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i ‘ 
\f ry 


AN INTRODUCTION 


TO THE 


PIUDY OF BISHES 


y Division of Fishes, 
F U. S. National Museu 


Se AN INTRODUCTION 
1p ° f) TO THE 
Fist} 


STUDY OF FISHES 


BY 


ALBERT C. L. G. GUNTHER 
M.A. M.D. Ph.D. F.R.S. 


KEEPER OF THE ZOOLOGICAL DEPARTMENT IN THE BRITISH MUSEUM 


Carpit aquas pinnis. 


EDINBURGH 
ADAM AND CHARLES BLACK 
1880 


- [All rights reserved.) 


Printed by R. & R. CLARK, Edinburgh. 


PREFACE. 


— 


THE-scope of the present work is to give in a concise 
form an account of the principal facts relating to the 
structure, classification, and life-history of Fishes. It 
is intended to meet the requirements of those who are 
desirous of studying the elements of Ichthyology ; 
to serve as a book of reference to zoologists generally ; 
and, finally, to supply those who, like travellers, have 
frequent opportunities of observing fishes, with a 
ready means of obtaining information. The article 
on “ Ichthyology,” prepared by the late Sir J. Richard- 
son for the eighth edition of the “ Encyclopedia 
Britannica,” is the only publication which has _hither- 
to partly satisfied such requirements; and when I 
undertook, some years ago, to revise, or rather rewrite 
that article for the new edition of that work, it 
occurred to me that I might at the same time prepare 
a Handbook of Ichthyology, whilst reserving for the 
article an abstract so condensed as to be adapted for 
the wants of the general reader. 

From the general plan of the work I have only 
departed in those chapters which deal with the 
Geographical Distribution of Fishes. This is a sub- 
ject which has never before been treated in a general 


vi PREFACE. 


and comprehensive manner, and seemed to demand 
particular attention. I have, therefore, thought it 
right to give nominal lists of the Faun, and the 
other details of fact on which I have based my con- 
clusions, although all the necessary materials may be 
found in my ‘‘ Catalogue of Fishes.” 

A few references only to the numerous sources 
which were consulted on the subjects of Chapters 1-12, 
are inserted in the text; more not required by the 
beginner; he is introduced to a merely elementary 
knowledge of facts well known to the advanced 
student. 

With regard to the illustrations, about twenty 
have been prepared after originals published by 
Cuvier, J. Miiller, Owen, Traquair, Duméril, Cunning- 
ham, Hasse, Poey, Siebold, and Gegenbaur, A similar 
number, representing extinct fishes, have been taken, 
with the kind permission of the author, from Owen’s 
“ Palzeontology” My best thanks are due also to the 
Committee of Publications of the Zoological Society, 
and to the Editors of the “ Annals and Magazine of 
- Natural History,” and of the “Journal des Museum 
Godeffroy,” for the loan of woodcuts illustrating some 
of my papers on South American fishes and on larval 
forms. The remainder of the illustrations (about 
three-fourths) are either original figures, or formed 
part of the article on ‘Ichthyology’ in the former 
edition of the ‘ Encyclopeedia Britannica.” 


Lonpon, 3d October 1880. 


CONTENTS. 


— 


. INTRODUCTORY REMARKS. 


PAGE 
FISH DEFINED—ICHTHYOLOGY DEFINED . 3 A : ] 
CHAPTER I. 
HISTORY AND LITERATURE . ‘ : : ‘ é 2 
Aristotle, 2—Belon, 4—Salviani, 5—Rondelet, 6—Faunists and 
Anatomists of the Seventeenth Century, 7—Ray and Willughby, 
8—Artedi, 9—Linneus, 10—Gronow and Klein, 12—Pupils 
and Successors of Linneeus, 12—Bloch, 183—Lacépede, 15— 
Anatomists and Faunists preceding Cuvier, 16—Cuvier, 17— 
Agassiz, 20—J. Miiller, 22—Discovery of Ceratodus, 25—Recent 
publications on Fishes, 26—Latest systematic works, 33. 
CHAPTER II. 
TOPOGRAPHICAL DESCRIPTION OF THE EXTERNAL PARTS OF 
FISHES ; : , ‘ : ; ’ ie Boo 
Form of the body, 35—External parts of the head, 36—Trunk and 
Tail, 39—Fins ; their structure, position, and function, 40— 
Skin and Scales, 45. 
CHAPTER III. 
TERMINOLOGY AND TOPOGRAPHY OF THE SKELETON iD 


Axial portion, 51—Vertebra and its parts ; terms defined, 51— 
Skull ; bones topographically enumerated, 53—Bones of the 
limbs, 59—Synonymic list of bones, 59. 


Vil CONTENTS. 


CHAPTERSLY. 


PAGE 
MODIFICATIONS OF THE SKELETON : : : , 63 


Branchiostoma, 63 —Cyclostomes, 64 —Chondropterygians, 66 — 
Holocephali, 70—Ganoids, 71—Dipnoi, 71—Chondrostei, 74— 
Polypteroidei, 77 —Lepidosteoidei, 80—Amioidei, 82—Teleostei, 
83—Classification of the bones of the Teleosteous skull accord- 
ing to the vertebral doctrine, 85—their morphological classifi- 
cation, 86—Limb-bones of Teleosteans, 92. 


CHAPTER V. 


Myouocy . : 2 f : : : ; : 93 


General arrangement of the Muscles, 93—Electric organs, 94. 


CHAPTER VI. 


NEUROLOGY : : : . ; ; ; . 96 


Of Branchiostoma, 96—Spinal chord, 96—Brain, its size, 97— 
Brain of Osseous fishes, 97—of Ganoids, 98—of Chondroptery- 
gians, 100—of Cyclostomes, 101—Spino-cerebral nerves, 103 
-—Spinal nerves, 107—Sympathic system, 108. 


CHAPTER Vil, 


THE ORGANS OF SENSE : : ‘ ; ; 109 


Smell, 109--Sight, 111—Hearing ; connection of the ear with the 
air-bladder, 116—Taste, 119—Touch, 120. 


CHAPTER VIII. 


THE ORGANS OF NUTRITION AND DIGESTION . : Sy LAL 


Food and mode of feeding, 121—Buccal and abdominal cavities and 
their openings, 123—Mouth and tongue, 123—Forms, texture, 
and arrangement of teeth, 124—Intestinal tract, 127—Liver, 
132—Pancreas, 133—Spleen, 133. 


CONTENTS. 


CHAPTER, IX: 


ORGANS OF RESPIRATION 


Respiration, 135—Structure and arrangement of the gills, 136— 
Pseudobranchie, 140— Accessory respiratory organs, 142— 
Air-bladder ; its varieties, structure, and functions, 142. 


CHAPTER YX 


ORGANS OF CIRCULATION 5 , : > 


CHAPTER XL. 


URINARY ORGANS 


CHAPTER XII. 


ORGANS OF REPRODUCTION . 


Fishes are dioecious, 157—Hermaphroditism, 157—Oviparous and 
viviparous fishes, 157—Generative organs of Branchiostoma, 
157—of Cyclostomes; their ova, 158—Female organs of 
Teleosteans and their ova, 158—TInstances of females taking 
care of their progeny, 160—Male organs of Teleosteans, 162— 
Instances of males taking care of their progeny, 163—Genera- 
tive organs of Ganoids, 163—of Chondropterygians and their 
ova, 166. 


CHAPTER XIII. 


GROWTH AND VARIATION OF FISHES 


Changes of form of the body or certain parts, normally accompany- 
ing growth, 170—Changes dependent on sexual development, 
176—Secondary sexual differences, 176—Mixogamous, poly- 
gamous, and monogamous fishes, 177—Hybridism as a cause 
of variation, 178—Regular and irregular growth of fishes, 178 
—Leptocephali not a normal state of development, 179— 
Changes of colour of the muscles and external parts ; chroma- 
tophors, 182—Albinism, 183. 


be 


PAGE 


135 


150 


155 


15 


1 


d 


0 


x CONTENTS. 


CHAPTER XIV. 


DOMESTICATED AND ACCLIMATISED FISHES, ETC. 


Domesticated fishes, 185—Acclimatisation of fishes, 185—Artificial 
impregnation of ova, 186—Tenacity of life, 186—Reproduction 
of lost parts, 188—Hybernation, 188—Useful fishes, 189— 
Poisonous fishes, 189—Poison-organs, 190. 


CHAPTER XV. 


DISTRIBUTION OF FISHES IN TIME : : ; 


Oldest fish-remains, 193—Devonian fishes, 194— Carboniferous, 
196—Permian, 197—Triassic, 197—Liassic, 198—Oolitic, 199 
—Cretaceous, 199—Tertiary, 200—Post-pliocene, 201. 


CHAPTER XVI. 


Tue DISTRIBUTION OF EXISTING FISHES OVER THE 
EARTH’S SURFACE.—GENERAL REMARKS 


Freshwater-, Marine-, and Brackish-water Fishes, 202—-Changes of 
the habitat of numerous fishes, active, 203—or dependent on 
geological changes, 204—Agencies operating upon the distri- 
bution of Freshwater and Marine fishes, 205. 


CHAPTER XVII. 


THE DISTRIBUTION OF FRESHWATER FISHES. 


List of Freshwater Fishes, 208—Continuous and interrupted range 
of distribution, 209—The ways of dispersal of Freshwater 
fishes, 211—A wide range of a type is not necessarily proof of 
its antiquity, 212—Each fauna is composed of ancient, autoch- 
thont, and immigrant species, 213—Division of the globe 
into zoological regions ; freshwater fishes have been spread in 
cireumpolar zones, 215—Cyprinide and Siluride, most im- 
portant families in recognising the zoo-geographical regions, 
216—Division of the faune of Freshwater fishes, 217 —I. 
Equatorial Zone, 218—Indian Region, 220—African Region, 
227 —Tropical American or Neotropical Region, 2833—Tropical 
Pacific Region, 238—II. Northern Zone, 240—Kuropo-Asiatic 
or Palearctic Region, 243— North American or Nearctic 
Region, 246—III. Southern Zone, with Tasmanian, New 
Zealand, and Fuegian Sub-regions, 248. 


1 


bo 


93 


CONTENTS. 


CHAPTER XVIII. 


THE FISHES OF THE BRACKISH WATER 


CHAPTER XIX. 


THE DISTRIBUTION OF MARINE FISHES : 


Shore-fishes, Pelagic, and Deep-sea fishes, 255—List of Shore-fishes, 
257—Oceanic ares as determined by Shore-fishes, 259—Distri- 
bution of Shore-fishes compared with that of Freshwater-fishes, 
260—I. Arctic Ocean, 261—II. Northern Temperate Zone, 262 
—Temperate North-Atlantic, 262—with British, 263—Medi- 
terranean, 264—and North American districts, 266—Temperate 
North-Pacific, 268—with Kamtschatkan, 269—Japanese, 270 
—and Californian districts, 271—III. Hquatorial Zone, 272— 
with Tropical Atlantic, 278—Indo-Pacific Ocean, 278—and 
the Pacific Coasts of Tropical America, 279—IV. Southern 
Temperate Zone, 281—with the Cape of Good Hope, 283— 
South Australia and New Zealand, 283—Chile, 288—and 
Patagonia, 289—V. Antarctic Ocean, 289. 


CHAPTER XxX. 


DISTRIBUTION OF PELAGIC FISHES 


CHAPTER XXI. 


THE FISHES OF THE DEEP SEA 


Deep-sea fishes a recent discovery, 296—Physical conditions affect- 
ing these fishes, 297—Characteristics of Deep-sea fishes, 299— 
Their vertical and horizontal distribution, 304—List of Deep- 
sea fishes, 305. 


PAGE 


251 


255 


SYSTEMATIC AND DESCRIPTIVE PART. 


First SUB-CLASS—PALAICHTHYES. 


First ORDER—CHONDROPTERYGII 


I. Plagiostomata 
A. Selachoidei—Sharks 


Families: Carchariidz (Blue Shark, Tope, Hammer-head, 
Hound), 316—Lamnide (Porbeagle, Carcharodon, 
Fox-Shark, Basking-Shark), 319 — Rhinodontide, 
323—Notidanide, 324—Scylliide (Dog-fishes), 325 
Hybodontide, 328—Cestraciontide (Port Jackson 
Shark), 328—Spinacide (Spiny Dogs, Greenland 
Shark), 330—Rhinide, 334—Pristiophoride, 335. 


B. Batoidei—Rays : ; 
Families: Pristidz (Saw-fishes) 8336—Rhinobatide, 337 
—Torpedinide (Electric Rays), 338—Rajide (Rays 
and Skates), 340—Trygonide (Sting Rays), 342— 
Myliobatide (Eagle Rays), 344. 
Il. Holocephala 


Family ; Chimeride, 348. 


SECOND ORDER—GANOIDEI 
I. Placodermi 
II. Acanthodini 
III. Dipnoi 


Families: Sirenide (Lepidosiren, Protopterus, Cera- 
todus), 355 —Ctenododipteride, 359 — Phanero- 
pleuride, 360. 


IV. Chondrostei 


Families: Acipenseride (Sturgeons), 360—Polyodontide, 
362. 


PAGE 


313 
313 
314 


335 


348 


350 


351 
355 
355 


360 


CONTENTS. 


V. Polypteroidea . 


Families : Polypteride, 364—Saurodipteride, 365— 
Coelacanthide, 365—Holoptychide, 365. 


VI. Pycnodontoider 
Families: Pleurolepide, 366—Pycnodontide, 366. 


VII. Lepidosteoider 


Families: Lepidosteide, 367—Sauride, 368— Stylo- 
dontide, 368—Spherodontide, 368 — Aspidorhyn- 
chide, 369—Paleoniscide, 369—Platysomide, 370. 


VIII. Amioider . 


Families: Caturide, 371—Leptolepide, 371—Amiide 


(Bow-fin), 371. 


Second SUB-CLASS—TELEOSTEI. 
First ORDER—ACANTHOPTERYGII 


I. A. perciformes 
Families: Percide (Freshwater-Perches, Bass, Sea- 
Perches, Centrarchus), 375—Squamipinnes (Coral- 
Fishes), 397—Mullide (Red-Mullets), 403—Sparide 
(Sea-breams), 405 — Hoplognathide, 410 — Cirrhi- 
tide, 410—Scorpenide, 412—Nandidex, 418—Poly- 
centride, 418—Teuthidide, 418. 


Il. A. beryciformes 
Family : Berycide, 420. 
Ill. A. kurtiformes . 
Family : Kurtide, 424. 


IV. A. polynemiformes 
Family : Polynemide, 425. 


. A. sciceniformes , 
Family : Scienide Clea), 426. 


VI. A. xiphiiformes 
Family : Xiphiide (Sword- dana 431. 


VII. A. trichiuriformes : : : 
Families : Trichiuride cnaere rae Hair-tails), 483 
—Paleorhynchide, 437. 


xl 
PAGE 


363 


366 


367 


370 


374 
374 


419 


433 


X1V CONTENTS. 
PAGE 
VIII. A. cotto-scombriformes : 438 
Families: Acronuride (Surgeons), 438 — Carangide 
(Horse - Mackerels, Pilot - fish, Boar - fish), 440 — 
Cyttide (John Dorey), 450—Stromateide, 452 — 
Coryphenide (Dolphin, Sun-fish), 452—Nomeide, 
455—Scombride (Mackerel, Tunny, Bonito, Alba- 
core, Sucking-fish), 456—Trachinide (Stare-gazer, 
Weever, etc.), 462—Malacanthide, 467—Batrach- 
ide, 467—Psychrolutide, 469—Pediculati (Angler, 
Antennarius, ete.), 469—Cottide (Bull-heads, Gur- 
nards), 476—Cataphracti (Flying Gurnards), 480— 
Pegaside, 482. 
IX. A. gobiiformes ‘ 4 ; : . 483 
Families: Discoboli (Lump-suckers), 483 — Gobiide 
(Gobies, Dragonets), 485. 
X. A. blenniiformes : : . 490 
Families : Cepolidee (Band-fishes), 490—Trichonotide, 
490—Heterolepidotide, 491— Blenniide (Wolf-fish, 
Blennies), 492—Acanthoclinide, 498—Mastacem- 
belidee, 499. 
XI. A. mugiliformes 499 
Families : Sphyrenidee (Badtedaash 490—Atherinides 
(Atherines), 500—Mugilide (Mullets), 501. 
XII. A. gastrosteiformes : : . 504 
Families: Gastrosteide (Stickle- bast, noes 
iidz (Flute-mouths), 507. 
XIII. A. centrisciformes 508 
Family : Centriscide, 508. 
XIV. A. gobiesociformes 510 
Family : Gobiesocide, 512. 
XV. A. channiformes 3 : : ‘ : . 513 
Family : Ophiocephalide, 513. 
XVI. A. labyrinthibranchii . 514 
Families : Labyrinthici (Climbing Pate our 514 
—Luciocephalide, 519. 
XVII. A. lophotiformes 519 


Family : Lophotide, 519. 


CONTENTS. XV 


XVIII. A. teniiformes . : : , . 520 
Family : Trachypteride (Ribbon- fishes), 520. 


XIX. A. notacanthiformes . : . : : . 523 
Family : Notacanthidie, 523. 


SECOND ORDER—ACANTHOPTERYGIL PHARYNGOGNATHI . 523 


Families: Pomacentridse (Coral-fishes), 524—Labridz 
(Wrasses, Parrot-wrasses), 525—Embiotocide, 533 
—Chromides, 534. 


THIRD ORDER—ANACANTHINI : d ‘ : ES sir 


I, A. gadoidet é ; ; ; ; >| Oo 
Families: Lycodide, 537—Gadide (Cod-fishes, Hake, 
Burbot, Ling, Rockling, Torsk), 539—Ophidiide 
(Brotula, Fierasfer, Sand-eel, Congrogadus), 546— 
Macruride, 551. 


II. A. plewronectoider ‘ ; : . 553 
Family : Pleuronectide (Flat- fishes), 553. 


FourTH ORDER—PHYSOSTOMI \ A : f . 559 


Families : Siluridee ; their skeleton, 559—divided into eight sub- 
divisions and sixteen groups ; Clariina, 563—Plotosina, 563— 
Silurina, 565—Hypophthalmina, 566—Bagrina, 567—Amiur- 
ina, 567—Pimelodina, 568—Ariina, 569—Doradina, 572— 
Rhinoglanina, 573—Malapterurina (Electric Catfish), 574— 
Hypostomatina (Prefiadillas, Loricaria, ete. ), 575—Aspredin- 
ina, 580—Nematogenyina and Trichomycterina, 581—Stego- 
pholina, 581. 

Families of Physostomi continued: Scopelide, 582—Cyprinidce 
(Carps), 587—divided into fourteen groups, viz. Catostomina 
(Suckers), 588—Cyprinina (Carp, Crucian Carp, Goldfish, 
Barbels, Gudgeons), 589—Rohteichthyina, 596— Leptobar- 
bina, 597—Rasborina, 597—Semiplotina, 598—Xenocypri- 
dina, 598—Leuciscina (White fish, Tench, Dace, etc.), 598— 
Rhodeina, 601— Danionina, 601 — Hypophthalmichthyina, 
602—Abramidina (Bream, Bleak), 602—Homalopterina, 604 
—Cobitidina (Loaches), 604. 

Families of Physostomi continued: Kneriide, 606—Characinide, 
606—Cyprinodontide, 613—Heteropygii (Blind Fish of the 
Mammoth Cave), 618—Umbride, 619—Scombresocide (Gar- 


Xvl1 CONTENTS. 


pike, Saury, Half-beak, Flying Fish), 619—Esocide (Pike), 
623 — Galaxiide, 624—Mormyride, 625 — Sternoptychide, 
627—Stomiatide, 629. 

Families of Physostomi continued—Salmonide : Salmo, difficulty 
of distinguishing species, 630; constant specific characters, 
635 — hybrids, 638—vsexual development, 638 — migratory 
species and their retention in freshwater, 639—Growth of 
Salmonoids, 641—their domestication and acclimatisation, 
641—species enumerated, 642—Smelt and Capelin, 646—Cor- 
egonus, 647—-Grayling, 649—marine genera, 650. 

Families of Physostomi continued: Percopside, 651—Haplochi- 
tonide, 651—Gonorhynchide, 652—Hyodontide (Moon-eye), 
653 — Pantodontide, 653 —Osteoglosside, 653 — Clupeide 
(Herrings, Anchovies, Shads, Mossbanker, Menhaden, etc. ), 
655—Bathythrisside, 663—Chirocentride, 663—Alepocepha- 
lide, 664—Notopteride, 664—Halosauride, 665—Hoplopleu- 
ride, 665—Gymnotide (Electric Eel), 666—Symbranchide, 
668—Murenide (Eels, Congers, Murenas, etc. ), 669. 


FrrrH OrDER— LOPHOBRANCHII 


Families : Solenostomide, 678 —Syngnathide (Pipe-fishes, Sea- 
horses), 679. 


SrxtTH ORDER—PLECTOGNATHI 


Families: Sclerodermi (File-fishes, Coffer-fishes), 684 — Gymno- 
dontes (Globe-fishes, Sunfish), 686. ‘ 


THIRD SUB-CLASS—-CYCLOSTOMATA. 


Families: Petromyzontide (Lampreys), 691—Myxinide, 694. 


FourtH SuB-CLASS—-LEPTOCARDII. 


Family : Cirrhostomi (Lancelets), 696. 


APPENDIX. 


DIRECTIONS FOR COLLECTING AND PRESERVING FISHES 


ALPHABETICAL INDEX . 


PAGE 


678 


683 


697 
707 


INTRODUCTORY REMARKS. 


ae ee 


ACCORDING to the views generally adopted at present, all 
those Vertebrate animals are referred to the Class of Fishes, 
which living in water, breathe air dissolved in water by means 
of gills or branchize ; whose heart consists of a single ventricle 
and single atrium; whose limbs, if present, are modified into 
fins, supplemented by unpaired, median fins; and whose skin 
is either naked, or covered with scales or osseous plates or 
bucklers. With few exceptions fishes are oviparous. How- 
ever, there are not a few members of this Class which show a 
modification of one or more of these characteristics, as we 
shall see hereafter, and which, nevertheless, cannot be separated 
from it. The distinction between the Class of Fishes and that 


of Batrachians is very slight indeed. 


The branch of Zoology which treats of the internal and 
external structure of fishes, their mode of life, and their 


distribution in space and time, is termed Ichthyology.’ 
1 From iy6us, fish, and Noyos, doctrine or treatise. 


B 


CHAPTER I. 
HISTORY AND LITERATURE. 


Aristotle. THE commencement of the history of Ichthyology coincides 
with that of Zoology generally. ARISTOTLE (384-322 B.C.) 
had a perfect knowledge of the general structure of fishes, 
which he clearly discriminates from the Aquatic animals with 
lungs and mamme, 7.e. Cetaceans, and from the various groups 
of Aquatic Invertebrates. He says that “the special charac- 
teristics of the true fishes consist in the branchize and fins, 
the majority having four fins, but those of an elongate form, 
as the eels, having two only. Some, as the Murena, lack the 
fins altogether. The Rays swim with their whole body, which 
is spread out. The branchiz are sometimes furnished with 
an opercle, sometimes without one, as is the case in the carti- 
laginous fishes. . . . No fish has hairs.or feathers ; most are 
covered with scales, but some have a rough or smooth skin. 
The tongue is hard, often toothed; and sometimes so much 

~ adherent that it seems to be wanting. The eyes have no lids; 
nor are any ears or nostrils visible, for what takes the place 
of nostrils is a blind cavity. Nevertheless they have the 
senses of tasting, smelling, and hearmg. “All have blood. All 
scaly fishes are oviparous, but the cartilaginous fishes (with 
the exception of the Sea-devil, which Aristotle places along 
with them) are viviparous. All have a heart, liver, and gall- 
bladder; but kidneys and urinary bladder are absent. They 
vary much in the structure of their intestines: for whilst the 
mullet has a fleshy stomach like a bird, others have no 


HISTORY. a 


stomachic dilatation. Pyloric coeca are close to the stomach, 
variable in number; there are even some, like the majority of 
the cartilaginous fishes, which have none whatever. ‘Two 
bodies are situated along the spine, which have the function 
of testicles, and open towards the vent, and which are much 
enlarged in the spawning season. The scales become harder 
with age. Not being provided with lungs, they have no voice, 
but several can emit grunting sounds. They sleep like other 
animals. In the majority the females exceed the males in 
size; and in the Rays and Sharks the male is distinguished 
by an appendage on each side of the vent.” 

Aristotle’s information on the habits of fishes, their migra- 
tions, mode and time of propagation, utility, is, as far as it 
has been tested, surprisingly correct. Unfortunately, only too 
often we lack the means of recognising the species of which 
he gives a description. His ideas of specific distinction were 
as vague as those of the fishermen whose nomenclature he 
adopted ; it never occurred to him that such popular names 
are subject to change, or may be entirely lost with time, and the 
difficulty of deciphering his species is further increased by the 
circumstance that popular names are often applied by him 
to the same fish, or that different stages of growth are 
designated by distinct names. The number of fishes known 
to Aristotle seems to have been about 115, all of which are 
inhabitants of the Aigean Sea. 

That one man should have discovered so many truths, and 
formed so sure a base for Zoology, is less surprising than the 
fact that for about eighteen centuries a science which seemed 
to offer particular attractions to men gifted with power of 
observation, was no farther advanced. Yet this is the case. 
Aristotle’s disciples, as well as his successors, remained satis- 
fied to be his copiers or commentators, and to collect fabulous 
stories or vague notions. With very few exceptions (such 
as Ausonius, who wrote a small poem, in which he describes 


Belon. 


4 FISHES. 


from his own observations the fishes of the Mosel) authors 
entirely abandoned original research. And it was not until 
about the middle of the sixteenth century that Ichthyolog 
made a new step in advance by the appearance of Selon, 
Rondelet, and Salviani, who almost simultaneously published 
their grand works, by which the idea of species was established 
definitely and for all times. 


P. Beton travelled in the countries bordering on the 
eastern part of the Mediterranean, in the years 1547-50; he 
collected rich stores of positive knowledge, which he deposited 
in several works. The one most important for the progress 
of Ichthyology is that entitled “De aquatilibus lbri duo” 
(Paris 1553; small 4to.) Belon knows about 110 fishes, of 
which he gives rude, but generally recognisable, figures. In 
his descriptions he pays regard to the classical as well as 
vernacular nomenclature, and states the outward character- 
istics, sometimes even the number of fin-rays, frequently also 
the most conspicuous anatomical peculiarities. 

Although Belon but rarely gives definitions of the terms 
used by him, it is generally not very difficult to ascertain the 
limits which he intended to assign to each division of aquatic 
animals. He very properly divides them into such as are 
provided with blood, and into those without it: two divisions, 
called in modern language Vertebrate and Invertebrate aquatic 
animals. The former are classified by him according to sizes, 
the further subdivisions being based on the structure of the 
skeleton, mode of propagation, number of limbs, form of the 
body, and on the physical character of the localities inhabited 
by fishes. This classification is as follows :-— 


I. The larger fishes or Cetaceans. 


A. Viviparous Cetaceans with bony skeletons ( = Cetacea). 
B. Viviparous Amphibians. 


HISTORY. 5 


1. With four limbs: Seals, Hippopotamus, Beaver, 
Otter, and other aquatic Mammalia. 
2. With two limbs: Mermaids, ete. 
C. Oviparous Amphibians (= Reptiles and Frogs). 
D. Viviparous Cartilaginous fishes. 
1. Of an oblong form (= Sharks). 
2. Of a flat form (= Rays and Lophius). 
E. Oviparous Cartilaginous fishes (= Sturgeons and 
Silurus). 
F. Oviparous Cetaceans, with spines instead of bones 
(= large marine fishes, like the Thunny, Sword-fish, 
Scizenoids, Bass, Gadoids, Trachypterus). 
II. Spinous Oviparous fishes of a flat form (= Pleuronectide). 
III. Fishes of a high form, like Zeus. 
IV. Fishes of a snake-like form (= Eels, Belone, Sphyrzna). 


V. Small Oviparous, spinous, scaly, marine fishes, 
1. Pelagic kinds. 
2. Littoral kinds. 
3. Kinds inhabiting rocky localities. 


VI. Fluviatile and Lacustrine fishes. 


The work of the Roman ichthyologist, H. SALVIANI (1514- 
72), is characteristic of the high social position which the 
author held as the physician of three popes. Its title is 
“ Aquatilium animalium historia” (Rom. 1554-57, fol.) It 
treats exclusively of the fishes of Italy. Ninety-two species 
are figured on seventy-six plates which, as regards artistic 
execution, are masterpieces of that period, although those 
specific characteristics which now-a-days constitute the value 
of a zoological drawing, were entirely overlooked by the 
author or artist. No attempt is made at a natural classifica- 
tion, but the allied forms generally are placed in close proxi- 
mity. The descriptions are quite equal to those given by 
Belon, entering much into the details of the economy and 
usefulness of the several species, and were evidently composed 
with the view of collecting in a readable form all that might 


Salviani. 


Rondelet. 


6 FISHES. 


prove of interest to the class of society in which the author 
moved. Salviani’s work is of a high standard, most remarkable 
for the age in which he lived. It could not fail to convey valu- 
able instruction, and to render Ichthyology popular in the 
country to the fauna of which it was devoted, but it would not 
have advanced Ichthyology as science generally ; and in this 
respect Salviani is not to be compared with Rondelet or Belon. 


G. RonpeLer (1507-1557) had the great advantage over 
Belon in having received a medical education at Paris, and 
more especially in having gone through a complete course of 
instruction in anatomy as a pupil of Guentherus of Andernach. 
This is conspicuous throughout his works—“ Libri de Piscibus 
marinis” (Lugd. 1554, fol.) ; and “ Universe aquatilium his- 
tori pars altera” (Lugd. 1555, fol.) Nevertheless they cannot 
be regarded as more than considerably enlarged editions of 
Belon’s work. For although he worked independently of the 
latter, and differs from him in numerous details, the system 
adopted by him is characterised by the same absence of 
the true principles of classification. Rondelet had a much 
more extensive knowledge of details. His work is almost 
entirely limited to European, and chiefly Mediterranean, 
forms, and comprises not less than 197 marine and 47 fresh- 
water fishes. His descriptions are more complete and his 
figures much more accurate than those of Belon; and the 
specific account is preceded by introductory chapters in which 
he treats in a general manner on the distinctions, the external 
and internal parts, and on the economy of fishes. Like 
Belon, he had no conception of the various categories of 
classification—for instance, confounding throughout his work 
the terms “genus” and “species ;” but he had intuitively 
a notion of what his successors called a “species,” and his 
principal object was to collect and give as much information 
as possible of such species. 


HISTORY. vf 


For nearly a century the works of Belon and Rondelet 
remained the standard works of Ichthyology ; but this science 
did not remain stationary during this period. The attention 
of naturalists was now directed to the products of foreign 
countries, especially the Spanish and Dutch possessions in the 
New World; and in Europe the establishment of anatomical 
schools and academies led to the careful investigation of the 
internal anatomy of the most remarkable European forms. 
Limited as these efforts were as to their scope, being directed 
either only to the fauna of some district, or to the dissection 
of a single species, they were sufficiently numerous to enlarge 
the views of naturalists, and to destroy that fatal dependency 
on preceding authorities which had continued to keep in bonds 
the minds of even such men as Rondelet and Belon. 

The most noteworthy of those who were active in tropical W. Piso. 
countries are W. Piso and G. Marcrav. They accompanied ee 
as physicians the Dutch Governor, Prince Moritz of Nassau, 
to Brazil (1637-44). Marerav especially studied the fauna of 
the country, and although he died before his return to Europe, 
his observations were published by his colleague, and em- 
bodied in a work “ Historia naturalis Brazilie ” (Lugd. 1648, 
fol.), in which the fourth book treats of the fishes. He de- 
scribes about 100 species, all of which had been previously 
unknown, in a manner far superior to that of his predecessors. 

The accompanying figures are not good, but nearly always 
recognisable, and giving a fair idea of the form of the fish. 
Marerav himself, with the aid of an artist, had made a most 
valuable collection of coloured drawings of the objects 
observed and described by him, but many years were allowed 
to pass before it was scientifically utilised by Bloch and others. 

Of the men who left records of their anatomical researches, Anato- 
we may mention BorELit (1608-79), who wrote a work “De es 
motu animalium” (Rom. 1680, 4to), in which he explained 
the mechanism of swimming, and the function of the air- 


‘ 


Ray and 
Willughby 


8 FISHES. 


bladder; M. Mauprcut (1628-94), who examined the optic 
nerve of the sword-fish; the celebrated J. SWAMMERDAM 
(1637-80), who described the intestines of numerous fishes ; 
and J. DuverNey (1648-1730), who entered into detailed re- 
searches of the organs of respiration. 


A new era in the history of Ichthyology commences with 
Ray, Willughby, and Artedi, who were the first to recognise 
the true principles by which the natural affinities of animals 
should be determined. Their labours stand in so intimate a 
connection with each other that they represent only one 
stride in the progress of this science. 


J. Ray (born 1628 in Essex, died 1705), was the friend 
and guide of F. WintLuGHBY (1635-72). They had recognised 
that a thorough reform of the treatment of the vegetable and 


animal kingdoms had become necessary; that the only way 


of bringing order into the existing chaos was that of arranging 
the various forms with regard to their structure; that they 
must cease to be burdened with inapplicable passages and 
quotations of the ancient writers, and to perpetuate the 
erroneous or vague notions of their predecessors. They aban- 
doned speculation, and adhered to facts only. One of the first 
results, and perhaps the most important, of their method was, 
that having recognised the “species” as such, they defined 
this term, and fixed it as the base, from which all sound 
zoological knowledge has to start. 

Although they had divided their work thus that Ray 
attended to the plants principally, and Willughby to the 
animals, the “Historia piscium” (Oxford, 1686, fol.), which 
bears Willughby’s name on the titlepage, and was edited by 
Ray, is clearly their joint production. A great part of the 
observations contained in it were collected during their com- 
mon journeys in Great Britain and on the Continent, and it 
is no exaggeration to say that at that time these two English- 


HISTORY. 9 


men knew the fishes of the Continent, especially those of 
Germany, better than any other Continental zoologist. 

By the definition of fishes as animals with blood, breath- 
ing by gills, provided with a single ventricle of the heart, 
covered with scales or naked; the Cetaceans are excluded. 
Yet, at a later period Ray appears to have been afraid of so 
great an innovation as the separation of whales from fishes, | 
and, therefore, he invented a definition of fish which com- ; 
prises both. The fishes proper are then arranged in the 
first place according to the cartilaginous or osseous nature of 
the skeleton ; further subdivisions being formed with regard 
to the general form of the body, the presence or absence of 
ventral fins, the soft or spinous structure of the dorsal rays, 
the number of dorsal fins, etc. Not less than 420 species are 
thus arranged and described, of which about 180 were known 
to the authors from autopsy: a comparatively small propor- 
tion, descriptions and figures still forming at that time in a 
ereat measure a substitute for collections and museums. 
With the increasing accumulation of forms the want of a 
fixed nomenclature is now more and more felt. 


