfishes and their allies, retaining the name Anacanthini (ἄνακανθος, without spine) suggested by Johannes Müller. In this group the hypercoracoid is without foramen, the fenestra lying between this bone and the hypocoracoid below it. The tail is isocercal, the vertebræ in a right line and progressively smaller backward, sometimes degenerate or whip-like (leptocercal) at tip. Other characters are shown in the structure of the skull. There are no spines in any of the fins; the ventrals are jugular, the scales generally small, and the coloration dull or brownish. The numerous species live chiefly in the northern seas, some of them descending to great depths. The resemblance of these fishes to some of the Blennioid group is very strongly marked, but these likenesses seem analogical only and not indicative of true affinity. The codfishes probably represent an early offshoot from the ancestors of the spiny-rayed fishes, and their line of evolution is unknown, possibly from Ganoid types. Among recent fishes there is nothing structurally nearer than the Nototheniidæ and Brotulidæ, but the line of descent must branch off much farther back than either of these. For the present, therefore, we may regard the codfishes and their allies (Anacanthini) as a distinct order.

Fig. 485.—Codfish, Gadus callarias L. Eastport, Me.

The Codfishes: Gadidæ.—The chief family is that of the Gadidæ, or codfishes. These are characterized by a general resemblance to the common codfish, Gadus callarias. This is one of the best known of fishes, found everywhere on the shores of the North Atlantic, and the subject of economic fisheries of the greatest importance. Its flesh is white, flaky, rather tasteless, but takes salt readily, and is peculiarly well adapted for drying. The average size of the codfish is about ten pounds, but Captain Nathaniel Atwood of Provincetown records one with the weight of 160 pounds.

According to Dr. Goode:

"In the western Atlantic the species occurs in the winter in considerable abundance as far south as the mouth of the Chesapeake Bay, latitude 37°, and stragglers have been observed about Ocracoke Inlet. The southern limits of the species may be safely considered to be Cape Hatteras, in latitude 35° 10´. Along the coast of New England, the Middle States, and British North America, and upon all the off-shore banks of this region, cod are found usually in great abundance, during part of the year at least. They have been observed also in the Gulf of Bothnia, latitude 70° to 75°, and in the southeastern part of Baffin's Land to the northward of Cumberland Sound, and it is more than probable that they occur in the waters of the Arctic Sea to the north of the American continent, or away around to Bering Strait."

Dr. Gill says:

"The ocean banks of moderate depths are the favorite resorts of the cod, but it is by no means confined to those localities. The fish, indeed, occasionally enters into fresh, or at least brackish, water. According to Canadian authorities, it is found 'well up the estuary of the St. Lawrence, though how far up is not definitely stated, probably not beyond the limits of brackish water.' Even as far south as the Delaware River it has been known to enter the streams. Dr. C. C. Abbott records that in January, 1876, 'a healthy, strong, active codfish, weighing nearly four pounds, was taken in a draw-net in the Delaware River near Trenton, New Jersey; the stomach of the fish showed that it had been in river-water several days. Many of them had been taken about Philadelphia between 1856 and 1869.'

"The cod ranks among the most voracious of ordinary fishes, and almost everything that is eatable, and some that is not, may find its way into its capacious maw. Years ago, before naturalists had the facilities that the dredge now affords, cods' stomachs were the favorite resort for rare shells, and some species had never been obtained otherwise than through such a medium, while many filled the cabinet that would not otherwise have been represented. In the words of Mr. Goode, 'codfish swallow bivalve fish of the largest size, like the great sea-clams, which are a favorite article of food on certain portions of the coast'; further, 'these shells are nested, the smaller inside of the larger, sometimes six or seven in a set, having been packed together in this compact manner in the stomachs of the codfish after the soft parts have been digested out. Some of them had shreds of the muscles remaining in them and were quite fresh, having evidently been but recently ejected by the fish.' Even banks of dead shells have been found in various regions, which are supposed to be the remains of mollusks taken by the cod. Shell-fishes, however, form probably but the smaller portion of its diet, and fishes of its own class contribute materially to its food,—such as the herring family, the capelin, etc.

"The codfish in its mode of reproduction exhibits some interesting peculiarities. It does not come on the coast to spawn, as was once supposed, but its eggs are deposited in mid-sea and float to the surface, although it does really, in many cases, approach the land to do so. Prof. C. O. Sars, who has discovered its peculiarities, 'found cod at a distance of twenty to thirty Norwegian miles from the shore and at a depth of from one hundred to one hundred and fifty fathoms.' The eggs thus confided to the mercy of the waves are very numerous; as many as 9,100,000 have been calculated in a seventy-five-pound fish. 'When the eggs are first seen in the fish they are so small as to be hardly distinguishable; but they continue to increase in size until maturity, and after impregnation have a diameter depending upon the size of the parent, varying from one-nineteenth to one-seventeenth of an inch. A five- to eight-pound fish has eggs of the smaller size, while a twenty-five-pound one has them between an eighteenth and a seventeenth.' There are about 190,000 eggs of the smaller size to a pound avoirdupois. They are matured and ejected from September to November."

Unlike most fishes, the cod spawns in cooling water, a trait also found in the salmon family.

The liver of the cod yields an easily digested oil of great value in the medical treatment of diseases causing emaciation.

The Alaska cod, Gadus macrocephalus, is equally abundant with the Atlantic species, from which it differs very slightly, the air-bladder or sounds being smaller, according to the fishermen, and the head being somewhat larger. This species is found from Cape Flattery to Hakodate in Japan, and is very abundant about the Aleutian Islands and especially in the Okhotsk Sea. With equal markets it would be as important commercially as the Atlantic cod. In the codfish (Gadus) and related genera there are three dorsal and two anal fins. In the codfish the lateral line is pale and the lower jaw shorter than the upper.

Fig. 486.—Skull of Haddock, Melanogrammus æglifinus.

Fig. 487.—Haddock, Melanogrammus æglifinus (L.). Eastport, Me.

The haddock (Melanogrammus æglifinus) closely resembles the cod and is of similar quality as food. It is known at sight by the black lateral line. It is found on both shores of the Atlantic and when smoked is the "finnan haddie" of commerce.

The pollack, coalfish, or green cod (Pollachius carbonarius) is also common on both shores of the north Atlantic. It is darker than the cod and more lustrous, and the lower jaw is longer, with a smaller barbel at tip. It is especially excellent when fresh.

Fig. 488.—Pollock, Theragra chalcogramma (Pallas). Shumagin I., Alaska.

The whiting (Merlangus merlangus) is a pollack-like fish common on the British coasts, but not reaching the American shores. It is found in large schools in sandy bays. The Alaska pollack (Theragra chalcogramma) is a large fish with projecting lower jaw, widely diffused in the north Pacific and useful as a food-fish to the Aleutian peoples. It furnishes a large part of the food of the fur-seal (Callorhinus alascanus and C. ursinus) during its migrations. The fur-seal rarely catches the true codfish, which swims near the bottom. The wall-eyed pollack (Theragra fucensis) is found about Puget Sound. Smaller codfishes of this type are the wachna cod (Eleginus navaga) of Siberia and the Arctic codling (Boreogadus saida), both common about Kamchatka, the latter crossing to Greenland.

Several dwarf codfishes having, like the true cod, three dorsal fins and a barbel at the chin are also recorded. Among these are the tomcod, or frostfish, of the Atlantic (Microgadus tomcod), the California tomcod (Microgadus proximus), and Micromesistius poutassou of the Mediterranean. These little cods are valued as pan fishes, but the flesh is soft and without much flavor.

Fig. 489.—Tomcod, Microgadus tomcod (Walbaum). Wood's Hole, Mass.

Other cod-like fishes have but two dorsals and one anal fin. Many of these occur in deep water. Among those living near shore, and therefore having economic value, we may mention a few of the more prominent. The codlings (Urophycis) are represented by numerous species on both shores of the Atlantic. Urophycis blennoides is common in the Mediterranean. Urophycis regius, on our South Atlantic coast, is said to exhibit electric powers in life, a statement that needs verification. In the Gulf of Mexico Urophycis floridanus is common. Farther north are the more important species Urophycis tenuis, called the white hake, and Urophycis chuss, the squirrel-hake. The ling (Molva molva) is found in deep water about the North Sea.

A related genus, Lota, the burbot, called also ling and, in America, the lawyer, is found in fresh waters. This genus contains the only fresh-water members of the group of Anacanthini.

The European burbot, Lota lota, is common in the streams and lakes of northern Europe and Siberia. It is a bottom fish, coarse in flesh and rather tasteless, eaten sometimes when boiled and soaked in vinegar or made into salad. It is dark olive in color, thickly marbled with blackish.

The American burbot, or lawyer (Lota maculosa), is very much like the European species. It is found from New England throughout the Great Lakes to the Yukon. It reaches a length of usually two or three feet and is little valued as food in the United States, but rises much in esteem farther north. The liver and roe are said to be delicious. In Siberia its skin is used instead of glass for windows. In Alaska, according to Dr. Dall, it reaches a length of six feet and a weight of sixty pounds.

Fig. 490.—Burbot, Lota maculosa (Le Sueur). New York.

Fig. 491.—Four-bearded Rockling, Enchelyopus cimbrius (Linnæus). Nahant, Mass.

The rocklings (Gaidropsarus and Enchelyopus) have the first dorsal composed of a band of fringes preceded by a single ray. The species are small and slender, abounding chiefly in the Mediterranean and the North Atlantic. The young have been called "mackerel-midges." Our commonest species is Enchelyopus cimbrius, found also in Great Britain.

The cusk, or torsk, Brosme brosme, has a single dorsal fin only. It is a large fish found on both shores of the North Atlantic, but rather rare on our coasts.

Fossil codfishes are not numerous. Fragments thought to belong to this family are found in English Eocene rocks.

Nemopteryx troscheli, from the Oligocene of Glarus, has three dorsal fins and a lunate caudal fin. Other forms have been referred with more or less doubt to Gadus, Brosmius, Strinsia, and Melanogrammus.

Gill separates the "three-forked hake" (Raniceps trifurcus) of northern Europe as a distinct family, Ranicipitidæ. In this species the head is very large, broad and depressed, differing in this regard from the codlings and hakes, which have also two dorsal fins. The deep-water genus, Bathyonus, is also regarded as a distinct family, Bathyonidæ.

The Hakes: Merluciidæ.—Better defined than these families is the family of hakes, Merluciidæ. These pike-like codfishes have the skull peculiarly formed, the frontal bones being paired, excavated above, with diverging crests continuous forward from the forked occipital crest. The species are large fishes, very voracious, without barbels, with the skeleton papery and the flesh generally soft. The various species are all very much alike, large, ill-favored fishes with strong teeth and a ragged appearance, the flesh of fair quality. Merluccius merluccius, the hake or stock-fish, is common in Europe; Merluccius bilinearis, the silver hake, is common in New England, Merluccius productus in California, and Merluccius gayi in Chile.

Fig. 492.—California Hake, Merluccius productus (Ayres). Seattle.

Fig. 493.—Coryphænoides carapinus (Goode & Bean), showing leptoceral tail. Gulf Stream.

The Grenadiers: Macrouridæ.—The large family of grenadiers, or rat-tails, Macrouridæ, is confined entirely to the oceanic depths, especially of the north Atlantic and Pacific. The head is formed much as in the codfishes, with usually a barbel at the chin. There are two dorsals, the second like the anal being low, but the leptocercal tail is very long and tapering, ending in a filament without caudal fin. The scales are usually rough and spinous. The species are usually large in size, and dull gray or black in color.

Fig. 494.—Grenadier, Cœlorhynchus carminatus Goode & Bean. Martha's Vineyard.

The best-known genus is Macrourus. Macrourus berglax is found on both shores of the north Atlantic. Macrourus bairdi is abundant in off-shore dredgings from Cape Cod to Cuba. Macrourus cinereus, the pop-eye grenadier, outnumbers all other fishes in the depths of Bering Sea. Cœlorhynchus japonicus is often taken by fishermen in Japan. Coryphænoides rupestris is common in the north Atlantic. Bogoslovius clarki and Albatrossia pectoralis were dredged by the Albatross about the volcanic island of Bogoslof. Trachyrhynchus trachyrhynchus is characteristic of the Mediterranean. Nematonurus goodei is common in the Gulf Stream, and Dolloa longifilis is found off Japan. Other prominent genera are Bathygadus, Gadomus, Regania, and Steindachnerella.

Fig. 495.—Steindachnerella argentea (Goode & Bean). Gulf Stream.

The Murænolepidæ are deep-sea fishes, with minute eel-like scales, and no caudal fin. The ventrals are five-rayed and there are 10 pterygials.

CHAPTER XXXI
ORDER PEDICULATI: THE ANGLERS

The Angler-fishes.—The few remaining fishes possess also jugular ventral fins, but in other regards they show so many peculiarities of structure that we may well consider them as forming a distinct order, Pediculati (pedicula, a foot-stalk), although the relation of these forms to the Batrachoididæ seems a very close one.

The most salient character of the group is the reduction and backward insertion of the gill-opening, which is behind the pectoral fins, not in front of them as in all other fishes. The hypocoracoid and hypercoracoid are much elongate and greatly changed in form, so that the pectoral fin is borne on the end of a sort of arm. The large ventrals are similarly more or less exserted. The spinous dorsal is much reduced, the first spine being modified to form a so-called fishing-rod, projecting over the mouth with a fleshy pad, lure, or bait at its tip. The form of the body varies much in the different families. The scales are lost or changed to prickles and the whole aspect is very singular, and in many cases distinctly frog-like. The species are mostly tropical, some living in tide-pools and about coral reefs, some on sandy shores, others in the oceanic abysses.

The nearest allies of the Pediculates among normal fishes are probably the Batrachoididæ. One species of Lophiidæ is recorded among the fossils, Lophius brachysomus, from the Eocene of Monte Bolca. No fossil Antennariidæ are known. Fossil teeth from the Cretaceous of Patagonia are doubtfully named "Lophius patagonicus."

The Fishing-frogs: Lophiidæ.—In the most generalized family, that of the fishing-frogs (Lophiidæ), the body is very much depressed, the head the largest part of it. The mouth is excessively wide, with strong jaw-muscles, and strong sharp teeth. The skin is smooth, with dermal flaps about the head. Over the mouth, like a fishing-rod, hangs the first dorsal spine with a lure at the tip. The fishes lie flat on the bottom with sluggish movements except for the convulsive snap of the jaws. It has been denied that the bait serves to attract small fishes to their destruction, but the current belief that it does so is certainly plausible. As to this Dr. Gill observes:

"The name 'angler' is derived from the supposition that by means of the foremost dorsal spine, which bears leaf-like tags, or appendages, at the end, it angles for fishes itself, lying upon the ground with its head somewhat upraised. According to Mr. S. Kent, however, this is at most only partly the case: 'That the fish deliberately uses this structure as a fisherman does his rod and line for the alluring and capture of other fish is a matter of tradition handed down to us from the time of Pliny and Aristotle, and which scarcely any authority since their time has ventured to gainsay. Nevertheless, like many of the delightful natural-history romances bequeathed to us by the ancient philosophers, this one of the angler-fish will have to be relegated to the limbo of disproved fiction. The plain and certain ground of facts, all the same, has frequently more startling revelations in store for us than the most fervid imaginations of philosophers, and that this assertion holds good in the case now under consideration must undoubtedly be admitted. It is here proposed to show, in fact, that the angler is one of the most interesting examples upon which Nature has exercised her handicraft, in the direction of concealing the identity of her protégé, such ingenuity being sometimes utilized with the object of protecting the organism from the attacks of other animals, or, as illustrated in the present instance, for the purpose of enabling it by stealth to obtain prey which it lacks the agility to hunt down after the manner of ordinary carnivorous fishes. To recognize the several details here described, it will not suffice to refer to examples simply, and usually most atrociously stuffed, nor even to those preserved in spirit, in which all the life colors are more or less completely obliterated and the various membranous appendages shrunk up and distorted. In place of this, a healthy, living example fresh from the sea, or, better still, acclimatized in the tanks of an aquarium, must be attentively examined, and whereupon it will be found that this singular fish, throughout the whole extent of its superficies, may be appropriately designated a living sham."

It was, in the first place, observed by Mr. Kent "that the fish while quietly reclining upon the bottom of its tank presented a most astonishing resemblance to a piece of inert rock, the rugose prominences in the neighborhood of the head lending additional strength to this likeness. This resemblance being recognized, it was next found, on a little closer inspection, that the fish constituted, in connection with its color, ornamentations, and manifold organs and appendages, the most perfect facsimile of a submerged rock, with that natural clothing of sedentary animal and vegetable growths common to boulders lying beneath the water in what is known as the laminarian zone. In this manner the numerous simple or lobulated membranous structures dependent from the lower jaw and developed as a fringe along the lateral line of the body imitate with great fidelity the little flat calcareous sponges (Grantia), small compound ascidians, and other low organized zoophytic growths that hang in profusion from favorably situated submarine stones. That famous structure known as the angler's 'rod and bait' finds its precise counterpart in the early growing phase of certain sea-plants, such as the oarweed (Laminaria), while the more posterior dorsal fin-rays, having short lateral branchlets, counterfeit in a like manner the plant-like hydroid zoophytes known as Sertulariæ. One of the most extraordinary mimetic adaptations was, however, found in connection with the eyes, structures which, however perfectly the surrounding details may be concealed, serve, as a rule, to betray the animal's presence to a close observer. In the case of the angler, the eyes during life are raised on conical elevations the sides of which are separated by darker longitudinal stripes into symmetrical regions, the structure, as a whole, with its truncated summit upon which the pupil opens, reproducing with the most wonderful minuteness the multivalve shell of a rook barnacle (Balanus). To complete the simile the entire exposed surface of the body of the fish is mapped out by darker punctated lines into irregular polygonal areas, whose pattern is at once recognized by the student of marine zoology as corresponding with that of the flat, cushion-like expansions of the compound tunicate Botryllus violaceus. Thus disguised at every point, the angler has merely to lie prone, as is its wont, among the stones and débris at the bottom of the sea and to wait for the advent of its unsuspecting prey, which, approaching to browse from what it takes to be a flat rock—differing in no respect from that off which it obtained the last appetizing morsel of weed or worm—finds itself suddenly engulfed beyond recall within the merciless jaws of this marine impostor."

Fig. 496.—Anko or Fishing-frog, Lophius litulon (Jordan). Matsushima Bay, Japan.

The great fishing-frog of the North Atlantic, Lophius piscatorius, is also known as angler, monkfish, goosefish, allmouth, wide-gape, kettleman, and bellows-fish. It is common in shallow water both in America and Europe, ranging southward to Cape Hatteras and to the Mediterranean. It reaches a length of three feet or more. A fisherman told Mr. Goode that "he once saw a struggle in the water, and found that a goosefish had swallowed the head and neck of a large loon, which had pulled it to the surface and was trying to escape. There is authentic record of seven wild ducks having been taken from the stomach of one of them. Slyly approaching from below, they seize birds as they float upon the surface."

"The angler, or goosefish, spawns in summer along the eastern Atlantic coast, and the result of its labor is quite remarkable. 'The eggs are very numerous, inclosed in a ribbon-shaped gelatinous mass, about a foot in width and thirty or forty feet long, which floats near the surface. One of these ribbons will weigh perhaps forty pounds, and is usually partially folded together and visible a foot or eighteen inches from the top of the water, its color being brownish purple. The number of eggs in one of these has been estimated to be from forty to fifty thousand.' The growth of the young after exclusion from the egg is rather rapid, and Professor Goode saw 'young fish two or three inches long' while others were yet spawning, and these young fish were presumably the fry of those that had spawned the same year, only somewhat earlier. In a few days after hatching they present a striking appearance on account of the enormous development of the pectoral and ventral fins."

Aristotle gives, according to Professor Horace A. Hoffman, this account of the angler: "'Inasmuch as the flat, front part is not fleshy, nature has compensated for this by adding to the rear and the tail as much fleshy substance as has been subtracted from the front.' The βάτραχος is called the angler. He fishes with the hair-like filaments hung before his eyes. On the end of each filament is a little knob, just as if it had been placed there for a bait. He makes a disturbance in sandy or muddy places, hides himself and raises these filaments. When the little fish strikes at them he leads them down with the filaments until he brings them to his mouth. The βάτραχος is one of the σελάχη. All the σελάχη are viviparous or ovoviviparous except the βάτραχος. The other flat σελάχη have their gills uncovered and underneath them, but the βάτραχος has its gills on the side and covered with skinny opercula, not with horny opercula like the fish which are not σελαχώδη. Some fishes have the gall-bladder upon the liver, others have it upon the intestine, more or less remote from the liver and attached to it by a duct. Such are βάτραχος, ἔλλοψ, συνάγρίς, σμύραινα, and ξιφίας. The βάτραχος is the only one of the σελάχη which is oviparous. This is on account of the nature of its body, for it has a head many times as large as the rest of its body, and spiny and very rough. For this same reason it does not afterwards admit its young into itself. The size and roughness of the head prevent them both from coming out (i.e., being born alive) and from going in (being taken into the mouth of the parent). The βάτραχος is the most prolific of the σελάχη, but it is scarce because the eggs are easily destroyed, for it lays them in a bunch near the shore."

The genus Lophius of northern range has a vertebral column of about thirty vertebræ. Lophius litulon occurs in Japan. In the North Pacific is found Lophiomus, similar in appearance but smaller in size, ranging southward to the equator, a southern fish having but eighteen vertebræ. Lophiomus setigerus is the common anko of Japan, and other species are recorded from Hawaii, and the Galapagos.

The Sea-devils: Ceratiidæ.—The sea-devils, or Ceratiidæ, are degenerate anglers of various forms, found in the depths of the arctic seas. The body is compressed, the mouth vertical; the substance is very soft, and the color uniform black. Dr. Günther thus speaks of them:

Fig. 497.—Cryptopsaras couesi Gill. Gulf Stream.

Fig. 498.—Deep-sea Angler, Ceratias holbolli Kröyer. Greenland.

Fig. 499.—Caulophryne jordani Goode & Bean. Gulf Stream. Family Ceratiidæ.

"The bathybial sea-devils are degraded forms of Lophius; they descend to the greatest depths of the ocean. Their bones are of an extremely light and thin texture, and frequently other parts of their organization, their integuments, muscles, and intestines are equally loose in texture when the specimens are brought to the surface. In their habits they probably do not differ in any degree from their surface representative, Lophius. The number of the dorsal spines is always reduced, and at the end of the series of these species only one spine remains, with a simple, very small lamella at the extremity (Melanocetus johnsonii, Melanocetus murrayi). In other forms sometimes a second cephalic spine, sometimes a spine on the back of the trunk, is preserved. The first cephalic spine always retains the original function of a lure for other marine creatures, but to render it more effective a special luminous organ is sometimes developed in connection with the filaments with which its extremity is provided (Ceratias bispinosus, Oneirodes eschrichtii). So far as known at present these complicated tentacles attain to the highest degree of development in Himantolophus and Ægæonichthys. In other species very peculiar dermal appendages are developed, either accompanying the spine on the back or replacing it. They may be paired or form a group of three, are pear-shaped, covered with common skin, and perforated at the top, a delicate tentacle sometimes issuing from the foramen."

Of the fifteen or twenty species of Ceratiidæ described, none are common and all are rare catches of the deep-sea dredge. Caulophryne jordani is remarkable for its large fins and the luminous filaments, Linophryne lucifer for its large head, and Corynolophus reinhardti (Fig. 143, Vol. I) for its luminous fishing-bulb.

Fig. 500.—Sargassum-fish, Pterophryne tumida (Osbeck). Florida. Family Antennariidæ.

The Frogfishes: Antennariidæ.—The frogfishes, Antennariidæ, belong to the tropical seas and rarely descend far below the surface. Most of them abound about sand-banks or coral reefs, especially along the shores of the East and West Indies, where they creep along the rocks like toads. Some are pelagic, drifting about in floating masses of seaweed. All are fantastic in form and color, usually closely imitating the objects about them. The body is compressed, the mouth nearly vertical, and the skin either prickly or provided with fleshy slips.

The species of Pterophryne live in the open sea, drifting with the currents in masses of sargassum. Two species, Pterophryne tumida and Pterophryne gibba, are found in the West Indies and Gulf Stream. Two others very similar, Pterophryne histrio and Pterophryne ranina, live in the East Indies and drift in the Kuro Shiwo of Japan. All these are light olive-brown with fantastic black markings.

Fig. 501.—Fishing-frog, Antennarius nox Jordan. Wakanoura, Japan.

The genus Antennarius contains species of the shoals and reefs, with markings which correspond to the colors of the rocks. These fishes are firm in texture with a velvety skin, and the prevailing color is brown and red. There are many species wherever reefs are found. Antennarius ocellatus, the pescador, is the commonest West Indian species. Antennarius multiocellatus, with many ocellated spots, is the Martin Pescador of Cuba, also common.

On the Pacific coast of Mexico the commonest species is Antennarius strigatus. In Japan, Antennarius tridens abounds everywhere on the muddy bottoms of the bays. Antennarius nox is a jet-black species of the Japanese reefs, and Antennarius sanguifluus is spotted with blood-red in imitation of coralline patches. Many other species abound in the East Indies and in Polynesia. The genus Chaunax is represented by several deep-water species of the West Indies, Japan, etc.

Fig. 502.—Shoulder-girdle of a Batfish, Ogcocephalus radiatus (Mitchill).

The Gigactinidæ of the deep seas differ from the Ogcocephalidæ, according to Boulenger, in the absence of ventrals.

Fig. 503.—Frogfish, Antennarus scaber (Cuvier). Puerto Rico.

The Batfishes: Ogcocephalidæ.—The batfishes, Ogcocephalidæ, are anglers with the body depressed and covered with hard bony warts. The mouth is small and the bony bases of the pectoral and ventral fins are longer than in any other of the anglers. The species live in the warm seas, some in very shallow water, others descending to great depths, the deep-sea forms being small and more or less degenerate. These walk along like toads on the sea-bottoms; the ventrals, being jugular, act as fore legs and the pectorals extend behind them as hind legs.

Fig. 504.—Ogcocephalus vespertilio (L.). Florida.

The common sea-bat, or diablo, of the West Indies, Ogcocephalus vespertilio, is dusky in color with the belly coppery red. It reaches the length of a foot. The angling spine is very short, hidden under the long stiff process of the snout. Farther north occurs the short-nosed batfish, Ogcocephalus radiatus, very similar, but with the nostril process, or snout, blunt and short. Zalieutes elater, with a large black eye-like spot on each side of the back, is found on the west coast of Mexico. In deeper water are species of Halieutichthys in the West Indies and of Halieutæa in Japan. Dibranchus atlanticus has the gills reduced to two pairs. Malthopsis consists of small species, with the rostrum prominent, like a bishop's miter. Two species are found in the Pacific, Malthopsis mitrata in Hawaii and Malthopsis tiarella in Japan.

And with these dainty freaks of the sea, the results of centuries on centuries of specialization, degeneration, and adaptation, we close the long roll-call of the fishes, living and dead. And in their long genealogy is enfolded the genealogy of men and beasts and birds and reptiles and of all other back-boned animals of whom the fish-like forms are at once the ancestors, the cousins, and the younger brothers. When the fishes of the Devonian age came out upon the land, the potentiality of the higher methods of life first became manifest. With the new conditions, more varied and more exacting, higher and more varied specialization was demanded, and, in response to these new conditions, from a fish-like stock have arisen all the birds and beasts and men that have dwelt upon the earth.

Fig. 505.—Batfish, Ogcocephalus vespertilio (L.). Florida.

Fig. 506.—Batfish, Ogcocephalus vespertilio (Linnæus). Carolina Coast.

THE END.

INDEX

aal-mutter, ii, 144

Abbott, i, 415, 419, 422; ii, 307, 534

- on perch, ii, 307

abdominal fishes, ii, 39
Abdominales, i, 393; ii, 38, 39
Abeona, ii, 375

Abramis, ii, 167

- figure of, ii, 168

Aboma,

- figure of, ii, 462

abundance of food-fish, i, 329
abura-ainame, ii, 440
abura-bodzu, ii, 323
aburazame, i, 524
Acantharchus, ii, 297
Acanthistius, ii, 323
Acanthobatis, i, 553
Acanthocephala, i, 344, 351
Acanthocepola, ii, 363
Acanthoclinidæ, ii, 516
Acanthoclinus, ii, 516
Acanthocybium, ii, 266

Acanthodei, i, 65, 437, 447, 513, 519, 545, 561

- Dean on, i, 517
- families of, i, 516
- order of, i, 514
- Woodward on, i, 514

Acanthoëssidæ, i, 515, 516

Acanthoëssus, i, 446, 510-513

- figure of, i, 515

- scales of, figured, i, 521

Acantholabrus, ii, 387
Acanthonemus, ii, 286
Acanthopteri, ii, 157
Acanthopterygian, ii, 39, 293
Acanthopterygii, i, 391; ii, 189, 208-214
Acanthostracion, i, 377

Acanthuridæ, i, 206; ii, 405, 407, 410, 411

- family of, ii, 407

Acanthurus, i, 268, 271; ii, 407, 409
Acanus, ii, 330
Acara, ii, 381
Acentronura, ii, 236
Acerina, ii, 241, 309
Acentrophorus, ii, 23
Achirinæ, ii, 495

Achirus,

- figure of, ii, 496

Acipenser, i, 291, 332, 391, 452; ii, 18, 19, 20, 22

- figure of, ii, 19, 20

- larva of, figured, i, 141

Acipenseridæ, i, 290; ii, 18
Acipenseroidei, i, 382
Acraniata, i, 484
Acrocheilus, ii, 169
Acrogaster, ii, 252
Acrognathus, ii, 34
Acropoma, ii, 317
Acropomidæ, ii, 317
Acrotidæ, ii, 285
Acrotus, ii, 285

Actinistia, i, 602

- order of, i, 604

Actinopteri, i, 451, 507, 599, 610; ii, 1, 2, 4, 5, 208

Actinopterygii, i, 462; ii, 1
Actinosts, ii, 1, 33
actinotrichia, i, 80
Adaptation of fishes, i, 177-225
adaptive radiation,

- law of, i, 296

adder-fish, ii, 501
Adelfisch, ii, 65
Adelochorda, i, 461
Adinia, ii, 199
adipose fin, i, 25
Ægæonichthys, ii, 549

Æoliscus,

- figure of, ii, 235

Ærolepis, ii, 14
Æthalion, ii, 41
Ætheospondyli, ii, 24, 29

Æthoprora,

- figure of, i, 188

Aëtobatis, i, 557

- figure of, i, 558

African catfish,

- figure of, i, 457; ii, 185

Agassiz, A., i, 405

Agassiz, L., i, 419, 428, 614; ii, 1, 39, 183, 486

- on dispersion, i, 284
- on Embiotocidæ, ii, 378, 379
- on embryology of garpike, ii, 31
- on fish fauna of N. E., i, 302
- on fossil fishes, i, 404
- on ganoids, ii, 9
- on high and low forms, i, 381
- on Lepidosteus, ii, 5
- on Onchus, i, 530
- portrait of, i, 399
- pupils of, i, 405
- questions raised by, i, 284
- sketch of, i, 404

Age of fishes, i, 144-146
agency of ocean currents, i, 243
Agnatha, i, 508

Agonidæ, i, 208; ii, 3, 185, 452, 453, 456

- family of, ii, 449

Agonoid fish,

- figure of, i, 221; ii, 453

Agonostomus, ii, 107, 222
Agonus, i, 219; ii, 453
Agrammus, ii, 440
Ahl, i, 394
aholehole, ii, 304
air-bladder, i, 11

- air-duct, i, 12
- Aristotle on, 95
- Borelli on, i, 95
- of Carp, i, 93; ii, 159, 160
- in Cœlacanthus, i, 604
- defined, i, 92, 93
- De Fosse on, i, 97
- Delaroche on, i, 95
- figure of, i, 93, 604
- function of, i, 94
- in ganoids, i, 101
- gases in, i, 94
- in Labyrinthici, i, 91
- an organ of hearing, ii, 159
- origin of, i, 98
- position of, i, 35
- Sörensen on, i, 97
- Tower on, i, 95
- use of, i, 12
- wanting in sharks, i, 506
- Weber on, i, 96

akadai, ii, 344

Alaska blackfish, i, 51, 147, 290

- figure of, i, 149; ii, 206

Alaska cod, ii, 536

Alaska grayling,

- figure of, i, 328; ii, 120

Alaskan rivers,

- fishes of, i, 304, 305

Albacore, i, 210; ii, 136

- figure of, ii, 263
- Goode on, ii, 263
- long fin, ii, 263

Albatross, the i, 263, 408; ii, 60, 130, 138

Albatrossia, ii, 541

Albula, i, 142, 205; ii, 29, 46, 148

- figure of, i, 147; ii, 44

Albulidæ, ii, 41, 44
Alburnus, ii, 167
Alcock, i, 244, 408; ii, 290

Aldrich,

- photograph by, i, 303

Aldrovandi, i, 388

Aldrovandia,

- figure of, ii, 138

Alectis, i, 202; ii, 276
aleihi, ii, 253
Alepisauridæ, i, 134
Alepocephalidæ, ii, 60

Alepocephalus,

- figure of, ii, 60

alewife, ii, 49

- figure of, ii, 50

alfonsinos, ii, 251
alimentary canal, i, 31
alkaloid poisons, i, 182, 184, 185; ii, 411, 412
allantiasis, i, 183
alligator-fish, ii, 449, 453
alligator-gar,

- figure of, ii, 31

allmouth, ii, 545

Alopiidæ,

- family of, i, 536

Alosa, i, 204, 291; ii, 50

Alticus,

- figure of, i, 230; ii, 509

Alutera, i, 206; ii, 414, 415
amadai, ii, 363

Amanses, ii, 415

- figure of, ii, 414

Amaræcium, i, 477
Ambassis, ii, 317
Ambassidæ, ii, 317
amber-fish, ii, 272

- figure of, i, 458; ii, 273

amber-jack, ii, 274

Amblodon, i, 302

Ambloplites,

- figure of, ii, 299

- skull of, figured, ii, 296

Amblyopsidæ, 290; ii, 204

- family of, ii, 200

Amblyopsis, i, 220, 314

- figure of, i, 221, 222; ii, 203

Amblypterus, ii, 14

Amblystoma, i, 78

Ameiurus, i, 283, 293, 310, 356; ii, 35, 183, 185, 186, 299

- figure of, i, 344, 358; ii, 180, 181

- parasites of, i, 344

American charr, ii, 110

American fishes,

- Goode on, i, 335

Amia, i, 33, 101, 102, 204, 291, 344, 391, 612, 623; ii, 8, 9, 11, 31, 33, 36, 41, 160

- figure of, ii, 33, 35
- lower jaw of, ii, 33
- shoulder-girdle in, i, 86
- tail of, i, 82

Amiatus, i, 394

Amiidæ, i, 290; ii, 4, 34, 35, 36

Amioidei,

- Lütken on, ii, 33

Amiopsis, ii, 36
Amitra, ii, 454
Ammocœtes, i, 142

Ammocrypta, ii, 306

- figure of, i, 158; ii, 313

Ammodytes, ii, 224, 391, 514, 522

- figure of, ii, 521

Ammodytidæ, ii, 215, 520, 521

Amphacanthi,

- suborder of, ii, 409

Ampheristus, ii, 436

Amphibia, i, 393, 600, 606

Amphibians, ii, 9

- origin of, i, 600

Amphicœlian, i, 49
Amphiodon, i, 394
Amphioxides, i, 483
Amphioxus, i, 482, 495
Amphiplaga, ii, 243
Amphipnoidæ, 11, 141
Amphipnous, ii, 141
Amphiprion, ii, 384
Amphisile, ii, 235
Amphisticus, ii, 375

Amphistiidæ,

- family of, ii, 245, 247

Amphistium, ii, 485

- figure of, ii, 247

Amyzon, ii, 175

Anabantidæ, ii, 215, 370

- Gill on, i, 366

Anabas, i, 91, 103, 163

- figure of, ii, 366

Anableps, i, 117, 391; ii, 131

- eye of, ii, 194
- figure of, i, 117
- Marsh on, ii, 194
- Nelson on, ii, 196

Anacanthini, i, 405; ii, 484, 485, 499, 501, 532, 533, 538

- order of, ii, 532, 533

anadromous fishes, i, 291
anadromous salmon, ii, 68
anal fin, i, 10

- in Embiotocidæ, i, 125
- as intromittent organ, i, 124
- in Pœciliidæ, i, 125
- in sword-tail minnow, i, 124

analogy and homology, i, 368, 369

- Coues on, i, 369

Anampses, ii, 390

Anarhichadidæ, ii, 517

Anarhichas, i, 208, 391; ii, 518

- figure of, ii, 517

- food of, ii, 518

Anarchias, ii, 153

Anarrhichthys, i, 208, 364; ii, 518

- skull of, ii, 517

Anarthri, i, 509

Anarthrodira, i, 584, 585, 590

Anaspida, i, 573, 622

- order of, i, 579

anatomy of tunicates,

- figure showing, i, 472

Anchovia, i, 199, 205

- figure of, ii, 54

anchovy,

- figure of, ii, 54

anchovy, silvery,

- figure of, ii, 54

ancient outlet of Lake Bonneville,

- photograph of, i, 303

Ancylostylos, ii, 45

Andaman Islands,

- fishes of, i, 166

Andrews, i, 428

Anema, ii, 504
angel-fishes, i, 547, 549

- figure of, ii, 401, 404

angler-fishes, i, 189, 206; ii, 542-553

- carpels of, i, 51
- figure of, i, 52
- Gill on, ii, 543
- habits of, ii, 543-545
- Kent on, ii, 543

anglers,

- dorsal fin in, i, 202

angling, i, 336

- Young on, i, 337-339

Anguilla, i, 127, 162, 211; ii, 143

- figure of, ii, 142, 148

Anguillidæ, i, 290; ii, 148

- family of, ii, 142

angular, i, 606

Anisotremus, i, 271; ii, 341

Anomalopidæ,

- family of, ii, 317

anko,

- figure of, ii, 545

Anomalops, ii, 317

Anoplogaster, ii, 252

Anoplopoma,

- figure of, ii, 438

Anoplopomidæ,

- family of, ii, 438

Anoplus, i, 260; ii, 333

Antechinomys, ii, 471

Antennariidæ, i, 52; ii, 542, 549, 553

- Aristotle on, ii, 546
- deep-sea, ii, 548
- Goode on, ii, 545
- habits of, ii, 544-546
- Hoffmann on, ii, 546
- spawning of, ii, 546

Antennarius, i, 197, 206

- figure of, ii, 550, 553

Anthias, ii, 328

Antiarcha, i, 573, 581, 590, 622

- order of, i, 576

Antigonia, i, 262
Anyperodon, ii, 328
ao, ii, 274

Apeltes,

- figure of, ii, 232

Aphanopus, i, 210

Aphareus,

- figure of, ii, 339

Aphredoderidæ, i, 290; ii, 243, 294

Aphredoderus, ii, 204, 252, 291, 294, 296

- figure of, ii, 295

Apia,

- coral reef of, figured, i, 234

Apichthys, ii, 278

Aplidiopsis,

- figure of, i, 479

Aploactis, i, 202
Aplodactylidæ, ii, 363
Aplodactylus, ii, 364
Aplodinotus, i, 291, 302; ii, 354, 357
Apocopodon, i, 558

Apodes, i, 393, 611; ii, 40, 139-158, 532

- order of, ii, 141

Apodichthys, i, 227; ii, 512

Apogon,

- figure of, i, 455; ii, 316, 319

Apogonidæ,

- family of, ii, 316

Apomotis, i, 26, 310; ii, 301

- figure of, i, 27; ii, 350

Apostasis, ii, 406

Apostolides, i, 412

Appendicularia, i, 466

- Brooks on, i, 480

Appendiculariidæ, i, 474
Aprion, i, 325; ii, 338
Apsilus, ii, 338
aquatic worms, ii, 143
Aracana, ii, 417
Arapaima, ii, 11, 56

Arbaciosa,

- species of, ii, 531

Archæomænidæ, ii, 29

Archæus, ii, 278

Archencheli,

- suborder of, ii, 141, 142

archers, ii, 400
archicercal tail, i, 81, 83
archipterygium, i, 59-61, 68, 69, 73, 446, 459, 511, 512, 522, 598, 600, 601

- Boulenger on, i, 79
- Gegenbaur on, i, 60
- Günther on, i, 60

archnoid membrane, i, 109

Archoplites, i, 179, 240; ii, 297

- figure of, i, 258

Archosargus, i, 324; ii, 346

- figure of, i, 31; ii, 347

Archoteuthis, ii, 410

Arctic codling, ii, 537

Arctic species,

- in lakes, i, 316
- Loven on, i, 317
- Malmgren on, i, 317
- Smith on, i, 317

Arctoscopus, ii, 364
Argentina, i, 391
Argentinidæ, ii, 122, 124
Argidæ, ii, 185

Argyropelecus,

- figure of, i, 190; ii, 137

Argyrosomus, i, 315; ii, 62, 65, 67

- figure of, ii, 66

Ariscopus, i, 257

- figure of, ii, 504

Aristotle, ii, 146

- on fishes of Greece, i, 387

- on noises of fish, i, 95

Arius, ii, 178, 186
arm of frog, i, 601

- figure of, i, 71

ama-ama, ii, 221
armado, i, 169
arnillo, ii, 338
Arnoglossus, ii, 488
arrow-toothed halibut, ii, 491

Artedi, i, 374, 390

- on genera, i, 391

Artediellus, ii, 442

Artedius, ii, 442

Arthrodira, i, 573, 584, 585, 590, 612

- Dean on, i, 581

- Jækel on, i, 591

Arthrodires, i, 204, 241, 436, 437, 603, 622; ii, 3

- classification of, i, 584
- figure of, i, 445, 584
- occurrence of, i, 583
- relationships of, i, 588

Arthropteridæ, i, 553

Arthropterus, i, 553

Arthrognathi, i, 581, 584, 585, 589, 590

- Dean on, i, 584

Arthrothoraci, i, 584, 586, 587
articular, i, 606
artificial impregnation,

- Jacobian method, i, 150

Ascanius, i, 396; ii, 472

Ascelichthys, ii, 449

Ascidia,

- figure of, i, 474

Ascidiacea, i, 474
ascidians, i, 460, 467

- Kingsley on, i, 474

- Ritter on, i, 474

Ascidiiæ, i, 474, 475

Ascidina,

- figure of, i, 475

Aseraggodes, ii, 496

Ashmead,

- on leprosy transmission, i, 186

Asineopidæ, ii, 243, 296, 317
Asineops, ii, 243, 317
Asmuss, i, 427

Aspasma, ii, 531

- figure of, ii, 530

Aspidocephali, i, 568, 575

Aspidoganoidei, i, 568

Aspidophoroides,

- figure of, ii, 453

Aspidorhini, i, 568
Aspidorhynchidæ, ii, 24, 29
Aspidorhynchus, ii, 29
Aspius, ii, 175
Aspredo, ii, 184

Aspro, ii, 307, 310

- figure of, ii, 309

aspron, ii, 309

- figure of, ii, 310

Asterolepidæ, i, 576, 623

Asterolepis, i, 577, 591

Asterospondyli, i, 447, 510, 513, 532

- order of, i, 525

asterospondylous, i, 49
Asterosteidæ, i, 584, 585
Asterosteus, i, 585
Asterropteryx, i, 263
Astrodermiidæ, i, 551
Astrodermus, i, 551
Astrolabe, the, i, 408

Astrolytes,

- figure of, ii, 442

Astronesthidæ, ii, 128

Astrape, i, 554

Astroscopus, ii, 503

- Gilbert on, i, 187

- electric organs of, i, 187

Asymmetron, i, 483; ii, 467
Ateleaspis, i, 574
Atheresthes, i, 205; ii, 491
Atherina, i, 393; ii, 216
Atherinidæ, i, 290; ii, 215
Atherinops, ii, 218

Atherinopsis,

- figure of, ii, 218

Atherinosoma, ii, 218

Athlennes, ii, 211

Atka fish,

- figure of, i, 328; ii, 439

Atka mackerel, ii, 439
Atlantic creek, i, 308, 309
Atlantic oarfish, ii, 472
Atlantic salmon, ii, 89
attenuate, i, 19
Atthey, i, 426
Auchenopterus, ii, 508
atule, ii, 275
auditory ossicles, ii, 160
Aulichthys, ii, 233
Aulolepis, ii, 48
Aulopidæ, ii, 130, 132
Aulopus, i, 259; ii, 190
Aulorhamphus, ii, 406

Aulorhynchidæ,

- family of, ii, 232

Aulorhynchus, ii, 233

Aulostomidæ,

- family of, ii, 233

Aulostomus, ii, 233

- figure of, ii, 234

Australia, ii, 363

Australian flying-fish,

- figure of, i, 341

Australian lung-fish, i, 100
autochthonous, i, 245
autostylic skull, i, 561; ii, 8
Auxis, ii, 262
awa, ii, 45, 221
awaawa, ii, 43
awaous, i, 254; ii, 465
aweoweo, ii, 333
Axinurus, ii, 409
axonasts, i, 604, 605; ii, 17
Ayres, i, 419, 428
ayu, i, 256; ii, 115, 117, 118

- figure of, i, 321; ii, 116

- fishing for figured, i, 333, 335

Azevia, i, 271; ii, 489
d'Azyr, i, 390
Azygostei, i, 581
azygous, i, 88
Baer, i, 428
Bagarius, ii, 186
bagonado, ii, 344
bagre, ii, 182
bagre de Rio, ii, 182
Bagrus, ii, 183
Baikal cods, ii, 455

Baird, i, 419; ii, 142

- on bluefish, ii, 279-282
- on eel migrations, ii, 142
- portrait of, i, 407

Bairdiella, ii, 355

- figure of, ii, 355

Bakker, i, 428
Balanoglossidæ, i, 465
Balanglossus, i, 461
Balanus, ii, 544
balaos, ii, 212

Balfour, i, 428, 511, 513; ii, 8

- finfold theory, i, 69, 514
- lateral-fold theory, i, 71-73
- on paired fins, ii, 8
- on sharks, i, 511

Balfour and Parker,

- on Lepidosteus, ii, 5

Balistapus, i, 181; ii, 413

Balistes, i, 206, 391, 611; ii, 22

- figure of, i, 184; ii, 412

Balistidæ, ii, 413, 418

- family of, ii, 412

Ballou,

- on eels, ii, 417

banded rockfish,

- figure of, ii, 432

banded sunfish,

- figure of, ii, 299

bandfishes, ii, 363
bandfishes,

- the crested, ii, 291

Banks, i, 395
barbels, i, 115; ii, 170

- organs of touch, i, 122

barber-fish, ii, 328
barbero, ii, 408
barbudos, ii, 256
Barbulifer, ii, 462
Barbus, ii, 170, 175
Barkas, i, 426
Barneville, i, 412
Barracuda, ii, 34, 39, 215, 266, 317, 469

Barracuda,

- family of, ii, 222

- figure of, ii, 223

Barramunda, i, 116, 614, 615

- Günther on, i, 615

barreto, ii, 467
barriers,

- Alleghanies, i, 311
- artificial dams, i, 300
- Cape of Good Hope, i, 268
- checks to movement, i, 240
- crossing by fishes, i, 302
- to dispersion, i, 297
- Isthmus of Panama, i, 269
- local, i, 298
- mountain chains, i, 310
- Rocky Mountains, i, 305
- the Sierras, i, 310
- silt-bearing streams, i, 301
- species absent from, i, 239
- temperature, i, 298
- waterfalls, i, 300
- watersheds, i, 205

basal bone,

- of dorsal fin, i, 49
- figure of, i, 49, 56
- of pectoral fin, i, 59

baseosts, ii, 17
basilar, i, 88
Basilevsky, i, 411
basking shark, i, 539

- figure of, i, 540

- largest of fishes, i, 539

bass, i, 4, 21, 47, 290, 323, 440; ii, 316-350

- black, i, 303, 304
- white, i, 321
- yellow, i, 321

bassalian fishes, i, 245, 246; ii, 128

Bassani, i, 427

Bassozetus,

- figure of, i, 456

bastard halibut, ii, 489

Bateson, i, 463
batfish, ii, 402, 458

- figure of, ii, 553

- shoulder-girdle of, i, 88; ii, 551

Bathyclupeidæ, ii, 290
Bathygadus, ii, 541
Bathylagus, ii, 127

Bathymaster, ii, 502

- figure of, ii, 503

Bathymasteridæ, ii, 502
Bathyonidæ, ii, 540
Bathyonus, ii, 540
Bathypteroidæ, ii, 130
Bathypterois, ii, 131

Batoidei, i, 519

- suborder of, i, 549

Batrachians, i, 85, 87, 88

Batrachoides, i, 394; ii, 526

Batrachoides,

- shoulder-girdle of, i, 59

Batrachoididæ, i, 182, 192; ii, 525, 529, 542
Batrachoids, ii, 529
Batrictius, i, 394
Bdellostoma, i, 490
Beagle, the, i, 408
Bean, i, 408, 419
Beardslee, ii, 101
Beardslee trout, ii, 101
Belemnobatis, i, 551
Bellotti, i, 412
bellows fish, ii, 545

Belon,

- on fishes of Mediterranean, i, 388

Belone, ii, 210, 211

Belonidæ,

- family of, ii, 210

Belonorhynchidæ, ii, 514
Belonorhynchus, ii, 17
Belostomus, ii, 29
Bembradidæ, ii, 441, 499
Bembras, ii, 441

Benecke,

- on spawning of eels, ii, 146

Beneden, i, 427
benimasu, ii, 72
Bennett, i, 408, 416
Bentenia, ii, 286
Benthosauridæ, ii, 130
Benthosaurus, ii, 131

Berg, i, 415

- portrait of, i, 409

Berndt,

- opah taken by, ii, 244

- photograph by, i, 323

Berycidæ, i, 206; ii, 294, 499

- family of, ii, 251

Berycoidei, ii, 40, 245, 290, 484, 485

- suborder of, ii, 250-257

Berycoid fishes, ii, 250

- figure of, i, 439; ii, 253

- Starks on, ii, 250

Berycoids, ii, 247

Berycopsis, ii, 285

Beryx, i, 259, 263, 438; ii, 249, 289

- figure of, ii, 251

beshow, ii, 438
Betta, i, 163; ii, 370
biajaiba, ii, 336
Bianconi, i, 412
Bibron, i, 412
big-eye, ii, 333

- figure of, ii, 332

big-eyed scad, ii, 275

Birkenia, i, 580

- figure of, i, 579

Birkeniidæ, i, 579
bishop-fish, i, 361
bishop-fish,

- figure of, i, 361

Björnson,

- on fishing villages of Norway, i, 329

black angel, ii, 405
black angel-fish,

- figure of, ii, 403

black bass, i, 209; ii, 168, 301, 328

- Hallock on, ii, 302
- Henshall on, ii, 302
- large-mouthed, ii, 304
- small-mouthed, ii, 303

black bream, ii, 206
Black Current of Japan, sharks in, i, 536
black escolar, 338
black-fin snapper, ii, 336
blackfish, ii, 387
black grouper, ii, 323, 325
black-horse, ii, 173

Blackiston's line,

- relation to fishes, i, 257

black-jack, ii, 276
black nohu,

- figure of, i, 180; ii, 436

- stinging spines of, i, 180

black-nosed dace,

- figure of, i, 342; ii, 164

- parasites on, i, 342

black rockfish, ii, 429
black ruff, ii, 284
black sea-bass, ii, 329
black-sided darter,

- figure of, ii, 311

blacksmith, ii, 381
black-spotted sailor's choice, ii, 341
black-spotted trout, ii, 95
black swallower,

- figure of, i, 29; ii, 360

black tai, ii, 344
black will, ii, 328
black wrasse, ii, 387

Blainville, i, 400

- on Palæoniscum, ii, 14

Blake, i, 60, 408
Blanchard, i, 412
blanquillos, ii, 361, 362
blastoderm, i, 135
blastomeres, i, 135
blastopore, i, 138
blastula, i, 131, 132
bleak, ii, 163, 167
Bleeker, i, 376, 412, 414
Bleekeria, ii, 521
Bleekeriidæ, ii, 522
Blenniidæ, i, 208, 276, 290; ii, 506-531
Blennioidea, ii, 470
Blennius, i, 208, 391; ii, 511, 513

Blennius,

- figure of, i, 508

blenny, i, 209, 230, 290, 429; ii, 507-531

- figure of, ii, 509, 511
- Japanese, i, 9; ii, 513
- kelp, ii, 507
- northern, ii, 511
- sarcastic, ii, 507
- snake, ii, 512

Blepsias,

- figure of, ii, 448

blind Brotula,

- figure of, i, 222

blind catfish, ii, 181
blind cavefish,

- figure of, i, 116; ii, 202

blindfish, i, 290; ii, 202, 524

- descent of, ii, 202
- Eigenmann on, i, 117; ii, 202
- habits of, ii, 202
- theories regarding origin, ii, 202

blindfish of Mammoth Cave, ii, 202, 203

- Eigenmann on, i, 221, 222

- figure of, i, 221

blind goby, ii, 467
blob, ii, 444
Bloch, i, 389, 397
Blochiidæ, ii, 514

Blochius,

- figure of, ii, 514

Blossom, the, i, 408
blue-back, ii, 71, 73-76
blue-back salmon, ii, 68, 69
blue-breasted darter, i, 231; ii, 314

- figure of, i, 231

blue cod, ii, 440
bluefin, ii, 66
bluefin cisco,

- figure of, ii, 66

bluefish, ii, 278, 354

- Baird on, i, 279-282
- destructiveness of, ii, 281
- figure of, i, 324; ii, 279
- food of, ii, 280

bluegill,

- figure of, ii, 300

blue-green sunfish, i, 26

- figure of, i, 27; ii, 350

blue parrot-fish, ii, 396

- figure of, ii, 394

- figure of jaws, ii, 393

blue sharks, i, 534, 542
blue smelt,

- figure of, ii, 218

blue-spotted guativere, ii, 324
blue surf-fish, ii, 375
blue tang, ii, 408

- figure of, ii, 407

Blyth, i, 396
boarfishes, ii, 135, 398
bobo,

- figure of, ii, 222

boccaccio, ii, 429
Bocage, i, 414
Bocourt, i, 412
Bodianus, i, 207, 271; ii, 388
boga, ii, 347, 348
Bogoslovius, ii, 541
Bohr, i, 97

Boleophthalmus, ii, 465

- figure of, i, 118; ii, 466

Boleosoma, i, 302; ii, 313
Bollman, i, 420
Boltenia, i, 475
Bombay-duck, ii, 131
bonaci-arará, ii, 325
bonaci-cardenal, ii, 325
Bonaparte, i, 412
bones of the fish,

- actinosts, i, 42
- alisphenoid, i, 38, 39, 40, 53
- anal fin, i, 48
- angular, i, 42, 43, 54
- articular, i, 42, 43, 54
- basibranchial, i, 46
- basihyal, i, 42, 45
- basioccipital, i, 36, 38, 39, 40, 53
- basisphenoid, i, 36, 38, 39, 53
- branchiostegals, i, 42, 45

- carpals, i, 51

- of anglers, i, 51

- caudal fin, i, 48
- caudal vertebræ, i, 48
- ceratobranchial, i, 46
- ceratohyal, i, 42, 45

- clavicle, i, 42, 50, 52

- figured, i, 52

- coracoid, i, 50, 51

- of cranium, i, 39

- dentary, i, 42, 43, 54
- dorsal fin, i, 48
- epihyal, i, 42, 45
- epibranchial, i, 46
- epioccipital, i, 36
- epiotic, i, 36, 37, 38, 39, 40, 53
- epipleurals, i, 48
- ethmoid, i, 36, 37, 53
- exoccipital, i, 36, 37, 38, 39, 40, 53
- frontal, i, 36, 37, 38, 53
- glossihyal, i, 42
- hæmal spine, i, 48
- hæmaphysis, i, 48
- hyoid arch, i, 42
- hyomandibular, i, 42, 44, 54
- hypercoracoid, i, 42, 52
- hypobranchial, i, 46
- hypocoracoid, i, 42, 43, 52
- hypural, i, 48, 49
- infraclavicle, i, 51
- interclavicle, i, 51
- interhæmals, i, 49
- interhyal, i, 42, 45
- interneural, i, 48
- interopercle, i, 42, 45, 54
- interspinals, i, 49
- isthmus, i, 45
- maxillary, i, 41, 42
- mesopterygoid, i, 41, 42
- metapterygoid, i, 41, 42, 54
- nasal, i, 42, 53
- neural spine, i, 48
- neuropophysis, i, 48
- opercle, i, 42, 54
- opisthotic, i, 36, 37, 38, 39, 40
- palatine, i, 41, 42, 54
- parapophysis, i, 48
- parietal, i, 36, 37, 39, 40, 53
- parsasphenoid, i, 36, 38, 53
- pectoral fin, i, 42
- pelvic girdle, i, 42

- pharyngeals, i, 46, 47

- figure of, i, 47
- lower, i, 46
- suspensory, i, 46
- upper, i, 46

- postclavicle, i, 42, 51

- figured, i, 52

- postero-temporal, i, 50
- post-temporal, i, 42, 52
- prefrontal, i, 36, 37, 38, 53
- premaxillary, i, 42
- preopercle, i, 42, 54
- preorbital, i, 41, 42
- prootic, i, 36, 38, 53
- proscapula, i, 50
- pterotic, i, 36, 37, 38, 39, 40, 53
- pterygials, i, 51
- pterygoid, i, 41, 42, 54
- quadrate, i, 42, 43, 54
- ribs, i, 48
- scapula, i, 50
- shoulder-girdle, i, 42, 50, 51, 52
- sphenotic, i, 36, 37, 38, 53
- subopercle, i, 42, 54
- suborbital, i, 42
- supraclavicle, i, 42, 50
- supraoccipital, i, 36, 37, 38, 53
- suprascapula, i, 50

- supratemporal, i, 42, 50

- figured, i, 51

- symplectic, i, 42, 54
- urohyal, i, 42, 54
- ventral fin, i, 42
- vomer, i, 36, 37, 38, 53
- zygapophysis, i, 48

bonito, ii, 264
bonnaterre, i, 397
bony fish, i, 204, 454, 506; ii, 37

- classification of, ii, 38
- development of, i, 135
- figure of, ii, 438
- specialized, figured, i, 456

bony scales, i, 21
Boops, i, 260, 267; ii, 348, 350
Borassus, ii, 367

Borelli, i, 390

- on air-bladder, i, 95

Boreogadus, ii, 537
botolism, i, 183
Bothinæ, ii, 487
Bothriocephalus, i, 345
Bothriolepis, i, 577
Bothus, ii, 486
Botryllidæ, i, 476

Botryllus, i, 476; ii, 545

- figure of, i, 477, 478, 479

bottle-nosed chimæra,

- eggs of, figured, i, 127

Bougainville, i, 395

Boulenger, i, 360, 364, 370, 414, 428, 513, 600, 601, 606, 608, 609; ii, 41, 48, 128, 129, 136, 138, 158, 190, 485, 502, 522, 551

- on Archipterygium, i, 79
- on Galaxias, ii, 205
- catalogue of fishes, i, 402
- on opahs, ii, 243
- portrait of, i, 403
- on vertebræ, i, 213
- on zooid fishes, ii, 245

Bovichthyidæ, ii, 502
bowfin, i, 290, 440; ii, 33, 34

- figure of, ii, 35

- tail of, figured, i, 82

Bowring,

- on noises by fishes, i, 168

Brachydirus, i, 590
Brachyistius, ii, 375
Brachymystax, ii, 62, 67
brain,

- of chimæra, i, 410, 411
- figures of, i, 110, 111
- Günther on, i, 109
- in hagfish, i, 112
- of lamprey, i, 112
- of perch, i, 111
- of pike, i, 109
- of primitive fishes, i, 112
- reflex action of, i, 153
- of shark, i, 110, 111

Brama, ii, 135, 286

Bramidæ, ii, 291

- family of, ii, 286

branch herring, ii, 49
branchial bones, i, 46
Branchiostegi, i, 391

Branchiostoma, i, 34, 35, 120, 383, 483

- eggs of, i, 131

- figure of, i, 484

Branchiostomidæ, i, 484
Brandt, i, 412
Branner, i, 415
Brayton, i, 420
bream, ii, 163, 167
Bregmaceros, ii, 524
Bregmacerotidæ, ii, 524
Brevoort, i, 416

Brevoortia, ii, 51

- figure of, i, 340; ii, 51

brit, ii, 216, 217
broad-shad, ii, 347
broad-soles, ii, 495
Brongniart, i, 427, 428
brook lamprey,

- figure of, i, 120, 505
- larva of, figured, i, 492
- mouth of, figured, i, 492

Brooks,

- on Appendicularia, i, 480

brook trout, ii, 99, 107, 108, 110, 113, 115

- figure of, ii, 111

Brosme, ii, 539
Brosmius, ii, 539
Brosmophycis, ii, 524

Brotula,

- figure of, ii, 524

- blind, figured, ii, 524

Brotulidæ, i, 314; ii, 523, 533
Brotulids, ii, 39, 524
Broussonet, i, 396
Brown, i, 426
Browne, i, 389
brown tang,

- figure of, i, 181; ii, 408

Brünnich, i, 394

Bryactinus, i, 565

Brycon,

- figure of, ii, 162

Bryostemma,

- figure of, ii, 511, 514

Bryttosus, i, 256; ii, 297, 320
buccal cirri, i, 595

Buchanan,

- on hunting of Chaca, i, 170

Buckland, i, 423

- on soles, ii, 497

- on turbot roe, ii, 488

Bucklandium, ii, 186
budai, ii, 390
buffalo-cod, ii, 440
Buffalo Creek, i, 309
buffalo-fish, ii, 160, 172

- figure of, ii, 173

- shoulder-girdle of, i, 51

buffalo sculpin,

- figure of, ii, 443

bulbus arteriosus, ii, 10, 11
bullhead, i, 356
bullhead shark,

- figure of, i, 526

bumpers, ii, 276

Bunocephalidæ, ii, 184
burbot, i, 209; ii, 538

- figure of, ii, 539

Bürger, i, 414
butter-fish, ii, 283, 284, 324, 512
butterfly fish, i, 440; ii, 381

- figure of, i, 143; ii, 402

butterfly ray, i, 556
butterfly sculpin,

- figure of, i, 288

caballerote, ii, 335
cabezon, ii, 442
cabra mora,

- figure of, i, 20

cabrilla, ii, 324, 328, 329
cachucho,

- figure of, ii, 337

Cælorhynchus,

- figure of, ii, 541

Cæsio, ii, 342
cagon de le alto, ii, 337
cají, ii, 336
Calamoichthys, i, 76, 89, 608
Calamostoma, ii, 236

Calamus, i, 49, 238; ii, 344

- figure of, ii, 345, 347

calico-bass, ii, 297
calico-salmon, ii, 72

California lancelet,

- figure of, i, 484

California miller's thumb,

- figure of, ii, 446

California hake,

- figure of, ii, 540

California pampano, ii, 283

California sucker,

- figure of, ii, 174

Callbreath,

- on running of salmon, ii, 86

Callechelys, ii, 150
Callichthyidæ, ii, 185
Callichthys, i, 290
calling the fishes, i, 167, 168

- in Indian temples, i, 167

- in basins of Tuileries, i, 167

Callionymidæ, ii, 506

Callionymus, i, 246, 257, 259, 263, 393, 500, 504

Callipterygidæ, ii, 501
Callipteryx, ii, 501
Calliurus, i, 302

Callorhynchus, i, 565, 566

- egg of figured, i, 127

Callorhinus, ii, 537
Calotomus, ii, 390, 391
Camper, i, 389

Campostoma, ii, 164

- figure of, i, 33; ii, 167

Campyloprion, i, 529
candil, ii, 255
candle-fish, ii, 124
Canestrini, i, 412
Canobius, ii, 14
Canthidermis, ii, 413
Canthigaster, i, 206

Cantor, i, 416

- on fighting-fish, i, 163

Cape of Good Hope,

- as barrier, i, 269

capelin,

- figure of, ii, 126

capello, i, 414
capitaine,

- figure of, ii, 387

Capros, ii, 135, 398, 400

Caracanthidæ, ii, 438

Carangidæ, i, 144, 149, 210; ii, 15, 278, 470

- family of, ii, 272

Carangopsis, ii, 278
Carangus, i, 169, 324; ii, 275, 276, 285
Carapidæ, ii, 522
Caraproctus, ii, 455
Carapus, ii, 520, 522

Carassius, ii, 171

- figure of, i, 151

Caranx, ii, 245, 275, 470, 542

Carboniferous,

- fishes, i, 437

- sharks, i, 224

Carcharias, i, 447, 534, 543; ii, 468

- figure of, i, 542

Carchariidæ, i, 532, 534, 540, 542, 543
carcharioid sharks, i, 540
Carcharodon, i, 538
Carcharopsis, i, 522
cardenal, ii, 316
cardiform teeth, i, 29
cardinal fishes, the, ii, 316

- figure of, i, 455; ii, 316, 319

cardinal vein, i, 108

Carencheli, ii, 140, 153, 155
caribe,

- Günther on, ii, 161

carnivorous fishes, i, 29
carp, i, 21, 53, 93, 290; ii, 162, 164

- air-bladder of, figured, ii, 160
- native of China, ii, 170
- domestication of, ii, 170

Carpiodes, i, 302

- figure of, ii, 173

carp-sucker,

- figure of, ii, 173

carrying eggs in mouth, i, 170-173

- by catfish, i, 170

casabe, ii, 276

Cassiquiare,

- Branner on, i, 307

- crossing by fishes, i, 307

Castelnau, i, 415

Castour, i, 396

Castro,

- photograph by, ii, 522

catadromous fishes, i, 162, 291; ii, 143

Catalina flying-fish,

- figure of, ii, 214

catalineta, ii, 341

Catalogue,

- of Panama fishes, i, 272

catalufa de lo alto,

- figure of, ii, 289

catalufa, ii, 288, 333

- figure of, ii, 331

Catesby, i, 389
catfish, i, 4, 20, 53, 119, 122,128, 169, 290, 440; ii, 159, 160, 177-187

- African, ii, 185
- channel, ii, 179
- clavicle in, i, 87
- Cope on, i, 180
- descent from, ii, 186
- destroyed by lampreys, i, 357
- electric, ii, 183
- electric, figured, i, 186
- fossil, ii, 186
- of India, ii, 184
- Japanese, ii, 183
- Old World, ii, 182
- poison glands of, i, 180
- poison spine of, i, 179
- shoulder-girdle in, i, 86
- spines of, i, 179
- transfer to Sacramento, i, 310

Catopteridæ, ii, 16

Catopterus, ii, 16

Catostomidæ, i, 46, 290; ii, 172, 175

- family of, ii, 171

- figure of, i, 315

Catostomus, i, 198, 283, 302, 304, 316, 346; ii, 56

- figure of, i, 348; ii, 171

- pharyngeal teeth of, ii, 175

cat shark, i, 533
Catulus, i, 533
caudal fin, i, 10
caudal lancet, ii, 409

Caularchus,

- figure of, i, 198, 531

Caulolatilus, ii, 362

Caulolepis, ii, 252, 253

Caulophryne,

- figure of, i, 276, 548

causes of dispersion, i, 318
cavalla, ii, 266, 272-292
cavefish, ii, 201, 523, 524

- Eigenmann on, ii, 524

- figure of, i, 117

Cebedichthys, ii, 512

Centaurus,

- larva of figured, i, 143

centers of distribution, i, 244

Centrarchidæ, i, 209, 232, 290; ii, 304, 320, 327, 380

- family of, ii, 297

Centrarchus, i, 302; ii, 297

Centriscidæ, ii, 227, 235

- family of, ii, 234

Centriscus, i, 393; ii, 235
Centrogenys, ii, 320
Centrolepis, ii, 14
Centrolophiidæ, ii, 283
Centrolophius, i, 260; ii, 286
Centrophoroides, i, 546
Centrophorus, i, 546
Centropomidæ, ii, 319