Peter ARTEDI would have been a great ichthyologist if P. Artedi. 
Ray or Willughby had never preceded him. But he was 
fully conscious of the fact that both had prepared the way 
for him, and therefore he derived all possible advantages from 
their works. Born in 1705 in Sweden, he studied with Lin- 
neus at Upsala; from an early period he devoted himself 
entirely to the study of fishes, and was engaged in the 
arrangement and description of the ichthyological collection of 
Seba, a wealthy Dutchman who had formed the then perhaps 
richest museum, when he was accidentally drowned in one of 
the canals of Amsterdam in the year 1734, at an age of twenty- 
nine years. His manuscripts were fortunately rescued by an 
Englishman, Cliffort, and edited by his early friend Linneus. 


Linneus. 


10 FISHES. 


The work is divided into the following parts :— 

1. In the “ Bibliotheca Ichthyologica ” Artedi gives a very 
complete list of all preceding authors who have written on 
fishes, with a critical analysis of their works. 

2. The “Philosophia Ichthyologica ” is devoted to a descrip- 
tion of the external and internal parts of fishes; Artedi fixes 
a precise terminology of all the various modifications of the 
organs, distinguishes between those characters which determine 
a genus and such as indicate a species or merely a variety ; 
in fact he establishes the method and principles which subse- 
quently have guided every systematic ichthyologist. 

3. The “Genera Piscium ” contains well-defined diagnoses 
of forty-five genera, for which he fixes an unchangeable 
nomenclature. 

4, In the “Species Piscium ” descriptions of seventy-two 
species, examined by himself, are given; descriptions which 
even now are models of exactitude and method. 

5. Finally, in the “Synonymia Piscium” references to all 
previous authors are arranged for every species, very much in 
the same manner which is adopted in the systematic works 
of the present day. 

Artedi has been justly called the Father of Ichthyology. 
So perfect was his treatment of the subject, that even LINNZUS 
could no more improve it, only modify and add to it; and as 
far as Ichthyology is concerned, Linnzeus has scarcely done 
anything beyond applying binominal terms to the species 
properly described and classified by Artedi. 

Artedi had divided the fishes proper into four orders, viz. 
Malacopterygii, Acanthopterygvi, Branchiostegi, and Chondro- 
pterygri, of which the third only, according to our present 
knowledge, appears to be singularly heterogeneous, as it com- 
prises Balistes, Ostracion, Cyclopterus, and Lophius. Linnzeus, 
besides separating the Cetaceans entirely from the class of fishes 
(at least since the 10th edition of the “Systema Nature”) 


HISTORY. 11 


abandoned Artedi’s order of Branchiostegi, but substituted a 
scarcely more natural combination by joining it with Artedi’s 
Chondropterygians, under the name of “ Amphibia nantes.” 

His classification of the genera appears in the 12th edition 
of the “ Systema,” thus— 


AMPHIBIA NANTES. PIscES THORACICI. 
Spiraculis compositis. Cepola. 
Echeneis. 
USLEIN HONE Corypheena. 
Raia. Gobius. 
es) Cottus. 
Chimera. Scorpeena. 

: ? ye Zeus. 
Spiraculis solitariis. Bicunonected: 
Lophius. Cheetodon. 

Acipenser. Sparus. 
Cyclopterus. Labrus. 
Balistes. Scizena. 
Ostracion. Perea. 
Tetrodon. Gasterosteus. 
Diodon. Scomber. 
Centriscus. Mullus, 
Syngnathus. . Trigla. 
Pegasus. 
Pisces ABDOMINALES. 
Pisces APODES. Cobitis. 
Murena, Amia. 
Gymnotus. Silurus. 
Trichiurus. Teuthis. 
Anarhichas. Loricaria. 
Ammodytes. Salmo. 
Ophidium. Fistularia. 
Stromateus. Esox. 
Xiphias. Elops. 
Argentina. 
Atherina. 
PISCES JUGULARES. Mugil. 
Callionymus. Mormyrus. 
Uranoscopus. Exoccetus. 
Trachinus. Polynemus. 
Gadus. Clupea. 


Blennius. Cyprinus. 


Gronow 
and Klein. 


Pupils and 


Successors 


of Linnzus 


12 FISHES. 


Two contemporaries, of Zinneus attempted a systematic 
arrangement of fishes; both had considerable opportunities 
for their study, especially in possessing extensive collections ; 
but neither exercised any influence on the progress of Ichthy- 
ology. The one, L. T. Gronow, a German who resided in 
Holland, closely followed the arrangements proposed by 
Artedi and Linnzeus, and increased the number of genera and 
species from the contents of his own museum. He published 
two works, “Museum Ichthyologicum” (Lugd. 1754-6, fol.), and 
“ Zoophylacium” (Lugd. 1763-81, fol.) ; a posthumous work, 
containing numerous excellent descriptions of new forms was 
published by J. E. Gray in 1854 under the title of “Systema 
Ichthyologicum.” To Gronow also is due the invention of pre- 
paring flat skins of fishes in a dry state, and preserving them 
in the manner of a herbarium. The specimens thus prepared 
by him belong to the oldest which have been preserved down 
to our time. 

Much less important are the ichthyological labours of 
J.T. KiEtn (1685-1759). They are embodied in five parts 
(Missus) of a work entitled “ Historia naturalis piscium” 
(Sede, 1740-9, 4to.) He regarded a system merely as the 
means of recognising the various forms of animals, not as the 
expression of their natural affinities ; and that method seemed 
to him to be the most perfect by which an animal could be 
most readily determined. He eschewed all reference to 
minute or anatomical characters. Hence his system is a 
series of the most unnatural combinations, and we cannot be 
surprised that Linnzeus passed in silence over Klein’s labours. 


The works of Artedi and Linneus excited fresh activity, 
more especially in Scandinavia, Holland, Germany, and 
England, such as has not been equalled in the history of 
biological science either before or after. Whilst some of the 
pupils and followers of Linnzeus devoted themselves to an 


HISTORY. 13 


examination and study of the fauna of their native countries, 
others proceeded on voyages of discovery to foreign and 
distant countries. Of these latter the following may be 
specially mentioned :—0O, Fabricius worked out the Fauna of 
Greenland, Kalm collected in North America, Hasselquist in 
Egypt and Palestine, Briinnich in the Mediterranean, Osbeck 
in Java and China, Thwnberg in Japan; Forskal examined and 
described the fishes of the Red Sea; Steller, Pallas, S. T. Gmelin, 
and Giéildenstedt traversed nearly the whole of the Russian 
Empire in Europe and Asia. Others attached themselves as 
naturalists to the celebrated circumnavigators of the last cen- 
tury, like the two orsters (father and son), and Solander, who 
accompanied Cook; Commerson, who travelled with Bougain- 
ville; and Sonnerat. Numerous new and startling forms were 
discovered by those men, and the foundation was laid of the 
knowledge of the geographical distribution of animals. 

Of those who studied the fishes of their native country the 
most celebrated are Pennant (Great Brita), 0. F. Miiller 
(Denmark), Duhamel (France), Meidinger (Austria), Cornide 
(Spain), Parra (Cuba). 

The materials brought together by those and other zoolo- 
gists were so numerous that, not long after the death of 
Linnzeus, the necessity was felt of collecting them in a com- 
pendious form. Several compilators undertook this task ; 
they embodied the recent discoveries in new editions of 
Artedi’s and Linné’s classical works, but not possessing either 
a knowledge of the subject or any critical discernment, they 
only succeeded in covering those noble monuments under a 
mass of confused rubbish. For Ichthyology it was fortunate 
that two men at least, Bloch and Lacépéde, made it a subject 
of long and original research. 


Mark Exiezer Biocu, born in the year 1723 at Anspach M. E. 


. : aoe: : loch. 
in Germany, practised as a physician in Berlin; he had reached 


14 FISHES, 


an age of fifty-six years when he commenced to write on 
ichthyological subjects. To commence at his age a work in 
which he intended not only to give full descriptions of the 
species known to him from specimens or drawings, but also 
to illustrate every species in a style truly magnificent for 
his time, was an undertaking of the execution of which an 
ordinary man would have despaired. Yet he accomplished 
not only this task, but even more, as we shall see hereafter. 

His work consists of two divisions :— 

1. “Oeconomische Naturgeschichte der Fische Deutsch- 
lands” (Berl. 1782-4, 4to. Plates in fol.) | 

2. “Naturgeschichte der auslendischen Fische” (Berl. 
1785-95, 4to. Plates in fol.) 

Bloch’s work is unique, and probably will for ever remain 
so. Although Cuvier fifty years later undertook a similar 
general work on fishes, the subject had then become too ex- 
tensive to allow of an attempt of giving illustrations of all 
the species, or illustrations of a similar size and costliness. 

The first division of the work, which is devoted to a de- 
scription of the fishes of Germany, is entirely original, and 
based upon Bloch’s own observations. His descriptions as 
well as figures were made from nature, and are, with but few 
exceptions, still serviceable; many continue to be the best 
existing in literature. 

Bloch was less fortunate and is much less reliable in his 
natural history of foreign fishes. For many of the species 
he had to rely on more or less incorrect drawings and de- 
scriptions of travellers ; frequently, also, he was deceived as 
to the origin of specimens which he acquired by purchase. 
Hence his accounts contain numerous confusing errors which 
it would have been difficult to correct, if not nearly the whole 
of the materials on which his work is based had been pre- 
served in the collections at Berlin. 

After the completion of his Ichthyology Bloch occupied 


HISTORY. 15 


himself with systematic work. He prepared a general system 
of fishes, in which he arranged not only those described in his 
great work, but also those with which he had become ac- 
quainted afterwards from the descriptions of others. The 
work was ably edited and published after Bloch’s death by 
a philologist, J. G. Schneider, under the title “M. E. Blochii 
Systema ichthyologiz iconibus cx. illustratum” (Berl. 1801, 
8vo.) The number of species enumerated in it amounts to 
1519. The system is based upon the number of the fins, the 
various orders being termed Hendecapterygui, Decapterygit, etc. 
We need not add that an artificial method like this led to the 
most unnatural combinations or severances. 

Bloch’s Ichthyology remained for many years the standard 
work, and, by the great number of excellent illustrations, 
proved a most useful guide to the student. But as regards 
originality of thought, Bloch was far surpassed by his con- 
temporary, B. G. E. DE LACEPEDE, born at Agen, in France, Lacépéde. 
in 1756, a man of great and general erudition, who died as 
Professor of the Museum of Natural History of Paris in 1826. 

Lacépede had to contend with great difficulties in the 
preparation of his “Histoire des Poissons” (Paris, 1798- 
1803, 4to, in 5 vols.), which was written during the most dis- 
turbed period of the French Revolution. A great part of it 
was composed whilst the author was separated from collections 
and books, and had to rely on his notes and manuscripts only. 
Even the works of Bloch and other contemporaneous authors 
remained unknown, or at least inaccessible, to him for a long 
time. Therefore we cannot be surprised that his work abounds 
in all those errors to which a compiler is subject. The same 
species not only appears under two and more distinct specific 
names, but it sometimes happens that the author understands 
so little the source from which he derives his information 
that the description is referred to one genus and the accom- 
panying figure to another. The names of genera are unduly 


Anato- 
mists. 


Faunists. 


16 FISHES. 


multiplied ; and the figures with which the work is illustrated 
are far inferior to those of Bloch. Thus the influence of 
Lacépéde on the progress of Ichthyology was infinitely less 
than that of his fellow-labourer; and the labour caused to 
his successors by correcting the numerous errors into which 
he has fallen, probably outweighs the assistance which they 
derived from his work. 

The work of the principal cultivators of Ichthyology in 
the period between Ray and Lacépéde was chiefly systematic 
and descriptive, but also the internal organisation of fishes 
received attention from more than one great anatomist. 
Haller, Camper, and Hunter, examined the nervous system 
and organs of sense; and more especially Alexander Monro 
(the son) published a classical work, “The Structure and 
Physiology of Fishes explained and compared with those of 
Man and other Animals” (Edinb. 1785, fol.) The electric 
organs of fishes (Torpedo and Gymnotus) were examined by 
Réaumur, Allamand, Bancroft, Walsh, and still more exactly 
by J. Hunter. The mystery of the propagation of the Eel 
called forth a large number of essays, and even the artificial 
propagation of Salmonide was known and practised by 
Gleditsch (1764). 

Bloch and Lacépéde’s works were almost immediately suc- 
ceeded by the labours of Cuvier, but his early publications 
were of necessity tentative, preliminary, and fragmentary, so 
that a short period elapsed before the spirit infused by this 
ereat anatomist into Ichthyology could exercise its influence 
on all workers in this field. Several of such antecuvierian 
works must be mentioned on account of their importance to 
our knowledge of certain Faunas: the “ Descriptions and 
Figures of Two Hundred Fishes collected at Vizagapatam on 
the coast of Coromandel” (Lond. 1803; 2 vols. in fol.), by 
Patrick Russel ; and“ An Account of the Fishes found in the 
River Ganges and its branches” (Edinb. 1822; 2 vols. in 


HISTORY. 17 


4to), by F. Hamilton (formerly Buchanan)—works distin- 
guished by a greater accuracy of their drawings (especially in 
the latter), than was ever attained before. A “Natural His- 
tory of British Fishes” was published by &. Donovan (Lond. 
8vo, 1802-8) ; and the Mediterranean Fauna formed the study 
of the lifetime of A. Risso (“Ichthyologie de Nice.” Paris, 
1810, 8vo ; and “ Histoire naturelle de ? Europe Meridionale.” 
Paris, 1827, 8vo). A slight beginning in the description of 
the fishes of the United States was made by S. LZ. Mitchell, 
who published, besides various papers, a “ Memoir on the 
Ichthyology of New York,” in 1815. 


G. Cuvier did not occupy himself with the study of fishes G. Cuvier. 
merely because this class formed part of the “ Régne animal,” 
but he devoted himself to it with particular predilection. 
The investigation of their anatomy, and especially of their 
skeleton, was taken up by him at an early period, and con- 
tinued until he had succeeded in completing so perfect a frame- 
work of the system of the whole class that his immediate 
successors could content themselves with filling up those details 
for which their master had no leisure. Indefatigable in exam- 
ining all the external and internal characters of the fishes of a 
rich collection, he ascertained the natural affinities of the in- 
finite variety of fishes, and accurately defined the divisions, 
orders, families, and genera of the class, as they appear in 
the various editions of the “Regne animal.” His industry 
equalled his genius: he opened connections with almost every 
accessible part of the globe; not only French travellers and 
naturalists, but also Germans, Englishmen, Americans, rivalled 
one another to assist him with collections ; and for many years 
the Muséum of the Jardin des Plantes was the centre where 
all ichthyological treasures were deposited. Thus Cuvier 

1 Down to this period the history of Ichthyology is fully treated in the 


first volume of Cuvier and Valenciennes ‘‘ Hist. nat. d. Poiss.” 
C 


18 FISHES. 


brought together a collection the lke of which had never 
been seen before, and which, as it contains all the materials 
on which his labours were based, must still be considered 
to be the most important. Soon after the year 1820, Cuvier, 
assisted by one of his pupils, A. VALENCIENNES, commenced 
his great work on fishes, “ Histoire naturelles des Poissons,” 
of which the first volume appeared in 1828. The earlier 
volumes, in which Cuvier himself took his share, bear evi- 
dence of the freshness and love with which both authors 
devoted themselves to their task. After Cuvier’s death in 
1832 the work was left entirely in the hands of Valenciennes, 
whose energy and interest gradually slackened, to rise to the 
old standard in some parts only, as, for instance, in the treatise 
on the Herring. He left the work unfinished with the twenty- 
second volume (1848), which treats of the Salmonoids. Yet, 
incomplete as it is, it is indispensable to the student. 

There exist several editions of the work, which, however, 
have the same text. One, printed in 8vo, with coloured or 
plain figures, is the one in common use among ichthyologists. 
A more luxurious edition in 4to has a different pagination, 
and therefore is most inconvenient to use. 

As mentioned above, the‘various parts of the work are 
very unequally worked out. Many of the species are de- 
scribed in so masterly a manner that a greater excellency of 
method can hardly be conceived. The history of the litera- 
ture of these species is entered into with minuteness and 
critical discernment; but in the later volumes, numerous 
species are introduced into the system without any descrip- 
tion, or with a few words only, comparing a species with one 
or more of its congeners. Cuvier himself, at a late period of 
his life, seems to have grown indifferent as to the exact defini- 
tion of his species: a failing commonly observed among 
Zoologists when attention to descriptive details becomes to 
them a tedious task. What is more surprising is, that a man 


HISTORY. 19 


of his anatomical and physiological knowledge should have 
overlooked the fact that secondary sexual characters are 
developed in fishes as in any other class of animals, and that 


fishes undergo great changes during growth; and, consequently, 
that he described almost all such sexual forms and different 
stages of growth under distinct specific and even generic names, 

The system finally adopted by Cuvier is the following :— 


A. PoIssons OSSEUX. 


].—A BRANCHIES EN PEIGNES OU EN LAMES. 


1. A MACHOIRE SUPERIEURE LIBRE. 


Percoides. 
Polynemes. 
Mulles. 

Joues cuirassées. 
Scienoides. 


Abdominaux. 
Cyprinoides. 
Siluroides. 
Salmonoides, 
Clupeoides. 
Lucioides. 


a. Acanthoptérygiens. 


Sparoides. Branchies labyrinthiques, 
Chétodonoides. Lophioides. 
Scomberoides. Gobioides. 

Muges. Labroides. 


b. Malacoptérygiens. 
Subbrachiens. A podes. 
Sparoides. Murenoides. 
Pleuronectes. 

Discoboles, 


2. A MACHOIRE SUPERIEURE FIXEE. 
Sclérodermes. Gymnodontes. 


II. A BRANCHIES EN FORME DE HOUPPES. 


Lophobranches. 


B. CARTILAGINEUX OU CHONDROPTERYGIENS. 


Sturioniens. 


Plagiostomes. Cyclostomes. 


We have to compare this system with that of Linnzus 
if we wish to measure the gigantic stride Ichthyology has 
made during the intervening period of seventy years. The 
various characters employed for classification have been ex- 


20 FISHES. 


amined throughout the whole class, and their relative import- 
ance has been duly weighed and understood. Though 
Linneus had formed a category of “ Amphibia nantes” for 
fishes with a cartilaginous skeleton, which should coincide 
with Cuvier’s “ Poissons Cartilagineux,” he had failed to 
understand the very nature of cartilage, apparently comprising 
by this term any skeletal framework of less firmity than ordi- 
nary bone. Hence he considered Lophius, Cyclopterus, Syng- 
nathus to be cartilaginous fishes. Adopting the position and 
development of the ventral fins as a highly important charac- 
ter, he was obliged to associate fishes with rudimentary and 
inconspicuous ventral fins, like 7richiurus, Xiphias, ete., with 
the true Eels. The important category of a “family” appears 
now in Cuvier’s system fully established as that termediate 
between genus and order. Jmportant changes in Cuvier’s 
system have been made and proposed by his successors, but 
in the main it is still that of the present day. 

Cuvier had extended his researches beyond the living 
forms, into the field of paleontology ; he was the first to 
observe the close resemblance of the scales of the fossil 
Paleoniscus to those of the living Polypterus and Lepidosteus, 
the prolongation and identity of structure of the upper caudal 
lobe in Palwoniscus and the Sturgeons, the presence of peculiar 
“fulcra ” on the anterior margin of the dorsal fin in Paleoniscus 
and Lepidosteus: inferrmg from these facts that that fossil 
genus was allied either to the Sturgeons or to Lepidosteus. 
But it did not occur to him that there was a close relationship 
between those recent fishes. Zepidostews and, with it, the fossil 
genus remained in his system a member of the order of 
Malacopterygit abdominales. 

It was left to L. AGassiz (born 1807, died 1873) to point 
out the importance of the character of the structure of the 
scales, and to open a path towards the knowledge of a whole 
new sub-class of fishes, the Ganovdez. 


HISTORY. aL 


Impressed with the fact that the peculiar scales of Poly- 
pterus and Lepidosteus are common to all fossil osseous fishes 
down to the chalk, he takes the structure of the scales 
generally as the base for an ichthyological system, and distin- 
euishes four orders :— 

1. Placoids.—Without scales proper, but with scales of 
enamel, sometimes large, sometimes small and reduced to 
mere points (Rays, Sharks, and Cyclostomi, with the fossil 
Hybodontes). 

2. Ganoids—With angular bony scales, covered with a 
thick stratum of enamel: to this order belong the fossil 
Lepidoides, Sauroides, Pyecnodontes, and Coelacanthi; the 
recent Polypterus, Lepidosteus, Sclerodermi, Gymnodontes, 
Lophobranches, and Siluroides ; also the Sturgeons. 

3. Ctenoids—With rough scales, which have their free 
margins denticulated : Cheetodontidee, Pleuronectide, Percide, 
Polyacanthi, Scisnidee, Sparidee, Scorpeenidze, Aulostomi. 

4. Cycloids—With smooth scales, the hind margin of 
which lacks denticulation: Labride, Mugilidee, Scombridee, 
Gadoidei, Gobiide, Mureenide, Lucioidei, Salmonidee, Clupeidee, 
Cyprinidee. 

We have no hesitation in affirming that if Agassiz had 
had an opportunity of acquiring a more extensive and inti- 
mate knowledge of existing fishes before his energies were 
absorbed in the study of,their fossil remains, he himself would 
have recognised the artificial character of his classification. 
The distinctions between cycloid and ctenoid scales, between 
placoid and ganoid fishes are vague, and can hardly be main- 
tained. As far as the living and post-cretacean forms are 
concerned, the vantage-ground gained by Cuvier was aban- 
doned by him; and therefore his system could never supersede 
that of his predecessors, and finally shared the fate of every 
classification based on the modifications of one organ only. 
But Agassiz has the merit of having opened an immense new 


J. Miller. 


a2 FISHES. 


field of research by his study of the infinite variety of fossil 
forms. In his principal work, “ Recherches sur les Poissons 
fossiles,” (Neuchatel, 1833-43, 4to, atlas in fol.), he placed 
them before the world arranged in a methodical manner, with 
excellent descriptions and illustrations. His power of discern- 
ment and penetration in determining even the most frag- 
mentary remains is truly astonishing; and if his order of 
Ganoids is an assemblage of forms very different from that 
as it is circumscribed now, he was at any rate the first who 
recognised that such an order of fishes exists. 


The discoverer of the Ganoidei was succeeded by their 
explorer, JOHANNES MULLER (born 1801, died 1858). In his 
classical memoir “Ueber den Bau und die Grenzen der 
Ganoiden” (Berlin, 1846 ; 4to), he showed that the Ganoids 
differed from all the other osseous fishes, and agreed with the 
Plagiostomes, in the structure of their heart. By this primary 
character, all heterogeneous elements, as Stlwroids, Osteoglos- 
side, ete., were eliminated from the order as understood by 
Agassiz. On the other hand, he did not recognise the affinity 
of Lepidosiren to the Ganoids, but established for it a distinct 
sub-class, Dipnoi, which he placed at the opposite end of the 
system. By his researches into the anatomy of the Lam- 
preys and Amphioxus, their typical distinctness from other 
cartilaginous fishes was proved; they became the types of 
two other sub-classes, Cyclostomi and Leptocardi. 

Miiller proposed several other not unimportant modifica- 
tions of the Cuvierian system; and although all cannot be 
maintained as the most natural arrangements, yet his re- 
searches have given us a much more complete knowledge of 
the organisation of the Teleosteous fishes, and later en- 
quiries have shown that, on the whole, the combinations pro- 
posed by him require only some further modification and 
another definition to render them perfectly natural. 


HISTORY. 23 


Under the name of Pharyngognathi he combined fishes 
with the lower pharyngeals coalesced into one bone, viz. the 
Labroids, Chromides, and Scombresoces. The association of 
the third family with the two former seemed to himself a 
somewhat arbitrary proceeding; and it had to be abandoned 
again, when a number of fishes which cannot be separated 
from the Acanthopterygians, were found to possess the same 
united pharyngeals. 

A more natural combination is Te union of the Cod-fishes 
with the Flat-fishes into the order Anacanthini. Flat-fishes 
are in fact nothing but asymmetrical Cod-fishes. Miiller 
separates them from the remaining Malacopterygians by the 
absence of a connecting duct between the air-bladder and 
oesophagus. However, it must be admitted that the examina- 
tion of those fishes, and especially of the young stages, is not 
complete enough to raise the question beyond every doubt, 
whether the presence or absence of that duct is an absolutely 
distinctive character between Anacanths and Malacoptery- 
glans. 

Many of the families established by Cuvier were re- 
examined and better defined by Miiller, as may be seen from 
the following outline of his system :— 


Sub-classis I—Dipnoi. 
Ordo I.—Sirenoidei. 
Fam. 1. Sirenoidei. 
Sub-classis IJ.—Teleostei. 
Ordo I.—Acanthopteri. 


Fam. 1. Percoidei. Fam. 9. Squamipennes. 

» 2. Cataphracti. » 10. Taenioidei. 

5 9 Sparoidei. » Ll. Gobioidei. 

» 4. Scienoidei., » 12. Blennioidei. 

, 0. Labyrinthiformes. », 13. Pediculati. 

» 6. Mugiloidei. » 14. Theutyes. 

» 1. Notacanthini. » 15. Fistulares. 

» 8. Scomberoidei. 


24 FISHES. 


Ordo II.—Anacanthini. 
Sub-ordo I.—Anacanthini sub-brachii. 
Fam. 1. Gadoidei. 


» 2. Pleuronectides. 


Sub-ordo IJ.—Anacanthini apodes. 
Fam. 1. Ophidini. 


Ordo III.—Pharyngognathi. 
Sub-ordo I.—Pharyngognathi acanthopterygii. 
Fam. 1. Labroidei cycloidei. 

» 2. Labroidei ctenoidei. 

5, 93 Chromides. 
Sub-ordo Il.—Pharyngognathi malacopterygii. 


Fam. 1. Scomberesoces. 


Ordo IV.—Physostomi. 
Sub-ordo I—Physostomi abdominales. 


Fam. 1. Siluroidei. Fam. 7. Galaxie. 
» 2. Cyprinoidei. », 8. Salmones. 
» 9 Characini. », 9. Scopelini. 
», 4. Cyprinodontes. » 10. Clupeide. 
»5 9. Mormyri. » 11. Heteropygii. 
6. Esoces. 


Sub-ordo Il.—Physostomi apodes s. anguillares. 


Fam. 12. Murenoidei. 
» 13. Gymnotini. 
» 14. Symbranchii. 


Ordo V.—Plectognathi. 
Fam. 1. Balistini. 

» 2. Ostraciones. 

» 9% Gymnodontes. 
Ordo VI.—Lophobranchii. 
fam. 1, Lophobranchi. 


HISTORY. 20 


Sub-classis IJJ.—Ganoidei. 
Ordo I.—Holostei. 
Fam. 1. Lepidosteini. 

», 2. Polypterini. 
Ordo II.—Chondrostei. 


Fam. 1. Acipenserini, 


» 2. Spatularie. 


Sub-classis IV.—Elasmobranchi s. Selachii. 
Ordo I.—Plagiostomi. 


Sub-ordo I.—Squalidee. 


Fam. 1. Scyllia. Fam. 6. Rhinodontes. 
» 2. Nyctitantes. » «. Notidani. 
», 3 Lamnoidei. » 8. Spinaces. 
» 4. Alopeciee. » 9. Seymnoidei. 
» 0. Cestraciones. », 10. Squatine. 
Sub-ordo IIT.—Rajidee. 
Fam. 11. Squatinoraje. Fam. 14. Trygones. 
» 12. Torpedines. » 15. Mylobatides. 
» 13. Raje. », 16. Cephalopterze. 


Ordo II.—Holocephali. 


Fam. 1. Chimaerz. 


Sub-classis V.—Marsipobranchii s. Cyclostomi. 
Ordo I.—Hyperoartii. 


Fam. 1, Petromyzonini. 


Ordo II.—Hyperotreti. 
Fam. 1. Myxinoidei. 


Sub-classis VI.—Leptocardil. 
Ordo I.—Amphioxini. 


Fam. 1. Amphioxini. 


The discovery (in the year 1871) of a living representative Discovery 
: : E f 
of a genus hitherto believed to be long extinct, Ceratodus, Cantons 


Recent 
Works. 


26 FISHES. 


threw a new light on the affinities of Fishes. The author who 
had the good fortune of examining this fish, was enabled to 
show that, on the one hand, it was a form most closely allied 
to Lepidosiren ; on the other, that it could not be separated 
from the Ganoid fishes, and therefore that also Lepidosiren 
was a Ganoid: a relation pointed at already by Huxley in a 
previous paper on “Devonian Fishes.” This discovery led to 
further considerations! of the relative characters of Miiller’s 
sub-classes, and to the system which is followed in the pre- 
sent work. 

Having followed the development of the ichthyological 
system down to the latest time, we have to retrace our steps 
to enumerate the most important contributions to Ichthyology 
which appeared contemporaneously with or subsequently to 
the publication of Cuvier and Valenciennes’s great work. As 
in other branches of Zoology, activity increased almost with 
every year; and for convenience’s sake we may arrange these 
works in three rubrics. 


I.— VOYAGES, CONTAINING GENERAL ACCOUNTS OF ZOOLOGICAL 
COLLECTIONS. 


A. French. 


1. “Voyage autour du monde sur les Corvettes de 8. M. 
PUranie et la Physicienne, sous le commandement de M. 
Freycinet. Zoologie: Poissons par Quoy et Gaimard.” (Paris, 
1824, 4to, atlas fol.) 

2. “Voyage dela Coquille. Zoologie par Lesson.” (Paris, 
1826-30, 4to, atlas fol.) 

3. “Voyage de l’Astrolabe, sous le commandement de M. 
J. Dumont d’Urville. Poissons par Quoy et Gavmard.” (Paris, 
1834, 8vo, atlas fol.) 


1 Description of Ceratodus. ‘‘ Phil. Trans.,”’ 1871, ii. 


RECENT LITERATURE. D/ 


4, “Voyage au Pole Sud par M. J. Dumont d’Urville. 
Poissons par Hombron et Jacquinot.” (Paris, 1853-4, 8vo, 
atlas fol.) 

B. English. 


1. “Voyage of H.M.S. Sulphur. Fishes by J. Richardson.” 
(Lond. 1844-5, 4to.) 

2. “ Voyage of H.M.S.S. Erebus and Terror. Fishes by 
J. Richardson.” (Lond. 1846. 4to.) 

3. “Voyage of H.MS. Beagle. Fishes by Z. Jenyns.” 
(Lond. 1842, 4to.) 

4, “Voyage of H.M.S. Challenger. Fishes by 4. Gunther” 
(in course of publication). 


C. German. 


1. “Reise der Osterreichischen Fregatte Novara. Fische 
von &. Kner.” (Wien. 1865, 4to.) 


IL—FAUNAE. 


A. Great Britain. 


1. R. Parnell, “The Natural History of the Fishes of the 
Firth of Forth.” (Edinb. 1838, 8vo.) 

2. W. Yarrell, “A History of British Fishes.” (8d edit. 
Lond. 1859, 8vo.) 

3. J. Couch, “A History of the Fishes of the British 
Islands.” (Lond. 1862-5, 8vo.) 


B. Denmark and Scandinavia. 


1. H. Kroyer, “Danmark’s Fiske.’ (Kjobnh. 1838-53, 
8vo.) 

2. S. Nilsson, “Skandinavisk Fauna.” (Vol. IV. Fiskarna. 
Lund. 1855, 8vo.) 

3. Fries och Ekstrom, “Skandinavians Fiskar.” (Stockh. 
1836, 4to, with excellent plates.) 


28 FISHES. 


C. Russia. 


1. Nordmann, “ Ichthyologie Pontique,” in “ Voyage dans 
la Russie meéridionale de Demidoff” (Tom. ii. Paris, 1840, 
8vo, atlas fol.) 

D. Germany. 

1. Heckel and Kner, “ Die Siisswasser-fische der Oester- 
reichischen Monarchie.” (Leipz. 1858, 8vo.) 

2. 0. T. E. Siebold, “ Die Siisswasser-fische von Mittel- 
europa.” (Leipz. 1863, 8vo.) 


E. Jtaly and Mediterranean. 


1. Bonaparte, “ Iconografia della Fauna Italica.” Tom. 
ill. Pesci. (Roma, 1832-41, fol.) (Incomplete.) 

2. Costa, “Fauna del Regno di Napoli.” Pesci. (Napoli, 
Ato, about 1850.) (Incomplete.) 


F. France. 


1. H. Blanchard, “Les Poissons des eaux douces de la 
France.” (Paris, 1866, 8vo.) 


G. Pyrenean Peninsula. 


The freshwater Fish-fauna of Spain and Portugal was 
almost unknown, until F. Steindachner paid some visits to 
those countries for the purpose of exploring the principal 
rivers. His discoveries are described in several papers in the 
“Sitzungsberichte der Akademie zu Wien.” £. du Bocage 
and F. Capello contributed towards the knowledge of the 
marine fishes on the coast of Portugal. (“ Jorn. Scienc. Acad. 
Lisb.”) 

H. North America. 


1. J. Richardson, “Fauna Boreali Americana.” Part 
III. Fishes. (Lond. 1836, 4to.) The species described in this 
work are nearly all from the British possessions in the North. 


RECENT LITERATURE. 29 


2. Dekay, “ Zoology of New York.” Part IV. Fishes. 
(New York, 1842, 4to.) 

3. “Reports of the United States Commission of Fish and 
Fisheries.” (5 vols. Washingt. 1873-79, 8vo. In progress. 
Contains most valuable information.) 

Besides these works, numerous descriptions of North 
American freshwater fishes have been published in the 
Reports of the various U.S. Government expeditions, and 
in North American scientific journals, by Storer, Baird, 
Girard, W. O. Ayres, Cope, Jordan, Brown Coode, etc.; but 
a good general, and especially critical, account of the fishes 
of the United States is still a desideratum. 


I.—Japan. 
1. “Fauna Japonica.” Poissons par H. Schlegel. (Lugd. 
Bat. 1850, fol.) 


J.—LKast Indies; Tropical parts of the Indian and Pacific Oceans, 


1. #. Riippell, “ Atlas zu der Reise im Nordlichen Afrika.” 
(Frankf. 1828, fol.) 