Centropomus, i, 271, 273; ii, 309

- figure of, i, 324; ii, 319

Centropristes, i, 136; ii, 328, 329

- eggs of, figured, i, 135

Centroscymnus, i, 546

Centrolabrus, ii, 387

Cephalacanthidæ, i, 208

- family of, ii, 458

Cephalacanthus, ii, 458

- figure of, ii, 456

Cephalaspidæ, i, 576, 623

Cephalaspis, i, 444, 569, 571

- figure of, i, 576, 577, 579

Cephalopholis, ii, 324, 325
Cephaloscyllium, i, 197
Cepola, i, 260, 264, 393; ii, 363
Cepolidæ, the, ii, 363
Ceratacanthus, ii, 414

Ceratias,

- figure of, ii, 548

Ceratiidæ, i, 276
Ceratobatis, i, 560
Ceratocottus, ii, 443

Ceratodontidæ, i, 600, 612

- family of, i, 613

Ceratodus, i, 77, 85, 613-616

Ceratoscopelus,

- figure of, ii, 133

Ceratiidæ, ii, 547-549
Cerdale, i, 271
Cerdalidæ, ii, 516
cestodes, i, 344

Cestraciont shark, i, 526, 527, 530

- Eastman on, i, 529

- teeth, figured, i, 527

Cestraciontes, i, 438, 519, 566

- Eastman on, i, 529
- families of, i, 528
- suborder of, i, 526
- teeth of figured, i, 527, 529

Cetomimidæ, ii, 132

Cetomimus,

- figure of, ii, 132

Cetorhinus,

- figure of, i, 540

Cetorhinidæ,

- family of, i, 539

Cette, i, 396
Chaca, i, 170
Chacidæ, ii, 184
Chænobryttus, i, 302; ii, 300
Chætobranchus, ii, 381

Chætodipterus,

- figure of, i, 325, 401

Chætodon, i, 235, 242, 267, 391; ii, 400, 403, 405, 406

- figure of, i, 143; ii, 402

Chætodontidæ, i, 206; ii, 245, 291, 381, 398, 402, 404, 405

Chætodonts, ii, 247
Chalacodus, i, 566
Challenger, the, ii, 60, 130
Champsodon, ii, 361
Champsodontidæ, ii, 361

Chanos, i, 205; ii, 221

- figure of, ii, 45

Chanidæ,

- family of, ii, 44

Channa,

- figure of, ii, 370

channel bass, ii, 355
channel catfish,

- figure of, i, 280

channel-cats, the, ii, 179, 182
Channomuræna, ii, 153
Chanoides, ii, 44

Chapala Lake,

- fishes of, ii, 216

Characidæ, ii, 161, 162
Characin, i, 290
Characinidæ, i, 205, 290; ii, 381
Characins, ii, 61, 160-162, 186
Characodon, ii, 201
characters,

- of Elasmobranchs, i, 507

- of species, i, 292

Charitosomus, ii, 56
charr, ii, 67, 99, 107, 114, 122
Charlevoix, ii, 64
Chasmistes, i, 304, 316; ii, 172
Chasmodes, ii, 509
Chauliodontidæ, ii, 129

Chauliodus,

- figure of, ii, 129

Chaunax, ii, 551
Cheilio, ii, 390
Cheilinus, ii, 390

Cheilodipteridæ,

- family of, ii, 278

Cheilodipterus, ii, 278

- figure of, ii, 279

Cheiracanthus, i, 517
Cheirodopsis, ii, 15
Cheirodus, ii, 14
Cheirolepis, ii, 14
Chelidonichthys, i, 260; ii, 456
Chelmo, ii, 404
Chelonichthyidæ, i, 586
Chelonopsis, ii, 425
Chonerhinus, ii, 419
cherna, ii, 324
chevron, ii, 89
chiasma, ii, 4

Chiasmodon, ii, 136

- figure of, i, 29; ii, 360

Chiasmodontidæ, ii, 215, 360

Chilobranchidæ, ii, 141

Chilomycterus,

- figure of, ii, 423

Chiloscyllium, i, 56, 533

- pectoral fin of, i, 66

Chimæra, i, 23, 35, 85, 204, 393, 435, 437, 448, 507, 509, 512-514, 545, 561-567, 595, 610

- of California, i, 564
- Dean on, i, 563
- figure of, i, 449, 564, 565
- Parker on, i, 563

Chimæridæ,

- family of, i, 564

Chimæroids, i, 224, 583

Chimæropsis, i, 566

China fish,

- snake-headed, ii, 371

Chinese whitebait, ii, 127, 128
chinook, ii, 69
chirivita, ii, 405
Chirocentridæ, ii, 46
Chirocentrus, ii, 46, 48
Chirolophis, ii, 512
Chiropterygium, i, 600, 605

Chirostoma,

- figure of, i, 329; ii, 217

Chirothricidæ, ii, 133

Chirothrix,

- figure of, ii, 46, 134

chisel-mouth, ii, 169

Chlamydoselachidæ,

- family of, i, 525

Chlamydoselachus, i, 361, 447, 448, 509, 521, 536

- figure of, i, 523

Chlarias, i, 98, 290; ii, 186, 187

- figure of, i, 457; ii, 185

Chlariidæ, ii, 184, 185

Chlevastes, ii, 150

- figure of, i, 232

Chloropthalmus, i, 260; ii, 130
Chloroscombrus, ii, 276
chochouwo, ii, 403
chogset, ii, 387

Chologaster, i, 203, 204, 223

- Eigenmann on, ii, 203
- figure of, i, 116; ii, 201
- Garman on, ii, 202
- Hoppin on, ii, 203

Chondrenchelys, i, 521
Chondropterygians, i, 508
Chondropterygii, i, 391

Chondrostei, i, 623, 624; ii, 2, 5, 13

- order of, ii, 17

Chondrosteidæ, ii, 17, 18
Chondrosteus, i, 622
Chonerhinidæ, ii, 419

Chopa, ii, 344, 350

- figure of, ii, 349

Chordata, i, 460

Chordate animals, i, 460

- lowest forms figured, i, 465

Chordates, i, 508, 584, 597; ii, 1
Chorisochismus, ii, 531
Chriodorus, ii, 212

Chromides,

- suborder of, ii, 380

Chromis, i, 166; ii, 381

Chrondrosteus,

- figure of, ii, 18

Chrosomus, i, 304; ii, 164, 167
chub, ii, 118, 147, 163

- figure of, ii, 169
- of Great Basin, ii, 169
- of Pacific, ii, 169

chub of Great Basin,

- figure of, i, 287

chub-mackerel, i, 94
chub-sucker, i, 292

- figure of, i, 315; ii, 172

chum, ii, 72
cichla, ii, 380
Cichlasoma, ii, 381
cichlid, i, 290

Cichlidæ, i, 209, 290; ii, 380, 381

- organs of smell in, i, 115

cigar-fish, ii, 274
ciguatera, i, 182-185; ii, 335, 411, 413
Cimolichthys, ii, 133
Ciona, i, 481
Cirrhilabrus, ii, 390
Cirrhitidæ, the, ii, 363, 426

Cirrhitus, i, 271

- figure of, ii, 364

Cirrostomi, i, 482, 595
cisco, ii, 65
Citharichthys, i, 274; ii, 489
Citharinus, ii, 162
Citula, i, 202; ii, 276

Cladistia, i, 602

- order of, i, 605

Cladodontidæ, i, 520, 522

Cladodus, i, 65, 80, 437

- pectoral fin of, i, 521
- shoulder-girdle in, i, 521
- teeth of, figured, i, 522

Cladoselache, i, 64, 66, 79, 80, 437, 446, 448, 510, 571, 573, 623

- Dean on, i, 518
- figure of, i, 65, 514, 515
- primitive character of, i, 514
- teeth of, figured, i, 515
- ventral view of, i, 515

Cladoselachidæ, i, 514

- family of, i, 523

clam-cracker, i, 556

Clark,

- on eulachon, ii, 125

Clarke, i, 416
claspers, i, 124, 125
classification,

- Coues on, i, 370
- of Elasmobranchs, i, 509, 510
- of fishes, i, 367-386
- of instincts, i, 154
- morphological, i, 371
- natural, i, 370
- terms used in, i, 462

Clastes,

- Eastman on, ii, 32

Clavellinidæ, i, 475
clavicle,

- figure of, i, 87

- of sea catfish, i, 87

Claypole, i, 426

- portrait of, i, 409

cleavages, i, 135
Clepticus, ii, 388
Clidoderma, ii, 494

Climatius, i, 446

- figure of, i, 518

climbing-fish, ii, 367
climbing-perch,

- figure of, ii, 366

clingfish, ii, 529

- figure of, i, 198; ii, 531
- Günther on, ii, 529, 530
- sucking-disk in, i, 198

Clinocottus, ii, 448
Clinton, ii, 64
Clinus, i, 208; ii, 507, 511, 513, 516
Cloquet, i, 397
Cloudy Bay cod, ii, 520
Clupanodon, ii, 53

Clupea, i, 204, 329, 391

- figure of, i, 331, ii, 49

Clupeidæ, i, 204, 290; ii, 49, 52, 53
clupeiform, ii, 11
clupeoid, ii, 10
Clupeidea, the, ii, 41
coalfish, i, 209; ii; 438, 537

Coal measures,

- fishes of, i, 223

- teeth found in, i, 65

Costa, i, 412
coast lines,

- effect on distribution, i, 248

cobbler-fish, ii, 276
cobia, ii, 282
Cobitidæ, ii, 175, 185
Cobitis, i, 391; ii, 176

Cobitopsidæ,

- family of, ii, 224

Cobitopsis,

- figure of, ii, 224

Coccoderma, i, 605
Coccosteans, i, 581
Coccosteidæ, i, 622, 623, 584, 586

Coccosteus, i, 583, 584, 587, 590, 593, 596, 623

- figure of, i, 582

cochino, ii, 413

Cochliodontidæ, i, 530

- family of, i, 531

Cochliodus,

- lower jaw figured, i, 531

cock-and-hen paddle, ii, 453
cock-of-palace-under-sea, ii, 472
cockeye pilot,

- figure of, ii, 382

Coccolepis, ii, 14
cod, ii, 51
codfish, i, 122, 128, 290; ii, 481, 501, 532, 533

- figure of, i, 331; ii, 535
- Gill on, ii, 534
- Goode on, ii, 534
- pectoral fin of, i, 66
- reproduction of, ii, 535
- Sars on, ii, 535

codling, ii, 538

Cœlacanthidæ, i, 605

Cœlacanthus,

- figure of, i, 604

Cœlolepia, i, 573
Cœlodus, ii, 22
Cœlolepidæ, i, 573
coho, ii, 72
collection of fishes, i, 429-434

- by explosives, i, 430
- by poison, i, 430
- tackle for, i, 430

Collett, i, 408, 427

- portrait of, i, 403

Collie, i, 564

Collins,

- on catastrophe to tilefishes, ii, 362

- on halibut, ii, 490

Cololabis, ii, 212

Colocephali, ii, 140-142, 153

- suborder of, ii, 152

Colomesus, ii, 421

Colorado trout,

- figure of, ii, 106

colors of fishes, i, 226-236

- of coral-fishes, i, 235
- fading of, in spirits, i, 235
- intensity of, i, 232
- nuptial, i, 230
- protective, i, 226-229
- sexual, i, 230
- variation of, i, 235

Columbia,

- figure of, ii, 242

Comephoridæ, the, ii, 455
Comephorus, ii, 524
Commerson, i, 395
commissure, i, 112
common eel,

- figure of, ii, 143

common skate,

- figure of, i, 552

common sucker,

- figure of, ii, 174

common sunfish,

- figure of, i, 7, 13; ii, 301

conceptions of genus, i, 375

Conchopona, i, 613
conclusions,

- of Cope on dispersion, i, 286
- of Evermann, i, 274
- of Hill, 277-279
- as to Isthmus of Suez, i, 269
- of Jenkins, i, 274

conger eels, ii, 149, 151

- figure of, ii, 150

Congiopodidæ, ii, 436

Congiopus, ii, 436

Congo River,

- fishes from, i, 78, 607

Congriopus, ii, 514

Congrogadidæ, ii, 519

Connoly,

- on calling fishes, i, 168

Conocara, ii, 60

Conodontes, i, 487

- figure of, i, 488

Conorhynchus, i, 128
constantino, ii, 320

Cooper, i, 419

- on long-jawed goby, ii, 463

Cope, i, 84, 311, 419, 428, 512, 602; ii, 1, 4, 13, 24, 35, 56, 159

- on classification, i, 406
- conclusions of, 286
- on dispersion, i, 286, 287
- on eels, ii, 139
- on fossil forms, ii, 32
- on isocercal tail, i, 84
- on ostracophores, ii, 569
- portrait of, i, 407
- sketch of, i, 406

Copeland, i, 420

- portrait of, i, 421

Copelandellus, ii, 315
Coquille, i, 408
coracoid, i, 88, 90
coraco-scapular, i, 87
coral reefs,

- at Apia, figured, i, 234
- fishes of, i, 235, 297
- fish life in, i, 215

Corax,

- teeth of, figured, i, 543

Coregoni, ii, 67

Coregonus, i, 291, 305, 316, 322, 391; ii, 62, 65, 439

- figure of, i, 321; ii, 63

Coreoperca, ii, 320

Coris, ii, 390
cormorant-fishing, ii, 116-119

- illustrations of, i, 333, 335

cornet-fishes, ii, 390

- family of, ii, 233

Cornide, i, 396
coronado, ii, 274
corpus vestiforme, i, 112
corsair, ii, 430
Corvula, ii, 355

Corynolophus, i, 189; ii, 549

- figure of, i, 188

- luminous bulb in, i, 188

Coryphæna, i, 210, 391

- figure of, ii, 287

Coryphænidæ,

- family of, ii, 286

Coryphænoides,

- figure of, i, 83; ii, 541

- leptocercal, tail of, i, 83

Coryphopterus, ii, 462
Corythroichthys, ii, 236
Costa, i, 412

Cottidæ, i, 208, 290; ii, 363, 442, 449, 453, 455, 501, 504, 525

- family of, i, 441

- fossil forms, i, 449

Cottocomephorus, ii, 525
Cottogaster, i, 300
Cottunculus, i, 219; ii, 441, 447, 449

Cottus, i, 169, 219, 312, 391; ii, 443, 445, 449

- figure of, ii, 444, 445, 446

Couch, i, 410

- on fighting-fish, i, 165

- on skippers, ii, 21

Coues,

- on classification, i, 368
- on meaning of species, i, 379
- on synonymy, i, 374

cowfish,

- figure of, i, 373; ii, 416

- skeleton of figured, i, 215; ii, 418

cow's tongue, ii, 497
crab-eater, ii, 282
Cragin, i, 171
craig-fluke, ii, 494
Cramer, i, 408, 420, 422
cramp-fishes, i, 554
cranial nerves,

- figure of, i, 111

Craniomi,

- suborder of, ii, 456

Craniotes, i, 588
cranium,

- bones of, i, 36-39
- inferior view, i, 38
- lateral view, i, 36
- posterior view, i, 40
- of Roccus, figured, i, 36-39
- of Sebastolobus, i, 53
- superior view, i, 37

crappie, ii, 168, 297

- figure of, ii, 297

- photograph of, ii, 298

Cratinus, i, 271
cravo, ii, 244
crawl-a-bottom, ii, 312
crayfish, ii, 147
creek fish,

- figure of, i, 315; ii, 172

Crenilabrus, i, 207, 260, 267; ii, 387
creole-fish, ii, 328, 329
Crescent lake trout, ii, 101
Cricodus, i, 603
Cristiceps, i, 208; ii, 508, 513

Cristivomer, i, 291; ii, 62, 115

- figure of, ii, 114

croaker, ii, 353, 355
Cromeriidæ, ii, 56
cross-bow shooter, ii, 413

Crossognathidæ, ii, 215, 521

- family of, ii, 224

Crossopholis, ii, 21

Crossopterygians, i, 78, 79, 89, 91, 204, 436, 457, 511-515, 591, 602, 623, 624; ii, 38

- figure of, i, 451

- fins of, i, 601

Crossopterygii, i, 382, 462, 599, 600, 601, 608
crustacean parasites, i, 340

Cryptacanthididæ, ii, 516

Cryptacanthodes,

- figure of, i, 516

Cryptocentrus, i, 264; ii, 462

Cryptopsaras,

- figure of, ii, 547

Cryptotomus,

- figure of, ii, 391

crystal darter,

- figure of, ii, 313

crystal goby, ii, 466

Crystallias,

- figure of, i, 218; ii, 454

Crystallogobius, ii, 466
Ctenochætus, ii, 409
Ctenodentex, ii, 340

Ctenodipterini,

- order of, i, 612

Ctenodontidæ, i, 613
Ctenodus, i, 613
ctenoid scales, i, 20, 21; ii, 39
Ctenoidei, ii, 39, 209
Ctenolabrus, ii, 387
Ctenolates, ii, 320
Ctenoptychius, i, 555

Ctenothrissa,

- figure of, ii, 48

Ctenothrissidæ,

- figure of, ii, 48

cuatro ojos, ii, 194
Cuban fishes, i, 314
cubero, ii, 335
cuboid, i, 19
cub-shark,

- figure of, i, 542

cuckold, ii, 417

- figure of, i, 373; ii, 416

cucugo, ii, 413
cultus cod, ii, 442

- figure of, ii, 440

Cunias, i, 541
cunner, ii, 387

Cunningham,

- on eye of flounder, i, 176

Curimatus, ii, 162
cusk-eel, i, 187, 314; ii, 539

- figure of, ii, 520

cutlass-fishes, i, 149, 210; ii, 267

- figure of, ii, 268

- species of, ii, 472

cutthroat trout, ii, 95-97, 102, 104, 106

Cuvier, i, 103, 105, 400, 404, 428; ii, 39, 307

- Günther on, i, 400
- Lyman on, i, 401
- portrait of, i, 399

Cycleptus, ii, 173

Cycliæ, i, 204, 437, 462, 592, 593

- subclass of, i, 591

Cyclobatis, i, 557
Cycloganoidei, ii, 34
cycloid scales, i, 20, 22; ii, 39
Cycloidei, ii, 39
Cyclopterichthys, ii, 454

Cyclopteridæ, i, 198, 208

- family of, ii, 453

Cyclopterus, i, 391; ii, 453, 455

- figure of, i, 220; ii, 454

Cyclospondyli, i, 510, 543

- order of, i, 545

cyclospondylous, i, 49
cyclospondylous sharks, i, 549
Cyclostomata, i, 593

Cyclostomes, i, 113, 443, 486-505, 570, 596, 592, 617

- extinct forms, i, 487

Cyclostomi, i, 462, 584
Cyclothone, ii, 129
Cyclurus, ii, 36

Cymatogaster, ii, 376

- figure of, i, 125; ii, 372

Cymolutes, ii, 390
Cymothoa, i, 340
Cynoglossinæ, ii, 497
Cynoglossus, ii, 497

Cynoscion, i, 94, 324; ii, 107

- figure of, ii, 353

Cynthia,

- figure of, i, 476

Cynthiidæ, i, 475

Cyprinidæ, i, 33, 46, 205, 230, 251, 285, 287, 290, 406; ii, 65, 161, 162, 164-171

- fossil forms, ii, 174

- species of, ii, 165

Cyprinodon, ii, 198, 201

- figure of, ii, 196

Cyprinodontes, ii, 194
Cyprinodontidæ, i, 290
Cyprinus, i, 391; ii, 170, 174

Cypselurus, ii, 213

- figure of, i, 157, 440

Cyrthaspis, i, 575
Cyttoides, ii, 249
Cyttus, ii, 249
dabonawa, i, 430
dace, i, 251; ii, 118, 162, 166, 168
Dactylagnus, ii, 506
Dactyloscopidæ, ii, 506
Dactyloscopus, ii, 506
daddy sculpin, ii, 445
Dalatias, i, 546
Dalatiidæ, i, 548

Daldorf,

- on capture of Anabas, i, 163

- on climbing-fish, ii, 367

Dale, ii, 539

Dallia, i, 51

- figure of, i, 149; ii, 206

Dalliidæ, i, 290; ii, 206

Damalichthys,

- figure of, ii, 374

damsel-fish, ii, 381

- figure of, ii, 382

Dapediidæ, ii, 25

Dapedium,

- figure of, ii, 25

Dapedoglossus, ii, 56
darters, i, 209, 231, 300, 304; ii, 166, 306, 310-315
darter goby,

- figure of, ii, 462

Darwin, i, 408

- on noises of catfish, i, 168

daruma-okose, ii, 436

Dasyatidæ,

- family of, i, 555

Dasyatis,

- figure of, i, 247, 556

Dasyscopelus, ii, 133

Davis, H. S., ii, 81, 84

- on chinook salmon, ii, 85

Davis, J. W., i, 426

- on fossil teeth, i, 525

Dawson, i, 427, 594

Day, i, 416; ii, 90, 92, 95

- on calling fishes, i, 168
- on electric eel, i, 170
- on grayling, ii, 121
- on Labyrinthici, ii, 365
- on sole, ii, 496, 497

day chub,

- head of, figured, ii, 167

dealfish, ii, 477, 480

- figure of, ii, 478

Dean, i, 512, 591, 594, 595

- on Acanthodei, i, 517, 518
- on Arthrodira, i, 518, 588
- on Chimæras, i, 563
- on fin migration, i, 75
- on fossil forms, i, 422
- on lateral line, i, 23
- on lung-fish, i, 618
- on Ostracophores, i, 571
- portrait of, i, 417
- on sharks, i, 511, 531
- on Teleosts, i, 135

Deania, i, 546
deathfish, i, 183

Death Valley fish,

- figure of, ii, 199

Decapterus, ii, 274
decurrent flounder,

- figure of, i, 441

deep-sea angler,

- figure of, ii, 548

deep-sea Chimæra,

- figure of, i, 449

deep-sea fishes, i, 246, 247, 408; ii, 129
degenerate fishes, i, 210, 211, 216, 218
degeneration,

- of eye, i, 220
- in fishes, i, 54
- in lamprey, i, 217
- of structure, i, 216
- in tunicates, i, 480

Delaroche, i, 95

Dekay, i, 418

Delfin,

- on hagfishes, i, 489

Deltistes, ii, 172
Deltodus, i, 531
Dendrodus, i, 603
dentary, i, 606
Dentex, i, 94; ii, 338, 340
Dercetes, ii, 136
Dercetidæ, ii, 136, 137, 158
Derepodichthyidæ, ii, 520
Derichthyidæ, ii, 155

Derichthys, ii, 153

- figure of, ii, 156

Dermopteri, i, 486

Desmarest, i, 396
development, i, 217

- of bony fishes, i, 135
- Dean on, i, 135
- embryonic, i, 133
- of flounders, i, 144
- heredity in, i, 134
- of horsehead-fish, i, 148
- of paired fins, i, 66

devil ray,

- figure of, i, 559

De Vis, i, 416

Devonian,

- fishes, i, 436
- lamprey, i, 563
- sharks from, i, 65

Diabasis, i, 375
diablo, ii, 552
Dialarchus, ii, 448
Dialommus, i, 117
diamond,

- fishes, ii, 398
- flounder, ii, 493
- snapper, ii, 337

Diaphus, ii, 133

- figure of, ii, 132

Dibothrium, 345

- figure of, ii, 103

Dibranchus, i, 207; ii, 552
Dicentrodus, i, 522
Dicentrarchus, i, 324; ii, 321, 330
dichotomous rays, i, 596
Dicranodus, i, 521
Dictyorhabdidæ, i, 565
Dictyorhabdus, i, 435, 565, 578
Dictyopyge, ii, 16
Dictyopygidæ, ii, 14
Dictyosoma, 512
Didemnidæ, i, 477
Didymaspis, i, 576
Didymodus, i, 521, 525
Dinematichthys, ii, 524
Dinichthyidæ, i, 587

Dinichthys, i, 587, 589

- figure of, i, 445, 584

- jaws of figured, i, 583

Diodon, i, 273, 393, 394

- figure of, i, 17; ii, 422

Diodontidæ,

- family of, ii, 422

diœcious fishes, i, 124
diphycercal tail, i, 49, 81, 83, 84, 507, 513, 516, 598

- Boulenger on, i, 84

- Dollo on, i, 84

Diplacanthidæ, i, 517, 518

Diplacanthus,

- figure of, i, 517

Diplectrum, ii, 329

Diplesion,

- figure of, i, 247; ii, 312

Diplodus, ii, 347

- figure of, ii, 346

Diplognathus, i, 584, 589
Diplomystes, ii, 178
Diplomystidæ, ii, 178

Diplomystus,

- figure of, i, 205, 453; ii, 52

Diploneumoni, i, 612, 619
Diploprion, ii, 327
Diplopterus, i, 82, 604
Diplospondyli, i, 509, 523
Diplurus, i, 605

Dipneusti, i, 405, 462, 582, 599, 601, 605, 607, 622, 624; ii, 4

- relationship of, i, 609, 610

- subclass of, i, 609-622

Dipnoans, i, 436, 512, 572, 582, 583; ii, 3, 8

- air-bladder in, i, 101
- classification of, i, 612
- ear sac in, i, 120
- figure of, i, 449
- pectoral fin in, i, 60
- shoulder-girdle in, i, 86, 88

Dipnoi, i, 77, 85, 89, 382
Diptera, ii, 306
Dipteridæ, i, 612

Dipterus, i, 612

- figure of, i, 437, 449

Discobatis, i, 553

Discocephali, ii, 459-480

- Gill on, ii, 470

- suborder of, ii, 468

diseases of fishes, i, 340-358

- contagious, i, 340
- parasitic, i, 342
- remedies for, i, 342

Dismal Swamp fish,

- figure of, i, 116; ii, 201

dispersion of fishes,

- Agassiz on, i, 284
- barriers to, i, 297, 310, 311
- causes of, i, 318
- Cope on, i, 286
- by floods, i, 301
- of fresh-water fishes, 282-296
- of river fishes, 297-319

dissection of the fish, i, 26-33

Distomidæ, i, 477
distribution of fishes,

- affected by coast line, i, 247, 261
- agency of currents in, i, 242
- centers of, i, 243
- determined by temperature, i, 241
- of fresh-water forms, i, 249
- general laws of, i, 238
- of marine forms, i, 245
- Panama, barrier to, i, 266
- of shore fishes, i, 263-265
- Suez, barrier to, i, 266
- zones of, i, 249, 251, 252

Ditrema, ii, 375
Dittodus, i, 521, 525
doctor-fish, ii, 408
Döderlein, i, 411, 416
dogfishes, i, 519

- figure of, i, 545

dogoro, ii, 381
dog salmon, ii, 71-73, 80, 81
dog snapper, ii, 336
Dolichoglossus, i, 463
Doliolum, i, 479
dollar-fish, ii, 283

Dollo, i, 415, 427, 600, 601; ii, 502

- portrait of, i, 413

- on tail forms, i, 84

Dolloa, ii, 541

Dolly Varden trout, i, 305; ii, 112, 113

- figure of, i, 327; ii, 114

dolphins, i, 210; ii, 286, 362

- figure of, ii, 287

Doncella,

- figure of, i, 297; ii, 180, 396

Donovan, i, 410
dorados, ii, 286

- figure of, ii, 287

Doras, ii, 183

Doratonotus, ii, 388

Dormeur,

- figure of, ii, 460

Dormitator,

- figure of, ii, 461

dorsal fin, i, 10, 603

- figured, i, 49

Dorosoma, i, 32, 300

- figure of, ii, 53

Dorosomatidæ, ii, 53
Dorosomidæ, i, 290
Doryichthys, ii, 236
Dorypteridæ, ii, 14-16
Dorypterus, ii, 15, 16

Draciscus,

- figure of, ii, 452

Draconetta, ii, 506
Draconettidæ, ii, 506
dragonets, i, 246; ii, 504
drawing net at Milo,

- photograph of, i, 281

Drepane, ii, 401

Drepanaspidæ, i, 574

Drepanaspis, i, 570

- figure of, i, 574

Drepanidæ, ii, 401

Drepaniodus, i, 488
drum, i, 290

- figure of, ii, 358

duck-billed eels, ii, 150, 151
Ductor, ii, 278
ducts, i, 28
ductus cholidechus, i, 32

Dufosse,

- on air-bladder, i, 97

Dugès, i, 90, 420
Dugunonutatatori, ii, 472
Duméril, i, 398, 401
duodenum, i, 32
Dussumieriidæ, ii, 52
Dussumieria, ii, 52
Duverncy, i, 390
Duymæria, i, 260; ii, 390
dwarf,

- herring, ii, 54
- perch, ii, 306
- salmon, ii, 117
- sunfish, ii, 467

Dybowsky, i, 411
Dynatobatis, i, 553
Dysommidæ, ii, 150
Dytiscus, ii, 144
eagle ray,

- figure of, i, 558

early writers on fishes, i, 272, 422, 423
earliest sharks, i, 436, 443
ear of fish, i, 119-121
ear sac, i, 119, 120
ear stones, i, 119
earthquakes,

- fatal to fishes, i, 356; ii, 137

Eastman, i, 427, 428

- on Cestraciont shark, i, 529
- on Clastes, ii, 32
- on Neoceratodus, i, 619
- portrait of, i, 425
- on teeth of Edestus, i, 530

Ebisu, the god of fishes, ii, 344

- figure of, ii, 343

Ebisus, ii, 323
Echeneididæ, ii, 468, 470
Echeneis, i, 391; ii, 468, 470, 471
Echidna, i, 211; ii, 152, 153
Echidnocephalus, ii, 138

Echinorhinidæ,

- family of, i, 547

Echinorhinus, i, 547
Echiodon, i, 84
economic fishes, i, 333
ectoblast, i, 152
ectocoracoid, i, 87
ectoderm, i, 139
ectopterygoid, i, 606
Edaphodon, i, 565

Edestus,

- teeth of, figured, i, 529

eel-back flounder,

- figure of, ii, 494

eel-fairs, ii, 142
eel-like fishes, ii, 137-158
eel-mother, ii, 144
eel-pouts,

- figure of, ii, 518, 519

eels, i, 21, 210, 217, 268, 290; ii, 40, 44, 147, 153, 157

- Cope on, ii, 139
- Günther on, ii, 141
- larva of, figured, ii, 148
- migration of, ii, 142
- reproduction of, ii, 143
- species of, ii, 148
- shoulder-girdle in, ii, 142
- Woodward on, ii, 140

effects on distribution,

- of shore line, i, 262

- of temperature, i, 149

Egerton, i, 423

Egertonia, ii, 396
eggs of fish,

- artificial impregnation of, i, 150
- of bottle-nosed chimæra, i, 127
- care of, i, 128
- carrying of, i, 128, 171
- of Embiotocidæ, i, 127
- embryo of, i, 128
- fertilization of, i, 125
- figures of, i, 127
- germ disk in, i, 135
- hatching of, i, 125
- of herring, i, 125
- month incubation of, i, 170, 171
- transportation of, i, 171

Eichwald, i, 411, 427

Eigenmann, i, 415, 420; ii, 147, 148, 376

- on blind fishes, i, 117, 221, 222; ii, 202, 523

- on Nematognathi, ii, 178
- photograph by, i, 222
- portrait of, i, 417

Eigenmannia, ii, 187
eighteen-spined sculpin,

- figure of, ii, 447

Ekström, i, 410
Elacate, ii, 282, 470, 471
Elagatis, ii, 274

Elanura,

- figure of, ii, 444

Elasmobranchiates, i, 384

Elasmobranchii, i, 462, 507, 584; ii, 7

Elasmobranchs, i, 92, 102, 204, 506-522, 571, 583, 588, 589

- characters of, i, 506-508
- classification of, i, 507-510
- ear sac in, i, 120
- geological distribution of, i, 459
- notochord in, i, 57
- subclass of, i, 507

Elassoma, i, 290; ii, 296, 307, 467

- figure of, ii, 295

Elassomidæ, i, 290; ii, 296

- family of, ii, 295

elastic spring, i, 96

Elater, i, 582
electric catfish,

- figure of, ii, 183

electric cells, i, 553
electric eel, i, 186; ii, 140

- Day on, i, 170

electric organs, i, 25, 186, 187
electrophores, ii, 187, 188
Electrophoridæ, ii, 187
Electrophorus, i, 170, 186
Eleotrids, ii, 460

Eleotris, i, 254

- figure of, ii, 460

Elera, i, 414

Eleginus, ii, 537
elephant sharks, i, 540

- figure of, i, 565

Elliott,

- on trout, ii, 105

Elonichthys, ii, 14
Elopidæ, i, 43; ii, 35, 41-44
Elopopsis, ii, 43

Elops, i, 205, 393; ii, 43, 221

- figure of, i, 454; ii, 42

Embiotoca, i, 404

Embiotocidæ, i, 207, 290; ii, 373

- Agassiz on, i, 377-379
- anal fin in, i, 125
- viviparity of, i, 376, 377

Emblemaria,

- figure of, ii, 510

embryo, i, 136, 138, 139
embryology and growth, i, 131-151

Embolichthys, ii, 522

- figure of, ii, 521

emerald-fish, ii, 462
Emery, i, 412; ii, 480, 481
Emmelichthys, i, 262; ii, 346, 347

Emmydrichthys,

- figure of, i, 180; ii, 436

Empetrichthys,

- figure of, ii, 199

Empo, ii, 137
Enantioliparis, ii, 455
Enchelurus, ii, 138

Enchelycephali, ii, 140, 141, 147, 152

- suborder of, ii, 142

Enchelynassa, ii, 153

Enchelyopus,

- figure of, ii, 539

Enchodontidæ, ii, 136, 137
Enchodus, ii, 136
Endoskeleton, i, 439
Enedrias, ii, 512
Engraulididæ, ii, 54
Engraulis, i, 205; ii, 54
Enneacanthus, ii, 301

Enophrys,

- figure of, ii, 443

Enoplosidæ, ii, 317

Enoplosus, i, 268; ii, 317

Enteropneusta, i, 457, 461, 462

- classification of, i, 464

entoderm, i, 138
Entosphenus, i, 490
entozoa, i, 348
Eocottus, ii, 449
Eomyrus, ii, 150
Eopsetta, i, 205; 491
Eothynnus, ii, 266
Epelasmia, ii, 397, 398
Eperlanus, ii, 123
Ephippidæ, ii, 400
Ephippus, i, 268; ii, 400
epiblast, ii, 5
Epigonichthys, i, 483
Epigonus, ii, 317