2. EH. Riippell, “Neue Wirbelthiere. Fische.” (Frankf. 
1837, fol.) 

These two works form the standard works for the student 
of the Fishes of the Red Sea, and are distinguished by a rare 
conscientiousness and faithfulness of the descriptions and 
figures; so that there is no other part of the tropical seas, 
with the fishes of which we are so intimately acquainted, as 
with those of the Red Sea. But these works have a still 
wider range of usefulness, in as much as only a small propor- 
tion of the fishes is limited to that area, the majority being 
distributed over the Indian Ocean into Polynesia. Ruppell’s 
works were supplemented by the two first of the following 
works :— 

3. BR. L. Playfair and A. Ginther, “The Fishes of Zanzi- 
bar.” (Lond. 1866, 4to) ; and 


30 FISHES. 


4. C. B. Klunzinger, “Synopsis der Fische des Rothen 
Meers.” (Wien. 1870-1, 8vo.) 

5. T. Cantor, “Catalogue of Malayan Fishes.” (Calcutta, 
1850, 8vo.) 

6. F. Day, “The Fishes of India” (Lond. 1875, 4to, in 
progress) ; contains an account of the freshwater and marine 
species, and is not yet complete. 

7. A. Gunther, “Die Fische der Siidsee.” (Hamburg, 4to ; 
from 1873, in progress.) 

Unsurpassed in activity, as regards the exploration of 
the fish fauna of the East Indian Archipelago, is P. Bleeker, a 
surgeon in the service of the Dutch East Indian Government 
(born 1819, died 1878), who, from the year 1840, for nearly 
thirty years, amassed immense collections of the fishes of the 
various islands, and described them in extremely numerous 
papers, published chiefly in the Journals of the Batavian 
Society. When his descriptions and the arrangement of his 
materials evoked some criticism, it must be remembered 
that, at the time when he commenced his labours, and for 
many years afterwards, he stood alone, without the aid of 
a previously named collection on which to base his first re- 
searches, and without other works but that of Cuvier and 
Valenciennes. He had to create for himself a method of dis- 
tinguishing species and of describing them; and afterwards 
it would have been difficult for him to abandon his original 
method and the principles by which he had been guided for 
so many years. His desire of giving a new name to every 
individual, to every small assemblage of species wherever 
practicable, or of changing an old name, detracts not a little 
from the satisfaction with which his works would be used 
otherwise. It is also surprising that a man with his ana- 
tomical knowledge and unusual facilities should have been 
satisfied with the merely external examination of the speci- 
mens. But none of his numerous articles contain anything 


RECENT LITERATURE. Sik 


relating to the anatomy, physiology, or habits of the fishes 
which came under his notice; hence his attempts at syste- 
matic arrangement are very far from indicating an advance in 
Ichthyology. 

Soon after his return to Europe (1860) Bleeker commenced 
to collect the final results of his labours in a grand work, 
illustrated by coloured plates, “Atlas Ichthyologique des 
Indes Orientales Néerlandaises.” (Amsterd. fol. 1862); the 
publication of which was interrupted by the author’s death 
in 1878. 

K.— Africa. 


1. A. Gunther, “The Fishes of the Nile” in Petherick’s 
“Travels in Central Africa.” (Lond. 1869, 8vo.) 

2. W. Peters, “ Naturwissenschaftliche Reise nach Mos- 
sambique. IV. Flussfische.” (Berl. 1868, 4to.) 


L.— West Indies and South America. 


1. LZ. Agassiz, “Selecta genera et species Piscium, quee in 
itinere per Brasiliam, collegit J. B. de Spix.” (Monach. 1829, 
fol.) 

2. F. de Castlenau, “ Animaux nouveaux ou rares, recueillis 
pendant l’expedition dans les parties centrales de Amérique 
du Sud. Poissons.” (Paris, 1855, 4to.) 

3. A. Gunther, “ An account of the Fishes of the States of 
Central America.” (In Trans. Zool. Soc. 1868.) 

4, L. Vaillant and F. Bocourt, “ Mission scientifique au 
Mexique et dans l’Amérique centrale. Poissons.” (Paris, 
1874, 4to.) (In progress.) 

F, Pocy, the celebrated naturalist of Havannah, devoted 
many years of study to the Fishes of Cuba. His papers 
and memoirs are published partly in two periodicals, issued 
by himself, under the title of “Memorias sobre la Historia 
natural de la Isle de Cuba” (from 1851), and “ Repertorio 


By FISHES. 


Fisico-natural de la Isla de Cuba” (from 1865), partly in 
North American scientific journals. And, finally, &. Stein- 
dachner has published many contributions, accompanied by 
excellent figures, to our knowledge of the Fishes of Central 
and South America. 

M.—WNew Zealand. 


1. F. W. Hutton and J. Hector, “ Fishes of New Zealand.” 
(Wellingt. 1872, 8vo.) 


N.—Aretie Regions. 


1. C. Liitken, “A revised Catalogue of the Fishes of 
Greenland,” in “ Manual of the Natural History, Geology, and 
Physics of Greenland.” (Lond. 1875, 8vo.) Although only a 
nominal list, this catalogue is useful, as it contains references 
to all the principal works in which Arctic fishes have been 
described. The fishes of Spitzbergen were examined by A. J. 
Malmgren (1865), 

ITI.— ANATOMICAL WORKS. 


The number of authors who worked on the anatomy of 
fishes is almost as great as that of faunists; and we should 
go beyond the hmits of the present work if we mentioned more 
than the most prominent and successful. JZ. H. Rathke, J. 
Miller, J. Hyrtl, and H. Stannius left scarcely any organ un- 
examined, and their researches had a direct bearmg either on 
the relation of the class of fishes to the other vertebrates, 
or on the systematic arrangement of the fishes themselves. 
EH. E. von Baer, F. de Filippi, C. Vogt, W. His, W. K. Parker, 
and F. M. Balfour worked at their embryology ; A. Kolliker 
and G. Pouchet at their histology. The osteology was specially 
treated by G. Bakker, F. C. Rosenthal, L. Agassiz, and C. 
Gegenbaur ; the nervous system by Grottsche, Philipeaua, 
Stannius, L. de Sanctis, L. Stieda, Baudelot and Miclucho- 
Maclay ; the organ of hearing by £. H. Weber, C. Hasse, and 
G. Retzius. The electric fishes were examined by L. Geoffroy, 


RECENT LITERATURE. 30 


‘O. Matteuci, P. Pacini, T. Bilharz, and Max Schultze. The 
development and metamorphosis of the Lamperns was made 
the subject of research by H. Miller, M. Schultze, and P. 
Owsjannikow; Miiller’s examination of Branchiostoma was 
continued by J. Marcusen, A. Kovalevsky, L. Stieda, W. 
 Miiller, C. Hasse, T. Hualey, and F. M. Balfour. The most 
comprehensive accounts of the anatomy of fishes are con- 
tained in the following works :— 

1. H. Stannius, “Zootomic der Fische,’ 2d edit. (Berl. 
1854, 8vo.) 

2. f. Owen, “Anatomy of Vertebrates,’ vol. i. (Lond. 
1866, 8vo.) 

3. A. Owen, “ Lectures on the Comparative Anatomy and 
Physiology of the Vertebrate Animals.” Part I. Fishes. 
(Lond. 1846, 8vo.) 

4. T. Huxley, “ A Manual of the Anatomy of Vertebrated 
Animals.” (Lond. 1871, 16mo.) 


It has been mentioned above that the great work of Cuvier Latest 

and Valenciennes had been left incomplete. Several authors, sae i 
therefore, supplied detailed accounts of the orders omitted in 
that work. Miller and Henle published an account of the 
Plagiostomes, and Kauwp of the Murzenidee and Lophobranchii. 
A. Duméril, finally, commenced an “ Histoire naturelle des 
Poissons ou Ichthyologie générale,” of which, however, two 
volumes only appeared, containing a complete account of the 
“ Plagiostomes ” (Paris, 1865, 8vo), and of the “Ganoids and 
Lophobranchs.” (Paris, 1870, 8vo.) 

So great an activity had prevailed in Ichthyology since 
the publication of the “Histoire naturelle” by Cuvier and 
Valenciennes, andthe results of the manifold enquiries were 
scattered over such a multitude of publications, that it became 
imperative to collect again all these materials in one com- 
prehensive work. This was done in the “ Catalogue of Fishes,” 

D 


34 FISHES. 


published by the Trustees of the British Museum, in eight 
volumes (Lond. 1859-70). Beside the species previously de- 
scribed many new forms were added, the number total of 
species referred to in those volumes amounting to 8525. As 
regards the systematic arrangement—Miller’s system was 
adopted in the main, but the definition of the families is much 
modified. This, however, need not be further entered into 
here, and will become sufficiently apparent in the subsequent 
parts of the present work. 


iN) 


Fig. 1.—Lower aspect of head of Raia lemprieri. 


CHAPTER. IT. 


TOPOGRAPHICAL DESCRIPTION OF THE EXTERNAL PARTS OF 


FISHES. 


In the body of a fish four parts are distinguished: the 
head, trunk, tail, and the fins; the boundary between the 
first and second being generally indicated by the gill-opening, 
and that between the second and third by the vent. The form Form of 
of the body and the relative proportions of those principal Bas 
parts are subject to much variation, such as is not found in 
any other class of Vertebrates. In fishes which are endowed 
with the power of steady and more or less rapid locomotion, 
a deviation from that form of body, which we observe in a 
perch, carp, or mackerel, is never excessive. The body forms a 
simple, equally-formed wedge, compressed or slightly rounded, 
well fitted for cleaving the water. In fishes which are in the 
habit of moving on the bottom, the whole body, or at least the 
head, is vertically depressed and flattened; the head may be so 
enormously enlarged that the trunk and tail appear merely as 
an appendage. In one family of fishes, the Plewronectide or 
Flat-fishes, the body is compressed into a thin disk; they 
swim and move on one side only, which remains constantly 
directed towards the bottom, a peculiarity by which the 
symmetry of all parts of the body has been affected. <A 
lateral compression of the body, in conjunction with a length- 
ening of the vertical and a shortening of the longitudinal 
axis, we find in fishes moving comparatively slowly through 


Hye. 


36 FISHES. 


the water, and able to remain (as it were) suspended in it. 
This deviation from the typical form may proceed so far that 
the vertical axis greatly exceeds the longitudinal in length ; 
generally all the parts of the body participate in this form, but 
in one kind of fish (the Sun-fish or Orthagoriscus) it is chiefly 
the tail which has been shortened, and reduced so much as 
to present the appearance of being cut off. An excessive 
lengthening of the longitudinal axis, with a shortening of the 
vertical, occurs in Eels and eel-like fishes, and in the so-called 
Band-fishes. They are bottom-fish, capable of insinuating 
themselves into narrow crevices and holes. The form of the 


body of these long fish is either cylindrical, snake-like, as in 


the Eels and many Codfishes, or strongly compressed as in 
the Band-fishes (7richiurus, Regalecus, etc.) It is chiefly the 
tail which is lengthened, but frequently the head and trunk 
participate more or less in this form. Every possible variation 
occurs between these and other principal types of form. The 
old ichthyologists, even down to Linnzeus, depended in great 
measure on them for classification; but although often the same 
form of body obtains in the same group of fishes, similarity of 
form by no means indicates natural affinity ; it only indicates 


~ gimilitude of habits and mode of life. 


The external parts of the Head.—The Eye divides the head 
into the ante-orbital and post-orbital portion. In most fishes, 
especially in those with a compressed head, it is situated on 
the side and in the anterior half of the length of the head; in 
many, chiefly those with a depressed head, it is directed up- 
wards, and sometimes situated quite at the upper side; in 
very few, the eyes look obliquely downwards. In the Flat- 
fishes both eyes are on the same side of the head, either the 
right or the left, always on that which is directed towards 
the light, and coloured. 

Fishes in general, compared with other Vertebrata, have 
large eyes. Sometimes these organs are enormously enlarged, 


HEAD. 37 


their great size indicating that the fish is either nocturnal, or 
lives at a depth to which only a part of the sun’s rays pene- 
trate. On the other hand, small eyes occur in fishes inhabit- 
ing muddy places, or great depths to which scarcely any light 
descends, or in fishes in which the want of an organ of sight 
is compensated by the development of other organs of sense. 
In a few fishes, more particularly in those inhabiting caves 
or the greatest depths of the ocean, the eyes have become 
quite rudimentary and hidden under the skin. 

In the ante-orbital portion of the head, or the Snout, Snout. 
are situated the mouth and the nostrils. 

The Mouth is formed by the intermaxillary and maxillary Mouth. 
bones, or by the intermaxillary only in the upper jaw, and 
by the mandibulary bone in the lower. These bones are 
either bare or covered by integument, to which frequently 
labial folds or lips are added. As regards form, the mouth 
offers as many variations as the body itself, in accordance 
with the nature of the food, and the mode of feeding. It 
may be narrow, or extremely wide and cleft to nearly the hind 
margin of the head; it may be semi-elliptical, semicircular, 
or straight in a transverse line; it may be quite in front of 
the snout (anterior), or at its upper surface (superior), or at 
its lower (inferior), or extending along each side (lateral) ; 
sometimes it is sub-circular, organised for sucking. The Jaws 
of some fishes are modified into a special weapon of attack 
(Sword-fish, Saw-fish) ; in fact, throughout the whole class of 
fishes the jaws are the only organ specialised for the purpose 
of attacking ; weapons on other parts of the body are purely 
defensive. 

Both jaws may be provided with skinny appendages, bar- 
bels, which, if developed and movable, are sensitive organs of 
touch. 

In the majority of fishes the Wostrils are a double opening Nostrils. 
on each side of the upper surface of the snout; the openings 


Gill-cover. 


Gill- 


opening. 


38 FISHES. 


of each side being more or less close together. They lead into 
a shallow groove; and only in one family (the Myxinoids) 
perforate the palate. In this family, as well as in the Lam- 
preys, the nasal aperture is single. In many Eels the open- 
ings are lateral, the lower perforating the upper lip. In the 
Sharks and Rays (Fig. 1, p. 34) they are at the lower surface 
of the snout, and more or less confluent; and, finally, in the 
Dipnoi and other Ganoids, one at least is within the labial 
boundary of the mouth. 

The space across the forehead, between the orbits, is called 
the inter-orbital space ; that below the orbit, the infra-orbital 
or sub-orbital region. 

In the post-orbital part of the head there are distinguished, 
at least in most Teleosteous Fishes and many Ganoids, (Fig. 
24) the preoperculum, a sub-semicircular bone, generally with 
a free and often serrated or variously-armed margin; the 
operculum, forming the posterior margin of the gill-opening, and 
the suboperculum and inter-operculum along its inferior margin. 
All these bones, collectively called opereles, form the gill-cover, 
a thin bony lamella covering the cavity containing the gills. 
Sometimes they are covered with so thin a membrane that 
the single bones may be readily distinguished; sometimes 
they are hidden under a thick integument. In some cases the 
inter-operculum is rudimentary or entirely absent (Siluroids). 

The Gill-opening is a foramen, or a slit behind or below the 
head, by which the water which has been taken up through 
the mouth for the purpose of breathing is again expelled. 
This slit may extend from the upper end of the operculum all 
round the side of the head to the symphysis of the lower jaw; 
or it may be shortened and finally reduced to a small opening 
on any part of ‘the margin of the gill-cover. Sometimes 
(Symbranchus) the two openings, thus reduced, coalesce, and 
form what externally appears as a single opening only. The 
margin of the gill-cover is provided with a cutaneous fringe, 


GILL-OPENINGS. 39 


in order to more effectually close the gill-opening; and this 
fringe is supported by one or several or many bony rays, the 
branchiostegals, The space on the chest between the two 
rami of the lower jaw and between the gill-openings is called 
the isthmus. 

The Sharks and Rays differ from the Teleosteous and 
Ganoid fishes in having five branchial slits (six or seven in 
Hexanchus and Heptanchus), which are lateral in the Sharks, 
and at the lower surface of the head in the Rays (Fig. 1, p. 34). 
In Myxine only the gill-opening is at a great distance from 


Fig. 2.—Head of Mordacia mordax, showing the single 
nostril, and seven branchial openings. 


the head; it is either single in this family (Cyclostomi), or 
there are six and more on each side (Fig. 2). 

In the Zrunk are distinguished the back, the sides, and the 
abdomen. It gradually passes in all fishes into the Zazd ; Tail. 
the termination of the abdominal cavity and the commence- 
ment of the tail being generally indicated by the position 
of the vent. The exceptions are numerous: not only certain 
abdominal organs, like the sexual, may extend to between the 
muscles of the tail, but the intestinal tract itself may pass far 
backwards, or, singularly, it may be reflected forwards, so 
that the position of the vent may be either close to the 
extremity of the tail or to the foremost part of the trunk. 

In many fishes the greater part of the tail is surrounded 
by the fins, leaving only a small portion (between dorsal, 
caudal, and anal fins) finless; this part is called the free por- 
tion or the pedunele of the tail. 


Fins. 


40 FISHES. 


The Fins are divided into vertical or unpaired, and into 
horizontal or paired fins. Any of them may be present or 
absent ; and their position, number, and form are most im- 
portant guides in determining the affinities of fishes. 

The vertical fins are situated in the median dorsal line, 
from the head to the extremity of the tail, and in the ventral 
line of the tail. In fishes in which they are least developed 
or most embryonic, the vertical fin appears as a simple fold of 
the skin surrounding the extremity of the tail. In its further 
progress of development in the series of fishes, it gradually ex- 
tends more forwards, and may reach even the head and vent. 
Even in this embryonic condition the fin is generally supported 
by fine rays, which are the continuations of, or articulated to, 
other stronger rays supported by the processes or apophyses 
of the vertebral column. This form of the vertical fin is very 
common, for instance in the Eels, many Gadoid, Blennioid 
and Ganoid fishes in which, besides, the rays have ceased to 
be simple rods, showing more or less 
numerous joints (simple articulated rays ; 
Fig. 3). Branched rays are dichotomically 
spht, the joints increasing in number to- 
wards the extremity. 

The continuity of the vertical fin, 
however, is interrupted in the majority of 
fishes; and three fins then are distin- 
guished: one in the dorsal line—the dorsal 
fin; one in the ventral line behind the 


Fig. 3. anus—the anal fin; and one confined to 
1. Simple ray. the extremity of the tail—the caudal fin. 
2. Spine. apa . Te 
3, imple articulated The caudal fin is rarely symmetrical, 


ray (soft). so that its upper half would be equal to 
4. Branched ray (soft). its lower; the greatest degree of asym- 
metry obtains in fishes with heterocercal termination of the 


vertebral column (see subsequently, Figs. 31, 41). In fishes in 


FINS. | 41 


which it is nearly symmetrical it is frequently prolonged into 
an upper and lower /obe, its hind margin being concave or more 
or less deeply excised; in others the hind margin is rounded, 
and when the middle rays greatly exceed in length the outer 
ones the fin assumes a pointed form. 

“Many and systematically important differences are ob- 
served in the dorsal fin, which is either spiny-rayed (spinous) 
(Acanthopterygian), or soft-rayed (Malacopterygian). In the 
former, a smaller or greater number of the rays are simple 
and without transverse joints; they may be flexible, or so 
much osseous matter is deposited in them that they appear 
hard and truly spinous (Fig. 3); these spies form always the 
anterior portion of the fin, which is detached from, or continuous 


Fig. 4.—Labrax lupus (Bass), an Acanthopterygian with anterior spinous, 
and posterior soft dorsal fin. 


with, the remaining jointed rays. The spines can be erected 
or depressed at the will of the fish ; if in the depressed posi- 
tion the spines cover one another completely, their points 
lying in the same line, the fish is called homacanth ; but if 
the spines are asymmetrical, alternately broader on one side 
than on the other, the fish is called heteracanth. The spinous 
division, as well as the one consisting of jointed rays, may 
again be subdivided. In the Malacopterygian type all the 
rays remain jointed ; indeed, sometimes the foremost ray, with 
its preceding short supports, is likewise ossified, and a hard 
spine, but the articulations can nearly always be distinctly 


42 FISHES. 


traced. Sometimes the dorsal fin of Malacopterygian fishes is 
very long, extending from the head to the end of the tail, some- 
times it is reduced to a few rays only, and in a few cases it is 


Fig. 5.—Saurus undosquamis, a Malacopterygian with anterior 
soft dorsal, and additional adipose fin. 


entirely absent. In addition to the rayed dorsal fin, many 
Malacopterygian fishes (as the Salmonoids, many Siluroids, 
Scopeloids, etc.) have another of greater or lesser extent, with- 
out any rays; and as always fat is deposited within this fold, 
it is called a fatty fin (pinna adiposa). 

The anal fin is built on the same plan as the dorsal, and 
may be single or plural, long or short, or entirely absent; in 
Acanthopterygians its foremost rays are frequently simple and 
spinous. 

The horizontal or paired fins consist of two pairs: the 
pectorals and ventrals. 

The pectoral fins (with their osseous supports) are the 
homologues of the anterior limbs of the higher Vertebrata. 
They are always inserted immediately behind the gill-opening ; 
either symmetrical with a rounded posterior margin, or asym- 
metrical, with the upper rays longest and strongest; in Mala- 
copterygians with a dorsal spine the upper pectoral ray is 
frequently developed into a similar defensive weapon. 

The ventral fins are the homologues of the hind-limbs, and 
inserted on the abdominal surface, either behind the pectorals 
(Pisces s. Pinne abdominales), or below them (Pisces s. Pinne 
thoracice), or in advance of them (Pisces s. Pinne jugulares). 
They are generally narrow, composed of a small number of 


FINS. 43 


rays, the outer of which is frequently osseous. In some small 
oroups of fishes, like the Gobies, the fins coalesce and form 


a suctorial disk. 


Fig. 8.—Burbot (Lota vulgaris), with jugular ventral fins. 


For the definition of the smaller systematic groups, and 
the determination of species, the numbers of the spines and 
rays are generally of the greatest importance. This holds 


good, especially for the ventral rays, by the number of which 


Function 
of the 
Fins. 


44 FISHES. 


the Acanthopterygian affinities of a fish can nearly always be 
determined. The numbers of the dorsal and anal rays gene- 
rally correspond to the number of vertebre in a certain 
portion of the spine, and are therefore constant specific, 
generic, or even family characters; but when their number 
is very great, a proportionally wide margin must be allowed 
for variation, and the taxinomic value of this character be- 
comes uncertain. The numbers of the pectoral and caudal 
rays are rarely of any account. 

The fins are organs of motion; but it is chiefly the tail 
and the caudal fin by which the fish impels itself forward. 
To execute energetic locomotion the tail and caudal fin are 
strongly bent, with rapidity, alternately towards the right 
and left; whilst a gentle motion forwards is effected by a 
simply undulating action of the caudal fin, the lobes of which 
act like the blades of a screw. Retrograde motions can be 
made by fish in an imperfect manner only, by forward-strokes 
of the pectoral fins. When the fish wants to turn towards the 
left, he gives a stroke of the tail towards the right, the right 
pectoral acting simultaneously, whilst the left remains ad- 
pressed to the body. Thus the pectoral fins assist in the 
progressive motions of the fish, but rather directing its course 
than acting as powerful propellers. The chief function of the 
paired fins is to maintain the balance of the fish in the water, 
which is always the most unsteady where there is no weight 
to sink it: when the pectoral of one side, or the pectoral and 
ventral of the same side are removed, the fish loses its balance 
and falls on the side opposite; when both pectorals are re- 
moved, the fish’s head sinks; on removal of the dorsal and 
anal fins the motion of the fish assumes a zig-zag course. A 
fish deprived of all fins, as well as a dead fish, floats with the 
belly upwards, the back being the heavier part of the body. 

In numerous groups of fishes which lve in mud, or are 
enabled to pass a longer or shorter time in soil periodi- 


FINS. 45 


cally dried and hardened during the hot season, forms occur 
entirely devoid of, or with only rudimentary, ventral fins 
(Cyprinodon, Ophiocephalide, Galaxiide, Siluride). The chief 
function of these fins being to balance the body of the fish 
whilst swimming, it is evident that in fishes moving during a 
great part of their life over swampy ground, or through more 
or less consistent mud, this function of the ventral fins ceases, 
and that nature can readily dispense with these organs 
altogether. 

In certain fishes the shape and function of the fins are 
considerably modified : thus, in the Rays, locomotion is almost 
entirely effected and regulated by the broad and expanded 
pectoral fins acting with an undulatory motion of their mar- 
gins, similar to the undulations of the long vertical fins of the 
Flat-fishes ; in many Blennies the ventral fins are adapted 
for walking on the sea-bottom ; in some Gobioids (Perioph- 
thalmus), Trigloids, Scorpzenioids, and Pediculati, the pectoral 
fins are perfect organs of walking; in the 
Gobies, Cyclopteri, and Discoboli the ventral 
fins are transformed into an adhesive disk, 
and finally in the Flying-fish, in which the ” 
pectorals act as a parachute. In the Eels 


and other snake-like fishes, the swimming 
as well as the gliding motions are effected Fig. 9.—Ventrals 
by several curvatures of the body, alternate OF ERI: 
towards the right and left, resembling the locomotion of Snakes. 
In the Syngnathi (Pipe-fishes) and Hzppocampi, whose body 
admits of but a sight degree of lateral curvature, and whose 
caudal fin is generally small, if present at all, locomotion is 
very limited, and almost wholly dependent on the action of 
the dorsal fin, which consists of a rapid undulating movement. 
The skin of fishes is either covered with scales, or naked, Skin and 
or provided with more or less numerous scutes of various Be 


forms and sizes. Some parts, like the head and fins, are more 


46 FISHES. 


frequently naked than scaly. All fishes provided with 
electric organs, the majority of Eels, and the Lampreys, are 
naked. Scales of fishes are very different from those of 
Reptiles; the latter being merely folds of the cutis, whilst 
the scales of fishes are distinct horny elements, developed in 
erooves or pockets of the skin, like hairs, nails, or feathers. 
Very small or rudimentary scales are 


extremely thin, homogeneous in struc- 
ture, and more or less imbedded in 


74 ( CAAA 
A the skin, and do not cover each other. 
When more developed, they are im- 
Fig. 10.—Cycloid scale of — bricated (arranged in the manner of 
Gadopsis marmoratus(m9g"-) +145) swith the posterior part extruded 
and free, the surface of the anterior portion being usually 
covered by the skin to a greater or less extent. On their 
surface (Figs. 10 and 11) may 
be observed a very fine striation 
concentric and parallel to the 
margin, and coarser striz radi- 
ating from a central point to- 
wards the hind margin. Scales 
without a covering of enamel, 
with an entire (not denticu- 
lated) posterior margin, and 


with a concentric striation, are 
Fig. 11,—Cycloid scale of Seopelus called Cycloid scales. Ctenoid 

resplendens (magn.) See 
scales (Figs. 12-15) are gene- 
rally thicker, and provided with spinous teeth on the posterior 
edges of the layers of which the scale consists. In some 
species only the layer nearest to the margin is provided with 
denticulations (Fig. 14). Scales, the free surface of which is 
spiny, and which have no denticulation on the margin, have 
been termed Sparoid scales ; but their distinction from ctenoid 


scales is by no means sharp, and there are even intermediate 


SCALES. 47 


forms between the cycloid and ctenoid types. Both kinds of 


wi | tllé#zzzze FE 
(CRIN el ee 
(in TN TOU Kt TT oS 
AWS 


RUUEHY 7 


Fig. 18.—Ctenoid scale of Platy- 
| Fig. 12.—Ctenoid scale of Scato- cephalus cirrhonasus (magn.) 
phagus multifasciatus (magn.) 


fr igeter oS 


ay 
Crammer 


Fig. 14.—Ctenoid scale of Gobius Fig. 15.—Ctenoid scale of 
ommaturus (magn.) Lethrinus (magn.) 


scales may occur not only in species of the 
same genus of fishes, but in the same fish. 
Ganoid scales are hard and bony, covered 
with a layer of enamel; they are generally 
rhombic or quadrangular, rarely rounded and 
imbricate; and arranged in oblique rows, 
those of one row being linked together by 
an articulary process. This type of scales, Fig. 16. 
common in fossil Ganoid fishes, occurs  Gncid Scales. 
among recent fishes in Lepidosteus and Polypterus only. 


48 FISHES. 


Finally, in Sharks, the Balistidz, and others, true scales 
are absent and replaced by the ossified papille of the cutis, 
which give the surface the appearance of fine-grained chagreen. 


Fig. 18.—Dermal papille of Monacanthus hippocrepis (magn. ) 


These generally small bodies, as well as the large osseous 
scutes of the Rays, Sturgeons, etc, have been comprised 
under the common name Placoid scales; a term which 
deservedly is being abandoned. 

Along the side of the body of osseous fishes runs a series 
of perforated scales, which is called the lateral line (Fig. 
21). The perforating duct is simple at its base, and may 


be also simple at its outer 


ita opening (Fig. 19), or (and this 


UU) i re ae 2 F 
Me ee Z is frequently the case) the 
7 MT [ti =) 


/==S portion on the free surface of 
the scale is ramified (Fig. 20). 
The lateral line runs from 
Fig. 19.—Cyeloid scale from the lateral the head to the tail, some- 

eae) times reaching the caudal 
fin, sometimes stopping in front of it, sometimes advanc- 
ing over its rays. It is nearer to the dorsal profile in some 
fishes than in others. Some species have several lateral 
lines, the upper one coasting the dorsal, the lower the 


abdominal outline, one running along the middle as usual. 


SCALES. 49 


The scales of the lateral line are sometimes larger than 
the others, sometimes smaller, sometimes modified into scutes, 


Fig. 20.—Cycloid scale from the lateral line of Labrichthys laticlavius (magn.) 


sometimes there are no other scales beside them, the rest of the 
body being naked. The foramina of the lateral line are the out- 
lets of a muciferous duct which is continued on to the head, 
running along the infraorbital bones, and sending off a branch 
into the preeopercular margin and mandible. In many fishes, 
as in many Scieenoids, Gadoids, and im numerous deep-sea 
fishes, the ducts of this muciferous system are extraordinarily 
wide, and generally filled with mucus, which is congealed or 
contracted in specimens preserved in spirits, but swells again 
when the specimens are immersed in water. This system is 
abundantly provided with nerves, and, therefore, has been 
considered to be the seat of a sense peculiar to fishes, but 
there cannot be any doubt that its function is the excretion 
of mucus, although probably mucus is excreted also from the 
entire surface of the fish. 

The scales, their structure, number and arrangement, are 
an important character for the determination of fishes ; in most 
scaly fishes they are arranged in oblique transverse series ; 
and as the number of scales in the lateral line generally cor- 
responds to the number of transverse series, it is usual to 
count the scales in that line. To ascertain the number of 
longitudinal series of scales, the scales are counted in one of 

E 


50 FISHES. 


the transverse series, generally in that running from the com- 
mencement of the dorsal fin, or the middle of the back to the 


i 

yy jy thy 
KCAL as Me H¢ A 
ALU COSY WA G0 ae 
LOAN ALU YMAAM ALY CCL (\ 
ay AW MIA eevee Mk i o Ase 


RAY 


Fig. 21.—Arrangement of scales in the Roach (Leuciscus ratilus): 27 = Lateral 
line; ¢ r = Transverse line. @, Transverse line from lateral line to ventral fin. 


lateral line, and from the lateral line down to the vent or 
ventral fin, or middle of the abdomen.! 

The scales of many fishes are modified for special pur- 
poses, especially to form weapons of defence or a protective 
armour, but the details of such modifications are better men- 
tioned under the several families in which they occur. All 
scales are continually growing and wasting away on the 
surface, and it seems that some fish, at least,—for instance, 
Salmonoids—“ shed” them periodically ; during the progress 
of this shedding the outlines of the scales are singularly 
irregular. 

1In the formula generally preceding the description of a fish, ‘*L. lat. 
40,” would express that the scales between the head and caudal fin are 
arranged in 40 transverse series ; and probably, that the lateral line is com- 
posed of the same number of scales, “ L. transv. $” would express that there 


are eight longitudinal series of scales between the median line of the back and 


the lateral line, and five between the lateral line and the middle of the 
abdomen. ; 


CHAPTER IT, 
TERMINOLOGY AND TOPOGRAPHY OF THE SKELETON. 


In order to readily comprehend the subsequent account of 
the modifications of the skeleton in the various sub-classes 
and groups of Fishes, the student has to acquaint himself with 
the terms used for the numerous bones of the fish skeleton, 
as well as with their relative position. The skeleton of any 
of the more common kinds of osseous fish may serve for this 
purpose; that of the Perch is chosen here, 

The series of bones constituting the axis of the body, and 
destined to protect the spinal chord and some large longi- 
tudinal blood-vessels, is called the vertebral or spinal column ; 
the single bones are the vertebrw. The skull consists of the 
bones surrounding the brain and organs of sense, and of a 
number of arches suspended from it, to support the com- 
mencement of the alimentary canal and the respiratory 
organs, 

The vertebra (Fig. 22) consists of a body or centrum (c), 
with a concave anterior and posterior surface, and gene- 
rally of several processes or apophyses, as—1. Two newra- 
pophyses (na), which, on the dorsal side, rising upwards, form 
the newral arch over the canal, in which the spinal chord 
is lodged. 2. Two parapophyses (pa) usually projecting from 
the lower part of the sides of the body, or two hwma- 
pophyses (ha) which actually coalesce to form on the ventral 
side the hemal canal for a large trunk of the vascular sys- 


52 FISHES. 


tem. 3. A neural spine (ns), which crowns the neura- 
pophyses, or is interposed between their tips. 4. A hemal 
spine (hs), having the same relation to the hemapophyses. 


Fig. 22.—Side and Front view of Fish-vertebra. 


5. Two pleurapophyses or floating ribs, suspended from, or 
from the base of, the parapophyses. 6. In most fishes the 
neural arches are connected together by articular or oblique 
processes, zygapophyses (za), which are developed from the base 
of each neurapophysis. 


SKELETON, 53° 


The vertebre are either abdominal or caudal vertebree, 
the coalescence of the parapophyses into a complete hemal 
ring, and the suspension of the anal fin generally forming a 
sufficiently well-marked boundary between abdominal and 
caudal regions (Fig. 23). In the Perch there are twenty- 
one abdominal and as many caudal vertebree. The centrum 
of the first vertebra or atlas is very short, with the apo- 
physes scarcely indicated, and lacking ribs like the succeeding 
vertebra. All the other abdominal vertebrze, with the ex- 
ception of the last or two last, are provided with ribs, many 
of which are bifid (72). A series of flat spines (74), called 
interneurals, to which the spmes and rays of the dorsal 
fins are articulated, are supported by the neural spines, the 
strength of the neurals and interneurals corresponding to 
that of the dermal spines (75). The caudal vertebra 
differ from the abdominal in having the hemapophyseal 
elements converted into spines similar to the neurals, the 
anterior being likewise destined to support a series of 
interhemals (79), to which the anal rays are articulated. 
The last and smallest caudal vertebra articulates with the 
hypural (70), a fan-like bone, which, together with the dilated 
hindmost neural and hemal elements, supports the caudal 
rays. 

Looking at a perch’s skull from the side (Fig. 24), the 
most superficial bones will be found to be those of the jaws, 
a chain of thin bones round the lower‘half of the eye, and the 
opercles. 

The anterior margin of the upper jaw is formed by the 
intermaaillary or premaxillary (17) which bears teeth, ter- 
minates in a pedicle above, to allow of a forward sliding motion 
of the jaw, and is dilated into a flat triangular process behind, 
on which leans the second bone of the upper jaw, the maz- 
ilary (18). This bone is toothless, articulates with the vomer 
and palatine bone, and is greatly dilated towards its distal 


54 ; FISHES. 


extremity. Both the maxillary and intermaxillary le and 
move parallel to each other, being connected by a narrow 
membrane ; in many other fishes their relative position is very 
different. 

The mandible or lower jaw consists of a right and left 
ramus; their union by a ligament in front is called symphysis. 
Each ramus is formed of several pieces; that which, by a 
sigmoid concavity articulates with the quadrate, is the 
articulary bone (35); it sends upwards a coronoid process, to 
which a ligament from the maxillary and the masticatory 
muscles are attached; and forwards a long-pointed process, 
to be sheathed in the deep notch of the anterior piece. A 
small separate piece (36) at the lower posterior angle of the 
mandible is termed angular. The largest piece (34) is tooth- 
bearing, and hence termed dentary ; at its inner surface it is 
always deeply excavated, to receive a cylindrical cartilage, 
called Meckel’s cartilage, the remains of an embryonic con- 
dition of the jaw, the articulary and angular being but ossified 
parts of it. In other Zeleostei this number is still more in- 
creased by a splenial and other bones. 

The infraorbital ring of bones (Fig. 23, 1%) consists of 
several (four) pieces, of which the anterior is the largest, and 
distinguished as preorbital. 

The so-called preoperculwm (30) belongs rather to the bones 
of the suspensorium of the mandible, presently to be described, 
than to the opercles proper. It is narrow, strong, angularly 
bent, so as to consist of a vertical and horizontal limb, with 
an incompletely closed canal running along both limbs. As 
it is quite a superficial bone, and frequently armed with 
various spines, its form and configuration form an important 
item in the descriptive details of many fishes. 

The principal piece of the gill-cover is the operculum (28), 
triangular in shape, situated behind, and movably united 
with, the vertical limb of the praoperculum. There is an 


SKELETON. Ly) 


articulary cavity at its upper anterior angle for its junction 
with the hyomandibular. The oblong lamella below the 
operculum is the swbopereulum (32), and the one in front of 
this latter, below the horizontal limb of the praeoperculum, 
is the interoperculum (33), which is connected by lgament 
with the angular piece of the lower jaw, and is also attached 
to the outer face of the hyoid, so that the gill-covers cannot 
open or shut without the hyoid apparatus executing a corre- 
sponding movement. 

The chain of flat bones which, after the removal of the 
temporal muscles, appear arranged within the inner concavity 
of the preeoperculum (Fig. 24), are comprised with the latter 
under the common name of mandibulary suspensorium. They 
connect the mandible with the cranium. The uppermost, the 
epitympanic or hyomandibular (23), is articulated by a double 
articulary head with the mastoid and posterior frontal. An- 
other articulary head is destined for the opercular joint. The 
mesotympanic or symplectic (31) appears as a styliform prolonga- 
tion of the lower part of the hyomandibular ; is entirely 
cartilaginous in the young, but nearly entirely ossified in the 
adult. The position of this bone is noteworthy, because, 
directly inwards of its cartilaginous junction with the hyo- 
mandibular, there is situated the uppermost piece of the 
hyoid arch, the stylo-hyal. The next bone of the series is the 
pretympanic or metapterygoid (27), a flat bone forming a bridge 
towards the pterygoid, and not rarely absent in the teleosteous 
sub-class. Finally, the large triangular hypotympanic or 
quadrate (26) has a large condyle for the mandibulary 
joint. 

The palatine arch (Fig. 26) connects the suspensorium with 
the anterior extremity of the skull, and is formed by three 
bones : the entopterygoid (25), an oblong and thin bone attached 
to the inner border of the palatine and pterygoid, and increas- 
ing the surface of the bony roof of the mouth towards the 


56 FISHES. 


median line; it constitutes also the floor of the orbit. The 
pterygoid (24) (or os transversum) starts from the quadrate, and 
is joined by suture to the palatine, which is toothed, and 
reaches to the vomer and anterior frontal. 

In the occipital region there are distinguished the bast- 
occipttal (5), readily recognised by the conical excavation corre- 
sponding and similar to that of the atlas, with which it is 
articulated through the intervention of a capsule filled with a 
gelatinous substance (the remains of the notochord); the ex- 
occipitals (10), articulated, one on each side, to the basioceipital, 
and expanding on the upper surface of that bone, so as to 
meet and support the spinal column; a superficial thin 
lamella (15), suturally connected with the exoccipitals, not 
constant in fishes, and erroneously believed by Cuvier to be the 
wetrosal (os petrosum) of higher animals; further, the parocci- 
pitals (9), which are wedged in between the exoccipitals and 
supraoccipital. This last bone (8) forms the key of the arch 
over the occipital foramen, and raises a strong high crest from 
the whole length of its mesial line; a transverse supraocci- 
pital ridge, coming from each side of the base of this spine 
runs outwards laterally to the external angles of the bone. 
The supraoccipital separates the parietals, and forms a suture 
with the frontals. 

In front of the basioccipital the base of the skull is formed 
by the basisphenoid (parasphenoid of Huxley) (6). This very 
long and narrow bone extends from the basioccipital beyond 
the brain-capsule to between the orbits, where it forms the 
support of the fibro-membranous interorbital septum. Ante- 
riorly it is connate with another long hammer-shaped bone (16), 
the vomer, the head of which marks the anterior end of the 
palate, and is beset with teeth. The alisphenoids (11) are short 
broad bones, rising from the basisphenoid; their posterior 
margins are suturally connected with the anterior of the basi- 
and ex-occipitals, 


‘POLI JO TMYG JO META TaMOT—'9zZ “SIT /) 
2 ak > = = jee NZ 


Sid 


"Yotg oy} Jo euoq prlokH—"1] “SLT 


‘Youag JO [[MYG JO MITA IAMOT—'9Z “SLT | 


‘Yadeg ayy Jo yore Areqndvos pue ‘snqyvavdde perpouvaq ‘yore prloAGR—eCZ “Si TMYY 8 Yolag v Jo uojopoyg—'Fz “Sry 


= = rg y Zz Z = : ry Zp Zz - 
L- 


Br 


| IN ANN 
WW 


Y 
S 


SKELETON. 57 


The formation of the posterior part of the side of the skull 
is completed by the mastoid and parietal bones. The former 
(12) projects outwards and backwards farther than the paroc- 
cipital, forming the outer strong process of the side of the 
cranium. This process lodges on its upper surface one of the 
main ducts of the muciferous system, and affords the base 
of articulation to a part of the hyomandibular. Its extre- 
mity gives attachment to the strong tendon of the dorso- 
lateral muscles of the trunk. The parvetals (7) are flat bones, 
of comparatively much smaller extent than in higher Verte- 
brates, and separated from each other by the anterior prolonga- 
tion of the supra-occipital. 

The anterior wall of the brain-capsule (or the posterior of 
the orbit) is formed by the orbitosphenoids (14), between which, 
superiorly, the olfactory nerves, and inferiorly, the optic, pass 
out of the cranium. In addition to this paired bone, the 
Perch and many other fishes possess another single bone (15),— 
the os sphenoideum anterius of Cuvier, ethmoid of Owen, and 
busisphenoid of Huxley; it is Y-shaped, each lateral branch 
being connected with an orbitosphenoid, whilst the lower 
branch rests upon the long basal bone. 

A cartilage, the substance of which is thickest above the 
vomer, and which extends as a narrow stripe along the inter- 
orbital septum, represents the ethmoid of higher Vertebrata ; 
the olfactory nerves run alone, and finally perforate it. 

There remain, finally, the bones distinguishable on the 
upper surface of the skull; the largest, extending from the nasal 
cavities to the occipital, are the frontal bones (1), which also 
form the upper margin of the orbit. The postfrontals (4) are 
small bones placed on the supero-posterior angle of the orbit, 
and serving as the point from which the infraorbital ring is 
suspended. The prefrontals (2), also small, occupy the anterior 
margin of the orbit. A pair of small tubiform bones (20), the 
turbinals, occupy the foremost part of the snout, in front of 


58 FISHES. 


the frontals, and are separated from each other by intervening 
cartilage. 

After removal of the gill-cover and mandibulary suspen- 
sorium, the hyoid arch, which encloses the branchial apparatus, 
and farther behind, the humeral arch are laid open to view 
(Fig. 25). These parts can be readily separated from the 
cranium proper. 

The hyoid arch is suspended by a slender styliform bone, 
the stylohyal (29), from the hyomandibulars; it consists of three 
segments, the epihyal (37), ceratohyal (38), which is the longest 
and strongest piece, and the basihyal, which is formed by two 
juxtaposed pieces (39, 40). Between the latter there is a 
median styliform ossicle (41), extending forwards into the sub- 
stance of the tongue, called glossohyal or os linguale; and below 
the junction of the two hyoid branches there is a vertical single 
bone (42), expanded along its lower edge, which, connected by 
ligament with the anterior extremity of the humeral arch, 
forms the isthmus separating the two gill-openings. This 
bone is called the wrohyal. Articulated or attached by liga- 
ments to the epihyal and ceratohyal are a number of sword- 
shaped bones or rays (43), the branchiostegals, between which 
the branchiostegal membrane is extended. 

The branchial arches (Figs. 25 and 27) are enclosed within 
the hyoid arch, with which they are closely connected at the 
base. They are five in number, of which four bear gills, whilst 
the fifth (56) remains dwarfed, is beset with teeth, and called the 
lower pharyngeal bone. The arches adhere by their lower ex- 
tremities to a chain of ossicles (53, 54, 55), basibranchials, and, 
curving as they ascend, nearly meet at the base of the cranium, 
to which they are attached by a layer of ligamentous and 
cellular tissue. Each of the first three branchial arches consists 
of four pieces movably connected with one another. The 
lowest is the hypobranchial (57), the next much longer one (58) 
the ceratobranchial, and, above this, a slender and a short 


SKELETON. 59 


irregularly-shaped epibranchial (61). In the fourth arch the 
hypobranchial is absent. The uppermost of these segments 
(62), especially of the fourth arch, are dilated, and more or less 
confluent; they are beset with fine teeth, and generally dis- 
tinguished as the wpper pharyngeal bones. Only the cerato- 
branchial is represented in the fifth arch or lower pharyngeal. 
On their outer convex side the branchial segments are 
grooved for the reception of large blood-vessels and nerves ; on 
the inner side they support horny processes (63), called the 
gill-rakers, which do not form part of the skeleton. 

The scapular or humeral arch is suspended from the skull 
by the. (suprascapula) post-temporal (46), which, in the Perch, 
is attached by a triple prong to the occipital and mastoid bones. 
Then follows the (scapula) supraclavicula (47), and the arch is 
completed below by the union of the large (coracoid) clavi- 
cula (48) with its fellow. Two flat bones (51, 52), each with 
a vacuity, attached to the clavicle have been determined as 
the (radius and ulna) coracoid and scapula of higher verte- 
brates, and the two series of small bones (53) intervening 
between the forearm and the fin as carpals and metacarpals. 
A two-jointed appendage the (epicoracoid) post-clavicula, is 
attached to the clavicle: its upper piece (49) is broad and 
lamelliform, its lower (50) styliform and pointed. 

The ventral fins are articulated to a pair of flat triangular 
bones, the pubie bones (80). 

The bones of the skull of the fish have received so many 
different interpretations that no two accounts agree in their 
nomenclature, so that their study is a matter of considerable 
difficulty to the beginner. The following synonymic table will 
tend to overcome difficulties arising from this cause ; it contains 
the terms used by Cuvier, those introduced by Owen, and finally 
the nomenclature of Stannius, Huxley, and Parker. Those 
adopted in the present work are printed in italics. The 


60 


FISHES. 


numbers refer to the figures in the accompanying woodcuts 
(Figs. 23-27). 


Cuvier. 


. Frontal principal 
. Frontal antérieur 


. Ethmoid 
. Frontal postérieur 


. Basilaire 
. Sphénoide 


. Pariétal 
. Interpariétal or occi- 


pital supérieure 


. Occipital externe 
. Occipital lateral 


. Grande aile du 


sphénoide 


. Mastoidien 
. Rocher 
. Aile orbitaire 


. Sphenoide antérieur 


Vomer 


. Intermaxillaire 


. Maxillaire supérieur 
. Sousorbitaires 

. Nasal 

. Palatine 

. Temporal 


. Transverse 


. Ptérygoidien interne 


. Jugal 
. Tympanal 


Owen. 


Frontal 
Prefrontal 


Nasal 
Postfrontal 


Basioccipital 
Basisphenoid 


Parietal 
Supraoccipital 


Paroccipital 
Exoccipital 
Alisphenoid 
Mastoid 


Petrosal and 
Otosteal 
Orbitosphenoid 


Ethmoid and 
Ethmoturbinal 
Vomer 
Inter- or Pre- 
maxillary 
Maxillary 
Infraorbital ring 
Turbinat 
Palatin 
Epitympanic 


Pterygoid 


Entopterygoid 


Hypotympanic 
Pretympanic 


Stannius. 


Os frontale 

Os frontale 
anterius 

Os ethmoideum 

Os frontale 
posterius 

Os basilare 

Os sphenoideum 
basilare 

Os parietale 

Os occipitale 
superius 

Os occipitale 
externum 

Os occipitale 
laterale 

Ala temporalis 


Os mastoideum 
+ osextrascapulare 


Oberflaichliche 


Knochen-lamelle 


Ala orbitalis 


Os sphenoideum 
anterius 
Vomer 


Huxley, Parker, ete. 


' Lateral ethmoid 


(Parker) 


Sphenotic 
(Parker) 


Sometimesreferred | 
to as *‘ Basal” 


Epioticum 
(Huxley) 


Prooticum 
(Huxley) 


Opisthoticum! 
+ Squamosal 
(Huxley) 


Alisphenoid 
(Huxley) 

Basisphenoid 
(Huxley) 


Os intermaxillare 


Os maxillare 


Ossa infraorbitalia 


Os terminale 
Os palatinum 
Os temporale 


Os transversum 


Hyomandibular 
(Huxley) 


s. pterygoideum 


externum 
Os pterygoideum 


Mesopterygoid 
(Parker) 


Os quadratojugale Quadrate (Huxley). 


Os tympanicum 


1 Pterotic of Parker. 


Metapterygoid 
(Huxley) 


63. 
65. 


. Os lingual 


Cuvier. 


. Operculaire 

. Styloide 

. Préopercule 

. Symplectique 
. Sousopercule 
. Interopercule 
. Dentaire 

. Articulaire 

. Angulaire 


Grandes piéces 
latérales 
Petites piéces 
laterales 


. Queue de l’os hyoide 
. Rayon branchiostége 
. Surscapulaire 

. Scapulaire 


. Humeral 


Coracoid 


. Cubital 
52. 


Radial 


. Os du carpe 
53 bis. 


SYNONYMIC TABLE. 


Owen. 


Operculum 
Stylohyal 
Preoperculum 
Mesotympanic 
Suboperculum 
Interoperculum 
Dentary 
Articulary 
Angular 
Epihyal 
Ceratohyal 
Basihyal 


Glossohyal 
Urohyal 
Branchiostegat 
Suprascapula 
Scapula 


Coracoid 


Epicoracoid 


Radius 
Ulna 


Carpals 


Chaine intermédiaireBasibranchials 


. Pharyngiens inférieurs Lower 


Pharyngeals 


. Piece interne de partie Hypobranchial 


inférieure de l’arceau 


branchiale 


. Piéce externe ,, 
. Stylet de prémiére 


arceau branchiale 


. Partie supérieure de 
Yarceau branchiale » 
. Os pharyngian 


supérieur 


Ceratobranchial 
Upper epibranchia 
of first branchia 


arch 
Epibranchials 


Pharyngo- 
branchial 
Gill-rakers 


Rayons de la pectorale Pectoral rays 


| 
me 
‘| 
| 
J 


61 


Stannius. Huxley, Parker, ete. 


Operculum 

Os styloideum 
Preeoperculum 
Os symplecticum 
Suboperculum 
Interoperculum 
Os dentale 

Os articulare 

Os angulare 


Segmente der 


Zungenbein- 
Schenkel 
Os linguale s. 
entoglossum 
Basibranchiostegal 
(Parker) 
Radii branchio- 
stegi 
Omolita Post-temporatl 
(Parker) 
Scapula Supraclavicula 
(Parker) 
Clavicula Clavicula (Parker) 
Postelavicula 
(Parker) 


Coracoid (Parker) 
Scapula (Parker) 
Basalia (Huxley), 
Brachials (Parker) 


Ossa carpi 


Ossa metacarpi 


Copula 


Ossa pharyngea 
inferiora 


Segmente der 
Kiemenbogen- 


Schenkel 


Os pharyngeum 
superius 


Upper pharyngeals 


Brustflossen- 
Strahlen 


62 FISHES. 
Cuvier. Owen. Stannius. Huxley, Parker, ete. 
67, 68. Verttbres abdominales Abdominal verte- Bauchwirbel 
bre 
69. Vertébres caudales Caudal vertebree Schwanzwirbel 
70. Plaque triangulaire et [Aggregated Verticale Platte Hypural (Huxley) 
verticale interhemals] 
(a Caudal rays Schwanzflossen 
Strahlen 
72, Cote Rib Rippen 
73. Appendices or stylets Hpipleural spines Muskel-Grathen 
74. Interépineux Interneural spines Ossa interspinalia 
s. obere Flossen- 
treger 
75. Epines et rayons Dorsal rays und Riickenflossen- 
dorsales spines Strablen u. 
Stacheln 
76. First interneural 
78. Rudimentary 
caudal rays 
79. Apophyses épineuses Jnterheemal spines Untere Flossen- 
inférieures treger 
80. Pubic Becken 
81. Ventral spine Bauchflossen- 


Stachel 


CHAPTER: TV. 
MODIFICATIONS OF THE SKELETON. 


THE lowermost sub-class of fishes, which comprises one 
form only, the Lancelet (Branchiostoma [s. Amphioxus| lanceo- 
latum, possesses the skeleton of the most primitive type. 


Fig. 28.—Branchiostoma lanceolatum. 
a, Mouth ; 0, Vent; c, abdominal porus. 


The vertebral column is represented by a simple chorda 


Fig. 29.—Anterior end of body of Branchiostoma (magn.) 
d, Chorda dorsalis ; e, Spinal chord ; f, Cartilaginous rods; g, Eye ; 
h, Branchial rods ; 7, Labial cartilage ; #, Oral cirrhi. 


dorsalis or notochord only, which extends from one extremity 
of the fish to the other, and, so far from being expanded into 


64 FISHES. 


a cranial cavity, it is pointed at its anterior end as well as at 
its posterior. It is enveloped in a simple membrane like the 
spinal chord and the abdominal organs, and there is no trace 
of vertebral segments or ribs ; however, a series of short carti- 
laginous rods above the spine evidently represent apophyses. 
A maxillary or hyoid apparatus, or elements representing 
limbs, are entirely absent. 

[J. Miiller, Ueber den Bau und die Lebenserscheinungen des Branchio- 

stoma lubricwm, in Abhandl. Ak. Wiss. Berlin, 1844. ] 

The skeleton of the Cyclostomata (or Marsipobranchi) 
(Lampreys and Sea-hags) shows a considerable advance of 
development. It consists of a notochord, the anterior pointed 
end of which is wedged into the base of a cranial capsule, 
partly membranous partly cartilagious. This skull, there- 
fore, is not movable upon the spinal column. No vertebral 
seomentation can be observed in the notochord, but neural 
arches are represented by a series of cartilages on each side 
of the spinal chord. In Petromyzon (Fig. 30) the basis crani 
emits two prolongations on each side : an inferior, extending for 
some distance along the lower side of the spinal column, and 
a lateral, which is ramified into a skeleton supporting the 
branchial apparatus. A stylohyal process and a subocular 
arch with a palato-pterygoid portion may be distinguished. 
The roof of the cranial capsule is membranous in A/yxine and 
in the larvee of Petromyzon, but more or less cartilagimous in 
the adult Petromyzon and in Ldellostoma. <A cartilaginous 
capsule on each side of the hinder part of the skull contains 
the auditory organ, whilst the olfactory capsule occupies the 
anterior upper part of the roof. A broad cartilaginous lamina, 
starting from the cranium and overlying part of the snout, 
has been determined as representing the ethmo-vomerine 
elements, whilst the oral organs are supported by large, very 
peculiar cartilages (dabials), greatly differing in general con- 
figuration and arrangement in the various Cyclostomes, There 


SKELETON OF CYCLOSTOMES, 65 


are three in the Sea-lamprey, of which the middle one is 
joined to the palate by an intermediate smaller one; the fore- 


Fig. 30.—Upper (A) and side (B) views, and vertical section (C) of the skull of 
Petromyzon marinus. 

a, Notochord; b, Basis cranii; c, Inferior, and d, Lateral process of basis; @, 
Auditory capsule; 7, Subocular arch; g, Stylohyal process; /, Olfactory 
capsule ; 7, Ethmo-vomerine plate ; &, Palato-pterygoid portion of subocular 
arch ; d-n, Accessory labial or rostral cartilages ; with 0, appendage; 7, 
lingual cartilage ; g, neural arches ; 7, Branchial skeleton; s, Blind termina. 
tion of the nasal duct between the notockord and cesophagus. 


most is ring-like, tooth-bearing, emitting on each side a styli- 
form process. The lingual cartilage is large in all Cyclostomes. 
F 


66 FISHES. 


There is no trace of ribs or limbs. 
[J. Miiller, Vergleichende Anatomie der Myxinoiden. Erster Theil. 
Osteologie und Myologie, in Abhandl. Ak. Wiss. Berlin, 1835.] 

The Chondropterygians exhibit a most extraordinary diver- 
sity im the development of their vertebral column; almost 
every degree of ossification, from a notochord without a trace 
of annular structure to a series of completely ossified vertebree 
being found in this order. Sharks, in which the noto- 
chord is persistent, are the Holocephali (if they be reckoned 
to this order, and the genera Notidanus and Hehinorhinus). 
Among the first, Chimera monstrosa begins to show traces of 
segmentation ; but they are limited to the outer sheath of the 
notochord, in which slender subossified rings appear. In 
Notidanus membranous septa, with a central vacuity, cross 
the substance of the gelatinous notochord. In the other 
Sharks the segmentation is complete, each vertebra having a 
deep conical excavation in front and behind, with a central 


Fig. 31.—Heterocercal Tail of Centrina salviani. 
a, Vertebre ; b, Neurapophyses ; c, Hemapophyses. 


canal through which the notochord is continued; but the 
degree in which the primitive cartilage is replaced by con- 


SKELETON OF CHONDROPTERYGIANS. 67 


centric or radiating lamelle of bone varies greatly in the 
various genera, and according to the age of the individuals. 
In the Rays all the vertebree are completely ossified, and the 
anterior ones confluent into one continuous mass. 

In the majority-of Chondropterygians the extremity of the 
vertebral column shows a decidedly heterocercal condition 
(Fig. 31), and only a few, like Squatina and some Rays, possess 
a diphycercal tail. 

The advance in the development of the skeleton of the 
Chondropterygians beyond the primitive condition of the pre- 
vious sub-classes, manifests itself further by the presence of 
neural and hzemal elements, which extend to the foremost 
part of the axial column, but of which the hemal form a 
closed arch in the caudal region only, whilst on the trunk 
they appear merely as a lateral longitudinal ridge. 

The neural and hemal apophyses are either merely 
attached to the axis, as in Chondropterygians with per- 
sistent notochord, the Rays and some Sharks; or their basal 


Fig. 33. Fig. 34. 


Fig. 32.—Lateral view. Fig. 33.—Longitudinal section. Fig. 34.—Transverse 
section of Caudal vertebra of Basking Shark (Selache maxima). (After Hasse.) 
a, Centrum ; 4, Neurapophysis ; c, Intercrural cartilage; d, Hemapophysis ; ¢, 
Spinal ae J, Intervertebral cavity ; g, Central canal for Boreisbent portion of 
notochord ; #, Hemal canals for blood-vessels. 


portions penetrate like wedges into the substance of the 
centrum, so that, in a transverse section, in consequence of 


68 FISHES. 


the difference in their texture, they appear in the form of 
an X.! The interspaces between the neurapophyses of the 
vertebrae are not filled by fibrous membrane, as in other 
fishes, but by separate cartilages, laminw or cartilagines 
intercrurales, to which frequently a series of terminal pieces 
is superadded, which must be regarded as the first appear- 
ance of the interneural spines of the Teleostei and many 
Ganoids. Similar terminal pieces are sometimes observed on 
the hemal arches. bs are either absent or but imperfectly 
represented (Carcharvas). 

The substance of the skull of the Chondropterygians is 
cartilage, interrupted especially on its upper surface by more 
or less extensive fibro-membranous fontanelles. Superficially 
it is covered by a more or less thick chagreen-like osseous 
deposit. The articulation with the vertebral column is 
effected by a pair of lateral condyles. In the Sharks, be- 
sides, a central conical excavation corresponds to that of the 
centrum of the foremost vertebral segment, whilst in the 
Rays this central excavation of the skull receives a condyle 
of the axis of the spinous column. 

The cranium itself is a continuous undivided cartilage, 
in which the limits of the orbit are well marked by an 
anterior and posterior protuberance. The ethmoidal region 
sends horizontal plates over the nasal sacs, the apertures of 
which retain their embryonic situation upon, the under 
surface of the skull. In the majority of Chondroptery- 
gians these plates are conically produced, forming the base 
of the soft projecting snout; and in some forms, especially 
in the long-snouted Rays and the Saw-fishes (Pristis) this 
prolongation appears in the form of three or more tubiform 
rods. 


1 (, Hasse has studied the modifications of the texture of the vertebra 
and the structure of the Chondropterygian skeleton generally, and shown that 
they correspond in the main to the natural groups of the system, and, conse- 
quently, that they offer a valuable guide in the determination of fossil remains. 


SKELETON. 69 


As separate cartilages there are appended to the skull a 
suspensorium, a palatine, mandible, hyoid, and rudimentary 
maxillary elements. 

The suspensorium is movably attached to the side of the 
skull. It generally consists of one piece only, but in some 
Rays of two. In the Rays it is articulated with the mandible 
only, their hyoid possessing a distinct point of attachment to 
the skull. In the Sharks the hyoid is suspended from the 
lower end of the suspensorium together with the mandible. 

What is generally called the upper jaw of a Shark is, as 
Cuvier has already stated, not the maxillary, but palatine. 
It consists of two simple lateral halves, each of which articu- 
lates with the corresponding half of the lower jaw, which is 
formed by the simple representative of Meckel’s cartilage. 

Some cartilages of various sizes are generally developed 
on each side of the palatine, and one on each side of the 
mandible. They are called labial cartilages, and seem to 
represent maxillary elements. 

The hyoid consists generally of a pair of long and strong 
lateral pieces, and a single mesial piece. From the former 
cartilaginous filaments (representing branchiostegals) pass 
directly outwards. Branchial arches, varying in number, 
and similar to the hyoid, succeed it. They are suspended 
from the side of the foremost part of the spinous column, and, 
like the hyoid, bear a number of filaments. 

The vertical fins are supported by interneural and inter- 
hemal cartilages, each of which consists of two and more 
pieces, and to which the fin-rays are attached without articu- 
lation. 

The scapular arch of the Sharks is formed by a single 
coracoid cartilage bent from the dorsal region downwards and 
forwards. In some genera (Scylliwm, Squatina) a small sepa- 
rate scapular cartilage is attached to the dorsal extremities 
of the coracoid; but in none of the Elasmobranchs is the 


70 FISHES. 


scapular arch suspended from the skull or vertebral column ; 
it is merely sunk, and fixed in the substance of the muscles. 
Behind, at the point of its greatest curvature, three carpal 
cartilages are joimed to the coracoid, which Gegenbaur has 
distinguished as propterygium, mesopterygium, and metaptery- 
giwm, the former occupying the front, the latter the hind 
margin of the fin. Several more or less regular transverse 
series of styliform cartilages follow. They represent the 
phalanges, to which the horny filaments which are imbedded 
in the skin of the fin are attached. 

In the Rays, with the exception of Torpedo, the scapular 
arch is intimately connected with the confluent anterior por- 
tion of the vertebral column. ‘The anterior and posterior 
carpal cartilages are followed by a series of similar pieces, 
which extend like an arch forwards to the rostral portion of 
the skull, and backwards to the pubic region. Extremely 
numerous phalangeal elements, longest in the middle, are sup- 
ported by the carpals, and form the skeleton of the lateral 
expansion of the so-called disk of the Ray’s body, which thus, 
in fact, is nothing but the enormously enlarged pectoral 
fin. 

The pubic is represented by a single median transverse 
cartilage, with which a tarsal cartilage articulates. The latter 
supports the fin-rays. To the end of this cartilage is also 
attached, in the male Chondropterygians, a peculiar accessory 
generative organ or clasper. 

The Holocephali differ from the other Chondropterygians 
in several important points of the structure of their skeleton, 
and approach unmistakably certain Ganoids. That their 
spinal column is persistently notochordal has been mentioned 
already. Their palatal apparatus, with the suspensorium, 
coalesces with the skull, the mandible articulating with a 
short apophysis of the cranial cartilage. The mandible is 
simple, without anterior symphysis. The spine with which 


SKELETON OF DIPNOI. fill 


the dorsal fin is armed articulates with a neural apophysis, 
and is not immovably attached to it, as in the Sharks. The 
pubic consists of two lateral halves, with a short, rounded, 
tarsal cartilage. 

The skeleton of the Ganoid Fishes offers extreme varia- 
tions with regard to the degree in which ossifications replace 
the primordial cartilage. Whilst some exhibit scarcely any 
advance beyond the Plagiostomes with persistent cartilage, 
others approach, as regards the development and specialisa- 
tion of the several parts of their osseous framework, the 
Teleosteans so closely that their Ganoid nature can be 
demonstrated by, or inferred from, other considerations only. 
All Ganoids possess a separate gill-cover.! 

The diversity in the development of the Ganoid skeleton 
is well exemplified by the few representatives of the order in 
the existing Fish-fauna. Lowest in the scale (in this respect) 
are those with a persistent notochord, and an autostylic skull, 
that is, a skull without separate suspensorium—the fishes 
constituting the sub-order Dipnoi, of which the existing repre- 
sentatives are Lepidosiren, Protopterus, and Ceratodus, and the 
extinct (as far as demonstrated at present) Dipterus, Chirodus 
(and Phaneropleuron ?). In these fishes the notochord is 
persistent, passing uninterruptedly into the cartilaginous base 
of the skull. Only now and then a distinct vertical sement- 
ation occurs in the caudal portion of the column, but it does 
not extend to the notochord itself, but indicates only the 
limits between the superadded apophyseal elements, each 
neural being confluent with the opposite hemal. Some Dipnot 
are diphy-, others hetero-cercal. 


1 The Ganoids formed at former epochs the largest and most important 
order of fishes, many of the fossil forms being known from very imperfect 
remains only. It is quite possible that not a few of the latter, in which 
nothing whatever of the (probably very soft) endoskeleton has been preserved, 
should have to be assigned to some other order lower in the scale of organisa- 
tion than the Ganoids (for instance, the Cephalaspide). 


=I) 
bo 


FISHES. 


Neural and hemal elements and ribs are well developed. 
In Ceratodus each neurapophysis consists of a basal cartila- 
ginous portion, forming an arch over the myelon, and of a 
superadded second portion. The latter is separated from the 
former by a distinct line of demarcation, and its two branches 
are more styliform, cartilaginous at the ends and in the centre, 
but with an osseous sheath, and coalesced at the top, forming 
a gable over an elastic fibrous band which runs along and 
parallel to the longitudinal axis of the column (Ligamentum 
longitudinale superius). To the top of this gable is joined a 
single long cylindrical neural spine. From the eleventh 
apophyseal segment a distinct interneural spine, of the same 
structure as the neural, begins to be developed, and farther on 
a second interneural is superadded. Towards the extremity 
of the column these various pieces are gradually reduced in 
size and number, finally only a low cartilaginous band (the 
rudiments of the neurapophysis) remaining. The hemapophy- 
ses are in form, size, and structure, very similar to the neura- 
pophyses; and all these long bones, including the ribs, have 
that in common, that they consist of a solid rod of cartilage 
enclosed in a bony sheath, which, after the disappearance or 
decomposition of the cartilage, appears as a hollow tube. 
Such bones are extremely common throughout the order of 
Ganoids, and their remains have led to the designation 
of a family as Ca@lacanthi (kotdos, hollow; and dxavos, 
spine). 

The primordial cranium of the Dipnoi is cartilaginous, 
but with more or less extensive ossifications in its occipital, 
basal, or lateral portions, and with large teeumentary bones, 
the arrangement of which varies in the different genera. 
There is no separate suspensorium for the lower jaw. 
A strong process descends from the cranial cartilage, and 
offers by means of a double condyle (Fig. 35 s) attach- 
ment to corresponding articulary surfaces of the lower jaw. 


SKELETON OF DIPNOI. 73 


Maxillary and intermaxillary elements are not developed, 
but, perhaps, represented in 
Ceratodus by some inconstant 
rudimentary labial cartilages 
situated behind the posterior 
nasal opening. Facial cartil- 
ages and an infraorbital ring 
are developed at least in Cera- 
todus. ‘The presence of a pair 
of small teeth in front indicates 
the vomerine portion (v) which 
remains cartilage, whilst the 
posterior pair of teeth areim- ¢ > e AN US 


P 


planted in a pterygo-palatine Fig, 35.—Palatal view of Skull of 
ossification (J), which some- pares 

times is paired, sometimes continuous. The base of the skull 
is constantly covered by a large basal ossification (0). 

The hyoid is well developed, sometimes reduced to a pair 
of ceratohyals, sometimes with a basihyal and glossyhyal. 
The skeleton of the branchial apparatus approaches the Tele- 
osteous type, less so in Lepidosiren than in Ceratodus, in which 
five branchial arches are developed, but with the lateral and 
mesial pieces reduced in number. 