Epinephelus, i, 19; ii, 323, 330

- figure of, i, 20; ii, 324-326, 328

Epiphysis, i, 112

- figure of, i, 111

Eptatretidæ, i, 489

Eptatretus, i, 490

- figure of, i, 198

equatorial fishes,

- specialization of, i, 248

equatorial zone, i, 251
Eques, ii, 357
Equula, ii, 287
Erebus, i, 408

Ereunias,

- figure of, ii, 450

Ereuniidæ, ii, 449

Ericymba,

- figure of, ii, 165

Erimyzon, i, 292; ii, 175

- figure of, i, 315; ii, 172

Eriptychius, i, 435, 603, 578
Erisichthe, ii, 34
Erismatopteridæ, ii, 242, 296

Erismatopterus, ii, 243

- figure of, ii, 242

Ernogrammus, ii, 513
Erosa, ii, 436
Erpetichthys, i, 204

Erpetoichthys, i, 450

- figure of, i, 608

Erpichthys, i, 608; ii, 510
Erythrichthys, ii, 347
Erythrinidæ, ii, 162
Erythrinus, ii, 160
escolars, ii, 267, 317
Esmarck, i, 410
Esmeralda, ii, 462
esmeralda de mar,

- figure of, ii, 461

Esocidæ, i, 290; ii, 190, 192

Esox, i, 109, 253, 315, 327, 391; ii, 190, 194

- figure of, i, 328; ii, 192

Etelis, i, 262; ii, 338

- figure of, ii, 337

Etheostoma, i, 129, 283; ii, 310, 315

- figure of, i, 231; ii, 314

Etheostominæ, i, 230, 232; ii, 166, 306, 307, 310
ethmoid, ii, 142

Etmopterus,

- figure of, i, 189, 546

etrumei-iwashi, ii, 52
Etrumeus, ii, 52
Eucalia, ii, 232

Eucitharus,

- figure of, ii, 488

Eucinostomus, ii, 347

Eugnathidæ, ii, 26
eulachon, i, 321; ii, 19, 125, 126

- figure of, i, 320; ii, 124

Euleptorhamphus, ii, 212
Eumicrotremus, ii, 135
Euphaneropidæ, i, 576
Euphrosen, i, 396

Eupomotis, i, 283

- figure of, i, 7, 13; ii, 301

European chub,

- pharyngeals of, i, 48

- teeth of, figured, ii, 164

European lancelet,

- figure of, i, 120

European sculpin,

- figure of, i, 219

European soles, ii, 496

Eurylepis, ii, 14

Eurynotus,

- figure of, ii, 15

Eurypharyngidæ, ii, 156

Eurypharynx, ii, 156

Eurypholis,

- figure of, ii, 136, 137

Euselachii, i, 532

Eusthenopteron, i, 603

Eutæniichthys,

- figure of, ii, 467

Euthynotus, ii, 34
Evenchelys, ii, 153
Eventognathi, i, 405; ii, 160, 162
everglade minnow,

- figure of, ii, 197

everglade pigmy perch,

- figure of, ii, 295

Evermann, ii, 69, 100, 103, 354

- on Panama fishes, i, 274
- portrait of, i, 421
- on Two Ocean Pass, i, 307-310

Evermannellidæ, ii, 135
Evermannella, ii, 136
Eviota, ii, 460, 467
evolution of fishes, i, 223-225, 435-459

- Dean on, i, 223

Exerpes,

- figure of, i, 276; ii, 511

Exocœtidæ, ii, 210, 211, 214
Exocœtoididæ, ii, 134
Exocœtoides, ii, 133
Exocœtus, i, 391; ii, 213

Exoglossum,

- head of, figured, ii, 167

Exonautes, ii, 213
exoskeleton, i, 20
Exostoma, ii, 184
extension of Indian fauna, i, 267
exterior of fish, i, 16-25
external gills,

- figure of, i, 78, 602
- Kerr on, i, 76
- Mauer on, i, 77
- Orr on, i, 77
- Rusconi on, i, 77

extinction of species, i, 240

- causes of, i, 241

Eyclesheimer, i, 428
Eydoux, i, 408
eye of fish, i, 119
eye of flounder,

- in larval stage, i, 174
- migration of, i, 173-176
- Williams on, i, 174-178

eye-of-the-sea, ii, 361
Faber, i, 396
Fabricius, i, 394
Facciola, i, 412
factors of extinction, i, 442
fading of pigment in spirits, i, 235
fair maid, ii, 344
fallfish, i, 311; ii, 167
fall-salmon, ii, 80
family,

- definition of, i, 373

fan-tailed darter, ii, 315

Farquhar,

- on Opah, ii, 244

fat cod, ii, 440
fat head, ii, 388
fatherlasher, ii, 445
faunal areas,

- minor, i, 248

- of Japanese fishes, i, 257

faunal resemblances, i, 259, 260
faunal differences, i, 260, 261
favorable waters have most species, i, 301
fear in fishes, i, 163

- expressions of, i, 165

Felichthys,

- figure of, ii, 179

fiatola, ii, 283

Fierasfer, i, 84; ii, 520

- figure of, i, 159; ii, 522, 523

Fierasferidæ, ii, 158, 522
fighting-fish, ii, 370

- of Siam, i, 163

filefish, ii, 413-415

- figure of, i, 182

filiform, i, 19

Filippi, i, 412
finfold, i, 63, 64

- Balfour's theory of, i, 69

fin migration,

- Dean on, i, 75

- of Heterodontus, i, 75

finnan haddie, ii, 537
fins of fishes,

- described, i, 9, 10, 20, 24, 25
- migration of, i, 75
- morphology of, i, 62-90
- origin of, i, 62

fin-spines, i, 528, 529; ii, 39

- of Hybodus, i, 528, 529

- of Onchus, figured, i, 509

Fischer,

- on fishes of Panama, i, 275

Fish Commission,

- fish stocking by, i, 346

fisheries,

- economic, i, 337

- salmon, i, 81, 87

fishes,
in action, i, 11
adaptation to environment, i, 156
affection of, i, 167
affected by temperature, i, 149
age of, i, 144, 146
air-bladder of, i, 12, 92, 93
alimentary canal in, i, 31
anadromous, i, 156, 160, 291
anger of, i, 165
in aquaria, i, 150, 165
blood of, i, 11
body form of, i, 16
bones of, i, 10
bony, i, 454, 506
brain of, i, 12, 14, 109, 112
breathing of, i, 5, 91, 103
of British Museum, i, 402
burrowing of, ii, 463, 465
care of eggs by, i, 128
catadromous, i, 162, 291
catalogues of, i, 402
channel, i, 291
circulatory organs of, i, 26
classification of, i, 367-386
of Coal Measures, i, 223
collecting of, i, 429
color and coloration of, i, 6, 129, 226-236
conditions of life of, i, 215
of coral reefs, i, 235
currents affecting, i, 243, 244
deep sea, i, 408
definition of, i, 3
degeneration in, i, 54, 216, 218-220; ii, 547
digestion and digestive organs of, i, 11, 26
diœcious, i, 124
dispersion of, i, 318
diseases of, i, 340-358
dissection of, i, 26, 27
distortion in, i, 129
distribution of, i, 237-255, 435
domestication of, i, 149, 151
ear of, i, 8, 119-121
earliest forms of, i, 443
eggs of, i, 125-135
electric organs of, i, 25; ii, 187
embryology of, i, 131-151
evolution in, i, 223, 435-459
exterior of, i, 16-25
extinct, i, 224
eye of, i, 6, 119
eye-stalks of, ii, 466
face of, i, 5
fins of, i, 9, 10, 24
flight of, i, 167
flow of blood in, i, 107
as food for man, i, 320-339
food of, i, 11, 29
form of, i, 4
fossil, i, 422-428
fresh-water, i, 250
gall-bladder in, i, 26
generalized forms of, i, 224
gills of, i, 92
growth of, i, 30, 144
habits of, i, 152
hearing of, i, 8, 119
heart of, i, 11, 28, 106
herbivorous, i, 30, 155; ii, 364
hermaphrodite, i, 124
homologies of bones in, i, 34
hybridism in, i, 144
instincts of, i, 154
intestines of, i, 33
intromittent organ in, i, 124
with jugular fins, i, 456
kidneys of, i, 11, 28
killed by earthquakes, i, 356
Labyrinthine, ii, 365
larval forms, i, 142, 620, 621
lateral line of, i, 9
life cycle of, i, 3-5, 152
lowland, i, 291
luminous organs of, i, 188-190
lungs of, i, 98
measurements of, i, 19
migration of, i, 160
monstrosities among, i, 151
mortality among, i, 357
mountain, i, 291
mouth of, i, 29
muscles of, i, 25
mythology of, i, 359
naturalization of, i, 150
nerves of, i, 12, 14, 109, 113; ii, 368
nests and nest-building of, i, 15, 167, 128; ii, 184, 229-231
noises of, i, 121, 168
nostril of, i, 6
nuptial colors in, i, 155, 156
nutrition organs of, i, 29
organs of,

- locomotion, i, 24
- phosphorescence, i, 194
- reproduction, i, 28, 124-130
- sense, i, 115-123
- sight, i, 6, 116
- smell, i, 115
- taste, i, 121
- touch, i, 122

ovaries, i, 26
oviparous, i, 125
ovoviviparous, i, 125
pain, sense of, in, i, 123
parasites of, i, 340-344
parasitic, i, 198
pectoral limb of, i, 50
pelagic, i, 156
pineal eye in, i, 111
poisonous, i, 180-185, 236; ii, 177, 411, 413, 421, 433,436, 526
postembryonic development, i, 132
posterior limbs of, i, 53
preservation of, i, 431
problem of highest, i, 383
protection of young by, i, 128
pugnacity of, i, 162
recognition marks in, i, 7, 232, 236
records of, i, 433
scales of, i, 20
sensitiveness to change, i, 150
sexual modifications in, i, 129
shoulder-girdle of, i, 50, 52
skeleton of, i, 10, 214, 215
specialization in, i, 219, 220, 224, 249; ii, 438
spinal cord of, i, 112
spineless, i, 25
spiral valve in, i, 32
tail of, i, 49
teeth of, i, 5, 29
tenacity of life in, i, 146, 147
timidity of, i, 166
tongue of, i, 6, 31
upland, i, 291
variety in tropics, i, 333
viscera of, i, 26
viviparous, i, 125; ii, 376
voices of, i, 121
where found, i, 158, 159
zeoid, ii, 245
fishes as food, i, 320-339
fishes of Panama,

- Evermann on, i, 274
- Fischer on, i, 275
- Günther on, i, 272, 273
- Hill on, i, 277
- Upham on, i, 276
- Wright on, i, 275

fish faunas,

- genera in, i, 262, 263
- Indian, i, 267
- of Japan, i, 255, 256, 259
- of Mediterranean, i, 259
- of Panama, i, 267
- separated by barriers, i, 255-281

fish fighting, i, 162
fish god of Japan,

- figure of, ii, 343

fish guano, i, 538

Fish-Hawk, the, i, 408; ii, 147
fishing,

- apparatus for, i, 335
- for ayu, i, 333
- for tai, figured, i, 338
- with cormorants, i, 333, 335
- methods of, i, 334

fishing-frog, i, 202; ii, 542

- capture of prey by, i, 169

- figure of, i, 18; ii, 545, 550

fish-like vertebrates, i, 34
fish of Paradise, ii, 369

Fistularia, i, 85, 393; ii, 233, 390

- shoulder-girdle of, ii, 227

Fistulariidæ, ii, 227

- family of, ii, 233

Flammeo, ii, 254
flashers, ii, 331
flatfish family, i, 177; ii, 48
flatheads, ii, 441
Flesus, ii, 493
Fleurieu's whirlpool, ii, 242
flier, ii, 297
flight of fishes, i, 157
Floeberg, ii, 110

Florida jewfish,

- figure of, ii, 323

Florida lion-fish,

- figure of, ii, 433

flounder, i, 117, 178, 203, 440; ii, 483-485, 488, 493, 494

- development of, i, 144
- diamond, ii, 493
- eel-back, ii, 493
- eyes of, i, 118, 174-178
- frog, ii, 493
- lantern, ii, 488
- larval form, i, 176; ii, 483, 484
- migration of eye, figured, ii, 484
- newly hatched, figured, i, 177
- osteology of, ii, 484
- peacock, ii, 488
- pole, ii, 494
- shoulder-girdle of, i, 58; ii, 2
- starry, ii, 493
- tail of, figured, ii, 486
- vertebræ in, i, 205
- wide-eyed, ii, 488
- wide-eyed, figured, i, 175
- young, figured, i, 175; ii, 482

flower of the surf,

- figure of, ii, 218

flow of blood in fish, i, 107
flukes, ii, 494
flying-fish, ii, 211-214

- figure of, i, 157, 341, 440

- parasites of, i, 342

flyfish, ii, 429
flying gurnard, ii, 456, 458

- figure of, i, 457

flying robin, ii, 458

Fodiator,

- figure of, ii, 213

food-fishes,

- abundance of, i, 329

- relative rank of, i, 320

food of lampreys, i, 491
foolfishes, i, 206; ii, 413

Foot-notes to Evolution,

- reference to, i, 302

foramen, i, 92
forelle, i, 327
Forcipiger, ii, 404

Forgy,

- on oarfish, ii, 473

Forbes, i, 419

- on fish epidemics, i, 340

formalin,

- as preservative, i, 432

Forskål, i, 394
Forster, i, 395
fossil capelin, ii, 126, 127
fossil darters, ii, 315
fossil fishes, i, 205; ii, 48, 52, 53, 56, 174

- Agassiz on, i, 422, 423
- Dean on, i, 422
- earliest forms, i, 568
- figure of, i, 436, 454; ii, 47, 59
- first period of, i, 423
- from Green River, ii, 59
- morphological work on, i, 427
- second period, i, 424
- study of, i, 424
- third period, i, 427

fossil gobies, ii, 467
fossil herring,

- figure of, i, 453; ii, 52

fossil trout, ii, 62, 118
four-eyed fish,

- figure of, i, 117

four-spined stickleback,

- figure of, ii, 232

Fowler, i, 422
fox shark, i, 536
Frère Jacques, ii, 255
fresh-water eels, ii, 149
fresh-water fishes, i, 209; ii, 157, 160, 161

- dispersion of, i, 282-296
- distribution of, i, 249
- Günther on, i, 249
- of Japan, i, 256
- of North America, i, 290

fresh-water minnows, i, 33
fresh-water perch,

- figure of, ii, 373

Friar Odoric,

- on fear in fishes, i, 166

Fries, i, 410
frilled shark, i, 361, 516

- figure of, i, 525

Fritsch, i, 427, 428, 512
frog,

- arm of, figured, i, 601

frogfish, i, 197; ii, 549

- figure of, ii, 551

frog flounder, ii, 493
frostfish, ii, 537
Fucus, ii, 512
Fullarton, i, 177
function of lateral line, i, 23

Fundulus, ii, 194, 199

- figure of, i, 198

fur seal,

- food of, ii, 127, 537

Gadidæ, i, 290; ii, 522, 533

Gadopsidæ, ii, 516

Gadus, i, 209, 391

- figure of, i, 331; ii, 533

Gazza, ii, 287
gaff-topsail cat,

- figure of, ii, 179

Gaidropsarus, i, 209; ii, 539
Gaimard, i, 406
galafata, ii, 413

Galaxias, i, 223, 252, 253, 254

- Boulenger on, ii, 204, 205

Galaxiidæ,

- family of, ii, 204

Galei, i, 532

Galeidæ, i, 540

Galeichthys, i, 128, 242, 271, 273; ii, 178

- figure of, ii, 179

Galeocerdo, i, 541, 542
Galeoid sharks, i, 519
Galeorhinidæ, i, 532, 540
Galeorhinus, i, 454

Galeus,

- figure of, i, 541

gall-bladder, i, 26
galliwasp, ii, 130
galo, ii, 394
Gambusia, i, 64, 66, 67; ii, 199
Ganocephala, i, 85, 86
Ganoidei, i, 444, 599, 616; ii, 2, 3, 13

Ganoids, i, 22, 38, 88, 91, 139, 157, 159, 186, 204, 384, 569, 622; ii, 1-36

- Agassiz on, ii, 9
- air-bladder in, i, 109
- classification of, ii, 13
- Gill on, ii, 9
- as a group, ii, 4, 9

ganoid fish, i, 582

- figure of, i, 452, 453

Garden, i, 390

Garibaldi,

- figure of, i, 227; ii, 382

garfish, ii, 147, 210, 211

- shoulder-girdle in, i, 59

Garman, i, 405, 408, 420; ii, 183

- on blind fish, ii, 202
- on frilled shark, i, 525
- on Sunapee trout, ii, 109

garpike, i, 290; ii, 30-32

- figure of, ii, 27
- fossil, ii, 32
- tail of, i, 82
- vertebræ of, i, 48

garrupa, ii, 323
gaspergou, ii, 354

Gasteronemus, ii, 288

- figure of, ii, 289

Gasterosteidæ, i, 128, 290

- family of, ii, 228, 232

Gasterosteus, i, 161, 172, 391; ii, 229, 231, 236

- Lord on, ii, 230

- figure of, ii, 232

Gastrostomus,

- figure of, ii, 156

gastrula, i, 131, 132

Gaudry,

- on leptocercal tail, i, 84

Gay, i, 415

Gegenbaur, i, 428, 511, 512, 591, 594, 601

- on archipterygium, i, 60
- on morphology, i, 68
- on pectoral fin, i, 67
- theory of, i, 73

Gempylidæ,

- family of, ii, 267

Gempylus, ii, 267
general laws,

- of development, i, 133

- of distribution, i, 239

generalization and specialization, i, 380
genital organs, i, 124
genus, i, 375

- definition of, i, 372

Genyonemus, ii, 356

Genypterus, ii, 520
geographical distribution, i, 237-259

- of sharks, charted, i, 459

geological evidence of submergence, i, 268
Geophagus, ii, 381
Geotria, i, 491
Gephyrura, ii, 201
Gephyroberyx, ii, 252
gephyrocercal tail, i, 84, 604

- figure of, i, 85

German carp, ii, 175
germ-cells, i, 124

Germo, 210; ii, 262, 266

- figure of, ii, 263

Gerres, i, 271, 273

- figure of, ii, 349

Gerridæ, i, 206; ii, 372

- family of, ii, 347

Gervais, i, 408
ghost-fishes, ii, 150, 516
giant bass, ii, 324
Gibbes, i, 426

Gibbons, i, 419

- on Embiotocidæ, ii, 377

Gibbonsia,

- figure of, ii, 508

gibbus, ii, 45
Gigactinidæ, ii, 551
Giglioli, i, 412
Gila, i, 304; ii, 169

Gilbert, i, 408, 415, 420; ii, 239

- on Astroscopus, i, 187
- on coracoid plate, ii, 206
- on flight of fishes, i, 157
- on island forms, i, 240
- on larval forms, i, 142
- portrait of, i, 421

Gilbertidia, ii, 441, 447, 449

- figure of, ii, 451

Gill, i, 408, 419, 448, 528, 591, 594, 600; ii, 24, 34, 40, 52, 317, 365, 366, 502, 511

- on anglers, ii, 543
- on Discocephali, ii, 470, 471
- on eels, ii, 143, 156
- on high and low forms, i, 383
- on work of Lacépède, i, 398
- on New Zealand fauna, i, 252
- on paired limbs, i, 85
- portrait of, i, 407
- on Selachii, i, 509
- on shoulder-girdle, i, 86-89
- sketch of, i, 405
- on soles, ii, 496
- on swallowers, ii, 360, 361
- on tilefish, ii, 361, 362

gill,

- arches, i, 45, 91, 508
- basket, figured, i, 92, 485
- covers, i, 44
- filaments, i, 107
- offices of, i, 11
- openings, i, 91
- rakers, i, 31, 46
- septum, i, 73
- slits, i, 508

Gillellus, ii, 506

Gillichthys, ii, 462

- figure of, ii, 463

Gillicus, ii, 48
Ginglymodi, ii, 24, 30
Ginglymostoma, i, 533
Ginglymostomidæ, i, 533
Girard, i, 405, 419; ii, 378, 379
girdle in Dipnoans, i, 86
Girella, ii, 348
gisu, ii, 46
gizzard-shad, i, 290; ii, 51, 53
glacial epoch,

- effect on dispersion, i, 316

Glaucosoma, ii, 323, 340
Glandiceps, i, 465
Glanencheli, ii, 187
glassy darter, ii, 313
glenoid, i, 90

Glesnæs oarfish, ii, 472

- figure of, i, 363

globefishes, i, 197, 440, 455; ii, 419

- figure of, i, 244; ii, 422

Globulodus, ii, 15

Glossobalanus,

- figure of, i, 464

- larva of, figured, i, 463

glut-herring, ii, 50

Glyphisodon, i, 267

- figure of, ii, 383

Glyptocephalus, i, 206; ii, 494
Glyptolepis, i, 603
Glyptopomus, i, 604
Gmelin, i, 395, 397
Gnathanacanthidæ, ii, 514
Gnathodentex, ii, 341

Gnathonemus,

- figure of, ii, 189

Gnathostomata, i, 78
Gnathostomes, i, 35, 572, 573
Gnathostomi, i, 508, 570

Gnathypops,

- figure of, ii, 359

goatfish, i, 198; ii, 351, 379

- figure of, i, 122

gobies, i, 428; ii, 459

Gobiesox, ii, 529, 530, 531

Gobiidæ, i, 22, 206, 290; ii, 306

- family of, ii, 459

Gobius, i, 208, 273, 391; ii, 461, 467
Gobio, ii, 167, 175
Gobioides, ii, 467
Gobioidea, ii, 470

Gobioidei, 11, 459-480

- suborder of, ii, 459

Gobiomorus,

- figure of, i, 160

Gobionellus, i, 208

- figure of, ii, 461

Gobiosoma, i, 313; ii, 462
goblin sharks,

- figures of, i, 535

goby, i, 290; ii, 462, 466
gofu, ii, 434

- figure of, i, 229

goggler, ii, 275
golden,

- shiner, ii, 167

- goldsinny, ii, 387

- surmullet,

- figure of, i, 322; ii, 352

- trout, ii, 99

goldfish, ii, 170, 171

- of Japan, i, 151

Gomphosus, ii, 390
Goniistius, ii, 363
Goniognathus, ii, 287
Gonioplectrus, ii, 323
Gonorhynchidæ, ii, 54-56
Gonorhynchus, ii, 56
Gonostoma, ii, 129
Gonostomidæ, ii, 129
Gonzalez, i, 414

Goodea, ii, 199, 201

- figure of, i, 126; ii, 200

- with young, figured, i, 126

Goodsira, i, 476
goody, ii, 356
goosefish, ii, 545
Gorbuscha, ii, 73

Goode, i, 408, 419; ii, 307, 308

- on albacore, ii, 267
- on American fisheries, i, 335
- on codfish, ii, 534
- estimate of herring product, i, 330
- on fishing-frog, ii, 545
- on habits of mullets, ii, 219, 220
- on mackerel, ii, 260, 264, 265
- on menhaden, ii, 51
- portrait of, i, 407
- on swordfish, ii, 270

Gordiichthys, i, 211; ii, 153
Gordius, ii, 143, 144
Gosfordia, i, 613
Gosse, i, 415
Gouan, i, 397
gatasami, ii, 361
Gottsche, i, 428
goujon, ii, 182
gourami, ii, 369
gouramy,

- nest of, i, 167

Grammicolepidæ,

- family of, ii, 249

Grammicolepis, ii, 249

Grammistes, ii, 330
grande écaille,

- figure of, ii, 43

Granodus, i, 565
Grantea, ii, 544
Graphiurus, i, 605
Grassi, i, 428
grass rockfish, ii, 429
Gray, i, 416
grayling, i, 150, 305; ii, 120-138
gray snapper, ii, 335

- figure of, ii, 334

Great Basin,

- chub of, i, 287
- dispersion of fishes in, i, 316
- fishes of, i, 302

great blue cat, ii, 180
great oarfish, ii, 472
Greeley, i, 422

Green,

- on Sacramento perch, i, 179

green-backed trout, ii, 104

- figure of, ii, 105

green cod, ii, 537

Greene,

- on Porichthys, i, 190-197; ii, 526

greenfish, ii, 348
Greenland char, ii, 109
Greenland halibut, ii, 491
Greenland shark, i, 547
greenling, ii, 439

- figure of, ii, 440

green mackerel,

- figure of, ii, 275

Green River shales, i, 205; ii, 52, 57-59
green rockfish, ii, 429
green-sided darter,

- figure of, i, 247; ii, 312

green wrasse, ii, 387

Gregarinidia, i, 242
grenadier, i, 84; ii, 540

- figure of, ii, 541

grilse, ii, 91
grindle, ii, 35
griset,

- figure of, i, 523

Gronias, ii, 181
Gronovius, i, 390
groupers, ii, 323
grubby, ii, 446
grunt, i, 239

- figure of, ii, 340

grunters, ii, 340
gruntfishes, i, 121
Grystes, i, 302

Guacamaia, ii, 394

- figure of, i, 330

guahu, ii, 266
guasa, ii, 323
guavina de rio, ii, 459

- figure of, ii, 460

Guaymas,

- fishes of, i, 274

gudgeon, i, 122; ii, 167
Guichenot, i, 412, 415
guipo, ii, 512
guitar-fishes, i, 550

- figure of, i, 551

gular plate, i, 43; ii, 33

Güldenstadt, i, 395

Gulf Stream, i, 239

- deep-sea fish of, i, 276

gulper-eel, ii, 156
gulpers, ii, 155
gunnel,

- figure of, ii, 512

Gunner, i, 396; ii, 245

Günther, i, 88, 255, 259, 404; ii, 3, 95, 135, 161, 183, 229, 371

- on archipterygium, i, 60
- on Barramunda, i, 615
- catalogue of, i, 402
- on work of Cuvier, i, 400
- on deep-sea fishes, ii, 136
- on dispersion, i, 289
- on eels, ii, 141
- on electrophores, ii, 188
- estimate of eggs by, i, 128
- on fishes of Panama, i, 272, 273
- on Lepidosteus, ii, 5
- on month gestation, i, 173
- on pain in fishes, i, 123
- on poison glands, i, 180; ii, 527-529
- portrait of, i, 403
- on respiration, i, 91
- on salmon, ii, 92
- on sea-devils, ii, 547
- on trout, ii, 94
- on variation in vertebræ, i, 210
- on zones of distribution, i, 249, 251

gunwale, ii, 512

Gurley,

- on parasitic diseases, i, 342

gurnard, i, 122, 198, 208, 209; ii, 456
gurry shark, i, 547
Gymnarchidæ, ii, 188
Gymnarchus, ii, 188
Gymnelis, i, 209; ii, 519
Gymnocanthus, ii, 448
Gymnocephalus, ii, 241, 310
Gymnodontes, ii, 398, 411, 418, 422
Gymnosarda, ii, 262

Gymnothorax, i, 211, 274; ii, 152

- figure of, i, 458; ii, 154, 155

Gymnonoti, ii, 159-161, 188

- order of, ii, 187

Gymnotidæ, ii, 187
Gymnotus, i, 391
Gyrinidæ, ii, 222

Gyrodus,

- figure of, ii, 22

Gyrolepis, ii, 14

Gyrosteus, ii, 18

Gyroptychius, i, 82

- figure of, i, 604

habits of fishes, i, 152
haddock, ii, 537

- figure of, ii, 536

- skull of, figured, ii, 536

Hadrodus, ii, 22

Hadropterus, i, 300

- figure of, ii, 311

haë, ii, 117, 118

Hæckel, i, 411, 511

- on origin of fins, i, 62

hæmal arch, ii, 6

Hæmapophyres, i, 48

Hæmulidæ, i, 206; ii, 340, 342, 359

- family of, ii, 340

Hæmulon, i, 121, 238, 271, 274, 375

- figure of, ii, 340

hagfishes, i, 28, 488

- Delfin on feeding of, i, 489
- egg of, figured, i, 127
- figure of, i, 199, 489
- and lampreys, i, 189

hair-worm, ii, 144
hake, ii, 136, 539, 540

- isocercal tail of, i, 83

- shoulder-girdle of, i, 60

hakone dace, i, 257
Haldeman, i, 419
Halec, ii, 33, 136

Halecomorphi, ii, 13, 23, 24, 29, 35

- order of, ii, 33

half-beak,

- figure of, ii, 212

half-moon fish, ii, 350
halibut, 128; ii, 149, 489, 491

- figure of, i, 332; ii, 492

- fishery, ii, 490

Halichœres, i, 207, 257, 297; ii, 180, 388-390

- figure of i, 297; ii, 396

Halientichthys, ii, 552

Hallock,

- on black bass, ii, 302

- on Esox, ii, 192

Halosauridæ, ii, 158
Halosaurus, ii, 138
Hamilton, i, 416
hammerhead shark, i, 543

- figure of, i, 544

Hancock, i, 415
handsaw-fish, ii, 135

Hansen,

- on Chinook salmon, ii, 85

Haplistia, i, 602
Haplochiton, ii, 128
Haplochitonidæ, ii, 129, 204

Haplodoci, ii, 499

- sub order of, ii, 525

Haplomi, i, 405; ii, 34, 40, 41, 129, 188-207, 224, 250

- mesocoracoid arch in, ii, 189

- ventral fin, i, 67

Haplopagrus, i, 271
hard-tails, ii, 169

Hardwicke,

- on affection in fishes, i, 167

harelip-sucker, ii, 174
Harengula ii, 51
Harpagiferidæ, ii, 501
Harpodon, ii, 131

Harrimania,

- figure of, i, 465

Harrimaniidæ,

- family of, i, 465

- low organization of, i, 465

Harriottia, i, 199, 566

- figure of, i, 449

harvest-fish, ii, 283

- figure of, i, 18; ii, 284

Hasse, i, 428, 543

- on Elasmobranchs, i, 509
- on ossicles, i, 96
- on sharks, i, 509, 530, 561

Hasselquist, i, 389
Hatta, i, 418
Hauy, i, 397

Hawaii,

- fish fauna of, i, 243

Hay, i, 419, 427, 581; ii, 4 34, 36

- on fossil eels, ii, 22
- on Pycnodonti, ii, 22
- on varieties of sharks, i, 528, 529

hazé, ii, 118
headfishes, i, 19, 84, 206

- figure of, ii, 424

- larva of, figured, i, 143

headlight-fish,

- figure of, i, 188; ii, 132

Heart Lake tapeworm, i, 348

- Linton on, i, 348-350

heart of the fish, i, 106
Hector, i, 416
Helicolemus, i, 259; ii, 429, 432

Helicoprion,

- teeth of, figured, i, 530

Heller, i, 422
Helodus, i, 531
Helostoma, ii, 370
Helostomidæ, ii, 370
Hemerocœtidæ, ii, 506
Hemianthias, ii, 330

Hemibranchii, ii, 40, 157, 209, 227-240

- sub order of, ii, 227

Hemichordata, i, 461
Hemicyclaspis, i, 576
Hemiexocœtus, ii, 213
Hemigymnus, ii, 390

Hemilepidotus, ii, 442

- figure of, ii, 443

Hemipteronotus, ii, 390

Hemiramphus, ii, 214, 268

- figure of, ii, 212

Hemiscylliidæ, i, 533

Hemitripterus, i, 595; ii, 441

- figure of, i, 220; ii, 448

Heniochus, ii, 404

Henle, i, 405

Henshall,

- on black bass, ii, 302

Henshaw, ii, 523

- photograph by, i, 281

hepatic sinus, i, 108
Heptadiodon, ii, 423
Heptanema, i, 605
Heptatrema, i, 490

Heptranchias, i, 447, 509, 536

- pectoral fin in, figured, i, 57
- skull of, i, 56
- teeth of, figured, i, 524

Herald, i, 408

Herbert,

- on lake trout-fishing, ii, 115

herbivorous fishes, i, 30; ii, 364
Herdmania, i, 474
hermaphrodite fish, i, 124
Heros, i, 314; ii, 381
Herpetichthys, i, 608
herring, i, 21, 204, 290, 429, 440; ii, 33, 38, 43, 46, 49, 52, 73, 123, 159

- figure of, i, 331; ii, 48
- Goode on, i, 330
- product of, i, 330

Hertwig, i, 112
Herzenstein, i, 411
Heterandria, i, 314; ii, 194, 201, 467
Heterobranchus, ii, 186
heterocercal tail, i, 49, 507, 513, 516, 602

- of Acipenser, figured, i, 80
- of Amia, figured, i, 82
- of garpike, figured, i, 82
- of Lepisosteus, figured, i, 82
- of Salmo, i, 83
- of sturgeon, figured, i, 80
- of young trout, i, 83

Heterocongridæ, ii, 150

Heterodontus, i, 128, 447, 536

- eggs of, figured, i, 128, 527
- figure of, i, 75, 526
- lower jaw, figured, i, 526
- pectoral fin of, figured, i, 57

Heterodontidæ, i, 65, 127, 447, 511, 523, 529, 530, 545

- family of, i, 527

Heterognathi, ii, 161, 162

Heteromi, i, 405, 611; ii, 12 138, 532

- order of, ii, 157

Heteropleuron, i, 483
Heterostichus, ii, 507
Heterosomata, ii, 247, 481-498
Heterosteus, i, 586