A large operculum, and a smaller sub- or inter-opereulum 
are present. 

The scapular arch consists of a single median transverse 
cartilage, and a pair of lateral cartilages which bear the 
articular condyle for the pectoral limb. The latter cartilages 
form the base of a large membrane-bone, and the whole 
arch is suspended from the skull by means of an osseous 
supraclavicle. 

The fore-limb of the Dipnoi (Fig. 36) differs externally 
greatly from the pectoral fin of other Ganoid fishes. It is 
covered with small scales along the middle, from the root 


74 


FISHES. 


to its extremity, and surrounded by a rayed fringe similar to 


f Hf} if) 
“Aa 
f iI] 


Fig. 36.—Fore-limb of 
Ceratodus. 


the vertical fin. A muscle split into 
numerous fascicles extendsall the length 
of the fin, which is flexible in every part 
and in every direction. The cartilagin- 
ous framework supporting it is jomed to 
the scapular arch by an oblong cartilage, 
followed by a broad basal cartilage (a), 
generally single, sometimes showing 
traces of a triple division. Along the 
middle of the fin runs a jointed axis (0), 
the joints gradually becoming smaller 
and thinner towards the extremity ; 
each joint bears on each side a three, 
two, or one-jointed branch (c,d). This 
axial arrangement of the pectoral skele- 
ton, which evidently represents one of 
its first and lowest conditions, has been 
termed Archipterygium by Gegenbaur. 
It is found in Ceratodus and other 
genera, but in Lepidosiren the jointed 
axis only has been preserved, with the 
addition of rudimentary rays in Pro- 
topterus. 

The pubic consists of a_ single 


flattened subquadrangular cartilage, produced into a long 
single anterior process. Posteriorly it terminates on each 


side in a condyle, to which the basal cartilage of the ventral 


paddle is joined. The endoskeleton of the paddle is almost 
identical with that of the pectoral. 

The Ganoid fishes with persistent notochord, but with a 
hyostylic skull (that is, a skull with a separate suspensorium) 
consist of the sub-order Chondrostet, of which the existing 
representatives are the Sturgeons (Acipenser, Scaphirhynchus, 


SKELETON OF STURGEONS. 75 


Polyodon), and the extinct the Chondrosteidw, Palwoniscide, 
and (according to Traquair) Platysomide. 

Their spinal column does not differ essentially from that 
of the Dipnoi. Segmentation is represented only as far as the 
neural and hzemal elements are concerned. All are eminently 
heterocercal. Ribs are present in most, but replaced by liga- 
ments in Polyodon. 

The primordial cranium of the Sturgeons consists of per- 
sistent cartilage without ossifications in its substance, but 
superficial bones are still more developed and specialised than 
in the Dipnoi; so it is, at least, in the true Sturgeons, but less 
so in Polyodon (Fig. 37). The upper and lateral parts of the 
skull are covered by well-developed membrane bones, which, 


Fig. 37.—Skull of Polyodon (after Traquair). 


n, Nasal cavity; sq, squamosal; mh, hyomandibular; sy, symplectic; pa, 
palato-pterygoid ; m, Meckelian cartilage; ma, maxillary; d, dentary; h, 
hyoid; op, opercle; b7, branchiostegal ; s.cl, supra-clavicular; p.cl, post- 
clavicular ; cl, clavicle; 7.cl, infra-clavicular. 


from this sub-order, upwards in the series, will be found to exist 
throughout the remaining forms of fishes. They are bones, 
the origin of which is not in cartilage but Im membranous 
connective tissue. The lower surface of the skull is covered 
by an extremely large basal bone, which extends from the 
vomerine region on to the anterior part of the spinal column. 
The nasal excavation in the skull is rather lateral than inferior. 
The ethmoidal region is generally much produced, forming 


76 FISHES. 


the base of the long projecting snout. The suspensorium is 
movably attached to the side of the skull, and consists of 
two pieces, a hyomandibular and a symplectic, which now 
appears for the first time as a separate piece, and to which 
the hyoid is attached. The palato-maxillary apparatus is 
more complex than in the Sharks and Dipnoi; a_palato- 
pterygoid consists of two mesially-connected rami in Polyodon, 
and of a complex cartilaginous disk in Acipenser, being arti- 
culated in both to the Meckelian cartilage. In addition, the 
Sturgeons possess one or two pairs of osseous rods, which, in 
Polyodon at least, represent the maxillary, and therefore must 
be the representatives of the labial cartilages of the Sharks. 
The Meckelian cartilage is more or less covered by tegu- 
mentary bones. 

In the gill-cover, besides the operculum, a sub- and inter- 
operculum may be distinguished in 
Acipenser. 

The hyoid consists of three pieces, 
of which the posterior bears a broad 
branchiostegal in Polyodon. 

In the scapulary arch the primordial 
cartilaginous elements scarcely differ 
from those of the Dipnoit. The mem- 
brane-bones are much expanded, and 
offer a continuous series suspended from 
the skull. Their division in the median 
ventral line is complete. 


The pectoral is supported by a car- 
tilaginous framework (Fig. 38) similar 
to that of Ceratodus, but much more 


Fig. 38.—Fore-limb of 
Acipenser. 


shortened and reduced in its periphery, 
the branches being absent altogether on one side of the axis. 
This modification of the fin is analogous to the heterocercal 
condition of the end of the spinous column. To the inner 


SKELETON OF POLYPTERUS. WT 


corner of a basal cartilage (a) a short axis (6) is joined, 
which on its outer side bears a few branches (d) only, the 
remaining branches (c) being fixed to the basal cartilage. 
The dermal fin-rays are opposed to the extremities of the 
branches, as in the Dzpnoz. 

The pubic consists of a paired cartilage, to which tarsal 
pieces supporting the fin-rays are attached. 

The other living Ganoid fishes have the spinous column 
entirely or nearly entirely ossified, and have been comprised 
under the common name Holoste:. However, they form three 
very distinct types; several attempts have been made to 
coordinate with them the fossil forms, but this task is beset 
with extreme difficulties, and its solution hitherto has not 
proved to be satisfactory. 

The Polypteroidei have their spinous column formed by dis- 
tinct osseous amphicelous vertebye, that is, vertebree with 
concave anterior and posterior surfaces. It is nearly diphy- 
cercal; a slight degree of heterocercy obtains, inasmuch as 
the last vertebra is sueceeded by a very thin cartilaginous 
filament which penetrates between the halves of one of the 
middle rays of the terminal fin. The rays above this cartila- 
ginous filament are articulated to interneurals, those below | 
lack interheemals, and are attached either to the hemals or 
vertebral centres. The neural arches, though ossified, do not 
coalesce with the centrum, and form one canal only, for the 
myelon. There are no intermediate elements between the 
neural spines. Interneurals developed, but simple, articulat- 
ing with the dermoneurals. The abdominal vertebre have 
parapophyses developed with epipleural spines. Only the 
caudal vertebrae have heemal spines, which, like the inter- 
hemals, agree in every essential respect with the opposite 
neurals. ibs are inserted, not on the parapophyses, but on 
the centre, immediately below the parapophyses. 

The skull of Polypterus (Fig. 39) shows a great advance 


78 FISHES. 


towards the Teleosteous type, the number of separable bones 


“Fig. 39.—Skull of Polypterus. (After Traquair. ) 


Fig. I. Upper aspect of the Primordial Cranium, with the membrane-bones 
removed. Fig. II. Lower aspect of the same. Fig. III. Side view, with the 
membrane-bones. Fig. IV. Lower aspect of the Skull, part of the bones 
being removed on one side, The parts shaded with oblique lines are cartilage 
of the primordial skull. 

An, Angular; ao, anteorbital; Az, articulary ; B, basal; D, dentary; £, 


ee ee ee ee 


a 


SKELETON OF POLYPTERUS. 79 


ethmoid ; F, frontal ; Ma, mastoid; Mp, metapterygoid; Mz, maxillary ; 
N, nasal; O, operculum ; 0c, occipital ; Pa, parietal; P/, palatine; Pma, 
premaxillary ; po, postorbital; Prf, prefrontal ; Pt, post-temporals ; Pé/, 
postfrontal ; Ptr, pterygoid; Q, quadrate ; S, suspensorium ; So, suboper- 
+ culum; Sp, sphenoid; Spl, splenial; S¢, supratemporals; 7’, tympanic 
lamina; 7’, turbinal; v, vomer; x x, small ossicles ; x x’, spiraculars. 


being greatly increased. They are arranged much in the same 
fashion as in Teleostei. But a great portion of the primordial 
cranium remains cartilaginous. The membrane-bones which 
cover the upperand lowersurfaces of the brain-case are so much 
developed as to cause the underlying cartilage to disappear, 
so that a large vacuity or fontanelle exists in the substance 
of the upper as well as lower cartilaginous wall. Of ossifica- 
tions belonging to the primordial skull must be noticed the 
single occipital with a mastoid on each side. They are sepa- 
rated by persistent cartilage from the sphenoids and _post- 
frontals ; the former, which are the largest ossification of the 
primordial cranium, enclose the anterior half of the brain 
cavity. Finally, the nasal portion contains a median ethmoid 
and a pair of preefrontal bones. 

Only a very small portion of the bones described are 
visible externally, nearly the whole of the primordial cranium 
being covered by the membrane-bones. Of these are seen on 
the upper surface a pair of parietals, frontals, “nasals,” and 
turbinals ; on the lower surface a large cross-shaped basal, 
anteriorly bordered on each side by a pterygoid, parallel to a 
palatine which forms a suture with the double vomer. The 
suspensorium has in front a metapterygoid and quadrate 
bone, and an operculum and suboperculum are attached to it 
behind. 

Premaxillaries and maxillaries are now fully developed, 
but immovably attached to the skull. The lower jaw is ossi- 
fied, and consists of an articulary, angular, dentary, and 
splenial. Of labial cartilages a rudiment at the angle of the 
mouth has remained persistent. 


80 FISHES. 


The side of the skull, in front of the operculum, is covered 
by a large irregularly-shaped bone (7') (corresponding to the 
“tympanic lamina” of Ceratodus, Fig. 35, ¢), held by some to 
be the praoperculum; along its upper circumference les a 
series of small ossicles, of which two may be distinguished 
as spiraculars, as they form a valve for the protection of the 
spiracular orifice of these fishes. An infraorbital ring is repre- 
sented by a pree- and post-orbital only. 

Each hyoid consists of three pieces, none of which bear 
branchiostegals, the single median piece being osseous in front 
and cartilaginous behind. Four branchial arches are developed, 
the foremost consisting of three, the second and third of two, 
and the last of a single piece. There is no lower pharyngeal. 
Between the rami of the lower jaw the throat is protected by 
a pair of large osseous laminee (yular plates), which have been 
considered to represent the urohyal of osseous fishes. 

The scapulary arch is almost entirely formed by the well- 
developed membrane-bones, which in the ventral line are 
suturally united. The pectoral fin is supported by three 
bones, pro-, meso-, and metapterygium, of which the dilated 
middle one alone bears rays, and is excluded from the articu- 
lation with the shoulder-girdle. 

The pubic consists of paired bone, to which tarsal bones 
supporting the fin-rays are attached. 

In the Lepidosteoidet the vertebrae are completely ossified, 
and opisthocelous, having a convexity in front and a concavity 
behind, as in some Amphibians. Though the end of the body 
externally appears nearly diphycercal, the termination of the 
vertebral column is, in fact, distinctly heterocercal (Fig. 40). 
Its extremity remains cartilaginous, is turned upwards, and lies 
immediately below the scutes which cover the upper margin 
of the caudal fin. It is preceded by a few rudimentary verte- 
bree which gradually pass into the fully developed normal 
vertebre. The caudal fin is suspended from hzemapophyses 


re 


SKELETON OF LEPIDOSTEUS. 81 


only, and does not extend to the neural side of the vertebral 


Fig. 40.—Heterocercal Tail of Lepidosteus. 


nm, Vertebral column ; , hemal spines ; dn, fulera ; dh, lower fulcra. 


column. The neural arches coalesce with the centrum ; inter- 
neurals simple. The abdominal vertebree have parapophyses, 
to which the ribs are attached. Only the caudal vertebre 
have heemal spines. 

In the skull of ZLepidosteus the cartilage of the endo- 
cranium is still more replaced by ossifications than in Polyp- 
terus ; those ossifications, moreover, being represented by a 
greater number of discrete bones; especially the membrane- 
bones are greatly multiplied: the occipital, for instance, con- 
sists of three pieces; the vomer is double as in Polypterus ; 
the maxillary consists of a series of pieces firmly united by 
suture. The symplectic reaches the lower jaw, so that the arti- 
culary is provided with a double joint, viz. for the symplectic 
and quadrate ; the component parts of the lower jaw are as 
numerous as in reptiles, a dentary, splenial, articulary, angular, 
supra-angular, and coronary being distinct. The sides of the 
head are covered with numerous bones, and a preoperculum 
is developed in front of the gill-cover which, again, consists of 
an operculum and suboperculum. 

Each hyoid consists of three pieces, of which the middle 
is the longest, the upper bearing the largest of the three 

G 


82 . FISHES. 


branchiostegals which Lepidosteus possesses ; a long and large 
elossohyal is intercalated between the lower ends of the 
hyoids. There are five branchial arches, the hindmost of 
which is modified into a lower pharyngeal; upper pharyn- 
geals are likewise present as in the majority of Teleosteous 
fishes. No gular plate. 

Of the scapulary arch the two halves are separated by a 
suture in the median line; the membrane-bones are well 
developed, only a remnant of the primordial cartilage remain- 
ing; the supraclavicle is very similar to that of Teleosteous 
fishes, less so the post-temporal. The base to which the 
limb is attached is a single osseous plate, supporting on its 
posterior margin semi-ossified rods in small number, which 
bear the pectoral rays. 

The pubic consists of paired bone, the anterior ends of which 
overlap each other, the extremity of the right pubis being 
dorsad to that of the left. The elements representing a 
tarsus are quite rudimentary and reduced in number (two 
or three). 

The vertebral column of the Amioider shows unmistak- 
able characters of the Paleeichthyie type. The arrangement 
of its component parts is extremely simple. The centra of 
the amphiccelous vertebre are well ossified, but the neural 
and hemal arches do not coalesce with the centra, from which 
they are separated by a thin layer of cartilage. Singularly, 
not every vertebra has apophyses: in the caudal portion of 
Amia the vertebrae are alternately provided with them and 
lack them. The heterocereal condition of the spinous column 
is well marked: as in the other Holostei the hindmost 
vertebrae are turned upwards, become smaller and smaller in 
size, and lose their neural arches, the hemals remaining 
developed to the end. Finally, the column terminates in a 
thin cartilaginous band, which is received between the lateral 
halves of the fifth or sixth upper caudal ray. Interneurals 


SKELETON OF TELEOSTEI. 83 


and interhemals simple. Only the abdominal vertebra have 
parapophyses, with which the ribs are articulated. 

The configuration of the skull, and the development and 
arrangement of its component parts, approaches so much the 
Teleosteous type that, perhaps, there are greater differences in 
skulls of truly Teleosteous fishes than between the skulls of 
Amia and many Physostomi. Externally the cranium is 
entirely ossified ; and the remains of the cartilaginous primor- 
dial cranium (which, however, has no vacuity in its roof) can 
only be seen in a section, and are of much less extent than 
in many Physostomous fishes. The immovable intermaxillary, 
the double vomer, the plurality of ossifications representing 
the articulary, the double articulary cavity of the mandible 
for junction with the quadrate and symplectic bones, remind 
us still of similar conditions in the skull of Lepidosteus, but 
the mobility and formation of the maxillary, the arrange- 
ment of the gill-covers, the development of the opercles, 
the suspensorium, the palate, the insertion of a number of 
branchiostegals on the long middle hyoid piece, the composi- 
tion of the branchial framework (with upper and lower 
pharyngeals), are as in the Teleosteous type. A gular plate 
replaces the urohyal. 

The scapular arch is composed entirely of the membrane- 
bones found in the Teleostei, and the two sides are loosely 
united by ligament. The base to which the limb is attached 
is cartilaginous ; short semi-ossified rods are arranged along 
its hinder margin and bear the pectoral rays. 

The skeleton of the hind-limb agrees entirely with that 
of Lepidosteus. 

[T. W. Bridge, The Cranial Osteology of Amia calva ; in Journ. Anat. 
and Physiol. vol. xi.] 

In the Teleosteous fishes the spinous column consists of 
completely ossified amphiccelous vertebre ; its termination 
is homocercal—that is, the caudal fin appears to be more or 


84 FISHES. 


less symmetrical, the last vertebra occupying a central posi- 
tion in the base of the fin, and being coalesced with a flat 
osseous lamella, the hypural (Fig. 23,70), on the hind margin 
of which the fin-rays are fixed. The hypural is but a union 
of modified hemapophyses which are directed backwards, 
and the actual termination of the notochord is bent upwards, 
and lies along the upper edge of the hypural, hidden below 
the last rudimentary neural elements. In some Teleosteans, 
as the Salmonida, the last vertebree are conspicuously bent 
upwards : in fact, strictly speaking, this homocercal condition 
is but one of the various degrees of heterocercy, different from 
that of many Ganoids in this respect only, that the caudal fin 
itself has assumed a higher degree of symmetry. 

The neural and hemal arches generally coalesce with the 
centrum, but there are many exceptions, inasmuch as some 
portion of the arches of a species, or all of them, show the 
original division. 

The vertebree are generally united with one another by 
zygapophyses, and frequently similar additional articulations 
exist at the lower parts of the centra. Parapophyses and 
ribs are very general, but the latter are inserted on the centra 
and the base of the processes, and never on their extremities. 
The point of insertion of the rib, more especially on the 
anterior vertebra, may be still higher—viz. at the base of the 
neural arch, as in Cotylis and allied genera, and even on the 
top of the neurapophysis, as in Batrachus. 

There is a great amount of variation as regards the degree 
in which the primordial cranium persists ; it is always more 
or less replaced by bone; frequently it disappears entirely, 
but in some fishes, like the Salmonidea or Esocide, the earti- 
lage persists to the same or even to a greater extent than in 
the Ganoidei holostei. Added to the bones preformed in car- 
tilage are a great number of membrane-bones. The different 
kinds of these membrane-bones occur with greater or less 


SKELETON OF TELEOSTEI. 85 


constancy throughout this sub-class ; they often coalesce with, 
and are no more separable from, the neighbouring or under- 
lying cartilage-bones. All these bones have been topogra- 
phically enumerated in Chapter IV. 

Many attempts have been made to classify the bones of 
the Teleosteous skull, according to their supposed relation to 
each other, or with the view to demonstrate the unity of 
plan on which the skull has been built; but in all either 
the one or the other of the following two principles has been 
followed :— 

A. The “vertebral doctrine” starts from the undeniable 
fact that the skull is originally composed of several segments, 
each of which is merely the modification of a vertebra. The 
component parts of such a cranial segment are considered to 
be homologous to those of a vertebra. Three, four, or five 
cranial vertebree have been distinguished, all the various 
bones of the fully-developed and ossified skull being referred, 
without distinction as to their origin, to one or the other 
of those vertebral segments. The idea of the typical unity 
of the osseous framework of Vertebrates has been worked out 
with the greatest originality and knowledge of detail, by 
Owen, who demonstrates that the fish-skull is composed of 
Jour vertebre. 

The bones of the fish-skull are, according to him, primarily 
divisible into those of the newroskeleton, splanchnoskeleton, and 
dermoskeleton. 

The bones of the newro- or proper endo-skeleton are 
arranged in a series of four horizontally succeeding segments : 
the occipital, parietal, frontal, and nasal vertebra; each seg- 
ment consisting of an upper (neural) and a lower (hzemal) 
arch, with a common centre, and with diverging appendages. 

The neural arches of the four vertebre, in their succession 
from the occiput towards the snout, are :— 

1. Epencephalic arch, composed of the occipitals. 


86 FISHES. 


2. Mesencephalic arch, composed of basisphenoid, ali- 
sphenoid, parietal, and mastoid. 

3. Prosencephalie arch, composed of presphenoid, orbito- 
sphenoid, frontal, and postfrontal. 

4, Rhinencephalic arch, composed of vomer, prefrontal, and 
nasal. 

The hemal arches in the same order of succession are :-— 

1. Scapular or scapulo-coracoid arch, composed of supra- 
scapula, scapula, and coracoid ; its appendage consists of the 
ulna, radius and carpal. 

2. Hyoid or stylo-hyoid arch, composed of stylo-hyal, epi- 
hyal, ceratohyal, basihyal, glossohyal, and urohyal; its ap- 
pendage is the branchiostegals. 

3. Mandibular or tympano-mandibular arch, composed of 
epi-, meso-, pre-, and hypo-tympanic, and the bones of the 
lower jaw ; its appendage consists of the preeoperculum and 
the other opercles. 

4, Maxillary or palato-maxillary arch, composed of pala- 
tine, maxillary, and premaxillary ; its appendage consists of 
the pterygoid and entopterygoid. 

Parts of the splanchnoskeleton are held to be the ear-capsule 
or petrosal and the otolite, the eye-capsule or sclerotic, the 
nose-capsule or “ethmoid” and turbinal; the branchial 
arches. 

The bones of the dermoskeleton are the supratemporals, 
supraorbitals, suborbitals, and labials. 

B. In the second method of classifying the bones of the 
skull prominence is given to the facts of their different origin 
as ascertained by a study of their development. The parts 
developed from the primordial skull, or the cartilaginous case 
protecting the nervous centre are distinguished from those 
which enclose and support the commencement of the aliment- 
ary canal and the respiratory apparatus, and which, consisting 
of several arches, are comprised under the common name of 


SKELETON OF TELEOSTEI. 87 


visceral skeleton of the skull. Further, a distinction is made 
between the bones preformed in cartilage and those originat- 
ing in tegumentary or membranous tissue. It is admitted 
that the primordial cranium is a coalition of several segments, 
the number of which is determined by that of the visceral 
arches, these representing the hemal arclies of the vertebral 
column ; but the membrane-bones are excluded from a consi- 
deration of the vertebral division of the primordial skull, as 
elements originally independent of it, although these additions 
have entered into special relations to the cartilage-bones. 

With these views the bones of the Teleosteous skull are 
classified thus :— 

1. Cartilage-bones of the primordial skull_—The basi-occi- 
pital (5 in Figs. 23-26) has retained the form of a vertebral 
centrum; it is generally concave behind, the concavity contain- 
ing remains of the notochord ; rarely a rounded articulary head 
of the first vertebra fits into it, as in Symbranchus, and still 
more rarely it is provided with such an articulary head (F%stu- 
laria) ; frequently it shows two excavations on its inner surface 
for the reception of the saccus vestibuli. The exoccipitals (10) 
are situated on the side of the basi-occipital, and contribute the 
greater portion of the periphery of the foramen magnum ; 
frequently they articulate with the first vertebra, or meet in 
the upper median line, so as to exclude the supraoccipital 
from the foramen magnum. The supraoccipital (8) is interca- 
lated between the exoccipitals, and forms a most prominent 
part by the median crest, which sometimes extends far for- 
wards on the upper side of the skull, and offers attachment to 
the dorsal portion of the large lateral muscle of the trunk. 
When the interior portions of this bone remain cartilaginous, 
some part of the semicircular canals may be lodged in it. 

The region of the skull which succeeds the bones described 
encloses at least the greater portion of the labyrinth, and its 
component parts have been named with reference to it by 


88 FISHES. 


some anatomists.. The alisphenoids (11) (Prooticum) form 
sutures posteriorly with the basi- and ex-occipitals, and meet 
each other in the median line at the bottom of the cerebral 
cavity ; they contribute to the formation of a hollow in which 
the hypophysis cerebri and the saccus vasculosus are received ; 
in conjunction with the exoccipital it forms another hollow 
for the reception of the vestibulum; generally it is perforated 
by the Trigeminal and Facial nerves. The paroccipitals (9) 
(Epioticum) lodge a portion of the posterior vertical semi- 
circular canal, and form a projection of the skull on each side 
of the occipital crest, to which a terminal branch of the scapu- 
lar arch is attached. The Mastoid (12 + 15) (Opzisthoticum) 
occupies the postero-external projection of the head; it en- 
closes a part of the external semicircular canal; is generally 
coalesced with a membrane-bone, the superficial sguwamosal, 
which emits a process for the suspension of the scapular 
arch, and is frequently, as in the Perch, divided into two 
separate bones. 

The anterior portion of the skull varies greatly as regards 
form, which is chiefly dependent on the extent of the cerebral 
cavity ; if the latter is advanced far forwards, the lateral walls 
of the primordial cranium are protected by more developed 
ossifications than if the cerebral cavity is shortened by the 
presence of a wide and deep orbit. In the latter case parts 
which normally form the side of the skull are situated in 
front of the brain-case, between it and the orbit, and gener- 
ally reduced in extent, often replaced by membranes ; especi- 
ally the interorbital septum may be reduced to membrane. 
The most constant ossifications of this part of the skull are 
the orbitosphenoids (14), which join the upper anterior margin 
of the alisphenoids. They vary much with regard to their 
development —they are small in Gadoids; larger in the 
Perch, Pike, Salmonoids, Macrodon, and the Clupeoids; and 


1 As first proposed by Huxley. 


SKELETON OF TELEOSTEI. 89 


very large in Cyprinoids and Siluroids, in which they contri- 
bute to the formation of the side of the brain-case. The single 
Y-shaped Sphenoideum anterius (15) is as frequently absent 
as present; it forms the anterior margin of the fossa for the 
hypophysis. Finally, the post-frontal (4) belongs also to this 
group of cartilage-bones. 

The centre of the foremost part of the skull is occupied by 
the ethmoid (3), which shows great variations as regards its 
extent and the degree of ossification; it may extend back- 
wards into the interorbital septum, and reach the orbito- 
sphenoids, or may be confined to the extremity of the skull; 
it may remain entirely cartilaginous, or ossify into a lamina 
which separates the two orbits and encloses an anterior 
prolongation of the brain-case, along which the olfactory 
nerves pass: modifications occurring again in higher verte- 
brates. A paired ossification attached to the fore-part of the 
ethmoid is the prefrontals (2), which form the base of the 
nasal fossa. 

2. Membrane-bones attached to the primordial skull—To 
this group belong the parvetals (7) and frontals (1). The squa- 
mosal (12) has been mentioned above in connection with the 
mastoid. The swpraorbital is always small, and frequently 
absent. The lower surface of the skull is protected by the 
basisphenoid (parasphenoid) (6) and the vomer (16), both of 
which, especially the latter, may be armed with teeth." 

3. Cartilage bones of the alimentary portion of the visceral 
skeleton of the skull_—The suspensorium consists of three car- 
tilage-bones, and affords a base for the opercular apparatus as 
well as a point of attachment to the hyoid, whilst in front it 
is connected with the palato-pterygo-palatine arch. They 
are the hyomandibular (23), symplectic (31), and quadrate 


1 Stannius (pp. 60, 65) doubts the pure origin of these two bones from 
membranous tissue, and is inclined to consider them as ‘‘ the extreme end of 
the abortive axial system,” 


90 FISHES. 


(26), connected by means of the metapterygoid (27) with the 
ecto- (24) and ento-pterygoid (25), the foremost bone of the 
arch being the palatine (22). All these bones have been 
sufficiently described above (p. 55), and it remains only to be 
mentioned that the bones of the palatine arch are but rarely 
absent, as for instance in Murenophis ; and that the sym- 
plectic does not extend to the articulary of the mandible, as 
in Amia and Lepidosteus, though its suspensory relation to the 
Meckelian cartilage is still indicated by a ligament which 
connects the two pieces. Of the mandibulary bones the 
articulary (35) is distinctly part of Meckel’s cartilage. Fre- 
quently another portion of cartilage below the articulary 
remains persistent, or is replaced by a separate membrane- 
bone, the angular. 

4, Membrane-bones of the alimentary portion of the visceral 
skeleton of the skull—The suspensorium has one tegumentary 
bone attached to it, viz. the prwoperculum (30); it is but 
rarely absent, for instance in Murenophis. The premaail- 
lary (17) and maxillary (18) of the Teleostei appear to be 
also membrane-bones, although they are clearly analogous 
to the upper labial cartilages of the Sharks. The pre- 
maxillaries sometimes coalesce into a single piece (as in 
Diodon, Mormyrus), or they are firmly united with the 
maxillaries (as in all Gymnodonts, Serrasalmo, ete.) The 
relative position and connection of these two bones differs 
much, and is a valuable character in the discrimination of 
the various families. In some, the front margin of the jaw is 
formed by the premaxillary only, the two bones having a 
parallel position, as it has been described in the Perch (p. 
53); in others, the premaxillary is shortened, allowing the 
maxillary to enter, and to complete, the margin of the upper 
jaw; and finally, in many no part of the maxillary is situated 
behind the premaxillary, but the entire bone is attached to 
the end of the premaxillary, forming its continuation. In 


SKELETON OF TELEOSTEI. 91 


the last case the maxillary may be quite abortive. The 
mobility of the upper jaw is greatest in those fishes in which 
the premaxillary alone forms its margin. The form of the 
premaxillary is subject to great variation : the beak of Belone, 
Awphias is formed by the prolonged and coalesced premaxil- 
laries. The maxillary consists sometimes of one piece, some- 
times of two or three. The principal membrane-bone of the 
mandible is the dentary (54), to which is added the angular 
(86) and rarely a smaller one, the splenial or os operculare, 
which is situated at the inside of the articulary. 

5. Cartilage-bones of the respiratory portion of the visceral 
skeleton of the skull_—W ith few exceptions all the ossifications 
of the hyoid and branchial arches, as described above (p. 58), 
belong to this group. 

6. Membrane-bones of the respiratory portion of the visceral 
skeleton of the skull——They are the following: the opercular 
pieces, viz. operculum (28), suboperculum (32), and interoper- 
culum (33). The last of these is the least constant; it may 
be entirely absent, and represented by a ligament extending 
from the mandible to the hyoid. The wrohyal (42) which 
separates the musculi sternohyoidei, and serves for an in- 
creased surface of their insertion; and finally the branchio- 
stegals (43), which vary greatly in number, but are always 
fixed to the cerato- and epi-hyals. 

7. Dermal bones of the skull—tTo this category are referred 
some bones which are ossifications of, and belong to, the 
cutis. They are the turbinals (20), the suborbitals (19), and 
the supratemporals. They vary much with regard to the 
degree in which they are developed, and are rarely entirely 
absent. Nearly always they are wholly or partly transformed 
into tubes or hollows, in which the muciferous canals with 
their numerous nerves are lodged. Those in the temporal 
and scapulary regions are not always developed; on the 
other hand, the series of those ossicles may be continued on 


92 FISHES. 


to the trunk, accompanying the lateral line. In many fishes 
those of the infraorbital ring are much dilated, protecting the 
entire space between the orbit and the rim of the preeoper- 
culum; in others, especially those which have the angle of 
the przoperculum armed with a powerful spine, the infra- 
orbital ring emits a process towards the spine, which thus serves 
as a stay or support of this weapon (Scorpenida, Cottide). 
The pectoral arch of the Teleosteous fishes exhibits but a 
remnant of a primordial cartilage, which is replaced by two 
ossifications,t the coracoid (51) and scapula (52); they offer 
posteriorly attachment to two series of short rods, of which 
the proximal are nearly always ossified, whilst the distal 
frequently remain small cartilaginous nodules hidden in the 
base of the pectoral rays. The bones, by which this portion 
is connected with the skull, are membrane-bones, viz. the 
clavicle (49), with the postclavicle (49 +50), the supraclavicle 
(47), and post-temporal (46). The order of their arrangement 
in the Perch has been described above (p. 59). However, 
many Teleosteous fish lack pectoral fins, and in them the 
pectoral arch is frequently more or less reduced or rudi- 
mentary, as in many species of Murenide. In others the 
membrane-bones are exceedingly strong, contributing to the 
outer protective armour of the fish, and then the clavicles 
are generally suturally connected in the median line. The 
postclavicula and the supraclavicula may be absent. Only 
exceptionally the shoulder-girdle is not suspended from the 
skull, but from the anterior portion of the spinous column 
(Symbranchide, Murenide, Notacanthide). The number of 
basal elements of each of the two series never exceeds five, 
but may be less; and the distal series is absent in Siluroids. 
The pubic bones of the Teleosteous fishes undergo many 
modifications of form in the various families, but they are 
essentially of the same simple type as in the Perch. 


, Parker’s nomenclature is adopted here. 


CHAPTER V. 
MYOLOGY. 


In the lowest vertebrate, Branchiostoma, the whole of the 
muscular mass is arranged in a longitudinal band running 
along each side of the body; it is vertically divided into 
a number of flakes or segments (myocommas) by aponeu- 
rotic septa, which serve as the surfaces of insertion to the 
muscular fibres. But this muscular band has no connection 
with the notochord except in its foremost portion, where 
some relation has been formed to the visceral skeleton. A 
very thin muscular layer covers the abdomen. 

Also in the Cyclostomes the greatest portion of the mus- 
cular system is without direct relation to the skeleton, and, 
again, it is only on the skull and visceral skeleton where 
distinct muscles have been differentiated for special functions. 

To the development of the skeleton in the more highly 
organised fishes corresponds a similar development of the 
muscles; and the maxillary and branchial apparatus, the 
pectoral and ventral fins, the vertical fins, and especially the 
caudal, possess a separate system of muscles. But the most 
noteworthy is the muscle covering the sides of the trunk 
and tail (already noticed in Branchiostoma), which Cuvier 
described as the “great lateral muscle,” and which, in the 
higher fishes, is a compound of many smaller segments, cor- 
responding in number with the vertebre. Each lateral 
muscle is divided by a median longitudinal groove into a 
dorsal and ventral half; the depression in its middle is 


94 FISHES. 


filled by an embryonal muscular substance which contains 
a large quantity of fat and blood-vessels, and therefore 
differs from ordinary muscle by its softer consistency, and 
by its colour which is reddish or grayish. Superficially the 
lateral muscle appears crossed by a number of white parallel 
tendinous zigzag stripes, forming generally three angles, of 
which the upper and lower point backwards, the middle one 
forwards. These are the outer edges of the aponeurotic septa 
between the myocommas. Each septum is attached to 
the middle and the apophyses of a vertebra, and, in the 
abdominal region, to its rib; frequently the septa receive 
additional support by the existence of epipleural spines. The 
fibres of each myocomma run straight and nearly horizontally 
from one septum to the next; they are grouped so as to form 
semiconical masses, of which the upper and lower have their 
apices turned backwards, whilst the middle cone, formed by 
the contiguous parts of the preceding, has its apex directed 
forward; this fits into the interspace between the antecedent 
upper and lower cones, the apices of which reciprocally enter 
the depressions in the succeeding segment, whereby all the 
seoments are firmly locked together (Owen). 