Heterostraci, i, 568, 571, 622; ii, 13

- order of, i, 573

Heterotis, ii, 56

Hexagrammidæ, ii, 442, 501

- family of, ii, 439

- organs of smell in, i, 115

Hexagrammos, i, 257; ii, 107, 439

- figure of, ii, 440

Hexanchidæ, i, 509, 528

- family of, i, 524

Hexanchus, i, 447, 524

- figure of, i, 523

hickory shad,

- figure of, ii, 53

high and low forms,

- Agassiz on, i, 380, 381
- Gill on, i, 383
- Traquair on, i, 381, 382

Hilgendorf, i, 411, 416

- portrait of, i, 417

Hilgendorfia, ii, 455

Hill, i, 415

- conclusions of, i, 277, 279

Himantolophus, ii, 549
hinalea, i, 158
hingio, ii, 128

Hiodon, i, 291, 394; ii, 45, 46

- figure of, ii, 45

Hiodontidæ, i, 290; ii, 45

Hippocampus, i, 19; ii, 236

- figure of, i, 17, 250; ii, 238

Hippoglossinæ, ii, 489

Hippoglossoides, i, 205; ii, 491

Hippoglossus, i, 205, 329; ii, 489

- figure of, i, 332; ii, 492

hirondelle, i, 408; ii, 60
His, i, 428
Histiopteridæ, ii, 398
Histiopterus, i, 260; ii, 333
Histiothrissa, ii, 52
history of ichthyology, i, 387-428
Hoffman, i, 412; ii, 546
hog-choker,

- figure of, ii, 496

hogfish, ii, 388

- figure of, ii, 387

Holacanthus, ii, 403

- figure of, ii, 404, 405

- skeleton of, figured, i, 214

Holbrook, i, 419

Holcolepis,

- figure of, i, 454; ii, 43

Holconoti, ii, 365, 379, 380

- suborder of, ii, 372

Holconotus, i, 404; ii, 375

Holden, ii, 291

Holder, ii, 409, 474

- on oarfish, ii, 474

Holostei, i, 624; ii, 24
Holotrachys, ii, 256
Hollard, i, 412
Hollardia, ii, 412

Holocentridæ,

- family of, ii, 253

Holocentrus, i, 267; ii, 253, 255

- figure of, ii, 254

Holocephali, i, 448, 508, 519, 520, 561-567
Holopterus, ii, 41
Holoptychiidæ, i, 602, 603, 624

Holoptychius,

- basal fin of, figured, i, 603
- dorsal fin of, figured, i, 49
- figure of, i, 451

Holostomi, ii, 140, 141

Holothurian, ii, 522

- Fierasfer issuing from, i, 159

Holurus, ii, 14
Homalopteridæ, ii, 176
Hombron, i, 408
Home, i, 396
Homistius, i, 586
homocercal tail, i, 49, 81-83, 602

- figure of, i, 84

- of flounder, i, 84

homologies,

- of bones, i, 34, 35

- of pectoral limb, i, 85

Homonotus, ii, 253
homoplasy, i, 296
Homosoma, ii, 283

Hooker,

- on fishes prey of birds, i, 166

Hoplias, ii, 162
Hoplichthyidæ, ii, 441
Hoplichthys, ii, 441
Hoplopagrus, i, 271

Hoplopteryx,

- figure of, i, 438; ii, 253

Hoplostethus, i, 260, 263; ii, 252

Hoppin,

- on blind fish, ii, 202, 203

Hornbaum-Hornschuch, ii, 144
horn-dace, i, 122, 283; ii, 167

- figure of, i, 285; ii, 168

horned pout, ii, 35, 180

- figure of, ii, 181

horned trunkfish, i, 374

- figure of, i, 373, 376; ii, 416

hornfish, ii, 412
hornless trunkfish, i, 378; ii, 418

- face view of, i, 379

- figure of, i, 378; ii, 416

horse-eye-jack, ii, 276
horsehead-fish, ii, 276

- figure of, i, 148

horse-mackerel, ii, 135

- figure of, ii, 274

horseshoe-crab,

- figure of, i, 572

Houttuyn, i, 394, 416
how fish cross watersheds, i, 306
how fishes breathe, i, 91
how to secure fish, i, 429
Hoy, i, 419; ii, 64
huchen, ii, 106

Hucho, i, 253; ii, 62, 106

- figure of, ii, 107

Humboldt, i, 410

- on gas in swim-bladder, i, 95

humpback salmon, ii, 68, 72, 80

- figure of, ii, 70, 72

humpback sucker, ii, 174
humpback whitefish, ii, 65
Hutton, i, 416

Huxley, i, 424, 428, 593, 601; ii, 3

- on herring product, i, 330

- on Lepidostei, ii, 23

Hybocladodus, i, 522

Hybodus, i, 528, 529

- eggs of, figured, i, 527

- fin-spine of, figured, i, 528, 529

Hybopsis, ii, 167
hybridism, i, 144; ii, 94
Hydrocyon, ii, 162
Hydrolagus, i, 564
Hyodon, i, 302
Hyoganoidea, ii, 24
Hyoganoids, ii, 11
hyomandibular, i, 508, 521, 606
hyostylic skull, i, 508, 561; ii, 7

- figure of, i, 56

Hypamia, ii, 36
hypercoracoid, i, 89; ii, 1, 12
Hyperoartia, i, 488, 490, 593
Hyperoplus, ii, 521
Hyperotreta, i, 488, 593
Hyperprosopon, ii, 375
hypocoracoid, i, 89; ii, 12

Hypocritichthys,

- figure of, i, 309; ii, 375

Hypohomus, ii, 312

Hypophthalmidæ, ii, 185

Hypoplectrus, i, 235, 271; ii, 237

- figure of, ii, 329

Hyporhamphus, ii, 212

Hypostomides, ii, 227-240

- suborder of, ii, 239

Hypotrema, i, 549
hypural, ii, 142
Hypseleotris, ii, 460
Hypsoblennius, i, 242
Hypsopsetta, ii, 493

Hypsurus, ii, 375

- figure of, ii, 373

Hypsycormus, ii, 34

Hypsypops,

- figure of, i, 227; ii, 382

Hyrtl, i, 428

Hysterocarpus, i, 304; ii, 374

- figure of, ii, 373, 379

Icarus, ii, 43
icefish, i, 146; ii, 123, 127

- figure of, i, 149; ii, 128

Icelinus, ii, 442
Icelus, ii, 442, 449
Icosteidæ, ii, 285
Icosteus, ii, 285

Ictalurus, i, 291, 292; ii, 179-181

- figure of, i, 280

ichthyized fishes, i, 210
Ichthyocephali, ii, 140, 141
Ichthyodectes, ii, 48
Ichthyodectidæ, ii, 48
Ichthyodorolites, i, 516, 529, 566
ichthyologists,

- portraits of, i, 399, 403, 407, 409, 413, 417, 421, 425, 513, 516, 525, 545, 561, 599, 601

ichthyology,

- Aristotle on, i, 387

- history of, i, 387-428

Ichthyotomi, i, 437, 446

- order of, i, 519

- Parker & Haswell on, i, 520

Ichthyomyzon, i, 491
Ichthyopsida, i, 601
Ichthyosism, i, 183
Ichthysauroides, i, 586
Icthyscopus, ii, 503

Ictiobus, i, 291; ii, 172

- figure of, ii, 173

- shoulder-girdle of, i, 51; ii, 160

id, ii, 168
Idiacanthidæ, ii, 138
Idus, ii, 168
igami, ii, 390
Ilarches, ii, 400
Ilarchidæ, ii, 291, 400, 401
Ilarchus, ii, 398
Ilisha, i, 271; ii, 52
Ilyophidæ, ii, 150
imaginary garpike, i, 364
incisor teeth, figured, i, 31
inconnu,

- figure of, ii, 67

Indian fauna, i, 267

- extension of, i, 265

Indian fish, ii, 405

Indian sawfish,

- figure of, i, 200

Indian parrot-fish,

- figure of pharyngeals, ii, 393

Indigo damsel-fish

- figure of, ii, 384

infraclavicles, ii, 13
infundibulum, ii, 6
Iniistius, ii, 389, 390

Inimicus, i, 236; ii, 434

- figure of, frontispiece, II. Vol.

Iniomi, i, 405; ii, 38, 40, 41, 138, 189, 190, 204, 526

- suborder of, ii, 129

iniomous fishes,

- photophores of, i, 189

instincts in fishes,

- basis of, i, 154
- classification of, i, 154
- of courtship, i, 155
- heredity in, i, 154
- of migration, i, 156
- variability of, i, 155, 156
- Whitman on, i, 156

intensity of coloration, i, 232
interclavicle,

- Starks on, ii, 227

interhæmals, i, 49; ii, 348
interneurals, i, 49; ii, 15
intestine of fish, i, 33
intromittent organ, i, 124
Investigator, the, i, 408; ii, 60
Ioa, ii, 313
Ionoscopus, ii, 36
Ipnopidæ, ii, 131

Ipnops,

- figure of, i, 181; ii, 131

Irish lord, ii, 442

- figure of, ii, 443

Irish Pampano,

- figure of, ii, 349

isabelita,

- figure of, ii, 404

Isaciella, i, 270
isaki, ii, 342
Ischnacanthidæ, i, 517
Ischnacanthus, i, 517
Ischyodus, i, 565
ishigakidai, ii, 360
Ishikawa, i, 416
ishinagi, ii, 323

Iso,

- figure of, ii, 218

isocercal tail, i, 49, 83, 602

- Cope on, i, 84

- figure of, i, 83

Isopholidæ, ii, 26

Isopholis, ii, 26

- figure of, ii, 27

Isospondyli, i, 204, 406; ii, 26, 28, 29, 33, 34, 36, 37-60, 128, 129, 138, 139, 142, 148, 159, 160, 188-190, 209, 250

- order of, ii, 38

Isotœnia, i, 565
isthmus, i, 45
isthmus barriers, i, 255-281

Isthmus of Panama,

- as barrier, i, 269
- fish fauna of, i, 266, 271
- species of shores, i, 269

Isthmus of Suez, i, 255, 258

- as barrier, i, 266

- submergence of, i, 267

Istiæus,

- figure of, ii, 46

Istiophoridæ, ii, 268
Istiophorus, ii, 269
Istlarius, ii, 182

Isuropsis,

- figure of, i, 537

Isurus, i, 537, 538

Italian parrot-fish, i, 48

- figure of, ii, 391

ito,

- figure of, ii, 107

itoryori, ii, 340
iwana, ii, 114
jack mariddle, ii, 43

Jackson,

- on Embiotocidæ, ii, 375, 393

Jacobi,

- artificial impregnation by, i, 150

Jacoby,

- on origin of eels, ii, 144, 145

Jacquinot, i, 408
Jadgeska hatchery, ii, 86
Jækel, i, 427, 428, 591
jallao, ii, 341

Janassa,

- teeth of, i, 554

Japan,

- Black Current of, i, 255, 256, 258
- fishes of, i, 256
- fresh-water fauna of, i, 256

Japan and Mediterranean

- fish faunas, i, 259, 260

Japanese blenny,

- figure of, i, 9; ii, 513

Japanese catfish, ii, 183

Japanese dace, ii, 170

Japanese filefish,

- figure of, i, 241

Japanese samlet,

- figure of, i, 321

Japanese sea-horse,

- figure of, i, 250

jaqueta, ii, 383
jara-bakka, i, 171
jawfish,

- figure of, ii, 359

jaws, i, 201

- of Amia, i, 43
- bones of, i, 41, 43
- figured, i, 30, 43, 583; ii, 39
- of parrot-fish, i, 30; ii, 391, 393
- of shark, i, 35

Jenkins, i, 420; ii, 52

- on fishes of Panama, i, 274

Jenkinsia, ii, 52
Jenyns, i, 408
Jerdon, i, 416
Jerusalem haddock, ii, 244
Jeude, i, 414
jewfishes, ii, 321, 323
jiguagua, ii, 276
jocu, ii, 336

John,

- on climbing-fish, ii, 367

John dories, ii, 245, 247

- figure of, ii, 248

Johnny darter, ii, 313

John Paw,

- figure of, ii, 325

Johnson, i, 410

- on interbreeding of trout, ii, 94

Johnston, i, 428
jolt-head porgy,

- figure of, ii, 344

Jordan, i, 348, 408; ii, 522

- on parent stream theory, ii, 81

- portrait of, i, 421

- on return of salmon to spawning grounds, ii, 83

Jordanella, i, 314; ii, 198

- figure of, ii, 197

Jordania, ii, 441, 449

- figure of, ii, 442

Jordanicus, ii, 522
jorobado, ii, 276
joturo, ii, 26

- figure of, ii, 28, 222

Joturus,

- figure of, ii, 222

Jugulares, i, 393

- suborder of, i, 499-506; ii, 39, 499, 534

Julis, i, 158, 235; ii, 389, 390
jurel, ii, 276
kæpra, i, 171
kajika, ii, 118
kaku, ii, 221
Kalm, i, 390

Kamchatka lamprey,

- figure of, i, 495

Kamloops trout, ii, 101

Kansas River,

- blue-green sunfish from, i, 26

Kareius, ii, 494
Karpinsky, i, 529
Kaup, i, 411
kawamasu, ii, 95
kawamuki, ii, 415
Kellogg's Zoology, i, 26

Kelly

- on otoliths, i, 120

kelpfish, ii, 389, 390, 507
kelts, ii, 91

Kent,

- on anglers, ii, 543, 544

Kerr, i, 619

- on Balfour's theory, i, 72
- on fin migration, i, 74
- on Gegenbaur theory, i, 73
- on external gill, i, 76, 78
- on Lepidosiren, i, 61, 620
- on morphology, i, 68

Kessler, i, 411
Kessleria, i, 252, 452; ii, 18, 20
keta, ii, 73
Kettleman, ii, 545
kihi kihi, ii, 406
killer, i, 361
killifish, i, 290, 304; ii, 194, 198

- hearing of, i, 121

king crab,

- figure of, i, 572

king darter,

- figure of, ii, 311

kingfish, ii, 266, 356

- figure of, ii, 357

king of salmon, ii, 425

- figure of, ii, 478

king of herrings, ii, 425, 472
king of mackerels,

- figure of, ii, 425

king salmon, ii, 68, 69

- anadromous instinct of, i, 160

- grilse, figured, ii, 70, 72

Kingsley,

- on ascidians, i, 474
- on degeneration, i, 460
- on sense organs, i, 175
- on tunicates, i, 466-468

Kirsch, i, 422

Kirtland, i, 418; ii, 35

Kirtlandia,

- figure of, ii, 217

Kishinouye, i, 418
kisugo, ii, 358
Kittlitz, i, 410
Klein, i, 390
Klunzinger, i, 411

Kner, i, 410, 411, 427

- on Ganoids, ii, 10

Kneriidæ,

- family of, ii, 204

knightfish, ii, 257
Knox, ii, 477
kobini-iwashi, ii, 52
kochi, ii, 441
Koenen, i, 427
Koken, i, 427
kokopu, ii, 204
kokos, ii, 71
Kolliker, i, 428
Konwick, i, 427
konoshiro, ii, 53
Kölreuter, i, 396
Kowala, ii, 51
Kowalevskia, i, 474
Kowalevsky, i, 428
Krascheninnikov, i, 395; ii, 68
Krefft, i, 614
Kröyer, i, 410
Kuhlia, ii, 304
Kuhliidæ, ii, 297, 354
kumu, i, 322; ii, 352
Kundscha, ii, 114
Kuppfer's vesicle, i, 138
kurodai, ii, 343
kuromutsu,

- figure of, ii, 213

Kuro Shiwo, i, 242, 251, 258

- fishes in, i, 239

- goblin shark of, i, 534

Kurtidæ, ii, 287
Kurtus, ii, 288
Kyphosidæ, ii, 349, 364, 398

Kyphosus, ii, 350

- figure of, ii, 349

Labidesthes, i, 313; ii, 218
Labrodon, ii, 385
Labrax, ii, 330
Labridæ, i, 207; ii, 372, 385, 390, 396
Labrus, i, 207, 260, 267, 391; ii, 385, 387
labyrinthine fishes, ii, 365, 370

Labyrinthinci, i, 149; ii, 365, 379

- Day on, ii, 365

- Gill on, ii, 365

Labyrinthodontidæ, i, 86
lac de marbre, ii, 109

Lacépède, i, 376, 389

- portrait of, i, 399

Lachnolæmus, ii, 388

- figure of, ii, 387

Lactariidæ, ii, 356

Lactarius, ii, 358

Lactophrys, ii, 417

- figure of, i, 214, 373, 377, 378; ii, 416, 417

- skeleton of, figured, ii, 418

ladyfish, i, 117, 198; ii, 388

- figure of, i, 147; ii, 44

- transformations in, i, 147

La Favorite, the, i, 408

Lafayette, ii, 356

Lagocephalus,

- figure of, ii, 419

Lagodon, ii, 344

Lake Bonneville,

- ancient outlet of, i, 303

lake herring, ii, 65-67
lake lamprey,

- head of, figured, i, 111

- mouth figured, i, 492

Lake Nicaragua,

- shark from, i, 542

Lake Patzcuaro,

- viviparous fishes from, i, 126

Lake Pontchartrain,

- fish fauna of, i, 314

lake trout, ii, 66, 115

- figure of, ii, 114

lake whiting, ii, 65
Lamdodus, i, 522
Laminaria, ii, 544
Lamnidæ, i, 532, 537, 538, 542

Lamna, i, 534, 538

- teeth of, figured, i, 537

- figure of, 447

lamnoid sharks, i, 519, 533

- distinguished, i, 534

- families of, i, 534

Lampetra, i, 491

- figure of, i, 120, 492

lamprey, i, 28, 35, 56, 111, 204, 249, 290, 490, 506

- ascending brook figured, i, 496
- brain of, i, 112
- catfishes destroyed by, i, 358
- extinct forms, i, 487
- fate of, i, 504
- food of, i, 491
- gill-basket of, figured, i, 92, 485
- Kamchatka, i, 495
- method of attack, i, 493
- migration of, i, 494
- orders of, i, 488
- parasites of, i, 354
- Reighard on, i, 491
- spawning of, i, 498, 500
- structure of, i, 486
- Surface on, i, 491

Lamprididæ, ii, 16

- family of, ii, 243

Lampris, i, 210, 322; ii, 228, 245, 288

- figure of, i, 323

- shoulder-girdle, figured, ii, 243

Lanarkia, i, 570, 622

- figure of, i, 574

lancelet, i, 28, 31, 121, 204, 482-485, 506; ii, 467

- characteristics of, i, 482
- figure of, i, 484
- habits of, i, 483
- vertebral column of, i, 55

lancet-fish, ii, 408

- figure of, ii, 135

lancet of surgeon-fish, i, 181
lane-snapper,

- figure of, ii, 336

Lankester, i, 61, 87, 426, 571, 593
lantern-fishes, ii, 41, 61, 128, 129, 525

- figure of, ii, 133

lantern-flounder, ii, 488
laolach, i, 620
Laparus, ii, 518
large-mouthed black bass,

- figure of, ii, 305

Larimus, ii, 355

Larvacea, i, 470, 473

- figure of, i, 480

larval development of fishes, i, 139-141, 143-147, 174-176

- Dean on, i, 139
- in common eel, i, 141
- Gilbert on, i, 142
- figures showing, i, 140-142
- in brook lamprey, i, 140
- in sturgeon, i, 141

larval flounder,

- figure of, ii, 483

larval forms,

- of Chætodon, i, 144
- figures of, i, 140-142
- of flounder, figured, i, 147, 175, 176
- of ladyfish, i, 147
- of Lepidosiren, i, 620, 621
- of Mola, i, 143, 145
- of sailfish, i, 140
- of swordfish, i, 139

Lasianius,

- figure of, i, 580

Lateolabrax, i, 324; ii, 320
lateral fold, i, 64

- Balfour on, i, 71-73
- Kerr on, i, 72
- Mollier on, i, 71

lateral line, i, 9, 22, 23

- a mucous channel, i, 22
- Dean on, i, 23
- function of, i, 23
- relation to touch, i, 122
- in singing-fish, figured, i, 23

Lates, ii, 320, 330
Latham, i, 396
Latilidæ, the, ii, 361, 363
Latilus, ii, 362
Latrididæ, ii, 363, 364, 426
Latris, ii, 363
lavaret, ii, 65
lawyer, ii, 335, 538
Lay, i, 409
Leach, i, 396
leather-carp, i, 151
leather-jackets, ii, 272, 413
Lebias, ii, 198, 201
lectocephalous condition,

- Günther on, i, 142

Leidy, i, 426
Leiognathidæ, ii, 287, 348
Leiognathus, ii, 287
Leiostomus, ii, 356
Leiuranus, ii, 150
length of intestine, i, 33
Lentipes, ii, 466
leopard toadfish,

- figure of, ii, 525

Lepadogaster, i, 263; ii, 531

Lepechin, i, 396

Lepidaplois, ii, 390

- figure of, ii, 389

Lepidocottus, ii, 426, 449

Lepidopidæ,

- family of, ii, 267

Lepidopsetta, ii, 493
Lepidopus, i, 210; ii, 267
Lepidorhombus, i, 206; ii, 488

Lepidosiren, i, 60, 73, 85, 89, 100, 149, 450, 619, 621, 622

- adult male, figured, i, 620

- larval forms, figured, i, 620

- at 3 days, i, 620
- at 30 days, i, 621
- at 40 days, i, 621
- at three months, i, 621

- pectoral fin in, i, 60

Lepidosirenidæ, i, 88, 612, 619

Lepidostei, ii, 13, 26

- Huxley on, ii, 23

- Zittel on, ii, 23, 24

Lepidosteids, ii, 32
Lepidosteoidei, i, 382
Lepidotidæ, ii, 24
Lepidotes, ii, 24
Lepidotrigla, i, 259; ii, 456
Lepisoma, i, 208; ii, 508
Lepisosteidæ, i, 290; ii, 11, 29, 30

Lepisosteus, i, 32, 66, 85, 101, 102, 291, 314, 357, 604, 623; ii, 5, 6, 23, 29, 30, 32

- Agassiz on, ii, 5
- Balfour and Parker on, ii, 5
- Eastman on, ii, 32
- figure of, i, 452; ii, 31
- Günther on, ii, 5, 7
- Müller on, ii, 517
- tail of, figured, i, 82

Lepomis, i, 302; ii, 301

- figure of, i, 4; ii, 300

Leptecheneis,

- figure of, i, 197; ii, 468

leptocardial tail, i, 81, 83
Leptocardians, i, 383
Leptocardii, i, 55, 482-485
Leptocephalidæ, ii, 149

Leptocephalus, i, 211; ii, 148, 149

- figure of, ii, 150

leptocercal tail, i, 50, 81, 83, 507, 602

- Agassiz on, i, 81
- figure of, i, 82
- Gaudry on, i, 84

Leptocottus, ii, 448

Leptolepidæ, ii, 36, 41

Leptolepis, ii, 42

- figure of, ii, 41

Leptomylus, i, 565
Leptops, ii, 182
Leptoscopidæ, the, ii, 503, 506
Leptosmus, ii, 53
Leptotrachelus, ii, 136
Lepturus, i, 391
lesser-weaver, i, 169
Lesson, i, 408
Le Sueur, i, 418
Lethrinus, i, 268; ii, 347

Leuciscus, i, 254, 256, 346; ii, 168, 169

- figure of, i, 287; ii, 169
- pharyngeals of, i, 47
- teeth of, figured, ii, 163, 175

Leuckart, i, 609
Leucopsarion, ii, 467
Lias, ii, 14
Libys, i, 605
Ligul, a, i, 348
Lilljeborg, i, 410
Limanda, ii, 493
little roncador, ii, 356

Limulus, i, 569

- figure of, i, 572

Lindström, i, 427
ling, ii, 538

Linnæus, i, 375, 390; ii, 410, 424, 499

- followers of, i, 394

- Systema Naturæ of, i, 392

Linophryne, ii, 549

Linton,

- on parasitic diseases, i, 343-348

Liodesmidæ, ii, 34

Liodesmus, ii, 34
lion-fish, ii, 434

- figure of, ii, 433, 435

Liopsetta, ii, 493

- figure of, ii, 494

liparid, ii, 447, 454

- figure of, ii, 413, 454

Liparididæ,

- family of, ii, 454

Liparididæ, i, 189, 208, 218; ii, 313

Liparis, i, 202, 217, 219, 375, 380; ii, 449, 455

- figure of, i, 218

Lipogenyidæ, ii, 158
Lipogenys, ii, 158
Lister, i, 373, 375, 376
lithographic shales, ii, 42
Litholepis, i, 364
littoral fishes,

- distribution of, i, 247

Liuranus,

- figure of, i, 233

Liza, ii, 221
lizard-fishes, ii, 61

- figure of, ii, 130

lizard-skipper,

- figure of, i, 230; ii, 509

loach, i, 290; ii, 185

- fossil, ii, 175, 176

Lobotes,

- figure of, ii, 331

Lobotidæ,

- family of, ii, 331

local barriers, i, 298

Lockington, i, 419

- on long-jawed goby, ii, 462-465

log-perch,

- figure of, ii, 311

Lohest, i, 427
lok-sild, ii, 67
longe, ii, 114
long-eared sunfish, i, 3-15

- figure of, i, 2, 3; ii, 300

long-jawed goby, ii, 462, 463

- Cooper on, ii, 463
- figure of, ii, 463
- Lockington on, ii, 462

long-horned sculpin, ii, 447
long-jaw, ii, 66
long-necked eels, ii, 153
lophobranchii, ii, 9, 209, 227-240
lophobranchs, i, 92

- suborder of, ii, 235

Lophogobius, i, 208
Lophiidæ, i, 206; ii, 542
Lophiomus, i, 207, 271; ii, 547

Lophius, i, 169, 202, 206, 391; ii, 542, 545, 547, 548

- figure of, i, 18; ii, 545

lophocercal tail, i, 81, 83

Lopholatilus, i, 94, 357; ii, 361

Lophopsetta, ii, 488

- figure of, ii, 487

Lophotes, i, 260, 263; ii, 291

Lophotidæ, ii, 292

- family of, ii, 291

Loricaria, i, 393

- figure of, ii, 186

Loricariidæ, ii, 185, 186, 449
Loricati, ii, 426, 455
loro, ii, 394, 396

Lota, i, 109, 209, 316; ii, 538

- figure of, ii, 539

Lotella, i, 259
louse-fish, ii, 469
louvar,

- figure of, ii, 290

Loven,

- on Arctic species, i, 317

Lowe, i, 410

Lowell,

- on trout, ii, 108

lower jaw,

- figure of, i, 526
- of Cochliodus figured, i, 531
- of Neoceratodus figured, i, 616
- of Polypterus figured, i, 606

lower pharyngeals,

- figure of, ii, 171

Lower Silurian,

- shark teeth from, i, 508

lowland fishes,

- dispersion of, i, 313

Luciæ, i, 477

Lucifuga, i, 314; ii, 524

- figure of, i, 222; ii, 524

Lucigobius, ii, 467
Luciocephalidæ, ii, 370
Luciocephalus, ii, 370
Lucioperca, ii, 315

Lucas,

- on Therobromus, ii, 127

luminous organs, i, 187

- von Lendenfeld on, i, 189

- of Porichthys, figured, i, 191

Lumpenus, i, 209; ii, 513
lumpfish, i, 208; ii, 135, 453, 454

- figure of, i, 220; ii, 454

lump-sucker, ii, 453, 455
lung-fish, i, 100, 458, 609-622
lungs of the fish,

- origin of, i, 98, 99

- Morris on, i, 98

lurking-fishes,

- Whitmee on, i, 169

Lutianidæ, ii, 323, 335

- family of, i, 333; ii, 340

Lutianus, i, 324; ii, 330, 333, 335, 336

- figure of, i, 331; ii, 333, 335, 336

Lütken, i, 410; ii, 33, 133

- on Selene, i, 144

- on flying-fish, ii, 214

Luvaridæ, ii, 291

Luvarus, ii, 291

- figure of, ii, 290

Lycenchelys,

- figure of, ii, 519

Lycodapodidæ, ii, 520

Lycodes, ii, 518

- figure of, ii, 519

Lycodapus,

- figure of, ii, 520

Lycodopsis, ii, 518
Lycodes, i, 209
Lycoptera, ii, 41

Lyman,

- on the museum at Paris, i, 401

Lyomeri,

- order of, ii, 140, 155

Lyopomi, ii, 138, 158, 189
Lyopsetta, i, 205
Lyrifera, i, 462, 508
Lysopteri, i, 623; ii, 13
maaji, ii, 274
maccaroni piatti, i, 351
Macleay, i, 416, 428
Macdonald, i, 419
Macdonaldia, ii, 157
Mackenzie salmon, ii, 67
mackerel, i, 19, 117, 156, 210; ii, 258, 259

- figure of, i, 332; ii, 260
- fishery, ii, 260, 261
- Goode on, ii, 260

mackerel-midges, ii, 539
mackerel-scads, ii, 274
mackerel-shark, i, 533

- figure of, i, 447, 537

Mackinaw trout, ii, 114
Macrias, ii, 502
Macrodon, ii, 354

Macropetalichthyidæ,

- family of, i, 585

Macropetalichthys, i, 583, 585, 589, 590
Macropharyngodon, ii, 390
Macrophthalmia, i, 491
Macropistius, ii, 26
Macropodus, ii, 369, 370
Macropoma, i, 605
Macrorhamphosidæ, ii, 227, 234, 235

Macrorhamphosus, i, 259

- figure of, ii, 234

Macrosemiidæ, ii, 26, 28

Macrosemius, ii, 26

Macrouridæ, i, 84; ii, 541

- vertebræ in, 209; ii, 540

mademoiselle,

- figure of, ii, 355

mad tom, ii, 182

- figure of, i, 179; ii, 182

Mænidæ,

- family of, ii, 347

magifi, ii, 288
mahogany snapper, ii, 337
maigre, ii, 355
mail-cheek fishes, ii, 426
makrede, i, 171
makua, ii, 425
Malacanthidæ, ii, 361, 499
Malacanthus, ii, 361
Malacopterygii, i, 391; ii, 208
Malacopterygium, ii, 39
Malacorhinus, i, 553
Malacosteidæ, ii, 128, 134
Malapterurus, ii, 183
malau, ii, 253

Mallotus,

- figure of, ii, 126

Malm, i, 410
malma, i, 326

- figure of, ii, 112

Malmgren, i, 410

- on Arctic species, i, 317

Malpighi, i, 390
Malthe, i, 206
Malthopsis, ii, 552
mandible,

- suspensorium of, i, 43, 120

mandibular rami, i, 589
man-eating shark, i, 538

Maner,

- on external gill, i, 77

mangrove snapper, ii, 335
man-of-war fish, ii, 285

Manta, i, 448, 560

- figure of, i, 559

map of continents, i, 270
Mapo, ii, 461
Marcgraf, i, 389
Marcgravia, ii, 526
Marcusen, i, 428
marine blenny, i, 118
marine fishes,

- checked by barriers, i, 241

- distribution of, i, 246

Mariposa, ii, 244, 403

Marquette, ii, 64

Marsh,

- on eye of Anableps, ii, 195

Marsiobranch, i, 592, 593
Marsipobranchi, i, 486
Martin pescador, ii, 550
Mason, ii, 73
Mastacembelidæ, ii, 532

Mastacembelus, ii, 157

- figure of, ii, 532

Masticura, i, 555
masu, ii, 68, 73

- figure of, ii, 71, 72

matajuelo, ii, 252, 253
matajuelo blanco, ii, 361
matao, ii, 249
matodai, ii, 333
matsubara, i, 418
Matthew, i, 427

Mauer,

- on external gill, i, 77

Maurolicidæ,

- family of, ii, 134

Maurolicus, ii, 134
maxillary,

- figure of, i, 55

- of Sebastolobus, i, 55

mayfish,

- figure of, ii, 198

McClelland, i, 416
McCoy, i, 82, 410, 581
McGregor, i, 422
McKay, i, 420
McMurrich, i, 428
meaji, ii, 275
meaning of species, i, 293

- Coues on, i, 379

measurements of the fish, i, 19
mebaru, ii, 429, 431
Meckel's cartilage, i, 44, 57, 507, 596, 606
Meda, ii, 169

Meddagh,

- photograph by, i, 164

Medialuna, ii, 350
medregal, ii, 274

Meek,

- on trout, ii, 105

Megalaspis, ii, 274

Megalichthyidæ, i, 602, 603

Megalichthys,

- figure of, i, 604

Megalops, ii, 43

Megalurus,

- figure of, ii, 36

Megaperca, ii, 322
Megaprotodon, ii, 404
mejenidai, ii, 348
Melamphaës, ii, 252
Melaniris, ii, 218
Melanocetus, ii, 548

Melanogrammus, i, 209; ii, 539

- figure of, ii, 536

- skull of, figured, ii, 536

Melanotænia, ii, 218
Melanotæniidæ, ii, 218
Melichthys, ii, 413

Melletes,

- figure of, i, 288

membrane bone of face, i, 44

Mene,

- figure of, ii, 288

menhaden,

- figure of, i, 340; ii, 51

Menidia, ii, 218

Menidæ,

- family of, ii, 218

Menomonee whitefish, ii, 63

Menopneumona, i, 612

Menticirrhus,

- figure of, ii, 357

mergate fish, ii, 341

Merlangus, i, 209; ii, 537

Merluccius, i, 209; ii, 136

- figure of, ii, 540
- isocercal tail of, i, 83
- shoulder-girdle of, i, 60

Merluciidæ, ii, 540
mermaid, i, 359
merou, ii, 323, 324

Merriam,

- on fossil trout, ii, 62

Mesencephalon,

- figured, i, 109, 110

mesentary, i, 32
Mesichthys, ii, 190
mesocoracoid, i, 89; ii, 12
mesoderm, i, 138
Mesodon, ii, 22

Mesogonistius, ii, 301

- figure of, ii, 299

Mesolepis, ii, 15
mesopterygium, i, 58, 511, 512, 523; ii, 12

Mesopus, ii, 124

- Swan on, ii, 123

Mesozoic fishes, i, 437
metameral characters, i, 23
metapterygium, i, 58, 511, 512, 523; ii, 12
metencephalon, figured, i, 109

Michigan grayling,

- figure of, ii, 122

Microbranchium, i, 577
Microcanthus, ii, 404
Microdesmus, i, 271
Microdon, i, 204

Microgadus, ii, 537

- figure of, ii, 538

Microlepidotus, i, 271
Microperca, ii, 307, 315
Micropogon, i, 271; ii, 356

Micropterus, i, 291, 302; ii, 297, 302, 304

- figure of, i, 325; ii, 303, 305

Microspathodon, i, 271; ii, 384, 385

- figure of, ii, 384

Microstoma, ii, 127
Microstomidæ, ii, 127
Microstomus, ii, 494
midshipman, i, 121, 189; ii, 526

- luminous organs of, i, 191

migratory fishes, i, 160
milkfish,

- figure of, ii, 45

milktschitsch, ii, 73

Miller, i, 426
miller's thumb, ii, 444

- California, ii, 446
- figure of, ii, 445
- Yellowstone, ii, 444

Milner, i, 419

- on whitefish, ii, 64

minnow, i, 33, 124, 304; ii, 118, 161, 163, 193, 196-199

- treatment of eggs by, i, 129

Minous, ii, 436
Mioplosus, ii, 315
Mirbelia, ii, 531
mirror carp, i, 151; ii, 17

Misaki,

- tide pools of, i, 161

Misgurnus, i, 98; ii, 176

Mississippi Valley,

- blind fishes of, i, 117, 220

- stone-roller of, i, 33

Missouri sucker, ii, 173

Mistichthys, ii, 467

Mitchill, i, 376, 418

- on climbing-fish, ii, 367, 368

- on Spanish mackerel, ii, 264

Mitchillina, ii, 60

Mitsukurina, i, 199, 536, 566

- figures of, i, 535

Mitsukurinidæ, i, 534

Mitsukuri, i, 418

- on phosphorescent shark, i, 189

- portrait of, i, 417

Mivart,

- on paired limbs, i, 70

monana, ii, 353

Mobula, i, 448

- fœtus of, i, 560

Mobulidæ, i, 559
mojarra, ii, 348

- figure of, ii, 348

mojarra cardenal, ii, 254
mojarra de las piedras, ii, 405
mojarra de ley, ii, 348
mojarra verde, ii, 381

Mola, i, 19, 84, 142, 206, 272; ii, 424, 425

- figure of, ii, 424

- larva of, figured, i, 143

Molgula, i, 474
Molgulidæ, i, 474
Molidæ, ii, 424
Molina, i, 396

Mollier,

- on lateral fold, i, 71

Mollienesia, ii, 199
Mollusca, ii, 529
Molva, i, 209; ii, 538

Monacanthidæ, i, 242

- family of, ii, 413

Monacanthus, i, 181, 206; ii, 414
du Monceau, i, 396
Mondini, ii, 144
mongrel whitefish, ii, 67
monkfish, i, 359; ii, 545

- brain of, figured, i, 547

- pectoral fin, figured, i, 56

Monocentridæ, ii, 250

- family of, ii, 257

- Houttuyn, discoverer of, ii, 257

Monocentrus, i, 260

- figure of, ii, 257

Monoceros, i, 268; ii, 409

Monodactylus, ii, 398

- figure of, ii, 397

Monolene, i, 206
Monopteridæ, ii, 141
Monopterus, ii, 141
Monorhinus, i, 593
Monotaxis, ii, 344
Monro, i, 390
monstre marin, i, 360, 361
monstrosities among fishes, i, 150
monstrous goldfish,

- figure of, i, 151

Montagu, i, 396
month incubation, i, 170, 171, 172

- Günther on, i, 173

Moorish idols, ii, 406

- figure of, ii, 406

Moodeliar,

- on climbing-fish, ii, 367, 368

mooneye, i, 290; ii, 45
moonfishes, i, 144; ii, 243, 244, 276, 401

- figure of, i, 323

morays, ii, 152, 153

- figure of, i, 458; ii, 155

Mordacia, i, 491
Mordaciidæ, i, 491
Moreau, i, 95, 412
Morgan, i, 428
Moringua, ii, 153, 189

Moringuidæ, ii, 188, 189

- family of, ii, 153

Mormyrus, i, 393

Morone, ii, 321

- figure of, ii, 322

morphology, i, 511

- of fins, i, 62-90

Morris,

- on lungs of fishes, i, 98-106

mortality of filefish, i, 357

Moseley,

- on Ipnopidæ, ii, 131

Moser,

- on catching salmon, ii, 85

moss-bunker, ii, 51
motor nerves, i, 153
mountain chains,

- as barriers, i, 310

mountain-oopu, ii, 466
mountain-witch, ii, 445

Mount Whitney,

- golden trout of, ii, 99

Moxostoma, ii, 174
mu, ii, 344
mucous channels, i, 22, 23
mud-bass, ii, 297
mud-dab, ii, 493
mud-minnows, i, 290; ii, 35, 193, 194
mud-minnows,

- figure of, ii, 193

- tenacity of life in, i, 147

mud-skippers, ii, 465

- figure of, ii, 466

muffle jaws, ii, 444

Mugil, i, 32, 157, 343, 391; ii, 144, 219

- figure of, i, 330; ii, 221

Mugilidæ, i, 206; ii, 219
muki-muki, i, 183; ii, 420

Müller, i, 384, 396, 405, 415, 428, 609, 613; ii, 3, 24, 39, 40, 144, 533

- on elastic spring, i, 96
- on ganoids, ii, 9
- on gas in swim-bladder, i, 96
- on Lepidosteus, ii, 5
- portrait of, i, 399

Mullerian duct, i, 28
mullets, i, 117, 268, 328; ii, 39, 144, 215, 219, 221

- Goode on, ii, 219, 220

Mullidæ, i, 206; ii, 257, 351-379

Mullus, i, 261, 393; ii, 256

- figure of, i, 322; ii, 352

Munster, i, 423
munu, i, 322; ii, 352

Muræna, i, 211, 391; ii, 152

- figure of, ii, 153

Murænesocidæ, ii, 150
Murænesox, i, 211; ii, 150
Murænidæ, i, 211; ii, 152, 155
Murænolepidæ, ii, 541
Murchison, i, 423
murcielago, ii, 458
muroaji, ii, 274
muscles of the fish, i, 25
muskallonge,

- figure of, ii, 192

Musquaw whitefish, ii, 65
Mustelus, i, 71, 541
mutsu, ii, 317
mutton-fish, i, 324; ii, 518
mutton-snapper, ii, 335

- figure of, i, 331

Mycteroperca, 271; ii, 325, 327

- figure of, ii, 327

Myctophidæ, i, 189, 204; ii, 132-134, 526

Myctophum, i, 195; ii, 133, 134

- figure of, ii, 133

Myliobatis, i, 557, 558
Mylognathus, i, 565
Mylostoma, i, 583, 584, 587, 589, 590
Mylostomidæ, i, 587
myotomes, i, 71

Myoxocephalus, ii, 445

- figure of, i, 219; ii, 446, 447

Myriacanthidæ, i, 566

Myriacanthus, i, 566; ii, 255

Myrichthys,

- figure of, ii, 151

Myridæ, ii, 148, 150
Myriolepis, ii, 14
Myripristis, i, 162, 268, 271; ii, 254-256
Myrocongridæ, ii, 153
Myrophis, i, 313
Myrus, i, 259, 263; ii, 150
Mysis, i, 317

Mysore,

- walking-fish of, i, 167

mythology of fishes, i, 359-366
Myxine, i, 198, 490, 593
Myxinidæ, i, 489
Myxobolus, i, 343
Myxocyprinus, ii, 173
Myxodagnus, ii, 506
Myxodes, ii, 508
Myxosporidia, i, 342, 344
Myzontes, i, 486
Nagg's head-fish, i, 375, 376
Naisia, ii, 32
namazu, ii, 188
names of bones, i, 39
names of fishes, i, 372
nami-ho-hana, ii, 218
Nandidæ, ii, 358
Nannocharax, ii, 162
Nansenia, ii, 127

Narcine,

- figure of, i, 185, 553

Narcobatidæ,

- family of, i, 553

Narcobatis, i, 553

Nardo, i, 412

Nassau,

- figure of, ii, 324

natural selection,

- effect of, i, 318
- in fishes, i, 218
- process of, i, 297
- species changed by, i, 240

Naucrates, ii, 272, 278

- figure of, ii, 273

Nantichthys, ii, 448
Nebris, ii, 355
Necturus, i, 157, 600
needle-bearing filefish,

- figure of, ii, 414

needle-fishes, i, 128

- figure of, ii, 210

negro-chub, ii, 167
negro-fish, ii, 324

Nelson, i, 419

- on Anableps, ii, 196, 197

Nemachilus, ii, 176

Nematognathi, i, 405; ii, 9, 40, 161, 177, 178

Nematistiidæ, ii, 278

Nematocentrus, ii, 218

Nematodes, i, 344

- Linton on, i, 352

Nematonurus, ii, 541

Nemichthyidæ, ii, 151

Nemichthys, i, 211; ii, 151

- figure of, i, 17, 365; ii, 152

- jaws figured, i, 156

Nemipterus, ii, 340

Nemopteryx, ii, 539

Neoceratodus, i, 79, 80, 100, 116, 204, 450, 613

- eggs of, i, 618
- figure of, i, 614
- lower jaw of, figured, i, 616
- shoulder-girdle in, i, 68, 609
- skull of, i, 67

Neochanna, i, 252; ii, 206

Neoclinus, ii, 462

- figure of, ii, 507

Neoditrema, ii, 375

Neoliparis, ii, 455

- figure of, ii, 455

Neopercis, ii, 502
Neosebastes, ii, 433
nerka, ii, 73
nerve cells and fibres, i, 152
nerves of fishes, i, 113, 114
nervous system, i, 109-114
nest-building, ii, 229

- of sticklebacks, ii, 230, 231

nest of fish, i, 14, 172
Nettastoma, i, 211, 259; ii, 151
Nettastomidæ, ii, 148, 151
neurentric canal, i, 138
Newberry, i, 426, 428, 584, 589

New England,

- scanty fauna of, i, 302

Newton, i, 426

New Zealand,

- fauna of, i, 252

nezupo, ii, 441
nictitating membrane, i, 540
nijinge-rijinge, i, 171, 172
Nieuhof, i, 396
Nilsson, i, 410
Niphon, ii, 320
nohu, ii, 434
noises of fishes, i, 168, 169
Nomeidæ, ii, 283
nomenclature, i, 173

- beginning of, i, 374
- trinomial, i, 378
- of trunkfishes, i, 373

Nordmann, i, 410
northern blennies, ii, 511
northern zone, i, 250
Norway haddock, ii, 428
Notacanthidæ, ii, 157

Notacanthus, ii, 157, 532

- figure of, ii, 158

Notæus, ii, 36

Notagogus, ii, 26

- figure of, ii, 28

Notelops, ii, 44

Notidiani, i, 447, 513, 519, 526

- order of, i, 523

Notidanoid shark, i, 438

- skull of, figured, i, 56

Notidanus, i, 523, 524
notochord, i, 55, 56, 509

- in Chimæras, i, 59

- in Elasmobranchs, i, 57

Notogeneus, i, 456

- figure of, ii, 55

Notopteridæ, ii, 48, 49
Notopterus, ii, 49
Nototheniidæ, ii, 501, 502, 533

Notropis, i, 129, 283, 304, 307, 311, 313; ii, 164

- figure of, i, 343, 457; ii, 165, 167

Noturus, i, 180; ii, 177, 182
Novaculichthys, ii, 390
Novara, i, 410
Nozawa, i, 418
numbers of genera, i, 262
numbfish,

- figure of, i, 185, 553

number of vertebræ, i, 202-204
nuptial colors, i, 155, 156
nuptial tubercles, i, 33

- figure showing, ii, 167

Nyström, i, 416
oarfish, i, 361; ii, 472

- figure of, i, 362; ii, 476
- Forgy on, ii, 473
- Glesnæs, ii, 472
- Holder on, ii, 474

Oatka Creek, i, 282

Oblata, i, 260; ii, 348
ocean currents,

- agency of, i, 242

Ocyurus,

- figure of, ii, 337

Odacidæ, ii, 388
Odax, ii, 390
Odontaspididæ, i, 533
Odontaspis, i, 534
Odontoscion, ii, 355
Odontostomus, ii, 136
Odontotodontidæ, i, 576

Odontotodus,

- figure of, i, 570

Ogcocephalidæ, ii, 551

Ogcocephalus,

- figure of, ii, 551-553

- shoulder-girdle in, i, 88

Ogilby, i, 408, 416

- on ragfishes, ii, 285

oil shark, i, 524
Oikopleura, i, 474
ojanco, ii, 337
okose, i, 236, 429; ii, 436
oldwench, ii, 413
oldwife, ii, 413
Old World catfish, ii, 182
olfactory lobe,

- figure of, i, 111

Oligocottus, ii, 447, 449

- figure of, ii, 449

Oligopleuridæ, ii, 36, 41
Oligopleurus, ii, 36
Oligoplites, ii, 272
Oligorus, ii, 320
ombre chevalier, ii, 108, 109
Omosoma, ii, 284
Omosudis, ii, 136

Onchus,

- Agassiz on, i, 530

- fin-spine of, i, 509

Oncobatis, i, 553

Oncottus, i, 317; ii, 447, 449

- figure of, ii, 447

Oncolepis, ii, 513

Oncopterus, ii, 489

Oncorhynchus, i, 146, 160, 301, 329, 332; ii, 68, 70, 89, 94

- figure of, 354; ii, 69, 71, 72, 76

ontogeny, i, 511
ontology, i, 63
oopu, ii, 465
Onychodontidæ, i, 602, 604
Onychodus, i, 604
opahs, i, 210; ii, 243

- taken by Berndt, ii, 244
- Farquhar on, ii, 244
- figure of, i, 323

opercle, i, 7, 45
opercula,

- used in climbing, ii, 367

operculum, ii, 7
Ophicephalidæ, ii, 370
Ophidiidæ, ii, 520
Ophidion, i, 391, 612
Ophichthyidæ, i, 211; ii, 150

Ophichthus,

- figure of, ii, 151

Ophiocephalidæ, i, 103, 104; ii, 215

Ophiocephalus, i, 149

- figure of, i, 150

Ophiodon, ii, 442, 518, 520

- figure of, ii, 440

Ophioblennius, ii, 510

Ophiopsis, ii, 26

Ophocephalus,

- figure of, ii, 370

Opistharthri, i, 509
Opisthocentrus, ii, 512
Opisthocœlian, i, 49; ii, 29
Opisthocœlous, ii, 6
Opisthognathidæ, ii, 330, 359, 499, 502

Opisthognathus, ii, 462, 508

- figure of, ii, 360

Opisthomi, i, 611; ii, 499, 532-542

Opisthomyzon, ii, 469

- Storms on, ii, 469

Opisthonema, ii, 51, 53
opisthure, i, 84
Oplegnathus, i, 260

Opsanus, ii, 525

- figure of, ii, 524

Opsariichthys, ii, 165
optic nerves,

- of flounders, ii, 482

orbitophenoid, ii, 40
orca, i, 361, 536
order,

- defined, i, 373

organs of the fish,

- electric, i, 25
- of hearing, i, 119-121
- nutritive, i, 29

Orectolobus, i, 533

Orestias, ii, 200

Oregon lamprey,

- figure of, i, 496

Oregon sucker,

- teeth of, figured, ii, 175

Ordovician deposits,

- figure of, i, 435

origin,

- of air-bladder, i, 98
- of fins, i, 62, 64, 67
- of lungs, i, 98

origin of lancelets,

- Willey on, i, 484

Orodontidæ, i, 65, 66, 447, 528

Orr,

- on external gill, i, 77

Ortmann, i, 238, 256, 270

- map of continents, i, 270

Orthacanthus, i, 521
Orthodon, ii, 165
Orthopristis, ii, 342
Orthopsetta, i, 206; ii, 489
Orthostœchus, i, 271
Osbeck, i, 389

Osbeckia, ii, 414

- figure of, ii, 414

Osborn,

- on extinction of species, i, 239, 442

- on law of radiation, i, 296

Osmeroides, ii, 44, 134

Osmerus, i, 391; ii, 123, 127

- figure of, ii, 123

Osphromenidæ, ii, 368, 370

Osphromenus, ii, 368
ossicles,

- Hasse on, i, 96

Ostariophysi, i, 120; ii, 38, 40, 140, 209

- series of, ii, 159-165

Osteoglossidæ, ii, 56, 60, 160
Osteoglossum, ii, 11, 41, 42, 56, 57
Osteolepis, i, 602-604

Osteostraci, i, 568, 571, 573, 590

- order of, i, 575

Ostichthys,

- figure of, ii, 255

Ostraciidæ, i, 568

- family of, ii, 415

Ostracion, i, 206, 373, 391; ii, 416-418

- figure of, i, 16, 376; ii, 416

Ostracodermi, i, 568; ii, 398, 411, 415

Ostracophores, i, 240, 242, 246, 444, 488, 568, 581, 582, 590, 603; ii, 3

- figure of, i, 444
- nature of, i, 569
- order of, i, 573

Ostracophori, i, 462

- class of, i, 568, 569

Osurus, ii, 502
Otaki, i, 418, 422
Otodus, i, 538
otoliths, i, 119-121; 354
Otsego bass, ii, 64
Ouananiche, ii, 92, 93

Overland Monthly,

- reference to, ii, 69

oviducts, ii, 6
oviparous fishes, i, 125
ovoviviparous fishes, i, 125, 550

Owen, i, 88, 90, 424, 428

- on swordfish, ii, 270, 271

Owsjannikow, i, 428

Owston,

- sharks taken by, i, 534

Oxuderces, ii, 468
Oxudercidæ, ii, 468
Oxygnathus, ii, 14

Oxylabracidæ, ii, 320, 327

- family of, ii, 319

Oxylabrax, ii, 320, 355

- figure of, ii, 319

Oxylebius, ii, 440
Oxyjulis, ii, 388
Oxymonacanthus, ii, 415
Oxynotidæ, i, 546
Oxynotus, i, 546
Oxystomus, i, 259
oyster-fish, ii, 525

Ozorthe, ii, 513

- figure of, i, 9; ii, 513

Pachycormidæ, ii, 34
Pachycormus, ii, 34
Pachylebias, ii, 201
Pachyrhizodontidæ, ii, 44
Pachyrhizodus, ii, 44
Pacific Creek, i, 308, 309
paddle-fish, i, 199, 253, 290; ii, 20
Pagellus, i, 260, 267; ii, 344, 346

Pagrus, i, 94, 259, 263, 324; ii, 343, 344, 346

- figure of, ii, 342

paired fins,

- in Acanthodei, i, 515
- Balfour on, ii, 8
- migration of, i, 75
- origin of, i, 64
- Ryder on, i, 66

paired limbs,

- Dean on, i, 81
- Mivart on, i, 70
- relation of, i, 69
- Thacker on, i, 70
- Gill on, i, 85

palæichthyologists, i, 424, 426, 427
palæichthyology, i, 426
Palæichthys, ii, 3
Palæobalistum, ii, 22
Palæoniscidæ, i, 452, 580; ii, 4, 14, 15, 23

Palæoniscum, i, 437, 622

- Blainville on, ii, 14

- figure of, i, 453; ii, 14

palæontology, evidence of, i, 64

Palæorhynchidæ,

- family of, ii, 268

Palæorhynchus, ii, 268

- figure of, ii, 268

Palæospinax, i, 528

Palæospondylidæ, i, 593

Palæospondylus, i, 204, 437, 444, 593, 595, 596

- figure of, i, 591

- relationships of, i, 593

palatines, i, 6
palatopterygoid arch, ii, 152, 155
palato-quadrate apparatus, i, 508, 509, 523
Palinurichthys, ii, 284
Pallas, ii, 67, 135, 428, 522

Pallasina, ii, 453

- figure of, i, 221; ii, 453

Palœaspis, i, 575
palometa, i, 324; ii, 283
pampano, i, 210, 324; ii, 272-292

- gaff-topsail, ii, 277
- great, ii, 277
- round, ii, 277
- true, ii, 277

panai feri, ii, 367

Panama,

- as barrier, i, 270

- final hypothesis as to, i, 279

pancreas, i, 32
Pander, i, 427
pan fish, ii, 355
Panicum, ii, 369
Pantodon, ii, 60
Pantodontidæ, ii, 57
Pantosteus, i, 304, 316; ii, 172
papagallo, ii, 278
papilla, i, 115
Pappichthys, ii, 36
Parabatrachus, i, 604
Paracentropogon, ii, 436
Paracentropristis, ii, 328
Paracirrhites, ii, 363
paraglenal, i, 90; ii, 12
Paragobiodon, ii, 466
Paralabrax, ii, 328
Paralepidæ, ii, 136

Paralichthys, i, 206; ii, 482, 486, 492

- figure of, ii, 493
- shoulder-girdle of, i, 58; ii, 2
- tail of, figured, i, 83; ii, 486

Paraliparis, i, 202, 219; ii, 454, 455
Paramia, ii, 317
Paranguilla, ii, 150
Paranthias, ii, 328
Paraphyllodus, ii, 396
Parapristipoma, ii, 342
Parapegasus, ii, 240
Parapercis, ii, 502
Parasilurus, ii, 183
parasites of fishes,

- crustaceans, i, 340
- figures illustrating, i, 341-344
- fungi, i, 353
- Heart Lake tapeworm, i, 348
- hosts of, i, 343
- internal, i, 342
- protozoans, i, 342

parasitic diseases,

- Gurley on, i, 342
- Linton on, i, 343
- Megnin on, i, 343
- Railliet on, i, 343
- Stiles on, i, 343
- Ward on, i, 343

parasitic fungi, i, 353
parasitic worms,

- acanthocephala, i, 344
- cestodes, i, 344
- an article of food, i, 351
- nematodes, i, 344
- trematodes, i, 344

Paratrachichthys, i, 439; ii, 295

- figure of, ii, 253

Paraxus, i, 517
Pareioplitæ, ii, 426-458
parental affection in fishes, i, 166, 167
Parexocœtus, ii, 214
parent-stream theory, ii, 81
Parequula, ii, 287
pargo criollo, i, 324; ii, 335
pargo de lo alto, ii, 336
pargo guachinango, ii, 335
pargos, ii, 333
Park, i, 393

Parker, i, 90, 428, 594; ii, 160, 482

- on Chimæras, i, 563
- on hearing of fishes, i, 121, 122
- optic nerve of flounder, ii, 482, 483
- on soles, ii, 483

Parnell, i, 410
Parophrys, ii, 493
Parr, ii, 91
Parra, i, 396
parrot-fish, i, 21; ii, 56, 360, 385, 390, 393

- figure of, i, 330; ii, 392, 394, 395
- jaws of, figured, i, 30; ii, 391
- pharyngeals of, i, 47, 48; ii, 393

parts of skeleton, i, 35
paru, ii, 405
Patæcidæ, ii, 516
Patæcus, ii, 514
patao, ii, 348

Patten, i, 428

- on Ostracophores, i, 569

pesce re, ii, 218
peacock flounders, ii, 488
pearlfish, i, 84, 159; ii, 522

- figure of, i, 522, 523

pêche prêtre, ii, 429
Peck, i, 419
pecten, ii, 6
pectoral fin, i, 10, 521

- of Chiloscyllium, i, 66
- of codfish, i, 66
- figure of, i, 57, 66
- Gegenbaur on, i, 66, 67
- of Heptranchias, i, 57
- origin of, i, 67

pectoral limb, i, 50

- of Dipnoan, i, 60
- figure of, i, 85
- Kerr on, i, 61
- in shark, i, 60

peculiar,

- jaws and teeth, i, 201

- larval forms, i, 142

pediculates, i, 51, 206, 207, 405; ii, 40, 499

- order of, ii, 542-553

Pegador,

- figure of, i, 197; ii, 468

pegapega, ii, 468

Pegasidæ, ii, 240

- family of, ii, 239

Pegasus, i, 393; ii, 240
peixe rey, ii, 216
pelagic fishes, i, 245

- vertebræ in, i, 209

Pelamis, i, 364
Pelargorhynchus, ii, 136
Pelates, ii, 342
Pelecanus, i, 345
Pelecopterus, ii, 34
pelican,

- fish parasites in, i, 345

pelican-eel, ii, 156

Pellegrin, i, 412

- on poisonous fishes, i, 182-184

Pelor, i, 180; ii, 434
Peltacephalata, i, 568
pelvic girdle, i, 42
Pempheridæ, ii, 288

Pempheris, ii, 289

- figure of, ii, 289, 290

penfishes, ii, 344

Penella, i, 242

Pennant, i, 396

- on parental affection in fishes, i, 166

Pentacerotidæ,[14] ii, 333

14.  This family should stand as Histiopteridæ, the name Pentaceros, Pentacerotidæ, being used earlier for starfishes.

pentadactyle limb, i, 79

Pentapus, ii, 341

Peprilus, ii, 285

- figure of, i, 18; ii, 284

Perca, 391; ii, 307, 315, 367

- brain of, i, 111

- figure of, ii, 308

Percalates, ii, 320

Percarina, ii, 310

Percesoces, ii, 157, 208, 228, 290, 360, 370, 521, 522

- order of, ii, 215

perches, i, 21, 209, 290, 304; ii, 168, 258, 304, 307, 310

- brain of, figured, i, 111
- European, ii, 307
- everglade pigmy, figured, ii, 295
- white, ii, 304
- yellow, ii, 307, 308

Percichthys, ii, 320

Percidæ, i, 209, 248, 290, 406; ii, 171, 258, 294, 304, 309, 320

- family of, ii, 304

Percilia, ii, 320

Percina, ii, 306, 310

- figure of, ii, 311

Percis, ii, 453
Percoidea, ii, 293-315
Percoidei, ii, 398
percoid fishes, ii, 293-315

Percomorphi, ii, 258-271, 365, 397, 398, 426

- suborder of, ii, 258

Percophidæ, ii, 502

Percopsidæ, i, 290; ii, 241

- family of, ii, 241

Percopsis, i, 316; ii, 296

- figure of, ii, 241

periblast, i, 136

Periophthalmus, i, 117; ii, 465, 510

- figure of, i, 118; ii, 466

Peristediidæ, i, 208; ii, 457

Peristedion, i, 219

- figure of, i, 299; ii, 457

peritoneum, i, 32

Permian, ii, 14, 23

- sharks from, i, 517

Perugia, i, 412
pescado azul, ii, 382
pescadillo del red, ii, 354
pescado blanco, i, 328; ii, 216

- figure of, i, 217, 329

pescado del rey, ii, 216
pesce rey, ii, 216

Petalodontidæ, i, 531

- family of, i, 554

- teeth of, figured, i, 555

Petalodus, i, 554
Petalopteryx, ii, 26, 458
Peters, i, 411
peto, ii, 266

Petromyzon, i, 132, 142, 357, 372, 391, 490, 618

- figure of, i, 491
- mouth figured, i, 492
- head of, figured, i, 111

Petromyzonidæ, i, 290, 373, 490
Petroscirtes, ii, 509
pez ciego, ii, 524
pez del rey,

- figure of, ii, 218

pez de pluma, ii, 344
pez puerco, ii, 413
Phæbodus, i, 522
Phanerodon, ii, 375

Phaneropleuron, i, 612

- figure of, i, 613

Phanerosteon, i, 580

Phareodus, ii, 56, 57

- figures of, ii, 57-59

- fossils of, ii, 58, 59

pharyngeals, i, 5, 48

- figure of, i, 47
- of Italian parrot-fish, ii, 391
- of parrot-fish, figured, ii, 391
- use in voice, i, 121

pharyngeal teeth,

- figured, ii, 175

Pharyngognathi, i, 405; ii, 259, 380, 396

- suborder of, ii, 384

Philippi, i, 415

Philypnus, ii, 459

- figure of, ii, 460

Pholidophoridæ, ii, 26, 29, 36, 41

Pholidophorus, ii, 28

- figure of, ii, 29

Pholidurus, ii, 22

Pholis, i, 209; ii, 512

- figure of, ii, 512

phosphorescent groups, i, 187
phosphorescent organs,

- artificial stimulation of, i, 191
- chemical action in, i, 196
- cross-section of, i, 193
- Greene on, i, 194, 196, 197
- Lendenfeld on, i, 194, 195
- of Porichthys, i, 194

photophores, i, 187, 189
Phoxinus, ii, 167
Phractolamidæ, ii, 48
Phrynorhombus, ii, 488
Phtheirichthys, ii, 469
Phthinobranchii, i, 227-240
Phyllodus, ii, 396
Phyllolepidæ, i, 584
phylogeny, i, 63, 79
Phylopteryx, ii, 238
Phylyctænaspis, i, 586
Physoclysti, i, 405; ii, 39, 209
physostome, ii, 10
Physostomi, i, 405; ii, 39, 40
picarel, ii, 347
pickerel, i, 4; ii, 147
pigfish, ii, 342
pigmentation, i, 226

- effect of spirits on, i, 235

pigmy sunfishes, ii, 296
pike, i, 209, 239, 250, 290, 304, 328, 440; ii, 190

- figure of, i, 203, 328; ii, 191

- skeleton of, i, 203

pike-perch, ii, 309
pilchard, ii, 50
pilot-fish, i, 63; ii, 272

- figure of, ii, 273

Pimelodus, ii, 183, 186

Pimelometopon, ii, 388, 389

- figure of, ii, 389

pineal organ, i, 111

- Dean on, i, 112

- figure of, i, 111

pine-cone-fish,

- figure of, i, 16; ii, 257

pinfish, ii, 344
ping, ii, 91
Pinguipedidæ, ii, 363, 499
pink, ii, 72
pintado, ii, 266
pipefish, i, 64, 128, 440

- family of, ii, 236

pirate-perch, i, 290; ii, 294

- figure of, ii, 295

Pisces, i, 393, 588

- characteristics of, i, 506

Piso, i, 389
placoderm, i, 462, 584, 590, 591, 593
Placodermi, i, 568, 622, 623
placoid scales, i, 21

Placopharynx, ii, 174

- lower pharyngeal figured, ii, 171

Plagioscion, ii, 354
Plagiostomi, i, 507
Plagiuri, i, 392
Plagyodontidæ, ii, 134, 136

Plagyodus, ii, 136

- figure of, ii, 135

plaice, ii, 487, 493
plaice tribe, ii, 492
pla-kat, ii, 370
Platacidæ, ii, 398, 400, 401
Platax, i, 240, 268; ii, 243, 245, 398, 401

Platophrys,

- figure of, i, 174, 175

- larval form, i, 174

Platichthys, ii, 482, 493

- figure of, ii, 495

Platophrys, ii, 481, 482, 488

- larval stages of, figured, ii, 484

Platycephalidæ, i, 267

- family of, ii, 441

Platycephalus, ii, 441
Platycormus, ii, 283, 284, 485
Platyglossus, ii, 390
Platyptera, ii, 506
Platysomidæ, ii, 4, 14, 15

Platysomus, ii, 15

- figure of, i, 452

Platystacus, i, 128; ii, 184
Platyurus, i, 364
Playfair, i, 416

Plecoglossus, i, 260; ii, 62, 115, 117

- figure of, i, 321; ii, 116

plectognath fishes, i, 206

Plectognathi, ii, 9, 40

- series of, ii, 411

Plectognaths, ii, 291, 411
Plectorhynchus, ii, 341
Plectospondyli, ii, 40, 161, 162
plectospondylous, i, 48
Plectromus, ii, 253
Plectropoma, ii, 323
Plesiops, ii, 330, 359
Plethodus, ii, 44

Pleuracanthus, i, 65, 66, 204, 437, 510, 511, 513

- diphycercal tail of, i, 80
- figures of, i, 74, 519, 520
- headbones and teeth of, figured, i, 520

Pleurocanthidæ, i, 519, 520, 522, 566

Pleurogrammus, i, 209

- figure of, i, 328; ii, 439

Pleuronectidæ, i, 290

- family of, ii, 485

Pleuronectinæ, ii, 492

Pleuronectes, i, 391; ii, 493

Pleuronichthys, i, 206, 257; ii, 493

- figure of, i, 441

Pleuropholis, ii, 29
Pleuropterygii, i, 513, 514, 518
Plioplarchus, ii, 304
Plotosidæ, ii, 184
Plotosus, ii, 184
Plumier, i, 389
Pneumatosteus, ii, 32
Podopteryx, ii, 457
Podothecus, ii, 453
pond-skipper,

- figure of, i, 118; ii, 466

Pœcilia, ii, 199

Pœciliidæ, 22, 125; ii, 194, 198, 199, 201, 213

- figure of, i, 126

Pœcilodus, i, 531

Poey, i, 376, 415

- portrait of, i, 413

Pogonias, i, 595; ii, 354, 357

- figure of, ii, 358

Pogonichthys, ii, 169
poison fishes, i, 180-185, 236

- figure of, i, 229; ii, 436

poison glands, ii, 177, 527

- in catfishes, ii, 182

- Günther on, ii, 527, 528, 529

poisonous fishes, ii, 325, 335

- diseases arising from, i, 183

- varieties of, i, 180, 182, 183

Polistotrema,

- figure of, i, 489

Pollachius, i, 209; ii, 537
pollack,

- figure of, ii, 537

Pollard, i, 595, 600
Polycentridæ, ii, 358
Polyclinidæ, i, 477

Polydactylus,

- figure of, ii, 225

- shoulder-girdle of, i, 89; ii, 225

Polygnathus,

- figure of, i, 486

Polymixia, i, 122; ii, 257

Polymixiidæ,

- family of, ii, 256

Polynemidæ, i, 122; 11, 215, 224

Polynemus, i, 393

Polyodon, i, 199, 253, 302, 452, 534, 566, 622, 623; ii, 22

- figure of, ii, 22

Polyodontidæ, i, 290; ii, 20, 21, 22

Polyospondyli, i, 509, 530, 561

Polypteridæ, i, 602, 605

- Boulenger on, i, 608

Polypterus, i, 76, 79, 88, 89, 204, 450, 600, 601, 603, 606, 616; ii, 2

- figure of, i, 79, 602, 607

- shoulder-girdle of, figured, i, 600

Polyrhizodus, i, 555

Polystylidæ, i, 476

Pomacanthus, ii, 403, 405

- figure of, ii, 403

Pomacentridæ, i, 206, 209; ii, 380, 381, 382

- organs of smell in, i, 115

Pomacentrus, i, 235; ii, 383

- figure of, ii, 382

- species of, ii, 383

Pomadasis, ii, 341, 342

Pomatomidæ, ii, 278

Pomatomus, ii, 278

- figure of, i, 324

pomfret, ii, 286

Pomolobus, i, 300; ii, 49, 53

- figure of, i, 455; ii, 50

Pomotis, i, 302; ii, 379

Pomoxis, i, 302; ii, 297

- figure of, ii, 297, 298

pompon, ii, 341
pond-skipper,

- figure of, i, 118

pond-smelt, ii, 124
poolfishes, i, 159
pope, ii, 309
poppy-fish, ii, 283

Popular Science Monthly,

- reference to, ii, 69

porbeagle, i, 537
porc des rivières, ii, 369
porcupine-fish, i, 19, 197; ii, 422, 423