In connection with the muscles reference has to be made 
to the Electric organs with which certain fishes are provided, 
as it is more than probable, not only from the examination of 
peculiar muscular organs occurring in the Rays, Mormyrus, 
and Gymnarchus (the function of which is still conjectural), 
but especially from the researches into the development of 
the electric organ of Torpedo, that the electric organs have 
been developed out of muscular substance. The fishes 
possessing fully developed electric organs, with the power of 
accumulating electric force and communicating it in the 
form of shocks to other animals, are the electric Rays 
(Torpedinide), the electric Sheath-fish of tropical Africa 
(Malapterurus), and the electric Eel of tropical America 


ELECTRIC ORGANS. 95 


(Gymnotus). The structure and. arrangement of the electric 
organ is very different in these fishes, and will be subsequently 
described in the special account of the several species. 

The phenomena attending the exercise of this extraordi- 
nary faculty also closely resemble muscular action. The time 
and strength of the discharge are entirely under the control 
of the fish. The power is exhausted after some time, and it 
needs repose and nourishment to restore it. If the electric 
nerves are cut and divided from the brain the cerebral action 
is interrupted, and no irritant to the body has any effect to 
excite electric discharge; but if their ends be irritated the 
discharge takes place, just as a muscle is excited to contraction 
under similar circumstances. And, singularly enough, the 
application of strychnine causes simultaneously a tetanic state 
of the muscles and a rapid succession of involuntary electric 
discharges. The strength of the discharges depends entirely on 
the size, health, and energy of the fish : an observation entirely 
agreeing with that made on the efficacy of snake-poison. Like 
this latter, the property of the electric force serves two ends 
in the economy of the animals which are endowed with it; 
it is essential and necessary to them for overpowering, stun- 
ning, or killing the creatures on which they feed, whilst 
incidentally they use it as the means of defending themselves 
from their enemies. 


CHAPTER VI. 
NEUROLOGY. 


THE most simple condition of the nervous central organ 
known in Vertebrates is found in Branchiostoma. In this 
fish the spinal chord tapers at both ends, an anterior cerebral 
swelling, or anything approaching a brain, being absent. It 
is band-hke along its middle third, and groups of darker 
cells mark the origins of the fifty or sixty pairs of nerves 
which accompany the intermuscular septa, and divide into 
a dorsal and ventral branch, as in other fishes. The two 
anterior pairs pass to the membranous parts above the mouth, 
and supply with nerve filaments a ciliated depression near 
the extremity of the fish, which is considered to be an 
olfactory organ, and two pigment spots, the rudiments of 
eyes. An auditory organ is absent. 

The spinal chord of the Cyclostomes is flattened in its 
whole extent, band-like, and elastic; also in Chimera it is 
elastic, but flattened in its posterior portion only. In all 
other fishes it is cylindrical, non-ductile, and generally ex- 
tending along the whole length of the spinal canal. The 
Plectognaths offer a singular exception in this respect that 
the spinal chord is much shortened, the posterior portion of 
the canal being occupied by a long cauda equina ; this shorten- 
ing of the spinal chord has become extreme in the Sun-fish 
(Orthagoriscus), 12 which it has shrunk into a short and 
conical appendage of the brain. Also in the Devil-fish 
(Lophius) a long cauda equina partly conceals the chord which 
terminates on the level of about the twelfth vertebra. 


BRAIN. 97 


The brain of fishes is relatively small; in the Burbot 
(Lota) it has been estimated to be 7g pth part of the weight 
of the entire fish, in the Pike the ;s3'p5th part, and in the 
large Sharks it is relatively still smaller. It never fills the 
entire cavity of the cranium; between the dura mater which 
adheres to the inner surface of the cranial cavity, and the 
arachnoidea which envelops the brain, a more or less con- 
siderable space remains, which is filled with a soft gelatinous 
mass generally containing a large quantity of fat. It has 
been observed that this space is much less in young specimens 
than in adult, which proves that the brain of fishes does not 
erow in the same proportion as the rest of the body; and, 
indeed, its size is nearly the same in individuals of which one 
is double the bulk of the other. 

The brain of Osseous fishes (Fig.41) viewed from above shows 
three protuberances, respectively termed prosencephalon, mes- 
encephalon, and metencephalon, the two anterior of which are 
paired, the hindmost being single. The foremost pair are the 
hemispheres, which are solid in their interior, and provided 
with two swellings in front, the olfactory lobes. The second 
pair are the optic lobes, which generally are larger than the 
hemispheres, and succeeded by the third single portion, the 


Fig. 41.—Brain of Perch. 
I. Upper aspect. II. Lower aspect. 
a, cerebellum ; b, optic lobes ; c, hemispheres ; ¢, lobi inferiores ; /, hypophysis ; 
g, lobi posteriores ; 7, Olfactory lobes ; n, NV. opticus; 0, NV. olfactorius ; 
p, N. oculo-motorius ; g, NV. trochlearis ; 7, NV. trigeminus ; s, JV. acusticus ; 
t, NV. vagus ; wu, NV. abducens ; v, Fourth ventricle. 


cerebellum. In the fresh state the hemispheres are of a grayish 
colour, and often show some shallow depressions on their 
H 


98 FISHES. 


surface; a narrow commissure of white colour connects them 
with each other. The optic lobes possess a cavity (ventriculus 
lobioptict), atthe bottom of which some protuberances of variable 
development represent the corpora quadrigemina of higher 
anunals. On the lower surface of the base of the optic lobes, 
behind the erura cerebri, two swellings are observed, the lobe 
inferiores, which slightly diverge in front for the passage of 
the infundibulum, from which a generally large hypophysis or 
pituitary gland is suspended. The relative size of the cere- 
bellum varies greatly in the different osseous fishes: in the 
Tunny and Silurus it is so large as nearly to cover the optic 
lobes; sometimes distinct transverse grooves and a median 
longitudinal groove are visible. The cerebellum possesses in 
its interior a cavity which communicates with the anterior 
part of the fourth ventricle. The medulla oblongata is broader 
than the spinal chord, and contains the fourth ventricle, which 
forms the continuation of the central canal of the spinal 
chord. In most fishes a perfect roof is formed over the 
fourth ventricle by two longitudinal pads, which meet each 
other in the median line (obi posteriores), and but rarely it 
remains open along its upper surface. 

The brain of Ganoid fishes shows great similarity to that 
of the Teleostei; however, there is considerable diversity 
of the arrangement of its various portions in the different 
types. In the Sturgeons and Polypterus (Fig. 42) the hemi- 
spheres are more or less remote from the mesencephalon, so 
that in an upper view the crura cerebri, with the intermediate 
entrance into the third ventricle (fisswra cerebri magna), may be 
seen. A vascular membranous sac, containing lymphatic fluid 
(epiphysis), takes its origin from the third ventricle, its base 
being expanded over the anterior interspace of the optic lobes, 
and the apex being fixed to the cartilaginous roof of the 
cranium. This structure is not pecuhar to the Ganoids, but 
found in various stages of development in Teleosteans, mark- 


BRAIN. 99 


ing, when present, the boundary between prosencephalon and 
mesencephalon. The lobi optici are essentially as in Tele- 
osteans. The cerebellum penetrates into the ventriculus 
lobi optici, and extends thence into the open sinus rhomboid- 
alis. At its upper surface it is crossed by a commissure 
formed by the corpora restiformia of the medulla. 


Fig. 42.—Brain of Polypterus. (After Miiller.) 
I., Upper; II., Lateral ; III., Lower aspect. 


a, Medulla ; 0, corpora restiformia ; ¢, cerebellum ; d, lobi optici; e, hypophysis ; 

f, fissura cerebri magna; g, nervus opticus; g’, chiasma; h, hemispheres ; 

Z, lobus olfactorius ; %, sinus rhomboidalis (fourth ventricle). 

As regards external configuration, the brain of Lepidosteus 
and Amia approach still more the Teleosteous type. The 
prosencephalon, mesencephalon, and metencephalon are con- 
tiguous, and the cerebellum lacks the prominent transverse 
commissure at its upper surface. The sinus rhomboidalis is 
open. 

The brain of the Dipnoi shows characters reminding us 
of that of the Ganoids as well as the Chondropterygians, 
Ceratodus agreeing with Protopterus in this respect, as im 

; 


100 FISHES. 


most other points of its organisation. The hemispheres 
form the largest part of the brain; they are coalescent, as in 
Sharks, but possess two lateral ventricles, the separation being 
externally indicated by a shallow median groove on the upper 
surface. The olfactory lobes take their origin from the upper 
anterior end of the hemispheres. Epiphysis and hypophysis 
well developed. The lobi optici are very small, and remote 
from the prosencephalon, their division into the lateral halves 
being indicated by a median groove only. The cerebellum is 
very small, overlying the front part of the sinus rhomboidalis. 

The brain of Chondropterygians (Fig. 45) is more developed 
than that of all other fishes, and distinguished by well-marked 
characters. These are, first, the prolongation of the olfactory 
lobes into more or less long pedicles, which dilate into great 
ganglionic masses, where they come into contact with the 
olfactory sacs ; secondly, the space which generally intervenes 
between prosencephalon 
and mesencephalon, as in 
some Ganoids; thirdly, 
the large development of 
the metencephalon. 

The hemispheres are 


cenerally large, coalescent, 
Fig. 43.—Brain of Carcharias. (After Owen.) ; f : 
but with a median, longi- 
ac, Nerv. acusticus ; 0, corpus restiforme ; c, ae ty ete 

cerebellum ; d, lobus opticus; e, hypo- tudinal, dividing groove. 


physis; g, nervus opticus; f, hemi- Frequently their surface 
sphere ; 7, lobus olfactorius ; 2’, olfactory = 
pedicle ; , nerv. olfactorius ; 7, epiphysis ; 
m, nerv. oculo-motorius ; #7, nervy. trige- and when they are pro- 
minus ; v, nerv. vagus. 


shows traces of gyrations, 


vided with lateral vent- 
ricles, tubercles representing corpora striata may be ob- 
served. The olfactory pedicles take their origin from the 
side of the hemispheres, and are frequently hollow, and 
if so, their cavity communicates with the ventricle of the 
hemisphere. The optic lobes are generally smaller than the 


BRAIN. 101 


hemispheres, coalescent, and provided with an upper median 
eroove like the prosencephalon. At their base a pair of lobi 
inferiores are constant, with the hypophysis and saccus vascu- 
losus (a conglomeration of vascular loops without medullary 
substance) between them. 

The cerebellum is very large, overlying a portion of the 
optic lobes and of the sinus rhomboidalis, and is frequently 
transversely grooved. The side-walls of the fourth ventricle, 
which are formed by the corpora restiformia, are singularly 
folded, and appear as two pads, one on each side of the cere- 
bellum (lobi posteriores s. lobi nervi trigemine). 

The brain of the Cyclostomes (Figs. 44, 45) represents a type 
different from that of other fishes, showing at its upper surface 


Fig. 44.—Brain of Bdellostoma, (Enlarged, after Miiller.) 
I., Upper; II., Lower aspect. Letters as in Fig. 45. 
three pairs of protuberances in front of the cerebellum ; they 
are all solid. Their homologies are not yet satisfactorily deter- 
mined, parts of the Myxinoid brain having received by the 
same observers determinations very different from those given 


102 FISHES. 


to the corresponding parts of the brain of the Lampreys. The 


/ 
i 


ZZ EZ 


<A 
= 


// 


SS 


i\\\ 


4 


—\\\\ 


y/ 


Fig. 45.—Brain of Petromyzon. (Enlarged, after Miiller.) 
I., Upper ; II., Lower aspect. 

a, Medulla oblongata; ac, nerv. acusticus ; b, corpus restiforme or rudimentary 
cerebellum ; d, lobus ventriculi tertii; @’, entrance into the third ventricle ; 
e, hypophysis; fa, nervy. facialis; g, nerv. opticus; h, hemisphere; hy, 
nerv. hypoglossus (so named by Miiller); 7, lobus olfactorius; %, sinus 
thomboidalis ; 7, epiphysis; m, nerv. oculo-motorius; g, corpora quadri- 
gemina ; ¢7, nerv. trigeminus ; #70, nerv. trochlearis ; v, nerv. vagus. 


foremost pair are the large olfactory tubercles, which are 
exceedingly large in Petromyzon. They are followed by the 


BRAIN. 103 


hemispheres, with a single body wedged in between their 
posterior half; in Petromyzon, at least, the vascular tissue 
leading to an epiphysis seems to be connected with this body. 
Then follows the lobus ventriculi tertii, distinctly paired in 
Myxinoids, less so in Petromyzon. ‘The last pair are the 
corpora quadrigemina. According to this interpretation the 
cerebellum would be absent in Myxinoids, and represented in 
Petromyzon by a narrow commissure only (Fig. 45,0), stretching 
over the foremost part of the sinus rhomboidalis. In the 
Myxinoids the medulla oblongata ends in two divergent swell- 
ings, free and obtuse at their extremity, from which most of 
the cerebral nerves take their origin. 


The Nerves which supply the organs of the head are either 
merely continuations or diverticula of the brain-substance, or 
proper nerves taking their origin from the brain, or receiving 
their constituent parts from the foremost part of the spinal 
chord. The number of these spino-cerebral nerves is always 
less than in the higher vertebrates, and their arrangement 
varies considerably. 


A. Nerves which are diverticula of the brain (Figs. 41-45). 


The olfactory nerves (first pair) alwaysyretain their inti- 
mate relation to the hemispheres, the ventricles of which are 
not rarely continued into the tubercle or even pedicle of the 
nerves. The different position of the olfactory tubercle has 
been already described as characteristic of some of the orders 
of fishes. In those fishes in which the tubercle is remote 
from the brain, the nerve which has entered the tubercle as 
a single stem leaves it split up into several or numerous 
branches, which are distributed in the nasal organ. In the 
other fishes it breaks up into branchlets spread into a fan-like 
expansion at the point, where it enters the nasal cavity. The 
nerve always passes out of the skull through the ethmoid. 


104 FISHES. 


The optic nerves (second pair) vary in size, their strength 
corresponding to the size of the eye; they take their origin 
from the lobe optici, the development of which again is pro- 
portionate to that of the nerves. The mutual relation of the 
two nerves immediately after their origin is very character- 
istic of the sub-classes of fishes. In the Cyclostomes they have 
no further connection with each other, each going to the eye 
of its own side.t In the Teleostet they simply cross each other 
(decussate), so that the one starting from the right half of the 
brain goes to the left eye and vice versa. Finally, in Palawich- 
thyes the two nerves are fused together, immediately after 
their origin, into a chiasma. The nerve is cylindrical for 
some portion of its course, but in most fishes gradually changes 
this form into that of a plaited band, which is capable of 
separation and expansion. It enters the bulbus generally 
behind and above its axis. The foramen through which it 
leaves the skull of Teleostei is generally in a membranous 
portion of its anterior wall, or, where ossification has taken 
place, in the orbito-sphenoid. 


B. Nerves proper taking their origin from the brain 
(Figs. 41-45). 


‘ 

The Nervus oculorum motorius (third pair) takes its origin 
from the Pedunculus cerebri, close behind the lobi inferiores ; 
it escapes through the orbito-sphenoid, or the membrane 
replacing it, and is distributed to the musculi rectus superior, 
rectus internus, obliiquus inferior, and rectus inferior. Its 
size corresponds to the development of the muscles of the 
eye. Consequently it is absent in the blind Amblyopsis, and 
the Myxinoids. In JLepidosiren the nerves supplying the 
muscles of the eye have no independent origin, but are part 


1 According to Langerhans ‘* Untersuchungen iiber Petromyzon planeri” 
(Freiburg, 1873) an optic chiasma exists in that species. 


NERVES. 105 


of the ophthalmic division of the Trigeminus. In Petroimyzon 
these muscles are suppled partly from the Trigeminus, partly 
by a nerve representing the Oculo-motor and Trochlearis, 
which are fused into a common trunk. 

The Nervus trochlearis (fourth pair), if present with an 
independent origin, is always thin, taking its origin on the 
upper surface of the brain from the groove between lobus 
opticus and cerebellum; it goes to the Musculus obliquus 
superior of the eye. 


C. Nerves taking their origin from the Medulla oblongata 
(Figs. 41-45). 


The Nervus abducens (sixth pair) issues on the lower surface 
of the brain, taking its origin from the anterior pyramids of 
the Medulla oblongata, and supplies the Musculus rectus 
externus of the eye, and the muscle of the nictitating mem- 
brane of Sharks. 

The Nervus trigeminus ( fifth pair) and the Nervus facialis 
(seventh par) have their origins close together, and enter into 
intimate connection with each other. In the Chondroptery- 
gians and most Teleostei the number of their roots is four, in 
the Sturgeons five, and in a few Teleostei three. When there 
are four, the first issues immediately below the cerebellum 
from the side of the Medulla oblongata; it contains motory 
and sensory elements for the maxillary and suspensorial 
muscles, and belongs exclusively to the trigeminal nerve. The 
second root, which generally becomes free a little above the 
first, supplies especially the elements for the Ramus palatinus, 
which sometimes unites with parts of the Trigeminal, some- 
times with the Facialnerve. The third root, if present, is very 
small, and issues immediately in front of the acustic nerve, 
and supplies part of the motor elements of the facial nerve. 
The fourth root is much stronger, sometimes double, and its 


106 FISHES. 


elements pass again partly into the Trigeminal, partly mto the 
Facial nerve. On the passage of these stems through the 
skull (through a foramen or foramina in the alisphenoid) they 
form a ganglionic plexus, in which the palatine ramus and 
the first stem of the Trigeminus generally possess discrete 
ganglia. The branches which issue from the plexus and 
belong exclusively to the Trigeminus, supply the organs and 
integuments of the frontal, ophthalmic, and nasal regions, and 
the upper and lower jaws with their soft parts. The Facial 
nerve supplies the muscles of the gill-cover and suspensorium, 
and emits a strong branch accompanying the Meckelian car- 
tilage to the symphysis, and another for the hyoid apparatus. 

The Nervus acusticus (eighth pair) is strong, and takes its 
origin immediately behind, and in contact with, the last root 
of the seventh pair. 

The Nervus glosso-pharyngeus (ninth pair) takes its origin 
between the roots of the eighth and tenth nerves, and issues 
in Teleostei from the cranial cavity by a foramen of the 
exoccipital. In the Cyclostomes and Lepidosiren it is part 
of the Nervus vagus. It is distributed in the pharyngeal and 
lingual regions, one branch supplying the first branchial arch. 
After having left the cranial cavity it swells into a ganglion, 
which in Teleostei is always in communication with the 
sympathic nerve. 

The Nervus vagus or pneumogastricus (tenth pair) rises in 
all Teleostei and Palichthyes with two discrete strong roots : 
the first constantly from the swellings of the corpora resti- 
formia, be they thinner or thicker and overlying the sinus 
rhomboidalis, or be they developed into lateral plaited pads, 
as in Acipenser and Chondropterygians. The second much 
thicker root rises from the lower tracts of the medulla oblon- 
gata. Both stems leave the cranial cavity by a common fora- 


1 This nerve is not shown in the figure of the brain of the Perch (Fig. 41), 
as reproduced above from Cuvier. 


NERVES. 107 


men, situated in Teleosteous fishes in the exoccipital; and 
form ganglionic swellings, of which those of the lower stem 
are the more conspicuous. The lower stem has mixed elements, 
motory as well as sensory, and is distributed to the muscles 
of the branchial arches and pharynx, the cesophagus and 
stomach; it sends filaments to the heart and to the air- 
bladder where it exists. The first (upper) stem forms the 
Nervus lateralis, This nerve, which accompanies the lateral 
mucous system of the trunk and tail, is either a single longi- 
tudinal stem, gradually becoming thinner behind, running 
superficially below the skin (Salmonidie, Cyclopterus), or deeply 
between the muscles (Sharks, Chimeera), or divided into two 
parallel branches (most Teleostei): thus in the Perch there 
are two branches on each side, the superficial of which sup- 
plies the lateral line, whilst the deep-seated branch communi- 
cates with the spinal nerves and supplies the septa between 
the myocommas and the skin. In fishes which lack the lateral 
muciferous system and possess hard integuments, as the Ostra- 
cions, the lateral nerve is more or less rudimentary. It is 
entirely absent in Myxinoids, but the gastric branches of the 
Vagus are continued, united as a single nerve, along the intes- 
tine to the anus. 

No fish possesses a Wervus accessorius. Also a separate 
Nervus hypoglossus (twelfth pair)’ is absent, but elements 
from the first spimal nerve are distributed in the area 
normally supplied by this nerve in higher vertebrates. 


The number of Spinal nerves corresponds to that of the 
vertebrae, through or between which they pass out. Each 
nerve has two roots, an anterior and posterior, the former of 
which has no ganglion, and exclusively contains motor 
elements. The posterior or dorsal has a ganglionic enlarge- 


1 Miiller considers a nerve rising jointly with the Vagus in Petromyzon to 
be this nerve (Fig. 45, hy). 


108 FISHES. 


ment, and contains sensory elements only. After leaving the 
vertebral canal each spinal nerve usually divides into a 
dorsal and ventral branch. The Gadoids show that peculiarity 
that each of the posterior roots of some or many of the spinal 
nerves possesses two separate threads, each of which has a 
ganglion of its own; the one of these threads joins the dorsal 
and the other the ventral branch. In fishes in which the 
spinal chord is very short, as in Plectognaths, Lophius, the 
roots of the nerves are extremely long, forming a thick 
Cauda equina. The additional function which the (five) 
anterior spinal nerves of Z'rigla have to perform in supplying 
the sensitive pectoral appendages and their 
muscles has caused the development of a paired 
series of globular swellings of the corresponding 
portion of the spinal chord. A similar structure 
is found in Polynemus. 


A Sympathie nervous system appears to be 
Fig. 46. absent in Branchiostoma, and has not yet been 
Brain and an- clearly made out in Cyclostomes. It is well 


terior portion : f : 
of He spina) Ceveloped in the Palwichthyes, but’ without 


chordof Trig- cephalic portion. This latter is present in all 
la (Gurnard), 
showing the 
globularswel- Sympathic has been found to exist with all 
lings at the 
base of the 
anterior spi- acustic. The sympathic trunks run along each 
nal nerves. 


Osseous fishes, In which communication of the 
cerebral nerves, except the olfactory, optic, and 


side of the aorta and the back of the abdomen 
into the heemal canal; communicate in their course with the 
ventral branches of each of the spinal nerves; and, fihally, 
often blend together into a common trunk beneath the 
tail. At the points of communication with the cerebral and 
spinal nerves frequently gangha are developed, from which 
nerves emerge which are distributed to the various viscera. 


CHAPTER, VIE. 
THE ORGANS OF SENSE. 


CHARACTERISTIC of the Organ of Smell in Fishes is that it 
has no relation whatever to the respiratory function, with the 
exception of the Dipnot, in which possibly part of the water 
received for respiration passes through the nasal sac. 

The olfactory organ is single in Branchiostoma and the 
Cyclostomes. In the former a small depression on the front 
end of the body, clothed with a ciliated epithelium, is re- 
garded as a rudimentary organ of smell. In the adult 
Petromyzon a membranous tube leads from the single opening 
on the top of the head into the cartilaginous olfactory capsule, 
the inside of which is clothed by membranes prolonged into 
a posterior blind tube (Fig. 30, s), which penetrates the carti- 
laginous roof of the palate, but not the mucous membrane 
of the buccal cavity. In the Myxinoids the outer tube is 
strengthened by cartilaginous rings like a trachea; the capsule 
is lined by a longitudinally folded pituitary membrane, and 
the posterior tube opens backwards on the roof of the mouth ; 
the opening is provided with a valve. 

In all other Fishes the organ of smell is double, one being 
on each side; it consists of a sac lined with a pituitary 
membrane, and without, or with one or two, openings. The 
position of these openings is very different in the various 
orders or suborders of Fishes. 

In the Dipnoi the nasal sac opens downwards by two wide 
openings which are within the boundaries of the cavity of the 


110 FISHES. 


mouth. The pituitary membrane is transversely folded, the 
transverse folds being di- 
vided by one longitudinal 
fold. The walls of the sac 
are strengthened by sun- 
dry small cartilages. 

Also in Chondroptery- 
gians the openings, of 
which there is one to 
each sac, are on the lower 
part of the snout, and in 
the Rays, Holocephalh, and 
some Sharks, each ex- 


Fig. 47.—Nostrils of Raia lemprieri, with tends into the cleft of the 
nasal flaps reverted. 


mouth, The openings are 
protected by valvular flaps, supported by small cartilages, 
and moved by muscles, whence it may be concluded that 
these fishes are able to scent (actively) as well as to smell 
(passively). 

In the majority of TZeleostec the olfactory capsules are 
lateral or superior on the snout, covered externally by the 
skin, each usually pierced by two openings, which are either 
close together, or more or less remote from each other; the 
posterior is generally open, the anterior provided with a valve 
or tube. In the Chromides and Labroidei ctenoidec a single 
opening only exists for each sac. In the Murenide the two 
openings of each side are either superior, or lateral, or labial, 
that is, they are continued downwards and pierce the margin 
of the upper lip. In many Tetrodonts nasal openings are 
absent, and replaced by a conical papilla, in which the olfactory 
nerve terminates. 

It is certain that fishes possess the faculty of perceiving 
odours, and that various scents attract or repel them, A. 
mangled carcase or fresh blood attracts Sharks as well as the 


ORGAN OF SIGHT. Tat 


voracious Serrasal monoids of the South American rivers. 
There is no reason to doubt that the seat of that perception is 
in the olfactory sac; and it may be reasonably conjectured 
that its strength depends mainly on the degree of develop- 
ment indicated by the number and extent of the interior folds 
of the pituitary membrane. 

Organ of Sight—The position, direction, and dimensions 
of the eyes of fishes vary greatly. In some they have an 
upward aspect, and are often very close together; in others 
they are lateral, and in a few they are even directed down- 
wards. The Flat-fishes represent the extraordinary anomaly 
that both eyes are on the same side of the head, and rarely 
on the same level, one being generally placed more forward 
than the other. In certain species of marine fishes the eyes 
are of an extraordinary size, a peculiarity indicating that the 
fish either lives at a great depth, to which only a small pro- 
portion of the rays of light penetrate, or that it is of nocturnal 
habits. In fishes which have descended to such great depths 
that no rays whatever can reach them, or in fresh-water fishes 
living in caves, or in species which grovel and live constantly 
in mud, the eyes are more or less aborted, sometimes quite 
rudimentary, and covered by the skin. In very few this 
organ appears to be entirely absent. In some Gobioids and 
Trachinoids (Periophthalmus, Boleophthalmus, Uronoscopus, etc.) 
the eyes, which are on the upper side of the head, can be elevated 
and depressed at the will of the fish. In the range of their 
vision and acuteness of sight, Fishes are very inferior to the 
higher classes of Vertebrates, yet at the same time it is 
evident that they perceive their prey or approaching danger 
from a considerable distance; and it would appear that the 
visual powers of a Periophthalmus, when hunting insects on 
mud-flats of the tropical coasts, are quite equal to that of a 
frog. Again, the discrimination with which fishes sometimes 
prefer one colour or kind of artificial fly to another affords 


a2 FISHES. 


sufficient evidence that the vision, at least of certain species 
is by no means devoid of clearness and precision. 

The eye of Branchiostoma is of the most rudimentary con- 
dition. It is simply a minute speck coated by dark pigment, 
and receiving the end of a short nerve. In Myainoids the 
minute rudiment of the eye is covered by the skin and mus- 
cles. This is also the case in many of the blind Teleosteous 
fishes; however, whilst in the former fishes the organ of sight 
has not attained to any degree of development, the rudiment- 
ary eye of blind Teleostei is a retrogressive formation, in which 
often a lense and other portions of the eye can be recognised. 
In fishes with a well-developed eye it is imbedded in a layer 
of gelatinous and adipose substance, which covers the cavity of 
the orbit. A lacrymal gland is absent. In the orbit of one fish 
only, Chorismodentex, an organ has been found which can be 
compared toa saceus lacrymalis. It is a round, blind, wide 
sac, of the size of a pea, situated below the anterior corner of 
the orbit, between the maxillary bone and the muscles of the 
cheek, communicating by a rather wide foramen with the 
orbital cavity. The membrane by which it is formed is con- 
tinuous with that coating the orbita. In the Chondroptery- 
gians the eyeballis supported by and moves on a cartilaginous 
peduncle of the orbital wall. In the majority of Teleosteans, 
and in Acipenser, a fibrous ligament attaches the sclerotic to 
the wall of the orbit. The proper muscles of the eyeball 
exist in all fishes, and consist df the four Museuli rectt and the 
two JL. obliqui. In many Teleostei the former rise from a 
suberanial canal, the origin of the J/. rectus externus being 
prolonged farthest backwards. The fecti muscles are extra- 
ordinarily long in the Hammerheaded Sharks, in which they 
extend from the basis crani along the lateral prolongations 
of the head to the eyes, which are situated at the extremities 
of the hammer. 

In all fishes the general integument of the head passes 


ORGAN OF SIGHT. its 


over the eye, and becomes transparent where it enters the 
orbit; sometimes it simply passes over the orbit, sometimes 
it forms a circular fold. The anterior and posterior portions 
may be especially broad and the seat of an adipose deposit 
(adipose eyelids), as in Scomber, Caranx, Mugil, etc. In many 
of these fishes the extent of these eyelids varies with the 
seasons ; during the spawning season they are so much loaded 
with fat as nearly to hide the whole eye. Many Sharks pos- 
sess a nictitating membrane, developed from the lower part of 
the palpebral fold, and moved by a proper set of muscles. 
The form of the bulbus (Fig. 48) is subhemispherical, the 
cornea (co) being flat. If it were convex, as in higher Verte- 
brates, it would be more liable to injury; but being level with 
the side of the head the chances of injury by friction are dim- 
inished. The sclerotica(sc)is cartilaginousin Chondropterygians 
and Acipensers, fibrous and of varying thickness in oe 
in the majority of which it is supported 
by a pair of cartilaginous or ossified 
hemispheroid cups (c). In a few fishes, 
as in Ceratodus, Xiphias, the cups are 
confluent into one cup, which possesses 


a foramen behind to allow the passage 
of the optic nerve (0). The cornea of Fig. 48. 


Anableps shows an unique peculiarity. Vertical section through 
eye of Xiphias. (After 
Owen.) 
stripe of the conjunctiva, dividing it co, Cornea; sz, sclerotica ; 
0, nervus opticus; ¢, 
sclerotic capsule; 4, 
iris is perforated by two pupils. This fish membrana  argentea ; 
is observed to swim frequently with half membrana vasculosa ; 
uw, membrana uvea ; ch, 
of its head out of the water, and it is a choroid gland; 1, re- 
tina; jf, processus fal- 
Bens ciformis; h, humor 
well as in it. vitreus; 7, lens; 1, 
The membranes situated between is. 
the sclerotica and retina are collectively called choroidea, and 


I 


It is crossed by a dark horizontal 


into an upper and lower portion; also the 


fact that it can see out of the water as 


“ 


114 FISHES. 


three in number. The one in immediate contact with the 
sclerotic, and continued upon the iris, is by no means constantly 
present; it is the membrana argentea (a), and composed of 
microscopical crystals reflecting a silvery or sometimes golden 
lustre. The middle layer is the membrana vasculosa s. hallera 
(v), the chief seat of the ramifications of the choroid vessels ; 
the innermost layer is the membrana ruyscheana or wvea (w), 
which is composed of hexagonal pigment-cells, usually of a 
deep brown or black colour. 

In many Teleostei a rete mirabile surrounds the entry of 
the optic nerve; it is situated between the membrana argen- 
tea and vasculosa, and called the choroid gland (ch). It 
receives its arterial blood from the artery issuing from the 
pseudobranchia ; the presence of a choroid gland always being 
combined with that of a pseudobranchia. Teleosteans with- 
out pseudobranchia lack a choroid gland. In the Paleich- 
thyes, on the other hand, the pseudobranchia is present and 
a choroid gland absent. 

The zis (¢) is merely the continuation of the choroid 
membrane; its capability of contracting and expanding is 
much more limited than in higher Vertebrates. The pupil is 
generally round, sometimes horizontally or vertically elliptical, 
sometimes fringed. In the Rays and Pleuronectide a lobe 
descends from the upper margin of the pupil, and the outer 
integument overlying this lobe is coloured and non-trans- 
parent; a structure evidently preventing light from entering 
the eye from above. 

In most 7Zeleostet a fold of the Choroidea, called the Pro- 
cessus faleiformis (f), extends from the vicinity of the entrance 
of the optic nerve to the lens. It seems to be constantly 
absent in Ganoids. 

The retina (7) is the membrane into which the optic nerve 
penetrates, and in which its terminal filaments are distri- 
buted. It consists of several layers (Fig. 49). The outermost 


ORGAN OF SIGHT. 115 


is an extremely delicate membrane (a), followed by a layer 
of nerve-cells (0), from which the ter- 
minal filaments issue, passing through 
several granular strata (c, d, e), on which 
the innermost stratum rests. This stra- 
tum is composed of cylindrical rods (/) 
vertically arranged, between which twin 
fusiform corpuscles (g) are intercalated. 
This last layer is thickly covered with 
a dark pigment. The retina extends 
over a portion of the iris, and a well- 
defined raised rim runs along its anterior 
margin. 

The vitreous humour (Fig. 48, h) 
which fills the posterior cavity of the eye- 
ball, is of a firmer consistency than in the 


higher Vertebrates. The Jens is spheri- 


cal, or nearly so; firm, denser towards Fig. 49.—Vertical section 
of the Retina of the 


h ies in 
the centre, and lies in a hollow of the Pot naga S80. 


vitreous humour. When a _ falciform 

process is present, it is with one end attached to the lens, 
which is thus steadied in its position. It consists of con- 
centric layers consisting of fibres, 
which in the nucleus of the body 
have marginal teeth, by which they 
are interlocked together. In Petro- 


myzon this serrature is absent, or 
but faintly indicated. 
The anterior cavity of the eye 


is very small in Fishes, in conse- 
quence of the small degree of con- Fig. 50.—Interlocking fibres of 
a F lens, highly magnified. 

vexity of the cornea; the quantity 
of the aqueous humour, therefore, is very small, just suffi- 


cient to float the free border of the iris; and the lessened 


116 FISHES. 


refractive power of the aqueous humour is compensated by 
the greater convexity of the lens. 


Organ of Hearing—No trace of an organ of hearing has 
been found in Branchiostoma. In the Cyclostomes the laby- 
rinth is enclosed in externally visible cartilaginous capsules 
laterally attached to the skull; it consists of a single sem- 
circular canal in the Myxinoids, whilst the Petromyzontes 
possess two semicircular canals with a vestibulum. 