- figure of, i, 17; ii, 422

porgy, i, 239; ii, 342

- varieties of, ii, 344

Porichthys, i, 121, 190, 191, 192; ii, 526

- figure of, i, 23; ii, 526
- Greene on, i, 190; ii, 526
- luminous organs of, i, 172
- phosphorescent organs of, i, 191

porkfish, ii, 341

- figure of, ii, 341

portal vein, i, 108

Portheus, ii, 48

- skeleton of, ii, 47

Port Jackson shark,

- eggs of, figured, i, 128, 527

portugais, ii, 405

Portuguese man-of-war,

- figure of, i, 160

Porcus, ii, 183
postembryonic development of fishes, i, 132
posterior limbs, i, 53
postero-temporal, i, 90
post-temporal, i, 88, 90
Potamorrhaphis, ii, 211
Powrie, i, 424
predatory fishes, i, 116; ii, 164
premaxillary,

- figure of, i, 55

preopercle, i, 45
preservation of fishes,

- Günther on, i, 431

- methods of, i, 431, 432

Priacanthidæ, ii, 333

Priacanthus, ii, 333

- figure of, ii, 331

Pribilof sculpin,

- figure of, ii, 446

Priem, i, 427
priestfish,

- figure of, ii, 430

Prime,

- on crab-eater as game fish, ii, 282

primitive fishes,

- brain of, i, 112

- skeleton of, i, 54

primitive herring-like fishes, i, 454
primitive sharks, i, 511

- orders of, i, 513

Prionace, i, 542
Prionodus, i, 488
Prionodes, ii, 329

Prionotus, i, 246; ii, 283

- figure of, ii, 456

Prionurus, ii, 409
Priscacara, ii, 381
Pristipoma, i, 375
Pristididæ, i, 549
Pristodontidæ, i, 555

Pristiophoridæ,

- family of, i, 548, 549

Pristiophorus, i, 199

- figure of, i, 201, 548

Pristis, i, 199, 548

- figure of, i, 200

Pristiurus, i, 70
proach, ii, 445
Proantigonia, ii, 400
Proballostomus, ii, 201
problem of highest fishes,

- Gill on, i, 383

problem of Oatka Creek, i, 282
process of natural selection, i, 297, 302
Prochanos, ii, 45
Prognathodes, ii, 404
Progymnodon, ii, 423
Prolebias, ii, 201
Promethichthys, ii, 267
Promicrops, ii, 323
pronephros, i, 619; ii, 5, 8
Pronotocanthus, ii, 157
Propristis, i, 550
propterygium, i, 58, 511, 512, 523
Prosarthri, i, 509, 526
proscapula, i, 89
prosencephalon, i, 109

- figure of, i, 111

Protamia, ii, 36

Protaulopsis, ii, 233
protection,

- through poisonous flesh, i, 182

- of young, i, 128

protective,

- coloration, i, 226

- markings, i, 228

Proteus, i, 600

Protocatostomus, ii, 56
protocercal tail, i, 81, 598

- Wyman on, i, 81

Protochordata, i, 460-466

Protonotacanthidæ, ii, 157

Protopterus, i, 82, 85, 100, 204, 450, 613, 616, 617

- figure of, i, 622

Protoselachii, i, 523
Protosphyræna, ii, 34
Protosphyrænidæ, ii, 34
Prostospondyli, ii, 23, 34
Protosyngnathus, ii, 233
Prototroctes, i, 252; ii, 128
protozoan parasites, i, 342
Provençal i, 95
Psammobatis, i, 553
Psammodus, i, 558, 559
Psammosteidæ, i, 574
Psenes, ii, 285
Psenopsis, ii, 284
Psephodus, i, 531

Psephurus, i, 199, 253, 452, 622, 623

- figure of, ii, 21

Psettidæ, ii, 291

Psettus, ii, 398, 400

- figure of, ii, 399

Pseudecheneis, ii, 184
Pseudeleginus, ii, 502
Pseudobagrus, ii, 183
Pseudoberyx, ii, 52
Pseudoblennius, i, 260; ii, 448
pseudobranch, ii, 7
pseudobranchiæ, i, 92
Pseudocheilinus, ii, 390
Pseudochromipidæ, ii, 359
Pseudogaleus, i, 533
Pseudojulis, ii, 389
Pseudolabrus, ii, 390
Pseudomonacanthus, ii, 415

Pseudopleuronectes, i, 174; ii, 493

- larval figures of, i, 176; ii, 483

Pseudopriacanthus, ii, 332, 333

- figure of, ii, 332

Pseudorhombus, ii, 492

Pseudoscaphirhynchus, ii, 18, 20

Pseudoscarus, i, 329; ii, 394, 396

- figure of, i, 330

Pseudosciæna, i, 169; ii, 355, 356

Pseudotriakidæ,

- family of, i, 536

Pseudotriakis, i, 536
Pseudovomer, ii, 278, 286
Pseudogobio, i, 416

Pseudupeneus, ii, 352

- figure of, i, 122, 329; ii, 351

Psychrolutes, i, 219; ii, 441, 447, 449

- figure of, i, 221; ii, 451

Psychromaster, ii, 315
Pteraclidæ, ii, 286, 291
Pteraclis, ii, 286
Pteraspidæ, i, 570

Pteraspis, i, 569, 571, 591, 622

- figure of, i, 575

Pterichthyodes, i, 444, 622

- figure of, i, 576

Pterichthys, i, 581

Pterogobius,

- figure of, ii, 462

Pterois, i, 180, 202; ii, 434

- figure of, ii, 435

Pterophryne, ii, 550

- figure of, ii, 549

- species of, ii, 550

Pteroplatea, i, 556

Pteropsaridæ, ii, 502

Pteropsaron,

- figure of, ii, 502

Pterothrissidæ, ii, 46

- described, ii, 46

Pterothrissus, ii, 46

Pterophryne,

- figure of, i, 52

pterygials, ii, 1
Pterygocephalus, ii, 513
pterygoid, i, 606
Ptilichthyidæ, ii, 513

Ptilichthys,

- figure of, ii, 514

Ptychochelius, i, 164, 304; ii, 169

- figure of, i, 162

Ptychoderidæ, i, 465

Ptychodus, i, 557

Ptycholepis, ii, 26

- figure of, ii, 28

ptychopterygium, i, 510, 512
Ptychodus, i, 566
pudding-wife, ii, 388
pudiano, ii, 388
puffer, inflated,

- figure of, ii, 420

puffers, i, 206, 236;

- figure of, ii, 419, 420
- silver, ii, 419
- tiger, ii, 423

pugnacity of fishes, i, 162
pug-nosed eel, ii, 148

- figure of, ii, 149

Putnam, i, 405; ii, 522
Pycnodonti, ii, 13
Pycnodontidæ, ii, 22
Pycnodus, ii, 22
Pygæidæ, ii, 405
Pygæus, ii, 405, 410
Pygidiidæ, ii, 185, 186
Pygopterus, ii, 14
Pygosteus, ii, 231
pyloric cæca, i, 26, 32
Pyrosoma, i, 477
Pyrosomidæ, i, 477
quadrate, i, 606
Quassilabia, ii, 174
Quensel, i, 396
Querimana, ii, 222
questions,

- by Agassiz, i, 284

- by Cope, i, 288

quiescent fishes, i, 158
quillfish,

- the, ii, 513

- figure of, ii, 514

quinnat salmon, i, 150, 301; ii, 68, 73-76

- figure of, i, 354; ii, 69, 79

- young male figured, i, 355

rabbit-fishes,

- figure of, ii, 423

Rabirubia, ii, 337

Rachycentridæ,

- family of, ii, 282

Rachycentron, ii, 470, 468

- figure of, ii, 282

Rafinesque, i, 395; ii, 315

- on imaginary garpike, i, 364, 366

ragfishes, the, ii, 285

- Ogilby on, ii, 285

rainbow darter, ii, 315
rainbow trout, ii, 96-98, 100

- figure of, i, 326; ii, 98, 99

Raja, i, 72, 129, 391, 549

- figure of, i, 448, 552

Rajidæ, i, 551, 553

Ranicipitidæ, ii, 539

Rangeley trout, ii, 109

- figure of, i, 326

Raniceps, ii, 539

Ranzania, i, 84, 412

- figure of, ii, 425

Rapp, i, 411
Rascasio, ii, 433
ratfish, i, 564
Rathke, i, 428; ii, 144
rat-tail, i, 209; ii, 441, 540
Ray, i, 390
ray, i, 9, 24, 35, 117, 508, 509, 549

- electric organs of, i, 186

razor-back sucker, ii, 174

- figure of, ii, 175

razor-fish,

- figure of, ii, 388

recognition marks, i, 7, 231, 232
records of fishes, i, 433
red charr, ii, 108
red drum,

- figure of, ii, 356

redeye, ii, 168
Redfield, i, 423
redfin, ii, 166
Redfieldius, ii, 16
redfish, ii, 68, 324, 355, 388

- figure of, ii, 389

red goatfish, ii, 35

- figure of, i, 329

red grouper, ii, 324

- figure of, ii, 325

red hind, ii, 324

- figure of, ii, 326

red-mouth grunt, ii, 340
red mullet, ii, 352
red mumea, ii, 335
red parrot-fish,

- figure of, ii, 393

red porgy, ii, 343
red rockfish, ii, 429
red rock-trout, ii, 440

- skeleton of, figured, i, 214

red salmon, ii, 69, 71, 82

- figure of, ii, 70, 76

red snapper, ii, 330, 335
red tai, ii, 349

- figure of, ii, 342

red-throated trout, ii, 102
red voraz, ii, 338
red wrasse, ii, 387

Reed, ii, 112, 113

- on trout-fishing, ii, 112

Regalecidæ,

- family of, i, 472

Regalecus, i, 361; ii, 425, 472, 473, 479

- figure of, i, 362, 363

Regan, ii, 291

- on Teleostomi, i, 622, 623

Règnè Animal, i, 400

Reighard, i, 428

- on lampreys, i, 491

Reinhardt, i, 410; ii, 127

- portrait of, i, 409

Reinhardtius, ii, 491

Reis, i, 427, 428, 571
relations of fish faunas,

- Japan and Mediterranean, i, 270

relationships,

- of Chimæras, i, 563

- of Palæspondylus, i, 593, 595

relation of vertebræ to temperature, i, 202
Remora, i, 197; ii, 468, 469
Remorina, ii, 469
Remoropsis, ii, 469

Remsberg,

- photograph by, i, 362

Renard, i, 396
reproduction of lost parts, i, 150
Requins, i, 540
resemblances of fish faunas, i, 259, 260
respiration, i, 91-108
Retropinna, i, 252; ii, 123
Retzius, i, 428
Rhabdofario, ii, 62, 118

Rhacochilus, ii, 375

- figure of, ii, 374

Rhacolepis, ii, 44
Rhadinichthys, ii, 14
Rhamphognathus, ii, 218
Rhamphocottidæ, ii, 449

Rhamphocottus, ii, 449

- figure of, ii, 451

Rhamphosidæ, ii, 234

Rhamphosus, ii, 234

Rhegnopteri,

- order of, ii, 224

Rheopresbe, i, 256; ii, 445

Rhina, i, 551

Rhinæ,

- suborder of, i, 547

Rhineastes, ii, 186

Rhinellidæ, ii, 134

Rhinellus, ii, 134

- figure of, ii, 134

Rhineodon, i, 540
Rhineodontidæ, i, 540
Rhinesomus, i, 377

Rhinichthys, i, 283, 307

- figure of, i, 342; ii, 164

Rhinidæ, i, 551

Rhinobatidæ, i, 551

- family of, i, 550

Rhinobatis, i, 553

- figure of, i, 551

Rhinochimæra, i, 199, 566
Rhinochimæridæ, i, 565
Rhinoptera, i, 557
Rhinotriacis, i, 541
Rhipidistia, i, 602
Rhizodontidæ, i, 603
Rhizodopsis, i, 603
Rhodeus, i, 129; ii, 164

Rhombochirus,

- figure of, ii, 469

Rhomboganoidea, ii, 24
Rhomboplites, ii, 337
Rhombus, ii, 486
Rhyacichthyidæ, ii, 504
Rhyacichthys, ii, 504
Rhynchias, ii, 522
Rhynchobdella, ii, 532
Rhynchodus, i, 566
Rhynchorhinus, ii, 150
ribbon-fish, ii, 471, 475, 485

- Goode on, ii, 475

rice-field eels, ii, 141

Richardson, i, 408, 418; ii, 64

- on whitefish, i, 322

Richardson's sculpin,

- figure of, ii, 451

Rio Grande trout,

- figure of, ii, 106

Risso, i, 395

Rissola,

- figure of, ii, 520

Ritter,

- on ascidians, i, 474

- on Enteropneusta, i, 464

river-bullhead,

- spawning of, i, 166

river-drum, ii, 354, 355
river-fishes,

- dispersion of, i, 297-319

river-ruff, ii, 309
river-sculpin, ii, 445
river-sheepshead, ii, 354
river-trout, ii, 94
river-wolf, ii, 190
Rivulus, i, 314
roach, ii, 163, 168
robalito, ii, 320
robalo, the, i, 320, 355

- figure of, ii, 319, 324

Roccus, i, 291, 324; ii, 321, 330

- bones of, i, 35
- cranium of, i, 36-39
- figures of, i, 35-39, 46, 48

Roche, i, 396
rock-bass, i, 4; ii, 297

- figure of, ii, 299

- skull of, figured, ii, 296

rock-beauty, ii, 404

- figure of, ii, 405

rock-cod, i, 203; ii, 429
rock-cook, ii, 387
rockfish, i, 94, 125, 159; ii, 321, 429, 431

- figure of, i, 218

rock-hind, i, 19; ii, 324

- figure of, i, 29

rocklings, i, 209; ii, 520, 539
rock-pilots, the, ii, 381
rock-pool fishes,

- figure of, i, 294

rock-skipper, ii, 510

- figure of, ii, 509

Rocky Mountains,

- barriers to dispersion, i, 305

Rohon, i, 427, 428
romero, ii, 272
roncador, ii, 353, 355, 356
ronco amarilla, ii, 340
ronco arará, ii, 340

Rondelet, i, 361, 388

- on sea-monster, i, 360

Rondeletiidæ, ii, 132
Ronquilus, ii, 502
ronquils, ii, 502
rosefishes, i, 125; ii, 428

- figure of, ii, 427

Rosenthal, i, 428
rothfisch, ii, 106
rough-headed sea-robin, ii, 457
roundfish, ii, 63
round-herring, ii, 52
round-minnow,

- figure of, ii, 196

round-robin, ii, 274
rousettes, i, 533

Rudarius,

- figure of, i, 241

rudder-fish, ii, 273, 285, 349, 350

- figure of, ii, 349

runners, ii, 272

Rüppell, i, 411

Rusconi,

- on external gills, i, 77

Russell, i, 396; ii, 473
rusty-dab, ii, 493
Rutilus, ii, 164, 168

Rutter, i, 422; ii, 69, 84

- photograph by, i, 355

Ruvettus, ii, 267

Ryder, i, 408, 428

- on embryos, i, 64
- on nest-building, ii, 229
- on paired limbs, i, 66
- on tail forms, i, 81, 84

Rypticus,

- figure of, ii, 330

saboti, ii, 304

Saccopharynx, ii, 136, 157

Sacramento perch, i, 179

- figure of, i, 258

Sagenodus, i, 613
sailfish, ii, 268
sailor-fish, i, 199

St. Ambrose, ii, 120

- on Thymallus, ii, 120

St. Hilaire, i, 396, 428
St. John, i, 426
Salangidæ, ii, 127

Salanx, i, 146; ii, 123, 127, 128

- figure of, i, 147; ii, 128

sälbling, ii, 108
Salar, ii, 90, 93
Salarias, i, 208, 271; ii, 510, 511
salema, ii, 346

Salmo, i, 291, 304, 305, 316-318, 332, 345, 346, 378, 391; ii, 62, 68, 89, 94-96, 98

- figure of, i, 326; ii, 98, 99, 101, 104-106
- general description, ii, 89
- tail of, figured, ii, 486

salmon, i, 21, 25, 28, 39, 53, 146, 204, 209, 249, 256, 290, 440; ii, 67-69, 94, 107, 128, 159

- artificial propagation of, ii, 88
- ascent of cascades, ii, 76
- Callbreath on, ii, 89
- colors of, ii, 78
- family of, i, 61-119
- habits in ocean, ii, 73
- method of descent of stream, ii, 78
- mutilation of, ii, 75, 76
- nest of, ii, 78
- packing of, ii, 87
- scales of, i, 21
- sexual distortion in, i, 129
- spawning changes in, ii, 89
- spawning of, ii, 78-80
- spring running, ii, 73
- white-meated, ii, 78
- of Yukon, i, 73

salmonete, i, 329

- figure of, ii, 351

salmon fishery,

- of Japan, ii, 81

- output of, ii, 87

salmon fry,

- liberation of, ii, 84

- marking of, ii, 84

Salmonidæ, i, 204, 290; ii, 61-119, 127, 130, 161, 190

Salmonoidea, ii, 41, 61
salmonoids, ii, 94, 107
salmon pack,

- estimate of, ii, 80

salmon roe, ii, 76
salmon shark, i, 447, 537
salmon trout, ii, 94, 105, 114

Salmopercæ, ii, 241-249

- suborder of, ii, 241

Salpa, i, 477; ii, 348
Salpidæ, i, 477
Salvelini, ii, 95, 106

Salvelinus, i, 282, 306, 307, 311; ii, 62, 95, 99, 107, 108-110, 112-114

- description of, ii, 107

- figure of, i, 326; ii, 110, 111

samarang, i, 408

Samaris, ii, 489
samlet,

- figure of, ii, 116

Sancassini, ii, 144
Sandalodus, i, 531
sand-dab, ii, 491
sand-darter, ii, 313

- figure of, i, 158; ii, 313

sandfishes, ii, 364

- figure of, ii, 364

sand-lance,

- figure of, ii, 521

sand-pike, ii, 308
sand-roller,

- figure of, ii, 241

Sandroserrus, ii, 309

Sandrus, ii, 309
sandstone,

- fragment figured, i, 435

sand-sucker, ii, 357
sand-whiting, ii, 357
San Pedro fish, ii, 244
São Paulo, ii, 162

Saprolegnia, i, 353; ii, 76

- surface on, i, 354

sarcastic blenny,

- figure of, ii, 507

Sarda, i, 210; ii, 264
Sardinella, i, 204, 327, 332; ii, 50
sardines, i, 199, 268; ii, 50
Sardinia, i, 204
Sardiniodes, ii, 134
Sardinius, ii, 44

Sargassum fish,

- figure of, i, 52; ii, 549

sargo, ii, 345

Sars, ii, 535
saucer-eye porgy,

- figure of, ii, 345

sauger,

- figure of, ii, 309

Sauripterus, i, 603
Saurocephalus, ii, 48
Saurodon, ii, 48
Saurodontidæ, ii, 48
Sauropsida, i, 601
Sauropsis, ii, 34
Saurorhynchidæ, ii, 17
Saurorhynchus, ii, 17
saury,

- figure of, ii, 212

sausolele,

- figure of, ii, 435

Sauvage, i, 412, 427
savalo, ii, 43
sawfish, i, 199, 548

- figure of, i, 550

saw-shark, i, 549

- figure of, i, 201, 548

scabbard-fishes, ii, 267

Scænidæ, i, 206
scales of fish,

- classification of, i, 20

- figure of, i, 21, 22

scamp, ii, 327

Scapanorhinus,

- snout figured, i, 536

Scaphirhynchus, i, 253, 452; ii, 18, 20
Scardinius, ii, 168
Scaridæ, ii, 390, 393, 396
Scaridea, ii, 391

Scartichthys,

- figure of, i, 294; ii, 510

Scarus, ii, 352, 391, 393, 396

- figure of, ii, 394
- jaws of, figured, ii, 393
- pharyngeals of, i, 47, 48; ii, 393

Scatophagus, ii, 400
Scaumenacia, i, 612
Schedophilus, ii, 285

Schilbiosus,

- figure of, i, 179

Schilbeodes, i, 180, 202; ii, 177, 182

- figure of, ii, 182

- structure of, ii, 177

Schizocardium, i, 465
Schlegel, i, 414
Schmidt, i, 411
Schnäbel, ii, 63
Schnapper, ii, 343
Schneider, i, 398
schoolmaster, ii, 336
schoolmaster-snapper,

- figure of, i, 440

Schomburgk, i, 415
Schöpf, i, 395
Sciæna, i, 391; ii, 356-358
Sciænidæ, i, 290; ii, 225, 353-355, 358

Sciænops, ii, 355

- figure of, ii, 356

Sclerodermi, ii, 398, 411, 412
scleroderms, ii, 412, 415
Scoliodon, i, 542
Scolopsis, ii, 342

Scomber, i, 94, 210, 391; ii, 260, 262, 266

- figure of, i, 332; ii, 260

Scomberoides, ii, 272, 470

Scomberomorus, i, 210, 322; ii, 264, 266

- figure of, ii, 264

Scomberosomus,

- figure of, i, 322

Scomberidea, ii, 258, 271

Scombramphodon, ii, 266

Scombresox, ii, 211, 214

- figure of, i, 212

Scombridæ, i, 210; ii, 258, 272, 470

- family of, ii, 259

scombriform fishes, i, 209
Scombrinus, ii, 266
Scombroclupea, ii, 52

Scombroidea,

- suborder of, ii, 258

Scombroidei, ii, 291, 484, 485
scombroids, ii, 485
Scombropidæ, ii, 317
Scombrops, ii, 317
scopeloid, ii, 474
Scopelus, ii, 133
Scophthalmus, ii, 486, 488
Scopoli, i, 396

Scorpæna, i, 180, 211, 391; ii, 429, 432, 433, 438

- figure of, i, 433, 434

Scorpænichthys, ii, 442

- skull of, figured, i, 427

Scorpænidæ, i, 94, 207, 211; ii, 363, 426, 435, 441, 503

- family of, i, 426, 448

Scorpænopsis, ii, 434
Scorpænopterus, ii, 436
Scorpididæ, ii, 397, 398, 400
Scorpis, ii, 398, 400
scorpion-fishes, i, 207, 429; ii, 426, 433
Scudder, i, 405
sculpin, i, 21, 219, 257, 290, 429, 440; ii, 363, 441, 445, 447-449

- buffalo, ii, 443
- daddy, ii, 445
- eighteen-spined, ii, 446
- great, ii, 442
- little, ii, 446
- long-horned, ii, 447
- Pribilof, ii, 446
- red, ii, 443
- Richardson's, ii, 451
- river, ii, 445
- sleek, ii, 451
- stone, ii, 443

scup, ii, 344

- figure of, ii, 343

scutes, i, 570
Scuticaria, ii, 153
Scymnorhinus, i, 546
Scyliorhinidæ, i, 127, 532, 533

Scyliorhinoid shark,

- skull of, figured, i, 56

Scyliorhinus, i, 447, 533

Scyphophori, ii, 188, 207

- order of, ii, 188, 189

Scytalina,

- figure of, ii, 519

Scytalinidæ, ii, 519
sea-bass, i, 135; ii, 320, 323

- figure of, i, 137

sea-bat, ii, 552
sea-catfish, ii, 178

- eggs of, hatched in mouth, ii, 179

- figure of, ii, 179

sea-devil, i, 559; ii, 547
sea-drum, ii, 357
sea-horse, i, 19, 64, 128; ii, 449

- family of, i, 236

- figure of, i, 17

Seale, i, 422
sea-mink, ii, 356
sea-moth, ii, 239

- figure of, ii, 240

sea-poacher, i, 208; ii, 449, 453
sea-raven,

- figure of, i, 220; ii, 448

sea-robin, i, 246; ii, 457

- figure of, ii, 456
- rough-headed, ii, 457
- striped, ii, 457

sea-scorpion, ii, 363

- figure of, ii, 434

sea-serpent, i, 361; ii, 471, 473
sea-snail, i, 217; ii, 39, 454
sea-trout, ii, 94
sea-waifs, ii, 133
sea weed, ii, 512
sebago, ii, 92
Sebastapistes, ii, 434

Sebastes, i, 125, 211; ii, 428

- figure of, i, 218; ii, 427

Sebastichthys, ii, 428, 429, 433

- figure of, ii, 431, 432

Sebastiscus, ii, 432

Sebastodes, i, 125, 211, 219, 375; ii, 428, 429, 431-433, 438

- figure of, ii, 429

- skeleton of, figured, i, 214

Sebastolobus, i, 52-55, 211

- cranium of, i, 53
- figure of, ii, 428
- lower jaw of, i, 54
- maxillary of, i, 55
- shoulder-girdle of, i, 52

Sebastopsis, i, 271; ii, 432
Sectator, i, 271; ii, 350
Seeley, i, 410
Segemehl, i, 97
segments of Dibothrium figured, ii, 103
selachians, i, 572, 592
Selachii, i, 382, 507-509; ii, 9

Selachostomi, i, 623; ii, 13

- order of, ii, 20

Selenaspis,

- clavicle of, i, 87

- shoulder-girdle of, i, 86

Selene, ii, 276

- development of, figured, i, 148
- Lütken on, i, 144
- skeleton of, figured, i, 55

Selenichthyes, ii, 241-249

- suborder of, ii, 243

Selenosteus, i, 588
Selenosteidæ, i, 587
Semicossyphus, ii, 390
Semionotidæ, ii, 23, 24, 26

Semionotus,

- figure of, ii, 24

Semiophoridæ, ii, 245

Semiophorus, ii, 245

- figure of, ii, 246

Semon, i, 428

Semotilus, i, 282; ii, 167

- figure of, i, 285; ii, 268

señorita, ii, 388
sense organs, i, 115-123
sense of pain, i, 123
sense of taste, i, 121
sense of touch, i, 121
sensorium, i, 153
sensory nerves, i, 153
Sergeant Baker, ii, 130
sergeant-fish,

- figure of, ii, 282

Seriola, ii, 272, 278

- figure of, i, 459; ii, 273

Seriphus, ii, 354
serran, ii, 329
Serrana, ii, 357
Serranellus, ii, 329

Serranidæ, i, 206, 209, 259, 290; ii, 258, 293, 319, 320, 324, 327, 328, 330, 331, 333, 359, 363
serrano, ii, 327, 328
Serranus, ii, 328, 363
Serrasalmo, ii, 161, 162
Sertulariæ, ii, 544
sese de lo alto, ii, 336
sesele, ii, 304
Setarches, ii, 433
setiform, i, 30
sexual coloration, i, 230
sexual modification,

- in colors, i, 129

- in structure, i, 129

shad, ii, 50, 53, 147
shad waiter, ii, 63
shagreen grains, i, 570
sharks, i, 21, 23, 24, 28, 53, 75, 445, 446, 519, 523, 542, 543, 545, 546

- air-bladder wanting in, i, 506
- distribution of, i, 459
- eggs of, i, 127, 433
- fossil teeth of, i, 546
- jaws of, i, 35
- pectoral limbs of, i, 60, 66
- phosphorescent, i, 189
- primitive, i, 510, 511
- shoulder-girdle in, i, 507
- skull of, i, 56, 57

shark-sucker, i, 197; ii, 468, 469
sharp-nosed flying-fish,

- figure of, ii, 213

Shasta, ii, 97
Shaw, i, 398
sheatfish, ii, 182, 183
sheepshead, i, 30, 324; ii, 345, 346

- figure of, i, 31; ii, 346

shibi, ii, 263
shiner, i, 283; ii, 163, 168

- figure of, ii, 168

shiro-uwo, ii, 127, 467

Shooter,

- head-fish taken by, ii, 424

shore-fishes, i, 245

- distribution of, i, 263-265

short-nosed garpike,

- figure of, i, 452

shoulder girdle, i, 42, 50

- of batfish, ii, 551

- of buffalo-fish, ii, 160

- figure of, i, 51, 52, 58, 59, 60, 69, 70, 86, 88, 89, 600; ii, 225, 227

- figure of fossil, i, 521
- of flounder figured, i, 58; ii, 2
- of Ictiobus ii, 160
- inner view of, ii, 160
- of Neoceratodus, i, 609
- of Opah figured, ii, 243
- of Polypterus, i, 70
- of Sebastolobus figured, i, 52
- in sharks, i, 507
- in true eel, ii, 141

shovel-nosed sturgeon i, 253
shrimp, ii, 147
shrimpfishes, ii, 234

- figure of, ii, 235

Shufeldt,

- photographs by, i, 7, 13, 137; ii, 181, 305, 333

Siebold, i, 411, 414
sierra, ii, 266
Siganidæ, ii, 409, 410
Siganus, ii, 410
sight organs, i, 116-118
significance,

- of resemblance, i, 259

- of rare forms, i, 262

Sillaginidæ, ii, 358
sillago, ii, 358
silk-snapper, ii, 336

Siluridæ, i, 149, 205, 280, 290, 293; ii, 60, 178, 182, 186
siluroid, i, 290; ii, 529

Silurus, i, 391; ii, 182
silverfin,

- figure of, i, 457; ii, 166

silver-jaw minnow, ii, 165

- figure of, ii, 165

silver-jenny, ii, 348
silver-king, ii, 43
silver-perch, ii, 342
silver-salmon, ii, 68, 71, 73, 87
silversides, i, 290; ii, 215

- figure of, ii, 217

silver surf-fish,

- figure of, i, 309; ii, 375

silver-tail, ii, 512
silvery anchovy,

- figure of, ii, 54

silvery puffer,

- figure of, ii, 419

Simenchelyidæ, ii, 148

Simenchelys, ii, 148

- figure of, ii, 149

Sindo, i, 418, 422
singing-fish, i, 121

- figure of, i, 23; ii, 526

- species of, ii, 526

Siniperca, ii, 320
sinus impar, i, 120
sinus venosus, i, 108
Siphonognathidæ, ii, 390
Siphonognathus, ii, 390
Siphonostoma, ii, 236
Sirembo, ii, 524

Sirenoidei, i, 612

- order of, i, 613

sisco, ii, 66, 67
siscowet, ii, 66, 115
Sisoridæ, ii, 184
skates, i, 28, 551, 552
skeleton of cowfish,

- figure of, ii, 418

skeleton of fish, i, 10, 34-61

- of cowfish, i, 215
- of Chimæra, i, 564
- parts of, i, 35, 36
- primitive, i, 54
- of pike figured, i, 203
- of red rockfish, i, 214
- of Selene figured, i, 55
- of shark, i, 57
- of spiny-rayed fish, i, 214

skilfishes, ii, 438

- figure of, ii, 438

skin-peeler, ii, 415
skipjack, ii, 50
skippers,

- Couch on, ii, 211

skipping-goby, i, 117
skittle-dogs, i, 545
skull,

- of Anarrhichthys, ii, 517
- autostylic, i, 57
- figure of, ii, 296
- of haddock, ii, 536
- hyostylic, i, 56, 508
- of rock-bass, ii, 296
- of Scorpænichthys figured, ii, 427
- of shark figured, i, 56

sleek-sculpin,

- figure of, i, 221; ii, 451

sleeper-shark, i, 547
sleepy Argentine, ii, 134
slippery Dick, ii, 388

- figure of, i, 297; ii, 180, 396

Sloane, i, 389
small-mouthed bass,

- figure of, i, 325; ii, 303

smear-dab, ii, 494
smelt, ii, 66, 91, 120-138

- figure of, ii, 123

Smerdis, ii, 310, 330

Smith, i, 416, 419, 608

- on Arctic species, i, 317

Smitt, i, 410
snailfish, ii, 455
snake-blennies, ii, 512
snake-eels, ii, 150

- figure of, i, 233

snake-headed China-fish, ii, 371

- figure of, i, 150; ii, 371

snake-headed mullets, ii, 370
snapper, ii, 333, 335, 338

- diamond, ii, 337
- gray, ii, 334, 335
- lane, ii, 336
- mahogany, ii, 337
- mangrove, ii, 335
- mutton, ii, 335
- red, ii, 335
- silk, ii, 336
- true, ii, 337
- yellow-tail, ii, 337

snipe-eels, ii, 151
snipefishes, ii, 234
Snodgrass, i, 422; ii, 423
snooks, ii, 282, 320
snowy grouper,

- figure of, ii, 329

Snyder, i, 418, 420

Snyderina,

- figure of, ii, 437

soapfishes, ii, 330

- figure of, ii, 330

sobaco, ii, 413
sockeye, ii, 69
soft-rayed fishes, i, 204; ii, 39
soi, ii, 429
soldados, ii, 253
Solander, i, 395
soldier-fish, ii, 315

- family of, ii, 253

- figure of, ii, 254

Solea, i, 327; ii, 487, 496
Soleidæ, i, 290; ii, 495, 499
Soleinæ, ii, 496

Solenostomidæ,

- family of, ii, 236

Solenostomus, i, 128; ii, 236

- figure of, ii, 237

soles, ii, 495

- broad, ii, 495
- Day on, ii, 496, 497
- European, ii, 496
- Gill on, ii, 496
- habits of, ii, 496
- hog-choker, ii, 498
- Parker on, ii, 483

Sonnerat, i, 395

Sörensen,

- on elastic spring, i, 97

sounds of fishes, i, 168-170

- Bowring on, i, 168

soup-fin sharks,

- figure of, i, 541

southern zone, i, 253
spadefish, ii, 400

- figure of, i, 325; ii, 401

Spaniodon, ii, 43
Spaniodontidæ, ii, 47
Spanish-flag, ii, 323, 429

Spanish-mackerel, i, 64, 210, 322

- figure of, i, 322; ii, 264
- Goode on, ii, 264, 265
- Mitchill on, ii, 264

Sparidæ, i, 206; ii, 342, 344, 346, 372

- family of, ii, 342

Sparisoma, i, 268; ii, 352, 391, 392, 396

- figure of, ii, 392

- jaws figured, i, 30

Sparnodus, ii, 347
Sparus, i, 259, 263, 391; ii, 346
Spathiurus, ii, 36

Spaulding, ii, 84

- marking of fry by, ii, 84

spawning-grounds,

- return to, ii, 82

spawning of salmon, i, 160
special creation impossible, i, 295
spearfish, i, 199; ii, 469
specialized fishes, i, 249
species, i, 371

- absent through barriers, i, 238
- changed through natural
- selection, ii, 239
- characters of, i, 292
- conditions favorable to, i, 301
- extinction of, i, 239
- meaning of, i, 293, 379
- special creation, i, 295
- transfer of, i, 312

speckled flounder, ii, 488
speckled hind, ii, 324

- figure of, ii, 325

speckled trout,

- figure of, i, 326; ii, 110

Spengel,

- on Enteropneusta, i, 464

Spengelia, i, 465
Spengeliidæ, i, 465
sperling, ii, 123
Sphærodon, i, 268
Sphagebranchus, ii, 151
Sphagepæa, i, 565
sphenial, i, 606
Sphenocephalus, ii, 252

Spheroides, i, 206; ii, 419-421

- figure of, i, 420

Sphyrænidæ, i, 206

- family of, ii, 222

Sphyræna, ii, 221

- figure of, ii, 223

Sphyrænodus, ii, 266

Sphyrna, i, 543

- figure of, i, 544

Sphyrnidæ, i, 543
Spicara, i, 260; ii, 347
Spinacanthidæ, ii, 415
Spinacanthus, ii, 415
Spinachia, ii, 232
spinal cord, i, 112
spineless trunkfish,

- figure of, i, 378; ii, 417

spines of catfish, i, 179
spiny eels, ii, 157
spiny-rayed fishes, i, 21, 206-208; ii, 39, 208, 307

- skeleton of, figured, i, 214

spiracle, i, 92
Spiraculis, i, 393
spiral valve, i, 32
splenial, i, 43
split-tail, ii, 169
Spondyliosoma, i, 260, 267; ii, 348, 350
spookfishes, i, 564
spot, ii, 356
spotted trout, ii, 105
spotted trunkfish, ii, 416

- figure of, i, 377; ii, 417

spotted weakfish,

- figure of, ii, 353

sprat, i, 204; ii, 50, 123
spring salmon, ii, 80
Squalidæ, i, 531, 543, 545, 546, 566
Squaloraja, i, 566
Squalorajidæ, i, 566

Squalus, i, 391

- figure of, i, 545

Squamipinnes, ii, 209, 411
Squamipinus, ii, 397-410
square-tails, ii, 291

Squatina, i, 548

- brain of, figured, i, 547

- pectoral fin figured, i, 56

Squatinidæ, i, 549, 554
squawfish,

- figure of, i, 162; ii, 169

- spawning journey of, i, 164

squeteague, ii, 353
squirrel-fish, ii, 253, 329
Stannius, i, 428
star-gazer, ii, 364, 503

- figure of, i, 187, 504

Starks, C. L.

- drawings of fishes i, 36-39

Starks, E. C., i, 420

- on berycoid skull, ii, 250

- on fish skeleton, i, 39

starry-flounder, ii, 493

- figure of, ii, 495

star-spined ray,

- figure of, i, 448

Stearns, i, 419
steelhead, ii, 94, 96, 99, 100

- figure of, ii, 101

steelhead-trout,

- figure of, i, 327

Steenstrup, i, 410
Stegocephali, i, 606
Stegostoma, i, 533

Stegothalami, i, 584

- Dean on, i, 585

Steindachnerella, ii, 541

Steindachner, i, 411, 414, 427

- portrait of, i, 403

Steindachneria,

- figure of, ii, 541

Steinegeria, ii, 286

Steinegeriidæ, ii, 286

Stelgis,

- figure of, ii, 451

Steller, i, 395; ii, 135

- on quinnat salmon, ii, 68

Stellifer, i, 271; ii, 355

Stenodus, ii, 62, 68

- figure of, ii, 67

Stenotomus, ii, 344

- figure of, ii, 343

Stephanoberycidæ,

- family of, ii, 223

Stephanoberyx, ii, 223

Stephanolepis, ii, 414, 415

- figure of, i, 182, 415

Stereobalanus, i, 465
Stereolepis, ii, 321
Sternoptychidæ, ii, 137
Sternoptyx, i, 357; ii, 137
Stethojulis, ii, 390
Stichæiniæ, ii, 511

Stichæus, ii, 513

- figure of, ii, 513

stickleback, i, 51, 128, 250, 290; ii, 157, 215, 228, 229, 232

- fighting of, i, 165
- figure of, ii, 232
- shoulder-girdle of, ii, 227
- spines of, i, 179

Stieda, i, 428

Stiles,

- on parasitic diseases, i, 343, 344

stingaree, i, 556
sting-bull, ii, 501
stingfish, ii, 501
sting-rays, i, 84, 267, 549

- figure of, i, 246, 555

- spines of, i, 182

Stizostedion, ii, 308

- figure of, ii, 309

Stolephorus, ii, 52

Stomias,

- figure of, ii, 128

Stomiatidæ, i, 189, 204; ii, 128

Stone, ii, 80

- on rate of travel of salmon, ii, 80

stone-bass, ii, 323
stone-cats, ii, 182
stone-roller, i, 157; ii, 166

- figure of, i, 33; ii, 167

stone-sculpin, ii, 443
stonewall perch, ii, 359, 360
stony-flounder, ii, 482
Storer, i, 418

Storms, i, 427

- on fossil remora, ii, 469

Stratodontidæ, ii, 137
Stratodus, ii, 137
Strinsia, ii, 539
striped-bass, i, 48, 53; ii, 37, 321

- bones of, i, 39, 45
- figure of, i, 35
- tail of, i, 49
- vertebral column of, i, 48

striped-mullet,

- figure of, i, 330

striped sea-robin, ii, 457

Ström, i, 396

Stromateidæ, i, 160; ii, 215, 259, 284, 291, 398, 485

- family of, ii, 283

Stromateus, i, 391; ii, 283, 291
sturgeon, i, 128, 204, 250, 257, 290; ii, 18-21, 159, 160, 182, 186

- child swallowed by, ii, 182
- of Danube, ii, 182
- figure of, ii, 19, 20
- larva of, figured, i, 141

Styela,

- figure of, i, 475, 476

Stygicola, i, 314; ii, 524
Stylephoridæ, ii, 480
Stylephorus, ii, 480
subgenus, i, 373
suborbital stay, i, 44
subspecies, i, 294
sucker, i, 156, 198, 290, 304; ii, 56, 171, 172, 174

- California, ii, 174
- carp, ii, 173
- common, ii, 174
- figure showing parasites, i, 348
- Oregon, ii, 175
- razor-backed, figured, ii, 175

sucking-disks,

- of clingfish, i, 198

sucking-fish,

- figure of, i, 197; ii, 468

Suckley, i, 419
Sudis, ii, 9, 136
Suez Canal, i, 268
sukkegh, ii, 69
Suletind watershed, i, 307
Sulphur, the, i, 408
summer herring,

- figure of, i, 455

Sunapee trout,

- figure of, ii, 109

sunfish, i, 3-15, 28, 209, 290; ii, 37, 297, 424

- banded, ii, 299
- blue-green, i, 26
- common figured, i, 7; ii, 301
- description of, i, 4
- dwarf, ii, 467
- figure of, i, 2, 4, 27
- food of, i, 11
- long-eared, i, 3; ii, 300
- nine-spined, ii, 301
- photograph of, i, 13
- pigmy, ii, 297

supraclavicle, i, 89

Surface,

- on destruction of fish, i, 357
- on lampreys, i, 491-505
- on Saprolegnia, i, 354-356

surf-fish, i, 125, 207, 290; ii, 372, 373

- blue, ii, 375
- silver, ii, 375
- thick-lipped, ii, 374
- wall-eye, ii, 375
- white, ii, 374

surf-shiner, ii, 376
surf-smelt, ii, 123, 124, 127
surf-whiting, ii, 357
surgeon-fish, ii, 407

- lancet of, i, 181

surmullets, i, 122, 198, 322; ii, 351-379
suspensorium of mandible, i, 43
susuki, i, 324; ii, 320
Swain, i, 422
Swainson, i, 410
swallowers, ii, 360
Swammerdam, i, 390
swampy watersheds, i, 314

Swan, ii, 123

- on Mesopus, ii, 123

sweetfish, ii, 115
sweet-perch, ii, 363
swell-sharks, i, 197, 533
swell-toad, ii, 420, 423
swim-bladder, ii, 95
swordfish, i, 169, 199, 210; ii, 269

- adult, figured, ii, 270
- Goode on, ii, 270
- Owen on, ii, 270, 271
- vessels struck by, ii, 270
- young, figured, ii, 269

swordtail-minnow,

- figure of, i, 124; ii, 199

Syacium,

- figure of, ii, 488

Syllæmus, ii, 224

Symbranchia, ii, 140

- order of, ii, 140

Symbranchidæ, ii, 141
Symbranchus, ii, 141
Symphodus, i, 268; ii, 387

Symphurus,

- figure of, ii, 498

symplectic bone, ii, 156

Synagrops, ii, 317

Synanceia, i, 180; ii, 434

- figure of, i, 229

Synaphobranchidæ, ii, 149

Synaphobranchus, ii, 149

- figure of, ii, 149

Synaptura, ii, 497

Synchiropus, ii, 506

Synechodus,

- eggs of, i, 527

Synentognathi, ii, 190, 208-214

- suborder of, ii, 209

Syngnathidæ,

- family of, i, 236

Syngnathus, i, 170, 391; ii, 236
Synodontidæ, ii, 130, 133
Synodontis, ii, 182

Synodus, ii, 190

- figure of, ii, 130

synonymy and priority,

- Coues on, i, 374

Syntegmodus, ii, 44

Syrski, ii, 144, 145

- on eels, ii, 145

Systema Naturæ, i, 373
Tachysurus, ii, 178, 179, 86
Tænioides, ii, 467

Tæniosomi, ii, 292, 459-480

- suborder of, ii, 471, 472

Tæniotoca, ii, 375
Tæniura, i, 557
tahanohadai, ii, 363

Tahoe trout,

- figure of, i, 327; ii, 104

tai-fishing,

- illustration of, i, 338

tail forms, i, 49, 50, 80-85
taiva, ii, 342
Talisman, i, 408; ii, 60
Talismania, ii, 60
Tamiobatidæ, i, 532
Tamiobatis, i, 551
tangs, ii, 407
Tantogolabrus, ii, 387

Tarpon, i, 157, 205; ii, 35, 51

- figure of, ii, 43

Tarrassiidæ, i, 602
Tarrassius, i, 602
tarwhine, ii, 344
tautog, ii, 387

- figure of, ii, 385, 386

Tautoga, i, 207; ii, 385
taxonomy, i, 367, 368

Tectospondyli, i, 448, 510, 513, 519, 545, 549

- order of, i, 543

- Woodward on, i, 543

tectospondylous, i, 49
teeth, i, 29, 30, 201

- of Ceratodus figured, i, 614
- of Chimæra, i, 562
- of Corax, i, 543
- figured, i, 522, 524
- of Janassa, i, 554
- of sharks, i, 515, 527, 529, 537

Teleocephali, i, 405; ii, 39, 40, 209

Teleosteans, i, 384

Teleostei, i, 66, 204, 622, 624; ii, 2, 5, 37

- sympathetic system of, i, 114

Teleostomes, i, 599

Teleostomi, i, 462, 572, 583, 598, 599, 603

- Regan on, i, 622

teleosts, i, 35, 135, 139, 141, 204, 569; ii, 1, 3, 4, 159

Telepholis, ii, 133

Telescopias, ii, 317

- figure of, ii, 318

teleotemporal, i, 90

Temnothoraci, i, 584, 586
temperature,

- affecting distribution, i, 242

tenacity of life in fishes, i, 146, 147, 149
tench, ii, 168
tengudai, ii, 333
tengusame, i, 534
ten-pounder, ii, 35, 43

- figure of, i, 454; ii, 42

Terapon, ii, 342
Teraponidæ, ii, 342
Tertiary fishes, i, 440
Tertiary ganoids, ii, 140
tessellated darter,

- figure of, ii, 312

tessellated teeth, i, 30, 549

Tetragonolepis, i, 24

- figure of, ii, 26

Tetragonopterus, i, 314; ii, 161, 162, 381

Tetragonuridæ, ii, 215

- family of, ii, 291

Tetragonurus, ii, 291

Tetraodon, i, 169, 197, 206, 236, 393, 611; ii, 420

- figure of, i, 183, 244; ii, 421, 422

Tetraodontidæ, i, 182; ii, 421

- family of, ii, 419

Tetrapturus, i, 257; ii, 269
Tetrarhynchus, ii, 134
Tetronarce, i, 554
Teuthidæ, ii, 291
Teuthididæ, ii, 407, 409

Teuthis, i, 268, 271, 293; ii, 407

- figure of, i, 181; ii, 407, 408

Thacher,

- on paired limbs, i, 70

thalamencephalon, ii, 6, 8

Thalassoma, i, 207, 267, 271; ii, 389

Thalassophryne, i, 180; ii, 526, 527

- poison organ of, ii, 528, 529

- structure of, ii, 527, 528

Thalassothia, ii, 526

Thaleichthys, ii, 124

- figure of, i, 320; ii, 19, 124

- sketch of, ii, 125

Thaliacea, i, 477
Thaumaturus, ii, 119
Thelodontidæ, i, 574, 579
Thelodus, i, 570, 573

Theragra, i, 209

- figure of, ii, 537

Therobromus, ii, 127

Thetis, the, i, 410
thick-lipped surf-fish,

- figure of, i, 374

Tholichthys, i, 144; ii, 402
Thollière, i, 427
Thompson, i, 410, 418
Thoracici, i, 393; ii, 39
Thoracies, ii, 209
Thoreau, ii, 190, 308
thread-eel, ii, 151, 152

- figure of, i, 17, 365; ii, 152

threadfins, i, 122; ii, 215, 224

- figure of, ii, 225

- shoulder-girdle of, i, 89; ii, 225

threadfish, ii, 276
threadhead worms, i, 351
thread-herring, ii, 51, 53
three-forked hake, ii, 539
three-spined stickleback,

- figure of, ii, 232

thresher-shark, i, 536
Thrissopater, ii, 43
Thrissops, ii, 41
Thryptodontidæ, ii, 44
Thryptodus, ii, 44
Thunberg, i, 416
thunder-pumper, ii, 354, 355
Thunnus, i, 210, 272; ii, 262
Thursius, i, 604
Thwaite shad, ii, 50
Thyestes, i, 576
Thymallidæ, ii, 120

Thymallus, i, 305; ii, 120, 121, 122

- figure of, i, 328; ii, 120, 122

Thyrsites, ii, 267

Thyrsitocephalus, ii, 267
tide pools of Misaki,

- view of, i, 161

tiger-puffer, ii, 423
tiger-sharks, i, 533
Tilapia, ii, 380
tilefish, ii, 361

- catastrophe to, ii, 362
- Collins on, ii, 362
- Gill on, ii, 361, 362

Tilesius, i, 396, 416
Tinca, i, 345; ii, 168, 175
tiñosa, ii, 276
Tiphle, ii, 236
Titanichthyidæ, i, 587
Titanichthys, i, 583, 587, 589

Titicaca Lake,

- peculiar fish from, ii, 201

toadfish, ii, 525, 526

- Brazilian, ii, 526
- poison, ii, 526
- poison-organs of, i, 180
- shoulder-girdle of, i, 59

tomcod, ii, 537

- figure of, ii, 538

tomtates, ii, 341
tongue-fish, ii, 488, 497
tooth,

- of Hybodus, figured, i, 528

- of Lamnidæ, i, 538

topknot, ii, 488
top-minnow, i, 118; ii, 198, 199, 467

- figure of, ii, 198

toque, ii, 114
torabuku, ii, 423
tori, ii, 6

Tornaria,

- figure of, i, 463

torpedo, i, 268; ii, 183, 188

- figure of, i, 186; ii, 183

- fin rudiments in, i, 71

torsk, ii, 539
toto, ii, 398
totuava, ii, 354
Townsend, ii, 502

Tower,

- on gas in swim-bladder, i, 95, 96

- on weakfish, i, 94

Toxotes, i, 240, 268; ii, 400

Toxotidæ, ii, 400

Trachicephalus,

- figure of, i, 456; ii, 438

Trachichthyidæ, ii, 253
Trachichthys, i, 263; ii, 252
Trachidermus, ii, 445
Trachinidæ, ii, 500, 501, 506, 525
Trachinotus, i, 322; ii, 276

Trachinus, i, 169, 180, 391; ii, 500, 501

- Boulenger on, ii, 501

Trachosteus, i, 583, 588, 589, 590

Trachurops, ii, 275

Trachurus, i, 210, 274

- figure of, ii, 274

Trachypteridæ,

- family of, ii, 477

- Goode and Bean on, ii, 479

Trachypterus, i, 144; ii, 425, 477

- figure of, ii, 478

- Günther on, ii, 480

Trachyrhynchus, ii, 541
trahira, ii, 162
transportation of fishes, i, 150
Trautschold, i, 427

Traquair, i, 426, 428

- on Gnasthome, i, 573
- on high and low forms, i, 381, 382
- on Ostracophores, i, 569-571
- on Palæospondylus, i, 591
- portrait of, i, 425
- on sharks, i, 512

Traquairia, i, 517

Travailleur, the, i, 408; ii, 60
tree-climber of India,

- Daldorf on, i, 163

treefish, ii, 431
Tremataspidæ, i, 576
trematodes, i, 344
Triakis, i, 541
Triacanthidæ, ii, 412
Triacanthodes, ii, 412
Triacanthus, ii, 412
Trichina, i, 352
Trichiurichthys, ii, 268

Trichiuridæ, i, 210; ii, 472

- family of, ii, 267

Trichiurides, ii, 32

Trichiurus, ii, 268, 479

- figure of, ii, 268

Trichodon,

- figure of, ii, 364

Trichodontidæ, ii, 364, 506
trinomial nomenclature, i, 378
trigger-fishes, i, 440; ii, 412, 413

- figure of, i, 184, 412

Trigla, i, 169, 391; ii, 456, 457

- air-bladder of, i, 97

Triglidæ, i, 122, 208; ii, 455

- family of, ii, 455

Triglops, ii, 442

- figure of, ii, 443

Triglopsis, i, 317; ii, 447
Trigonodon, ii, 347
Triodon, ii, 419
Triodontidæ, ii, 418
Tripterygian, ii, 508
Tristichopterus, i, 603
Trochocopus, ii, 388
Troglichthys, i, 220, 222; ii, 202, 203
tropical fishes,

- species of, i, 271

- variety among, i, 333

Tropidichthyidæ, ii, 421
Tropidichthys, i, 115; ii, 422
Troschel, i, 415
trout, i, 156, 250, 290, 304, 326, 327; ii, 38, 41, 61, 89, 90, 107, 121, 128, 147, 168

- tail figure of, ii, 486
- of Utah basin, ii, 104
- of Yellowstone, i, 345

trout-perch, i, 241, 290; ii, 61

- figure of, ii, 242

trout-spotted darter, ii, 314
trout-worm, ii, 103

- figure of head, ii, 103

- segments of, figured, ii, 103

trucha, ii, 320
true eels, ii, 141

- shoulder-girdle in, ii, 141

true perches, ii, 304
true sharks, i, 523-560
true snapper, ii, 337
trumpeter, ii, 363
trumpet-fish, i, 51, 440

- family of, i, 233

- figure of, i, 234

truncate, i, 19
truncus arteriosus, ii, 6
trunkfishes, i, 16, 19, 206, 373, 375, 378, 429; ii, 415-417

- figure of, i, 373, 376, 377
- horned, ii, 416
- hornless, ii, 419
- spineless, ii, 417
- spotted, ii, 416

Trypauchen, ii, 467
tschawytscha, ii, 73
Tschudi, i, 415
tsuzume, ii, 402
tullibee, ii, 67
tunicates, i, 460, 462, 467-481

- adult, figured, i, 480
- anatomy, figured, i, 472
- Kingsley on, i, 467, 468, 469
- larva, figured, i, 471
- Ritter on, i, 474

tunny, i, 19, 210

- great, ii, 262

turbots, i, 206, 328; ii, 488, 489

- tribe, the, ii, 487

Turner,

- on Dallia, ii, 207

Turton, i, 410

Tutuila Island,

- lizard skipper from, i, 230

Twin Lakes,

- trout of, i, 241

Two-Ocean Pass, i, 307, 308, 309, 310

- Evermann on, i, 307

tyee, ii, 69

Tylosurus, i, 128

- figure of, ii, 210

- shoulder-girdle of, i, 59

Typhlichthys, i, 220, 314; ii, 201, 202

- figure of, i, 116; ii, 202

Typhlogobius, i, 198; ii, 467
Typodus, ii, 222
uku, i, 325; ii, 338
Ulæma, i, 271
ulchen, ii, 124

- figure of, i, 320; ii, 124

Umbra, i, 253; ii, 35

- figure of, ii, 193

Umbridæ, i, 290; ii, 193, 194

Umbrina, ii, 356, 357

- figure of, ii, 357

umiuma, i, 429
uncertain conclusions, i, 79
Undina, i, 204, 605
unicorn-fish, ii, 409, 415
U. S. Fish Commission, ii, 69
Upeneus, ii, 353

Upham,

- on glacial effects, i, 275

upland fishes, i, 311

Uranidea, ii, 443, 445

- figure of, ii, 445

Uranoplosus, ii, 22

Uranoscopus, i, 259, 260, 393; ii, 361, 364, 503, 504

Uranoscopidæ, ii, 503, 504, 506, 525
Urenchelyidæ, ii, 142
Urenchelys, ii, 142
ureters, ii, 6
Urochordata, i, 460
Urodela, i, 76
Urolophus, i, 555-557
Uronemidæ, i, 612
Uronemus, i, 612
Urophycis, i, 187; ii, 538
Uropterygius, ii, 153
urosome, i, 84, 85
Urosphen, ii, 234
Urosphenidæ, ii, 234
urostyle, i, 84
Usinosita, ii, 498
uu, i, 162
vaca, i, 235; ii, 327
Vahl, i, 396

Vaillant, i, 412

- portrait of, i, 413

Valenciennellus, ii, 134
Valenciennes, i, 401, 404
Valenciennesia, ii, 460
Valentyn, i, 396
Valisneri, ii, 144
Valisneria, ii, 144

Van Dyke, ii, 93

- on Ouananiche, ii, 93

vaqueta de dos colores, ii, 404
variability of instinct,

- Whitman on, i, 156

variation in colors, i, 235
variation in fin-rays, i, 211
Variola, ii, 327
vasa efferentia, ii, 6
vas deferens, i, 28
Velifer, ii, 286
Vellitor, i, 260; ii, 448
vendace, ii, 67
venomous spines,

- of catfish, i, 179

- of scorpion-fish, i, 180

ventral fins, i, 10
Venustodus, i, 531
Verasper, ii, 492
ver blanc, i, 351
Verilus, ii, 338
vertebræ, i, 203, 205
vertebræ in fishes, i, 212

- Boulenger on, i, 213

- figure of, i, 510

vertebral column, i, 46-48

- figure of, i, 48

vertebral column,

- of lancelet, i, 55

- of Roccus, i, 48

verrugato, ii, 356
vessels engaged in fish-collecting, i, 408, 410
villiform teeth, i, 29

Vinciguerra, ii, 408

- portrait of, i, 413

Vinciguerria, ii, 134

Vinson,

- on Gourami, ii, 369

Violante, the, i, 408; ii, 60
viper-fish, ii, 129

Vireosa, ii, 460

- figure of, ii, 461

viscera of fish, i, 26, 28
viviparous fishes,

- figure of, i, 125, 126, 222; ii, 200

viviparous perch,

- figure of, ii, 379

voices of fishes, i, 121
Vogmar, ii, 477
Vogt, i, 428
Volador, ii, 458
Vomer, ii, 276
vomer, i, 6
Vomeropsis, ii, 278
wachna cod, ii, 537
Wagner, i, 427
Waha Lake, ii, 104

Waite, i, 408, 416

- portrait of, i, 409

Walbaum, i, 397; ii, 68

Walcott, i, 428, 603

- on fossil chimæroids, i, 565

- on oldest forms, i, 435

walking-fish, i, 167
wall-eye, ii, 307
wall-eyed surf-fish, ii, 375
Walton, i, 336, 337

Ward,

- on parasitic diseases, i, 343, 344

Wardichthys, ii, 15
water-beetle, ii, 144
water-pig, ii, 369
watersheds, i, 305

- the Cassiquiare, i, 307
- how fishes cross, i, 306
- the Suletind, i, 306
- swampy, i, 314
- Two-Ocean Pass, i, 307

weakfish, ii, 353

Weber, i, 428

- on swim-bladder, i, 96

Weberian apparatus, i, 93, 96, 97; ii, 160

- figure of, i, 93; ii, 160

weevers, ii, 500

- Gill on, i, 500

weissfelchen, ii, 65
weissfisch, ii, 65
wels, ii, 182
welshmen, ii, 253
West Indian fish, i, 235
whale-shark, i, 540
whiff, ii, 488, 489
whips, i, 206
whiptail rays, i, 549
Whiteaves, i, 427
whitebait, ii, 123, 127, 216
white bass, ii, 321
white bullhead, ii, 180
white catfish,

- figure of, i, 344

white channel-cat, ii, 180
white chub,

- figure of, ii, 165

whitefish, i, 62-64, 305, 322; ii, 115, 362, 467

- figure of, i, 321

white-mouthed drummers, ii, 356
white perch, ii, 321

- figure of, ii, 322

white sea-bass, ii, 354
white sharks, i, 534
white shiner,

- figure showing parasites, i, 343

white surf-fish,

- figure of, ii, 374

- with young figured, i, 125; ii, 372

whiting, ii, 537

Whitman, i, 428

- on instincts, i, 156

Whitmee,

- on aquarium fishes, i, 165

Whitney, ii, 116
wide-eyed flounder,

- figure of, ii, 488

wide-gape, ii, 545
wide-mouthed flounder,

- figure of, ii, 493

Wiedersheim, i, 513

Williams,

- on eye of flounder, i, 174-178

Williamson, i, 423
Williston, i, 427
willow-cat, ii, 180
Willughby, i, 390
Winckler, i, 427
window-pane fish, ii, 488

- figure of, ii, 487

wine-colored eel, ii, 153
wolf-eel, ii, 517
wolf-fish, ii, 517

- figure of, ii, 517

Wolffian duct, i, 28

Woodward, i, 426, 428, 519, 543, 554, 582, 584, 591, 594, 602; ii, 4, 13, 24, 26, 34, 36, 43, 48, 140, 425, 514, 522

- on Acanthodei, i, 514, 516
- on Chondrostei, ii, 17
- on Dorypterus, ii, 16
- on eels, ii, 140
- on fossil fishes, i, 439
- on fossil garpike, ii, 32
- on Isospondyli, ii, 38
- portrait of, i, 425
- on Pycnodonti, ii, 23

Woolman, i, 422
worm-like eels, ii, 150
worm of the Yellowstone, i, 345
Worthen, i, 426
wrasse, i, 203; ii, 385, 387
wreckfish, ii, 323

Wright, i, 427, 428

- on fishes of Panama, i, 275

wrymouths,

- figure of, ii, 516

Wyman,

- on month gestation, i, 170

- on protocercal tail, i, 81

Xanthichthys, ii, 413

Xererpes, ii, 512

- figure of, ii, 511

Xenichthys, i, 271; ii, 338

Xenistius, i, 271; ii, 338

- figure of, ii, 338

Xenocephalidæ, ii, 520
Xenocephalus, ii, 520
Xenocys, i, 271; ii, 338

Xenomi, i, 405; ii, 157

- order of, ii, 206

Xenopterygii, ii, 499

- suborder of, ii, 529

Xesurus, ii, 409

Xiphasia,

- figure of, ii, 515

Xiphasiidæ, ii, 513

Xiphias, i, 210, 329, 391; ii, 269

- figure of, ii, 270

Xiphidiinæ, ii, 511

Xiphidion, ii, 512

Xiphiidæ,

- family of, ii, 269

Xiphiorhynchus, ii, 269

Xiphorphorus,

- figure of, i, 124; ii, 199

Xiphistes,

- figure of, ii, 512

Xyrauchen, ii, 172, 174

- figure of, ii, 175

Xyrias,

- figure of, ii, 151

Xyrichthys, i, 207; ii, 388-390

- figure of, ii, 388

Xystæma, ii, 348

- figure of, ii, 347

Xystreurys, ii, 492
Xystrodus, i, 531
yamabe, i, 327; ii, 95
yamanokami, ii, 445

Yarrell, i, 410

- on fishing-frog, i, 169

- on sounds, i, 168

yellowback rockfish,

- figure of, i, 218

yellow bass, ii, 321
yellow catfish, ii, 182
yellow-fin grouper, ii, 325

- figure of, ii, 327

yellow-fin trout, ii, 105

- figure of, ii, 105

yellow-fish, ii, 324
yellow goatfish, ii, 352
yellow grunt, ii, 340
yellow mackerel, ii, 276
yellow perch, ii, 307

Yellowstone Lake,

- trout of, i, 310, 345-347

Yellowstone Miller's Thumb,

- figure of, ii, 444

yellow-tail, ii, 273
yellow-tail roncador, ii, 356

- figure of, ii, 357

yellow-tail snapper,

- figure of, ii, 337

yezomasu, ii, 71, 72

Young, i, 426

- on angling, i, 337-339

Zacalles,

- figure of, ii, 511

Zacco, ii, 164
zakko, ii, 117, 120
Zalarges, ii, 134
Zalembrius, ii, 374, 376
Zalieutes, ii, 552

Zalises,

- figure of, ii, 240

Zanclidæ, ii, 406

- family of, ii, 406

Zanclus, i, 240, 268; ii, 406

- figure of, ii, 406

Zaniolepis, ii, 440
Zander, ii, 309
Zaprora, ii, 286
Zaproridæ, ii, 286
Zebrasoma, ii, 408, 409
Zebrias, ii, 497

Zeidæ, ii, 398

- family of, ii, 247

Zenarchopterus, ii, 212
Zenion, ii, 249
Zenopsis, ii, 249

Zeoidea, i, 241-249

- suborder of, ii, 245

Zeoidei, ii, 484
zeoid fishes, ii, 245
Zeorhombi, ii, 245
Zesticelus, ii, 447
Zeugopterus, ii, 488

Zeus, i, 259, 263, 267, 391; ii, 243, 249, 398

- figure of, ii, 248

Zigno, i, 427

Zingel, ii, 307

- figure of, ii, 310

Zittel, i, 427; ii, 13, 514

- on Lepidostei, ii, 23
- on Ostracophores, i, 569
- portrait of, i, 425

Zoarces, ii, 144, 518

- figure of, ii, 518

Zoarcidæ, ii, 518, 522
zoogeography, i, 237
zooids, i, 479
zootomists, i, 90
Zostera, i, 476
Zuieuw, i, 396

Zygonectes, ii, 199

- figure of, ii, 198

FERNS
A MANUAL FOR THE NORTHEASTERN STATES
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OUR NATIVE FERNS

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GUIDE TO THE STUDY OF INSECTS
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TRANSCRIBER'S NOTES

1. Corrected the ERRATA listed on p. xxiii with the exception of the table of changes in generic names.

2. Silently corrected simple spelling, grammar, and typographical errors.

3. Retained anachronistic and non-standard spellings as printed.

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Table of Contents

- A GUIDE TO THE STUDY OF FISHES
- CONTENTS VOL. II.
- LIST OF ILLUSTRATIONS VOL. II.
- ERRATA[1] Vol. II
- CHAPTER I THE GANOIDS
- CHAPTER II THE GANOIDS—Continued
- CHAPTER III ISOSPONDYLI
- CHAPTER IV SALMONIDÆ
- CHAPTER V SALMONIDÆ—(Continued)
- CHAPTER VI THE GRAYLING AND THE SMELT
- CHAPTER VII THE APODES, OR EEL-LIKE FISHES
- CHAPTER VIII SERIES OSTARIOPHYSI
- CHAPTER IX THE NEMATOGNATHI, OR CATFISHES

- CHAPTER X THE SCYPHOPHORI, HAPLOMI, AND XENOMI

- CHAPTER XI ACANTHOPTERYGII; SYNENTOGNATHI

- CHAPTER XII PERCESOCES AND RHEGNOPTERI

- CHAPTER XIII PHTHINOBRANCHII: HEMIBRANCHII, LOPHOBRANCHII, AND HYPOSTOMIDES

- CHAPTER XIV SALMOPERCÆ AND OTHER TRANSITIONAL GROUPS

- CHAPTER XV BERYCOIDEI
- CHAPTER XVI PERCOMORPHI
- CHAPTER XVII CAVALLAS AND PAMPANOS

- CHAPTER XVIII PERCOIDEA, OR PERCH-LIKE FISHES

- CHAPTER XIX THE BASS AND THEIR RELATIVES

- CHAPTER XX THE SURMULLETS, THE CROAKERS AND THEIR RELATIVES

- CHAPTER XXI LABYRINTHICI AND HOLCONOTI
- CHAPTER XXII CHROMIDES AND PHARYNGOGNATHI
- CHAPTER XXIII THE SQUAMIPINNES
- CHAPTER XXIV SERIES PLECTOGNATHI

- CHAPTER XXV PAREIOPLITÆ, OR MAILED-CHEEK FISHES

- CHAPTER XXVI GOBIOIDEI, DISCOCEPHALI, AND TÆNIOSOMI

- CHAPTER XXVII SUBORDER HETEROSOMATA
- CHAPTER XXVIII SUBORDER JUGULARES
- CHAPTER XXIX THE BLENNIES: BLENNIIDÆ
- CHAPTER XXX OPISTHOMI AND ANACANTHINI
- CHAPTER XXXI ORDER PEDICULATI: THE ANGLERS
- INDEX
- TRANSCRIBER'S NOTES
- THE FULL PROJECT GUTENBERG LICENSE