In all other fishes the labyrinth consists of a vestibule 
and three semicircular canals, the vestibule dilating into one 
or more sacs which contain the otoliths. A tympanum, tym- 
panic cavity, and external parts, are entirely absent in the 
class of fishes. 

In the Chondropterygians and Dipnoi, the labyrinth is 
enclosed in the cartilaginous substance of the skull. In the 
former the excavation in the cartilage is larger than the 
membranous labyrinth, but nearly corresponds to it in form ; 
the part which receives the membranous vestibulum is called 
Vestibulum cartilaginewm, from which a canal issues and 
penetrates to the surface of the skull, where it is closed by 
the skin in Sharks, but opens by a minute foramen in Rays. 
The otolithic contents are soft and chalklike. 

In the Holocephali part of the labyrinth is enclosed in the 
cartilage of the skull, another part being in the cranial cavity, 
as in Ganoids and Teleosteans. The membranous vestibulum 
is continued by a canal to a single opening in the roof of the 
skull, from which two smaller canals are continued to two 
small foramina in the skin covering the occipital region. 

In the Teleosteans the sac which contains the otoliths 
lies on each side of the base of the cranial cavity and is 
often divided by a septum into two compartments of unequal 
size, each containing a firm and solid ofolith; these bodies 
(Fig. 51), possess indented margins, frequently other impres- 


ORGAN OF HEARING. Lz 


sions and grooves, in which nerves from the N. acusticus are 
lodged ; they vary much in size and form, 
but in both respects show a remarkable 
constancy in the same kind of fishes. 
The vestibule is outwards in contact with 
the osseous side wall of the skull, inwards — - 

with the metencephalon and medulla a Bes, 


oblongata; it contains another firm con-  eglefinus). I. Outer, 
II. Inner aspect. 


cretion, and opens by five foramina 
into the three semicircular canals. The terminations of 
the acustic nerve are distributed over the vestibular con- 
eretion and the ampulliform ends (Fig. 52 p) of the semi- 
circular canals, without being continued into the latter, which 
are filled with fluid. The semicircular canals (Fig. 52 g), are 
sometimes lodged in the cranial bones, sometimes partly 
free in the cranial cavity. Many Teleostei have fontanelles 
in the roof of the skull, closed by skin or very thin bone only 
at the place where the auditory organ approaches the surface, 
by which means sonorous undulations must be conducted with 
greater ease to the ear. 

In many Teleostei a most remarkable relation obtains 
between the organ of hearing and the air-bladder. In the 
most simple form this connection is established in Percoids 
and the allied families, in which the two anterior horns of the 
air-bladder are attached to fontanelles of the occipital region 
of the skull, the vestibulum occupying the opposite side of 
the membrane by which the fontanelle is closed. The con- 
dition is similar, but more complicated in many Clupeoids. 
The anterior narrow end of the air-bladder is produced into a 
canal at the base of the skull, and divided into two very 
narrow branches, which again bifurcate and terminate in a 
globular swelling. An appendage of the vestibulum meets 
the anterior of these swellings, and comes into close contact 
with it. Besides, the two vestibules communicate with each 


FISHES. 


118 


other by a transverse canal, crossing the cranial cavity below 


the brain. 


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¢umnqrysea ‘0 { rappeyq-ary ‘w fsepoisso Jo ureyy ‘wu ‘7 “y f Leppe[q-1Te ey} Jo YUaUTYORI}e OY} IOF V.AGQO}IAA PII} OY 
Jo ssaooid 62 {vaqay1eA pily} pue puooes jo saskydodereg ‘2 “y { Biqaysoa YyINoJ pus “par, ‘puooes “y 2 ‘y f BIqayIAA 
qsag jo youre [emen “6 ‘ prousydsity Lf Syeydroooreg ‘8 fpeydwooxg ‘p £ peytdrooovidng ‘9 £ feytdtoog9 ‘gq { prousydsiseg ‘nv 
(Oq9M ‘HA YY) ‘drvp oy} Ut Loppelq-iIe pus uvsz0 fx0ypne TaIM oq WOTPBOIUNMIUIOQ— "ZG “Si 


The connection is effected by means of a chain of ossicles 


ORGAN OF TASTE. 119 


in Siluride, Characinide, Cyprinide and Gymnotide. A 
canal issues from the communication between vestibule and 
its sac, and meeting that from the other side forms with it a 
common sinus impar (Fig. 52,7), lodged in the substance of the 
basi-occipital; this communicates on each side by a small 
orifice with two subspherical atria, on the body of the atlas, 
close to the foramen magnum. LEach atrium is supported 
externally by a small bone (m); a third larger bone (/) com- 
pletes the communication with the anterior part of the air- 
bladder. From the sinus impar a bifid canal penetrates into 
the alisphenoids, in which it terminates. In Cobitis and 
several Loach-like Siluroids the small air-bladder consists of 
two globular portions placed side by side, and wholly included 
within two bulle, formed by the modified parapophyses of 
the second and third vertebree. The three ossicles on each side 
are present, but concealed by the fore part of the osseous bulla. 


Organ of Taste——Some fishes, especially vegetable feeders, 
or those provided with broad molar-like teeth, masticate their 
food ; and it may be observed in Carps and other Cyprinoid 
fish, that this process of mastication frequently takes some 
time. But the majority of fish swallow their food rapidly, 
and without mastication, and therefore we may conclude that 
the sense of taste cannot be acute. The tongue is often en- 
tirely absent, and even when it exists in its most distinct state, 
it consists merely of ligamentous or cellular substance, and 
is never furnished with muscles capable of producing ‘the 
movements of extension or retraction as in most higher 
Vertebrates. A peculiar organ on the roof of the palate of 
Cyprinoids, is perhaps an organ adapted for perception of 
this sense ; in these fishes the palate between and below the 
upper pharyngeal bones is cushioned with a thick, soft con- 
tractile substance, richly supplied with nerves from the Nervi 
vagus and glossopharyngeus. 


120 FISHES. 


Organs of Touwch—The faculty of touch is more developed 
than that of taste, and there are numerous fishes which possess 
special organs of touch. Most fishes are very sensitive to 
external touch, although their body may be protected by hard 
horny scales. They perceive impressions even on those parts 
which are covered by osseous scutes, in the same manner as 
a tortoise perceives the slightest touch of its carapace. The 
seat of the greatest sensitiveness, however, appears to be the 
snout and the labial folds surrounding the mouth. Many 
species possess soft and delicate appendages, called barbels, 
which are almost constantly in action, and clearly used as 
organs of touch. Among the Zvriglidw and allied families, 
there are many species which have one or more rays of the 
pectoral fin detached from the membrane, and supplied with 
strong nerves. Such detached rays (also found in the Poly- 
nemide, Bathypterois) are used partly for locomotion, partly 
for the purpose of exploring the ground over which the fish 
moves. 

Some fish appear to be much less sensitive than others, or 
at least lose their sensitiveness under peculiar circumstances. 
It is well known that a Pike, whose mouth has been lacerated 
and torn by the hook, continues to yield to the temptation 
of a bait immediately afterwards. The Greenland Shark 
when feeding on the carcase of a whale allows itself to be 
repeatedly stabbed in the head without abandoning its prey. 
A pair of Congers are so dead to external impression at the 
time of copulation, and so automatically, as it were, engaged, 
that they have been taken by the hand together out of the 
water. 


CHAPTER VIII. 
THE ORGANS OF NUTRITION AND DIGESTION. 


FISHES are either exclusively carnivorous or herbivorous, 
but not a few feed on vegetable substances as well as animal, 
or on mud containing alimentary substance in a living or 
decomposing state. Generally they are very voracious, espe- 
cially the carnivorous kinds, and the rule of “ eat or be eaten ” 
applies to them with unusual force. They are almost con- 
stantly engaged in the pursuit and capture of their prey, the 
degree of their power in these respects depending on the 
dimensions of the mouth and gullet and the strength of the 
teeth and jaws. If the teeth are sharp and hooked, they are 
capable of securing the most slender and agile animals; if 
this kind of teeth is combined with a wide gullet and disten- 
sible stomach, they are able to overpower and swallow other 
fish larger than themselves ; if the teeth are broad, strong 
molars, they are able to crush the hardest aliments; if they 
are feeble, they are only serviceable in procuring some small 
or inert and unresisting prey. Teeth may be wanting alto- 
gether. Whatever the prey, in the majority of cases it is 
swallowed whole; but some of the most voracious fishes, like 
some Sharks and Characinide, are provided with cutting 
teeth, which enable them to tear their prey to pieces if too 
large to be swallowed whole. Auxiliary organs for the pur- 
pose of overpowering their prey, which afterwards is seized 
or torn by the teeth, like the claws of some carnivorous 
mammals and birds, are not found in this class; but in a 


122 FISHES. 


few fishes the jaws themselves are modified for that pur- 
pose. In the Sword-fishes the bones of the upper jaw form 
a long dagger-shaped weapon, with which they not only 
attack large animals, but also frequently kill fishes on which 
they feed. The Saw-fishes are armed with a similar but 
still more complicated weapon, the saw, which is armed 
on each side with large teeth implanted in deep sockets, 
specially adapted for killing and tearing the prey before it is 
seized and masticated by the small teeth within the mouth. 
Fishes show but little choice in the selection of their food, 
and some devour their own offspring indiscriminately with 
other fishes. Their digestive powers are strong and rapid, 
but subject in some degree to the temperature, which, when 
sinking below a certain point, lowers the vital powers of 
these cold-blooded animals. On the whole, marine fishes are 
more voracious than those inhabiting fresh waters ; and whilst 
the latter may survive total abstinence from food for weeks 
or months, the marine species succumb to hunger within a 
few days. The growth of fishes depends greatly on the nature 
and supply of food, and different individuals of the same 
species may exhibit a great disparity in their respective dimen- 
sions. They grow less rapidly and to smaller dimensions in 
small ponds or shallow streams than in large lakes and deep 
rivers. The young of coast fishes, when driven out to sea, where 


they find a much smaller supply of food, remain in an unde- 


veloped condition, assuming an hydropic appearance. The 
growth itself seems to continue in most fishes for a great length 
of time, and we can scarcely set bounds to—certainly we know 
not with precision—the utmost range of the specific size of 
fishes. Even among species in no way remarkable for their 
dimensions we sometimes meet with old individuals, favour- 
ably situated, which more or less exceed the ordinary weight 
and measurement of their kind. However, there are certain 
evidently short-lived species of fishes which attain a remark- 


ORGANS OF NUTRITION. 2s 


ably uniform size within a very short time ; for instance, the 
Stickleback, many species of Gobiws and Clupea. 


The organs of nutrition, manducation, and deglutition, are 
lodged in two large cavities—an anterior (the mouth or buccal 
cavity), and a posterior (the abdominal cavity). In the 
former the alimentary organs are associated with those ful- 
filling the respiratory functions, the transmission of food to 
the stomach and of water to the gills being performed by 
similar acts of deglutition. The abdominal cavity commences 
immediately behind the head, so, however, that an extremely 
short thoracic cavity for the heart is partitioned off in front. 
Beside the alimentary organs it contains also those of the 
urogenital system and the air-bladder. The abdominal cavity 
is generally situated in the trunk only, but in numerous fishes 
it extends into the tail, being continued for some distance 
along each side of the heemal apophyses. 

In numerous fishes the abdominal cavity opens outwards 
by one or two openings. A single porus abdominalis in front 
of the vent is found in Lepidosiven and some Sturgeons ; a 
paired one, one on each side of the vent, in Ceratodus, some 
species of Sturgeon, Lepidosteus, Polypterus, Amia, and all 
Chondropterygians. As in these fishes semen and ova are 
discharged by proper ducts, the abdominal openings may serve 
-for the expulsion of semen, and those ova only which, having 
lost their way to the abdominal aperture of the oviduct, would 
be retained in the abdominal cavity. In those Teleosteans which 
lack an oviduct a single porus genitalis opens behind the vent. 

The mouth of fishes shows extreme variation with regard 
to form, extent, and position. Generally opening in front, it 
may be turned upwards, or may lie at the lower side of the 
snout, as in most Chondropterygians, Sturgeons, and some 
Teleosteans. Vogt regards this position as a persistent foetal 
condition. In most fishes the jaws are covered by the skin, 


124 FISHES. 


which, before passing over the jaws, is often folded, forming 
more or less fleshy lips. In the Sharks the skin retains its 
external character even within the teeth, but in other fishes 
it changes into a mucous membrane. A tongue may exist as 
a more or less free and short projection, formed by the glosso- 
hyal and a soft covering, or may be entirely absent. Salivary 
glands and a velum palate are absent in fishes. 

With regard to the dentition, the class of Fishes offers an 
amount of variation such as is not found in any of the other 
classes of Vertebrates. . As the teeth form one of the most 
important elements in the classification of fishes, their special 
arrangement and form will be referred to in the account of 
the various families and genera. Whilst not a few fishes are 
entirely edentulous, in others most of the bones of the buccal 
cavity, or some of them, may be toothed, as the bones of the 
jaws, the palatines, pterygoids, vomers, basi-sphenoid, glosso- 
hyal, branchial arches, upper and lower pharyngeals. In 
others teeth may be found fixed in some portion of the buccal 
membrane without being supported by underlying bone or 
cartilage ; or the teeth have been developed in membrane 
overlying one of the dentigerous bones mentioned, without 
having become anchylosed to the bone. When the tooth is 
fixed to the bone the attachment has generally been effected 
by the ossification of the bone of the tooth, but in some fishes 
a process of the bone projects into the cavity of the tooth; in 
others the teeth are implanted in alveoli. In these, again, 
frequently a process of bone rises from the bottom, on which 
the tooth rests. 

Many fishes, especially predatory fishes with long, lancet- 
shaped teeth, have all or some of the teeth capable of being 
bent inwards towards the mouth. Such “hinged” teeth 
resume at once the upright position when pressure is removed 
from them. They are, however, depressible in one direction 
only, thus offering no obstacle to the ingress, but opposing the 


TEETH. 125 


egress of prey. Mr. C. 8S. Tomes has shown that the means 
by which this mechanism is worked are different in different 
fishes ; for whilst, in the Pediculati and Gadoids (Hake) the 
elasticity resides solely in the tissue of the hinge (the tooth 
being as resilient as ever after everything else is severed), in 
the Pike the hinge is not in the least endowed with elasticity, 
but the bundles of fibres proceeding from the interior of the 
dentine cap are exceedingly elastic. 

As regards texture the teeth of fishes show considerable 
variation. The conical teeth of the Cyclostomes and the 
setiform teeth of many Teleosteans consist of a horny albumi- 
nous substance. The principal substance of the teeth of other 
fishes consists of dentine, with numerous dividing and anasto- 
mosing tubercles, sometimes covered by a stratum of unvas- 
cular dentine. An enamel-lke substance has been observed 
on the crown of the teeth of Sargus and Balistes, and an ossi- 
fication of the capsule of their matrix covers the enamel with 
a thin coating of cement. The teeth either possess a cavity 
in which the matrix is received, or, more frequently, they are 
solid, in which case vascular canals of the underlying bone 
are continued into the substance of the tooth. In the teeth 
of some fishes numerous sets of canals and tubes are so 
arranged that they do not anastomose with one another, each 
set being surrounded by a layer of dentine and cement. 
These apparently simple teeth are evidently composed of 
numerous small teeth, and called compownd teeth. 

The teeth may be, and generally are, very different as 
regards size or form in the different parts of the mouth; they 
may be also different according to the age or sex of the fish 
(Raja). The teeth may be few in number and ‘solated, or 
placed in a single, double, or triple series, distant from one 
another or closely set ; they may form narrow or broad bands, 
or patches of various forms. As regards form, they may be 
cylindrical or conical, pointed, straight, or curved, with or 


126 FISHES. 


without an angular bent near their base ; some are compressed 
laterally or from the front backwards; the latter may be 
triangular in shape, or truncated at the top like incisors of 
mammals; they may have one apex (cusp) only, or be bi- or 
tri-lobate (bi- or tri-cuspid); or have the margins denticu- 
lated or serrated. Compressed teeth may be confluent, and 
form a cutting edge in both jaws, which assume the shape 
of a parrot’s beak (Fig. 53). In some the apex is hooked 
or provided with barbs. 
Again, some teeth are 
broad, with flat or convex 
surface, like molar teeth. 
With regard to size, the 
finest teeth are like fine 
flexible bristles, ci/¢iform 
or setiform; or, if very 
short and anchylosed to 
the bone, they appear 


Fig. 53.—Jaws of Calliodon. 


only as inconspicuous asperities of the bone. Very fine conical 
teeth arranged in a band are termed villiform teeth; when 
they are coarser, or mixed with coarser teeth, they are card- 
like (dents en rape or en cardes) (Fig. 54); molar-like teeth 
of very small size are termed granular. 

In all fishes the teeth are constantly shed or renewed 
during the whole course of their life. In fishes which have 
compound teeth, as the Dipnoi, Chimeeroids, Scari,’ Gym- 
nodonts, as well as in those which have apparently permanent 
teeth, as in the saw of Pristis, the detrition of the surface is 
made up by a constant growth of the tooth from its base. 
When the teeth are implanted in alveoli, they are generally 
succeeded by others in the vertical direction, but in others 
they succeed one another, side by side. In the majority of 


1 On the development and structure of the dentition of Scarina, see Boas, 
«¢Pie Zahne der Scaroiden,” in Zeitschr. f. Wiss. Zoolog. xxxii. (1878). 


TEETH. Li 


fishes the new tooth is not developed (as in reptiles and 
mammals) in a diverticulum 
of the sack of its predecessor, 
but like this from the free sur- 
face of the buccal membrane. 
Generally there are more than 
one tooth growing, which are 
in various stages of develop- //// 
ment, and destined to replace AN 
the one in function. This is 
very conspicuous in Sharks, in 
which the whole phalanx of 
their numerous teeth is ever 
marching slowly forwards (or 
in some backwards), in rota- 


tory progress, over the alveolar 
border of the jaw, the teeth pig 54 Cardlike teeth of Plectropoma 
being successively cast off after dentex, with canines. 
having reached the outer margin, and fulfilled for a longer 
and shorter period their special function. 


[The richest materials for our knowledge of the teeth of fishes are con- 

tained in Owen’s ‘‘ Odontography.” Lond. 1840. 8vo.] 

The ¢ntestinal tract is divided into four portions: ceso- 
phagus, stomach, small and large intestine; two or more of 
these divisions may coalesce in fishes and become indistin- 
guishable. But it is characteristic of the class that the 
urinary apertures are constantly situated behind the termina- 
tion of the intestinal tract. 

In Branchiostoma the whole intestinal tract is straight, 
and coated with a ciliated mucous membrane. The wide 
pharynx passes into a narrow cesophagus, this into a gastric 
cavity, the remainder being again narrower and terminating 
in the anal aperture, which les somewhat to the left of the 
median line. The liver is represented by a green coloured 


128 FISHES. 


ccecal diverticulum of the stomachic dilatation. A mesenterium 
is absent. 

In the Cyclostomi the intestinal tract is likewise straight, 
and without clearly defined divisions ; however, in Petromyzon 
the cesophagus shows numerous longitudinal folds, and the 
intestine proper is provided with a single longitudinal fold. 
A mesentery, which is present in the Myxinoids, is represented 
by a short median fold only, by means of which the hind- 
most part of the intestine is fixed. 

The Palaichthyes show differences in the structure of their 
intestinal tract as considerable as are found among the 
Teleostei, but they have that in common that the absorbent 
surface of their intestine is enlarged by the development of a 
spiral valve, evidence of the presence of which in extinct 
Paleichthyes is still preserved in the fossilised fseces or 
coproliths, so abundant in some of the older strata. 

In Chondropterygians (Fig. 55) the stomach is divided into 
a cardiac and pyloric portion, the former frequently terminat- 
ing in a blind sac, and the latter varying in length. The 
pyloric portion is bent at its origin and end, and separated from 
the short duodenum (called Bursa entiana in these fishes) by 
a valve; the ductus hepaticus and pancreaticus enter the 
duodenum. This is succeeded by the straight intestine pro- 
vided with the spiral valve, the coils of which may be either 
longitudinal and wound vertically about the axis of the 
intestine, as in Carcharias, Galeocerdo, Thalassorhinus, and 
Zygena, or they may be transverse to that axis, as in the 
other genera. The number of gyrations in the latter case 
varies: there may be as many as forty. The short rectum 
passes into a cloaca, which contains also the orifices of the 
urogenital ducts. Only the commencement and end of the 
intestinal tract are fixed by mesenterial folds. 

In the Holocephali and Dipnoi, the intestinal tract is short, 
straight, and wide, without stomachic dilatation, a pyloric 


INTESTINE, ~ 129 


valve, close to which the ductus choledochus enters, indicating 


\ 


Fig. 55.—Siphonal stomach and spiral valve of Basking-Shark (Selache). 
(After Home and Owen.) 


a, (isophagus ; 0, Cardiac portion of stomach ; ¢, pyloric portion; d, pouch in- 
termediate between stomach and duodenum, with circular valves at both 
ends; ¢, Duodenum ; f, Valve of intestine ; g, Ductus hepaticus ; 2, Spleen. 


the boundary of the intestine proper (Fig. 57, p). The spiral 
valve is perfect, and makes from three (Chimera) to nine 
(Ceratodus) gyrations. A cloaca is present, as in Chon- 
dropterygians. A mesentery fixing the dorsal side of the 
intestine is absent. 

The other Ganoids resemble again more the Chondrop- 
terygians in the structure of their intestinal tract. The 
stomach has always a distinct pyloric portion, and has a still 
more complicated structure in Acipenser. The duodenal 
portion receives the contents of Appendices pyloricw, which 
are confluent into a gland-like mass in Acipenser, but separate 
in Polyodon, and numerous and short in Lepidosteus, whilst 
Polypterus possesses one such appendage only. A spiral 
valve is developed in the Sturgeons and Polypterus, but in 
Amia, in which the intestine performs several convolutions, 

K 


130 FISHES. 


the four gyrations of the valve are situated far back towards 
the end of the intestine. In Lepidostews the valve is rudi- 
mentary, and indicated only by three raised lines crossing the 
terminal portion of the intestine. In all these Ganoids the 
rectum has a separate opening, without cloaca. 

The structure of the intestinal tract of Teleosteous fishes 
is subject to so numerous modifications that we should go 
beyond the limits of the present work if we would attempt 
to enter into details. Great differences in this respect may 
be found even in groups of the same natural families. 
Frequently the intestinal tract remains of nearly the same 
width throughout its course, and only the entrance of the 
various ducts serves as a guide for the distinction of its 
divisions. An intestine of such uniform width may be 
straight and short, as in Scombresocide, Symbranchide, or it 
may be more or less convoluted and long, as in many 
Cyprinide, Doradina, etc. On the whole, carnivorous fishes 
have a much shorter and simpler intestinal tract than 
herbivorous. 

In the majority of Teleosteans, however, cesophagus, 
stomach, duodenum, small intestine and rectum, can be more 
or less distinctly, even externally distinguished. 

There are two predominant forms of the stomach, inter- 
mediate forms being, however, numerous. In the first, the 
siphonal, it presents the form of a bent tube or canal, one- 
half of the horse-shoe being the cardiac, the other the pyloric 
portion. In the second, the eweal, the cardiac division is pro- 
longed into a long descending blind sac, the cardiac and 
pyloric openings of the stomach lying close together (Clupea, 
Scomber, Thynnus, etc.) 

The duodenum receives always the hepatic and pancreatic 
secretions, and, besides, those of the appendices pylorice, 
which, in varying numbers (from 1 to 200), are of very common 
occurrence in Teleosteans (Fig. 56). They vary also in length 


INTESTINE. tow 


Fig. 56.—Siphonal Stomach and Pyloric Appendages of a Female Salmon, 34 feet long. 
aaa, Pyloric appendages; ch, ductus choledochus; o¢, cesophagus ; st, lower end of 
stomach ; p, pyloric region ; 7, ascending ; and 7’, descending portion of intestine. 


‘ 


132 FISHES. 


and width, and whilst the narrowest serve only as secretory 
organs, the widest are frequently found filled with the same 
contents as the intestine. When few in number, each opens 
by a separate duct into the duodenum; when their number is 
greater two or more coalesce into a common duct; in the 
latter case the appendages cease to be free, and are connected 
with one another by a more or less firm tissue. 

Coecal appendages at the end of the intestinal tract are of 
exceedingly rare occurrence in fishes (Bow). There is no 
cloaca in Teleosteans. 

In the majority of Teleosteous fishes the vent is situated 
on the boundary between trunk and tail, behind the ventral 
fins. In a few it les farther backwards, not far from the 
caudal fin; more frequently it is advanced forwards, under 
the middle of the abdomen or to the scapular arch. In two 
fishes, Aphredoderus and Amblyopsis, it lies before the pec- 
toral fins. 

A peritoneum envelops all the divisions ot the intestinal 
tract within the abdominal cavity. A broad, well-developed 
omentum has hitherto been found in Gobiesox cephalus 
only. 

Laver.—The existence of a liver in Branchiostoma as a long 
diverticulum of the intestine has been mentioned above. In 
the Myxinoids the liver is divided into two glandular bodies, 
an anterior rounded smaller one, and a posterior larger one of 
an elongate shape. The gall-bladder lies between both, and 
receives a cystic duct from each of them. In the other fishes 
the proportionally large liver is a single large gland, from 
which only now and then small portions are found to be 
detached. It is either simple, or with a right and left lobe, 
or with a third lobe in the middle; each lobe may have 
incisions or subdivisions, which, however, are very inconstant. 
The liver of fishes is distinguished by the great quantity of 
fluid fat (oil) which it contains. The gall-bladder is but 


INTESTINE, 133 


rarely absent, and attached to the right lobe, or towards the 
centre ; however, in some fishes it is detached from the liver 
and connected with it by the cystic duct only. The bile may 
be conveyed by one or more hepatic ducts into a common 
duct which is continued towards the gall-bladder as ductus 
cysticus, and towards the duodenum as ductus choledochus; or 
some of the hepatic ducts enter directly the gall-bladder, or 
directly the duodenum, without communicating with the 
common duct. Individual variations in this respect are of 
common occurrence. 

A pancreas has been found hitherto in all Chondroptery- 
gians, Acipenser, and many Teleosteans. In the first it is a 
glandular mass of considerable size behind the stomach, close 
to the spleen; its duct leads into the duodenum. In the 
Sturgeons the pancreas is attached to the duodenum, and 
opens close to the ductus choledochus. In Stlurus glanis it 
is very large, and the ductus choledochus passes through its 
substance; it is smaller in Belone and Pleuronectes, and 
situated in the mesentery ; its duct accompanies the terminal 
portion of the ductus choledochus. In the Salmon, which 
possesses a large lobed pancreas, the duct is so intimately 
connected with the ductus choledochus that both appear 
externally as a single duct only. 

The spleen, which is substantially a lymphatic gland, may 
be mentioned here, as it is constantly situated in the imme- 
diate vicinity of the stomach, generally near its cardiac portion. 
With the exception of Branchiostoma, it is found in all fishes, 
and appears as a rounded or oblong organ of dark-red colour. 
In the Sharks frequently one or more smaller pieces are de- 
tached from the principal body. In the Dipnoi a thin layer 
of a very soft substance of brownish-black colour below the 
mucous membrane of the stomach and upper part of the 
intestine has been regarded as the homologue of the spleen 
(Fig. 57, m). In most Teleostei the spleen is undivided, and 


134 FISHES. 


appended by its vessels and a fold of the peritoneum to the 
pyloric bend of the stomach or the beginning of the intestine. 


Fig. 57.—Upper part of Intestine of Ceratodus. The anterior wall of the 
intestine is opened, the liver (c) and gall-bladder (e) being drawn forward, A 
slit is made at ”, through which part of the next compartment of the spirally 
wound intestine may be seen. 


e’, Mouth of ductus choledochus ; f, stomach ; 27, adipose agglomeration ; J, first 


compartment of intestinal spire ; m, spleen ; oe, lower part of esophagus, 
opened ; p, double pyloric fold ; ¢ g, glandular patches. 


CHAPTER IX. 
ORGANS OF RESPIRATION. 


FisHEs breathe the air dissolved in water by means of gills 
or branchie. The oxygen consumed by them is not that 
which forms the chemical constituent of the water, but that 
contained in the air which is dissolved in water. Hence 
fishes transferred into water from which the air has been 
driven out by a high temperature, or in which the air absorbed 
by them is not replaced, are speedily suffocated. The ab- 
sorption of oxygen by fishes is comparatively small, and 
it has been calculated that a man consumes 50,000 times 
more than is required by a Tench. However, some fishes 
evidently require a much larger supply of oxygen than others : 
Eels and Carps, and other fishes of similar low vitality, can 
survive the removal out of their elements for days, the small 
quantity of moisture retained in their gill-cavity being suffi- 
cient to sustain life, whilst other fishes, especially such as 
have very wide gill-openings, are immediately suffocated after 
being taken out of the water. In some fishes noted for their 
muscular activity, like the Scombride, the respiratory process 
is so energetic as to raise the temperature of their blood far 
beyond that of the medium in which they live. <A few fishes, 
especially such as are periodically compelled to live in water 
thickened into mud by desiccation and vitiated by decompos- 
ing substances, breathe atmospheric air, and have generally 
special contrivances for this purpose. These are so much 
habituated to breathing air that many of them, even when 


136 FISHES. 


brought into pure water of normal condition, are obliged to 
rise to the surface at frequent intervals to take in a quantity 
of air, and if they be kept beneath the surface by means of 
a gauze net, they perish from suffocation. The special con- 
trivances consist of additional respiratory organs, lodged in 
cavities either adjoining the gill-cavity or communicating 
with the ventral side of the cesophagus, or of the air-bladder 
which enters upon respiratory functions (Dipnoi, Lepidosteus, 
Amia). 

The water used by fishes for respiration is received by the 
mouth, and by an action similar to that of swallowing driven 
to the gills, and expelled by the gill-openings, of which there 
may be one or several on each side behind the head; rarely 
one only in the median line of the ventral surface. 


The gills or branchie consist essentially of folds of the 


Fig. 58.—Fore-part of the body of au embryon of Carcharias, showing the 
branchial filaments (natural size). 


mucous membrane of the gill-cavity (laminw branchiales), in 
which the capillary vessels are distributed. In all fishes the 


RESPIRATION. 137 


gills are lodged in a cavity, but during the embryonic stage 
the Chondropterygians have the gill-laminz prolonged into 
long filaments projecting beyond the gill-cavity (Fig. 58), and 
in a few young Ganoids external gills are superadded to the 
internal. 

In Branchiostoma the dilated pharynx is perforated by 
numerous clefts, supported by cartilaginous rods (Fig. 29, 1). 
The water passes between these clefts into the peritoneal 
cavity, and makes its exit by the porus abdominalis situated 
considerably in advance of the vent. The water is propelled 
by cilia. 

In the Cyclostomes the gills of each side are lodged in a 
series of six or more antero-posteriorly compressed sacs, 
separated from each other by intervening septa. Each sac 
communicates by an inner duct with the cesophagus, the 
water being expelled by an outer duct. In SLdellostoma each 
outer duct has a separate opening, but in Myxine all the outer 
ducts pass outwards by one common gill-opening on each side. 
In the Lampreys the ducts are short, the outer ones having 
' separate openings (Fig. 2, p. 39). The inner ducts lead into 
a single diverticulum or bronchus, blind behind, situated 
below the cesophagus, and communicating in front with 
the pharynx, where it is provided with two valves by which 
the regurgitation of the water into the buccal cavity is 
prevented. 

The same type of branchial organs persists in Chondrop- 
terygians, which possess five, rarely six or seven, flattened 
pouches with transversely plaited walls. The septa between 
them are supported by cartilaginous filaments rising from the 
hyoidean and branchial arches. Each pouch opens by a cleft 
outwards, and by an aperture into the pharynx, without inter- 
vening ducts. The anterior wall of the first pouch is sup- 
ported by the hyoidean arch. Between the posterior wall of 
the first and the anterior of the second sac, and between the 


138 ; FISHES. 


adjacent walls of the succeeding, a branchial arch with its 
two series of radiating cartilaginous filaments is interposed. 
Consequently the first and last pouch have one set of gill- 
lamine only, viz. the first on its posterior and the last on its 
anterior wall. The so-called spiracles on the upper surface of 
the head of Chondropterygians are to be referred to in connec- 
tion with the respiratory organs. They are the external 
openings of a canal leading on each side into the pharynx, 
and situated generally close to and behind the orbit. They 
frequently possess valves or an irregularly indented margin, 
and are found in all species during the embryonic stage, but 
remaining persistent ina part only. The spiracles are the 
remains of the first visceral cleft of the embryo, and in the 
foetal state lone branchial filaments have been observed: to 
protrude, as from the other branchial clefts. 

The Holocephali and Ganoideit show numerous deviations 
from the Chondropterygian type, all leading in the direction 
towards the Teleosteans. As a whole they take an inter- 
mediate position between the preceding types and the Tele- 
osteans, but they show a great variation among themselves, 
and have in common only the imperfect separation of the 
branchial sacs and the presence of a single outer branchial 
aperture. 

In Chimera the septum separating the branchial sacs is 
confluent with the wall of the gill-cavity in a part of its 
extent only, and still more imperfect is the separation of those 
branchial divisions in Ceratodus (Fig. 60). The other Ganoids 
show no such division whatever. In Chimera the first gill 
is incomplete (uniserial), and belongs to the hyoid; then fol- 
low three complete gills; the last, belonging to the fourth 
branchial arch, being again incomplete. Aczpenser, Scaphir- 
hynchus, Lepidosiren, Protopterus, and Lepidosteus, possess like- 
wise an anterior incomplete gill (opercular gill), followed by 
four complete gills in the Sturgeons and Lepidosteus, whilst in 


GILLS. 139 


Lepidosiren and Protopterus a part of the branchial arches is 
gill-less. In Polyodon, Ceratodus, and Polypterus, an opercular ° 
gill is absent, the two former having four complete gills, the 
latter three and a half only. Spiracles are still in some 
Ganoids present, viz. in the Sturgeons and Polypterus. In all 
the Ganoids an osseous gill-cover is now developed. 

In the Teleostei the gills with their supporting branchial 
arches lie in one undivided cavity; more or less wide clefts 
between the arches lead from the pharynx to the gills, and a 
more or less wide opening gives exit to the water after it has 
washed the gills. The interbranchial clefts have sometimes 
nearly the same extent as the branchial arches; sometimes 
they are reduced to small openings, the integuments stretch- 
ing from one arch to the other. Sometimes there is no cleft 
behind the fourth arch, in which case this arch has only an 
uniserial gill developed. The gill-opening likewise varies 
much in its extent, and when reduced to a foramen may be 
situated at any place of the posterior boundary of the head. 
In the Symbranchide the gill-openings coalesce into a single 
narrow slit in the median line of the isthmus. In the 
majority of Teleosteans the integument of the concave side of 
the branchial arches develops a series of horny protuberances 
of various form, the so-called gill-rakers. They are destined 
to catch any solid corpuscles or substances which would be 
carried into the gill-cavity with the water. In some fishes 
they are setiform, and form a complete sieve, whilst in others 
they are merely rough tubercles, the action of which must be 
very incomplete if they have any function at all. 

Most Teleosteans possess four complete gills, but fre- 
quently the fourth arch is provided with an uniserial gill 
only, as mentioned above, or even entirely gill-less. The 
most imperfect gills are found in Malthe, which has two and 
a half gills only, and in Amphipnous cuchia, in which one 
small gill is fixed to the second arch. 


140 


FISHES. 


The gills of the Teleosteans as well as of the Ganoids’ 


Fig. 59.—A pair of 
branchial lamel- 
le (magnified) of 
the Perch. 

a, Branch of Arteria 
branchialis; 8, 
Ascending branch 
of the same; ¢. 
Branch of Vena 
branchialis ; 

d, Descending 
branch of the 
same; ¢é, Trans- 
verse section 
through the 
branchial arch. 


are supported by a series of solid cartila- 
ginous or horny pointed rods, arranged along 
the convex edges of the branchial arches. 
Arches bearing a complete gill have two series 
of those rods, one along each edge ; those with 
uniserial gills bear one row of rods only. The 
rods are not part of the arch, but fixed in 
its integument, the several rods of one row 
corresponding to those of the other, forming 
pairs ( feudllet, Cuvier) (Fig. 59). Each rod is 
covered by a loose mucous membrane pas- 
sing from one rod to its fellow opposite, which 
again is finely transversely plaited, the general 
surface being greatly increased by these plaits. 
In most Teleostei the branchial lamelle are 
compressed, and taper towards their free end, 
but in the Lophobranchs their base is atten- 
uated and the end enlarged. The mucous 
membrane contains the finest terminations 
of the vessels, which, being very superficial, 
impart the blood-red colour to living gills. 
The Arteria branchialis, the course of which 
les in the open canal in the convexity of 
the branchial arch, emits a branch (a) for every 
pair of lamellae which ascends (b) along the 
inner edge of the lamella, and supplies every 
one of the transverse plaits with a branchlet. 
The latter break up into a fine net of capillaries, 


from which the oxygenised blood is collected into venous 
branchlets, returning by the venous branch (d), which occu- 
pies the outer edge of the lamella. 

The so-called Pseudobranchic (Fig.60) are the remains of an 
anterior gill which had respiratory functions during the em- 
bryonic life of the individuals. By a change in the circulatory 


GILLS. 141 


system these organs have lost those functions, and appear in 
the adult fish as retia mirabilia, as they receive oxygenised 
blood, which, after having passed through their capillary system, 
is carried to other parts of the head. In Paleichthyes the 
pseudobranchia is a rete mirabile caroticum for the brain and 
eye; in Teleosteans a rete mirabile ophthalmicum only. 
Pseudobranchiz are as frequently absent as present in Chon- 
dropterygians as well as Teleosteans. As to the Ganoids, they 
occur in Ceratodus, Acipenser, 
Polyodon, and Lepidosteus, and | 
are absent in Lepidosiren, Pro- 
topterus, Scaphirhynchus, Poly- 
pterus, and Amia. 

In Chondropterygians and 
Sturgeons the pseudobranchiz 
are situated within the spiracles ; 
in those, in which spiracles have 
become obliterated, the pseudo- 
branchiz lie on the suspen- 
sorilum, hidden below cellular 
tissue ; but pseudobranchiz are 


not necessarily co-existent with 
spiracles. In the other Ganoids 


Fig. 60.—Gills of Ceratodus. 
; j _.,  #, Areus aorte; gl, Glossohyal ; 
branchiz (Fig. 60, 2) are within ch, Ceratohyal; wu, Attachment of 


and Teleosteans the pseudo- 


the first gill to the walls of the 
; . gill-cavity ; h, Pseudobranchia ; 
the gill-cover; in Ceratoduseven x, x”, two series of gill-rakers be- 


rudiments of the gill-rakers longing to the Pseudobranchia. 
(x, x”) belonging to this embryonic gill are preserved, part 
of them (x) being attached to the hyoid arch. Pseudo- 
branchie are frequently hidden below the integuments of 
the gill-cavity, and have the appearance of a glandular body 
rather than of a gill. 


[See Miiller, “ Vergleichende Anatomie des Gefass-systems der Myxinoi- 
den ;” and “Ueber den Bau und die Grenzen der Ganoiden.”] 


the gill-cavity, near the base of 


142 FISHES. 


Accessory respiratory organs for retaining water or breath- 
ing air, such as are found in the Labyrinthict, Ophiocephalide, 
certain Siluride, and Lutodira, are structures so specialised 
that they are better described in the accounts of the Fishes 
in which they have been observed. 


Air-Bladder.—The air-bladder, one of the most character- 
istic organs of fishes, is a hollow sac, formed of several tunics, 
containing gas, situated in the abdominal cavity, but without 
the peritoneal sac, entirely closed or communicating by a 
duct with the intestinal tract. Being compressible, its special 
functions consist in altering the specific gravity of the fish or 
in changing the centre of gravity. In a few fishes it assumes 
the function of the organ of higher Vertebrates, of which it is 
the homologue—viz. of a lung. 

The gas contained in the air-bladder is secreted from its 
inner surface. In most fresh-water fishes it consists of 
nitrogen, with a very small quantity of oxygen and a trace of 
carbonic acid; in sea-fishes, especially those living at some 
depth, oxygen predominates, as much as 87 per cent having 
been found. Davy found in the air-bladder of a fresh-run 
Salmon a trace of carbonic acid and 10 per cent of oxygen, 
the remainder of the gas being nitrogen. 

An air-bladder is absent in Leptocardii, Cyclostomi, Chon- 
dropterygu, and Holocephali ; but occurs in all Ganoids, in 
which, besides, its respiratory functions more or less clearly 
manifest themselves. Its occurrence in Teleosteans is most 
irregular, closely allied species sometimes differing from each 
other in this respect; it shows in this sub-class the most 
extraordinary modifications, but has no respiratory function 
whatever. 

Constantly situated within the abdominal cavity, below 
the vertebral column, but without the sac of the peritoneum 
which covers only its ventral portion, the air-bladder is fre- 


AIR-BLADDER. 143 


quently prolonged into the tail, the prolongation being either 
simple and lodged between the non-united parapophyses, or 
double and penetrating between the muscles and hemapo-’ 
physes of each side. In the opposite direction processes of 
the air-bladder may penetrate into the skull, as has been 
mentioned above (p. 117). In some fishes the air-bladder is 
almost loose in the abdominal cavity, whilst in others it ad- 
heres most intimately by firm and short tissue to the vertebral 
column, the walls of the abdomen, and the intestines. In the 
Cobitina and many Siluroids it is more or less completely 
enclosed in osseous capsules formed by the vertebre. 

The tunics of the majority of air-bladders are an extremely 
fine internal one, frequently shining silvery, containing crys- 
talline corpuscles, sometimes covered with a pavement- 
epithelium; and a thicker outer one of a fibrous texture, 
which sometimes attains to considerable thickness and yields 
isinglass. This wall is strengthened in many fishes by mus- 
cular layers for the compression of the whole organ or of 
some portion of it. 

A distinction has been made between air-bladders which 
communicate by a duct with the intestinal tract and those 
which are entirely closed. However, it is to be remembered 
that at an early stage of development all air-bladders are 
provided with such a duct, which in a part of the fishes more 
or less completely obliterates, being then represented by a fine 
ligament only. In young Lucioperca of six to eight inches in 
length the duct may be found still open for a considerable 
distance ; and, on the other hand, in adult Physostomz, that is 
Teleosteous fishes with a ductus pneumaticus, not rarely the 
whole duct is found very narrow, or, for some part of its 
length, even entirely closed. 

Air-bladders without duct are found in Acanthopterygians, 
Pharyngognaths, Anacanths, and Lophobranchs. They may 
consist of a single cavity or divided by constrictions into two 


144 FISHES. 


or three partitions situated behind one another; they may 
consist of twolateral partitions, assuming a horseshoe-like form, 
or they may be a single sac with a pair of simple or bifid 


% Pa 
iy Oe 


Fig. 62.—Vertical section through ab- 
dominal cavity of Collichthys lucida. 
6, air-bladder ; 7, liver; s, stomach ; 
epp and tpp, external and internal 

Fig. 61.—Air-bladderof laminz of peritoneum parietale ; epv 

: and zpv, external and internal lamine 
Otolithus sp. ‘ ; 

of peritoneum viscerale; dv, dorsal 

air-vessels ; vv, ventral air-vessels. 


processes in front or behind (Fig. 61). The families of Scvw- 
mide and Polynemide possess air-bladders with a most 
extraordinary development of appendages rising from each 
side of the air-bladder. In the Scienoid (Fig. 63) fifty-two 
branches issue from each side, each branch being bifurcate 
and bearing smaller appendages. In Pogonias chromis (Fig. 
64) the sides of the anterior half is provided with irregular 
broad-fringed appendages, the hindmost of which communi- 
cates by a narrow duct with the posterior extremity of the 
air-bladder. In Collichthys lucida (Fig. 62) twenty-five ap- 
pendages issue from each side; the anterior ones are directed 
towards the front, but the lateral assume a more posterior 


AIR-BLADDER. 


direction, the nearer they are to the 
posterior extremity of the air-bladder, 
where they form an assemblage 
giving the appearance of a cauda 
equina. All these appendages soon 
bifurcate in a dorsal and ventral 
stem; these stems bifurcate again 
and again, and either terminate after 
the first or second bifurcation or are 
so far prolonged as to reach the 
median line of the ventral and dorsal 
sides, anastomosing with the branches 
of the other side. The branches 
being enveloped in laminz of the 
peritoneum, form a dorsal and ventral 
sac of beautiful appearance, caused 
by the regular arrangement of the 
air-vessels. The dorsal sac is situated 
between the air-bladder and the roof 
of the abdominal cavity without 
being attached to the latter. The 
ventral sac receives within its cavity 
the intestine, liver, and ovaries.— 
A peculiar mechanism has been ob- 
served in the air-bladder of the 
Ophidiude, the anterior portion of 
which can be prolonged by the con- 
traction of two muscles attached to 
its anterior extremity, with or with- 
out the addition of a small bone. 
Air-bladders with a pneumatic 
duct are found in Ganoids and Phy- 
sostomes, the duct entering the dor- 


145 


Fig. 65.—Air-bladder of 
a Sciznoid. 

I. Visceral surface opened at 
b, to show openings of the 
lateral branches. 

II. Isolated lateral branch ; 
a, its opening into the cavity 
of the air-bladder, 


sal side of the intestinal tract, with the exception of Polyp- 


L 


146 FISHES. 


terus and the Dipnoi,in which it enters on the ventral side of 
the cesophagus. In the majority the orifice is in the ceso- 
phagus, but in some, as in Acipenser, in the cardiac portion 
of the stomach, or in its blind sac, as in many Clupeoids. 
The air-bladder may be single, or consist of two divisions 
situated one behind the other (Fig. 52); its inner surface may 
be perfectly smooth, or form manifold pouches and cells. If | 


aN wha 


ee 


Cy 


! 


Y 


yee 


Fig. 64.—Air-bladder of Pogonias chromis. 


two divisions are present the anterior possesses a middle 
elastic membrane which is absent in the posterior; each 
division has a muscular layer, by which it can be separately 
compressed, so that part of the contents of the posterior may 
be driven into the elastic anterior division, and vice versa. 
The posterior division being provided with the ductus pneu- 
maticus does not require the elasticity of the anterior. 


AIR-BLADDER. 147 


Some Siluroids possess a peculiar apparatus for voluntarily 
exercising a pressure upon the air-bladder. From the first 
vertebra a process takes its origin on each side, expanding at 
its end into a large round plate; this is applied to the side of 
the air-bladder, and by pressing upon it expels the air through 
the duct; the small muscle moving the plate rises from the 
skull. 

The connection of the air-bladder with the organ of hear- 
ing in some Physostomes has been described above, p. 117. 

In the modifications of the air-bladder, hitherto mentioned, 
the chief and most general function is a mechanical one ; this 
organ serves to regulate the specific gravity of the fish, to aid 
it in maintaining a particular level in the water, in rising or 
sinking, in raising or depressing the front part of its body 
as occasion may serve. Yet a secretion of gas from the blood 
into its cavity must take place; and if this be so, it is not at 
all impossible that also an exchange of gases between the 
two kinds of blood is effected by means of the extraordinary 
development of retia mirabilia in many air-bladders. 

In all fishes the arteries of the air-bladder take their origin 
from the aorta or the system of the aorta, and its veins return 
either to the portal, or vertebral, or hepatic veins; like the other 
organs of the abdominal cavity it receives arterial blood and 
returns venous blood. However, in many fishes the arteries 
as well as veins break up below the inner membrane into 
retia merabilia 1 Various ways. The terminal ramifications 
of the arteries may dissolve into fan-like tufts of capillaries 
over almost every part of the inner surface, as in Cypri- 
noids. Or these tufts of radiating capillaries are more 
localised at various places, as in Hsocide ; or the tufts are so 
ageregated as to form gland-like, red bodies, the capillaries 
reuniting into larger vessels, which again ramify freely round 
the border of the red body; the red bodies are formed not 
only by minute arteries but also by minute veins, both freely 
anastomosing with its kind, and being inextricably inter- 

e 


148 


a, Right half ; 6, Left half; c, Cellular pouches ; 


Fig. 65.—Lung of Ceratodus opened in its lower half to show its cellular pouches. 


e, Vena pulmonalis ; f, Arterial blood-vessel ; oe, sophagus opened, to show glottis (gl.) 


FISHES. 


woven. The rest of the inner 
surface of the air-bladder re- 
ceives its blood, not from the 
red bodies, but from normally 
ramifying vessels. This kind 
of rete mirabile or “vaso- 
ganglion” is found in the 
Perch and Gadoids; it is 
generally distributed in closed 
air-bladders, but also some- 
times observed in air-bladders- 
with pneumatic duct. In 
Anguilla and Conger two 
similar vaso-ganglia are situ- 
ated at the sides of the open- 
ing of the pneumatic, duct. 
Whilst the air-bladders 
of some Ganoids, anatomi- 
cally as well as functionally, 
closely adhere to the Teleo- 
steous type, that of Amia is 
more cellular and lung-like in 
its interior than the Teleo- 
steous air-bladder, and Polyp- 
zerus approaches the Dipnoi 
not only in having a laterally 
divided air-bladder but also 
in its pneumatic duct entering 
the ventral side of the cesopha- 
cus. The air-bladder of the 
Dipnot possesses still more 
the anatomical characteristics 
of a lung and assumes its 
functions, though, as it co- 
exists with gills, only perio- 


AIR-BLADDER. 149 


dically or in an auxiliary manner. The ductus pneumaticus 
is a membranous bronchus, entering the ventral side of the 
cesophagus, and provided at its entrance with a glottis. In 
Ceratodus (Fig. 65) the lung is still a single cavity, but with 
a symmetrical arrangement of its internal pouches; it has 
no pulmonal artery, but receives branches from the arteria 
celiaca. Finally, in Lepidosiren and Protopterus the lung is 
completely divided into lateral halves, and by its cellular 
structure approaches most nearly that of a reptile; it is 
supplied with venous blood by a true pulmonary artery. 


% 
tn} 
cil 


fH. 


Fig. 66.—Heart of Lepidosteus osseus. 
J. External aspect. II. Conus arteriosus opened. 

a, Atrium ; 6, Conus arteriosus; v, Ventricle ; h, Branchial artery for 
3d and 4th gill ; %, for the second ; /, for the first; m, branch for 
the opercular gill; d, Single valve at the base of the conus ; 
e-g, Transverse rows of Ganoid valves. 


CHAPTER X. 
ORGANS OF CIRCULATION. 


The Blood-corpuscles of fishes are, with one exception, of 
an elliptic shape; this exception is Petromyzon, which pos- 
sesses circular, flat, or shghtly biconvex blood-corpuscles. 
They vary much in size; they are smallest in Teleosteans and 
Cyclostomes, those of Acerina cernua measuring z7Z57 of an 
inch in their Jongitudinal, and 5,45 in their transverse 
diameter. As far as it is known at present the Salmonide 
have the largest blood-corpuscles among Teleosteans, those of 
the salmon measuring’; 334 by sso in., approaching those of 
the Sturgeon. Those of the Chondropterygians are still larger ; 


and finally, Lepidosiren has blood-corpuscles not much smaller 
than those of Perennibranchiates, viz.— 545 by ys}, In. 
Branchiostoma is the only fish which does not possess red 
blood-corpuscles. 
[See G. Gulliver, ‘‘ Proc. Zool. Soc.,” 1862, p. 91; and 1870, p. 844; and 
1872, p. 833.] 

Fishes, in common with the other Vertebrates, are pro- 
vided with a complete circulation for the body, with another 
equally complete for the organs of respiration, and with a 
particular abdominal circulation, terminating at the liver by 
means of the vena porte ; but their peculiar character con- 
sists in this, that the branchial circulation alone is provided 
at its base with a muscular apparatus or heart, corresponding 
to the right half of the heart of Mammalia and Birds. 

The Heart is situated between the branchial and abdo- 
minal cavities, between the two halves of the scapulary arch, 


HEART. $51 


rarely farther behind, as in Symbranchidw. It is enclosed in 
a pervcardium, generally entirely separated from the abdo- 
minal cavity by a diaphragma, which is, in fact, the an- 
terior portion of the peritoneum, strengthened by aponeurotic 
fibres. However, in some fishes there is a communication 
between the pericardial and peritoneal sacs, viz. in the 
Chondropterygians and Acipenser, whilst in the Myxinoids 
the pericardial sac is merely a continuation of the peritoneum. 

The heart is, relatively to the size of the body, very small, 
and consists of three divisions: the atriwm, with a large sinus 
venosus into which the veins enter; the ventricle; and a 
conical hollow swelling at the 
beginning of the arterial system, 
the structure of which forms one 
of the most important characters 
used in the classification of fishes. 
—Inall Paleichthyes (Figs. 66 and 
67) this swelling is still a division 
of the pulsating heart, being pro- 
vided with a thick muscular stra- 
tum; it is not separated from the 
ventricle by two valves opposite 
to each other, but its interior is 


fitted with a plurality of valves, 


Fig. 67.—Heart of Ceratodus. 
a, Atrium; 6, Conus arteriosus ; 
or less numerous in the various’ d, Papillary valve within the 
conus; ¢é-g, Transverse rows of 
Ganoid valves; h, 7, Anterior 
siren and P vrotopterus offer an ex-  arcus aorte ; k, l, Posterior arcus 


ample of a modification of this "#5 % Ventricle. 


arranged in transverse series more 


groups of Paleichthyes. Lepido- 


valvular arrangement, their valves being longitudinal, each 
valve in fact being formed by the confluence of several 
smaller ones situated behind one another. This Paleichthyan 
type is called conus arteriosus. 

In Cyclostomes and Teleosteans (Fig. 68) the enlargement 


152 FISHES. 


is a swelling of the artery, without muscular stratum and with- 
out contractility ; with the exception of the Myxinoids its walls 
are thick, fibrous, with many trabecule and pouches, but it 
has no valves in its interior, and is separated from the ven- 
tricle by two valves opposite to each other. This Teleostean 
type is called bulbus aorte. 

The sinus venosus sends the whole of the venous blood 
by a single orifice of its anterior convexity into the atrium; 


Fig. 68.—Bulbus aortz of Xiphias gladius, opened. 


a, Section through part of the wall of ventricle ; b, Section through the bulbus ; 
c, Teleosteous valves of the ostium arteriosum ; d, Accessory valves, of rudi- 
mentary nature and inconstant ; e, Trabecule carnez of the bulbus. 


two thin membranous valvules turned towards the atrium, 
prevent the blood from re-entering the sinus. A pair of other 
valves between atrium and ventricle have the same function. 
The walls of the ventricle are robust, and, internally, it is 
furnished with powerful fleshy trabeculz. 


BLOOD-VESSELS. ne} 


The bulbus or conus arteriosus is prolonged into the bran- 
chial artery which soon divides, sending off a branch to each 
branchial arch. On returning from the respiratory organ the 
branchial veins assume the structure and functions of arteries. 
Several branches are sent off to different portions of the head 
and to the heart, but the main trunks unite to form the great 
artery which carries the blood to the viscera and all the parts 
of the trunk and tail, and which, therefore, represents the 
aorta of higher animals. 

In the majority of Teleosteans the aorta has proper walls 
formed by its own membranes, but in the Sturgeons it is 
independent at its commencement only, and replaced by a 
canal formed by hemal elements of the vertebral column, 
and clothed inside with a perichondrium. In many Chon- 
dropterygians and some Teleosteans (Hsox, Clupea, Silurus), 
the aorta possesses its own firm membranes along its ventral 
side, dorsally being protected by a very thin membrane only, 
attached to the concavity of the centra of the vertebre. 

The circulatory system of Branchiostoma and of the Dipnor 
shows essential differences from that of other fishes. 

Branchiostoma is the only fish which does not possess a 
muscular heart, several cardinal portions of its vascular 
system being contractile. A great vein extends forwards along 
the caudal region below the notochord, and exhibits con- 
tractility in a forward direction; it is bent anteriorly, passing 
into another tube-like pulsatile trunk, the branchial heart, 
which runs along the middle of the base of the pharynx, 
sending off branches on each side to the branchiz; each of 
these branches has a small contractile dilatation (bulbillus) at 
its base. The two anterior branches pass directly into the 
aorta, the others are branchial arteries, the blood of which 
returns by branchial veins emptying into the aorta. The 
blood of the intestinal veins is collected in a contractile tube, 
the portal vein, situated below the intestine, and distributed 


154 FISHES. 


over the rudimentary liver. Of all other fishes, only in 
Myzxinoids the portal vein is contractile. All the blood- 
corpuscles of Branchiostoma are colourless and without 
nucleus. 

In Dipnoi a rudimentary division of the heart into a right 
and left partition has been observed; this is limited to the 
ventricle in Ceratodus, but in Lepidosiren and Protopterus an 
incomplete septum has been observed in the atrium also. 
All Dipnoi have a pulmonal vein, which enters the atrium 
by a separate opening, provided with a valve. The pulmonal 
artery rises in Lepidosiren and Protopterus from an arch of the 
aorta, but in Ceratodus it is merely a subordinate branch, 
rising from the Arteria caliaca. 


CHAPTER XI. 
URINARY ORGANS. 


In Branchiostoma no urinary organs have been found. 

In Myxinoids these organs are of a very primitive structure : 
they consist of a pair of ducts, extending from the urogenital 
porus through the abdominal cavity. Each duct sends off at 
regular intervals from its outer side a short wide branch (the 
uriniferous tube), which communicates by a narrow opening 
with a blind sac. At the bottom of this sac there is a small 
vaso-ganglion (Malpighian corpuscle), by which the urine is 
secreted. 

In the Lampreys the kidneys form a continuous gland- 
like body, with irregular detached small portions. The 
ureters coalesce before they terminate in the urogenital 
papilla. 

In Chondropterygians the kidneys occupy the posterior 
half or two-thirds of the back of the abdominal cavity, without 
the sac of the peritoneum (as in all fishes) which forms a firm 
tendinous horizontal septum. The kidneys of the two sides 
are never confluent, and generally show a convoluted or 
lobulated surface. The ureters are short; each is dilated into 
a pouch, and communicating with its fellow terminates by 
a single urethra (which also receives the vasa deferentia) 
behind the end of the rectum in the large common cloaca. 

In Ganoids the kidneys occupy a similar position as in 
Chondropterygians, but these fishes differ considerably with 
regard to the termination and the arrangement of the ends of 


156 FISHES. 


the urogenital ducts. The Dipnoi possess a cloaca. In 
Ceratodus the ureters open into it by a common opening, 
separate from the genital opening; and no closed urinary 
bladder has been developed. Lepidostren has a small urinary 
bladder ; the ureters do not communicate directly with it, but 
terminate separately on small papillz in the dorsal compart- 
ment of the cloaca. The other Ganoids lack a cloaca, and the 
urogenital opening is behind the vent as in Teleosteans. In 
all the genital and urinary ducts coalesce towards their end. 
The Sturgeons have no urinary bladder, whilst it is present 
in Ama, the ureters opening separately into it. 

The kidneys of Teleosteans are situated likewise without 
the peritoneal cavity, immediately below some part of the 
vertebral column, and vary exceedingly with regard to form 
and extent. Sometimes they reach from the skull to between 
the muscles of the tail, sometimes they are limited to the 
foremost part of the abdominal cavity (in advance of the 
diaphragm), but generally their extent corresponds to that of 
the abdominal portion of the vertebral column. Frequently 
they are irregular on their dorsal surface, filling every avail- 
able recess, flat, attenuated on the sides, more or less coales- 
cent towards the middle; in other fishes they are more 
compact bodies. The ureters terminate, either separate or 
united, in a urinary bladder, varying in shape, which opens 
by a short urethra behind the vent. The urinary opening 
may be separate or confluent with that of the genital ducts, 
and is frequently placed on a more or less prominent papilla 
(papilla urogenitalis). If separate, the urinary opening is 
behind the genital; and if a papilla is developed, its extre- 
mity is perforated by the urethra, the genital opening being 
situated nearer the base. A few Teleosteans show an arrange- 
ment similar to that of Chondropterygians and Dipnoi, the 
urogenital openings being in the posterior wall of the rectum 
(Symbranchide, Pediculati, and some Plectognatht). 


CHAPTER XII. 
ORGANS OF REPRODUCTION. 


Au fishes are dioecious, or of distinct sex. Instances of 
so-called hermaphroditism are, with the exception of Serranus, 
abnormal individual peculiarities, and have been observed in 
the Cod-fish, some Pleuronectidze, and in the Herring. Either 
the generative organ of one side was found to be male, that 
of the other female; or the organ of one or both sides was 
observed to have been developed partly into an ovary partly 
into a testicle. In the European species of Serranus a tes- 
ticle-like body is attached to the lower part of the ovary; 
but many specimens of this genus are undoubtedly males, 
having normally developed testicles only. 

The majority of fishes are oviparous, comparatively few 
viviparous ; the embryos being developed either in the ova- 
rium or in some dilated portion of the oviduct. In vivi- 
parous fishes actual copulation takes place, and the males of 
most of them are provided with copulatory or intromittent 
organs. In oviparous fishes the generative products are, 
during sexual excitement, discharged into the water, a very 
small quantity of semen being sufficient for effectual im- 
pregnation of a number of ova dispersed in a considerable 
quantity of water; circumstances which render artificial 
impregnation more practicable than in any other class of 
animals. 

In Branchiostoma the generative organs occupy the ventral 
side of the abdominal cavity, into which they discharge their 
contents. No ducts are developed in either sex. 


158 FISHES. 


In the Cyclostomes the generative organ is single, and 
fixed to or suspended from the median line of the back of 
the visceral cavity by a duplicature of the peritoneum (meso- 
arium); the testicle and ovary being distinguishable by 
their contents only. These escape by dehiscence of the cells 
or capsules and rupture of the peritoneal covering into the 
abdominal cavity, and are expelled by reciprocal pressure of 
the intertwined sexes through the porus genitalis, which is 
sunk between two labia of the skin in Myzxine, and produced 
into a long papilla in Petromyzon. 

The ova of the Lampreys are small, globular, like those of 
Teleosteans. Those of Myxine have a very peculiar shape 
when mature; they are of an oval form, about 15 millimetres 
long and 8 millimetres broad, enveloped in 
a horny case, which at each end is provided 
with a bundle of short threads, each thread 
ending in a triple hook. Whilst in the 
mesoarial fold the eggs are attached to one 
another by means of these hooks, and after 
being expelled they probably fix themselves 
by the same means to other objects. Asin all 
fishes producing ova of large size, the number 


of ova matured in one season is but small. 
Fer 60 Ovi of In Teleosteans the generative organs are 
Myxine glutinosa, comparatively large. In some families the 
ae ovaries are without closed covering and with- 
out oviducts, as in Salmonide, Galaxiide, Notopteride, Mure- 
wide, and others. The surface of such an open ovary— 
as, for instance, that of the Salmon—is transversely plaited, 
the ova being developed in capsules in the stroma of the 
lamin ; after rupture of the capsules the mature ova drop 
into the abdominal cavity, and are expelled by the porus 
genitalis. The ovaries of the other Teleosteans are closed 
sacs, continued into oviducts. Frequently such ovaries 


ORGANS OF REPRODUCTION, 159 


coalesce into a single body, or one in which the division 
is effected internally only by a more or less complete sep- 
tum. Fixed by a mesoarium, the ovaries occupy generally 
a position outwards of the intestine or air-bladder; their 
form varies as well as the thickness and firmness of their 
covering, which frequently is an extremely thin trans- 
parent membrane. The inner surface of the ovarian sac 
is transversely or longitudinally plaited or covered with 
fringes, on which the ova are developed, as in the open 
ovaries. In the viviparous Teleosteans the embryons are 
likewise developed within the ovary, notably in the Zmbio- 
tocide, many Llenniide, and Cyprinodontide, Sebastes vivi- 


Fig. 70.—Ditrema argenteum, with fully developed young, ready for expulsion 

by the genital orifice, 0; a, folds of the ovarian sac ; v, vent. 
parus, etc. Among the Cyprinodonts the end of the oviduct 
is attached to the anterior anal rays, which are modified 
into supports of its termination. In Rhodeus the oviduct 
is periodically prolonged into a long oviferous tube, by 
means of which the female deposits her ova into the shells 
of living Bivalves. 

The ova of Teleosteous Fishes are extremely variable in 
size, quite independently of the size of the parent species. 
The ova of large and small individuals of the same species, 
of course, do not differ in size; but, on the whole. larger 


160 FISHES. 


individuals produce a greater number of ova than smaller 
ones of the same species. The larger the size of the ova is 
in a species, the smaller is the number produced during one 
season. The ova of the Eel are almost microscopic. The 
small sized roe in the Herring, Lump-fish, Halibut, and 
Cod-fish, have been estimated at respectively 25,000, 155,000, 
3,500,000, and 9,344,000. Larger in size and fewer in num- 
ber are those of Antennarius, Salmo, Aspredo, Lophobranchs, 
etc. Comparatively largest are those of Gastrosteus; and 
the Siluroid genus Arius, the males of which 
take care of their progeny, produces ova from 
5 to 10 millimeters in diameter. The ova of 


all Teleosteans are perfectly globular and _ soft- 
Ovumof Arius shelled. Teleosteans without oviduct, deposit 
boakii (Cey- 
lon), showing 


embryo. Nat. Teleosteans with an oviduct the ova are en- 
size. 


them separated from one another; whilst in many 


veloped in a glutinous substance, secreted by its 
glands, swelling in the water and forming lumps or cords, in 
which the ova are aggregated. 

Instances of the female taking care of her progeny are 
extremely scarce in fishes. At present only two examples 
are known, that of the Siluroid genus Aspredo, and of Soleno- 
stoma. In the former, during the time of propagation, the 
integuments of the lower side of the flat trunk of the female 
assume a soft and spongy texture. After having deposited 
the eggs, the female attaches them to, and presses them 
into, the spongy integument, by merely lying over them. 
She carries them on her belly, as the Surinam Toad (Pipa) 
carries her ova on the back. When the eggs are hatched the 
excrescence on the skin disappears, and the abdomen becomes 
as smooth as before. In Solenostoma the inner side of the long 
and broad ventral fins coalesces with the integuments of the 
body, a large pouch being formed for the reception of the eggs. 
There is a peculiar provision for the retention of the eggs 


+ 


ORGANS OF REPRODUCTION. 161 


in the sac, and probably for the attachment of the embryo. 


Fig. 72.—Abdomen of Aspredo batrachus, with the ova attached; at a, the ova 
are removed, to show the spongy structure of the skin, and the processes 
filling the interspaces between the ova. (Natural size.) 


The inner walls of the sac are lined with long filaments, 
M 


162 


FISHES, 


arranged in series along the ventral rays, and more nume- 


Fig. 73.—Solenostoma cyanopterum ? (Indian Ocean). 


rous and longer at the base of the rays than in the middle 


Fig. 74.—Pouch with 
ova, formed by the 
ventral fins of Sole- 
nostoma. Lower 
aspect ; the edges of 
the fins have been 
pushed aside toallow 
of a view of the in- 
side of the pouch. 
(Natural size. ) 


of their length, behind which they disappear 
entirely. They are also more developed in 
examples in which eggs are deposited in 
the sac than in those which have the sae 
empty. The filaments most developed 
have a length of half an inch, and are beset 
with mamilliform appendages. <A slightly 
undulated canal runs along the interior of 
the filament. 

The Zestieles of the Teleosteans are al- 
ways paired, and occupy the same position 
as the ovaries. Their size varies extra- 
ordinarily at the different seasons of the 
year. Vasa deferentia are constant. In 
the males of viviparous Teleosteans the 
urogenital papilla is frequently enlarged, 


and clearly serves as an intromittent organ. In Clinus despictl- 


latus the vas deferens widens within the abdomen into a 


cavity occupied by a complex network of loose fasciculi, 


rising from the mucous membrane. The cavity can be com- 


pressed by a special powerful muscle, the accumulated semen 


being thus expelled with considerable force through the nar- 


row aperture of the penis. In many Cyprinodonts the vas 


deferens runs along the anterior anal rays, which may be 
thickened, and prolonged into a long slender organ. 


ORGANS OF REPRODUCTION. 


163 


exception of Aspredo and Solenostoma, mentioned above (p. 


160), it is the male on which this duty 
devolves. In some, as in Cottus, Gastrosteus, 
Cyclopterus, Antennarius, Ophiocephalus, 
Callichthys, the male constructs with more 
or less skill a nest, and jealously guards 
the ova deposited in it by the female. 
The male of some species of Arius carries 
the ova (Fig. 71) about with him in his 
capacious pharynx. The species of Chroms, 
inhabiting the sea of Galilee, are said to 
take care of their ova in the same manner. 
And, finally, in the Lophobranchs, nature 
has aided this instinct by the development 
of a pouch on the abdomen or lower side 
of the tail. In the Syngnathide this pouch 
is formed by a fold of the skin developed 
from each side of the trunk and tail, the 
free margins of the fold being firmly united 
in the median line, whilst the eggs are 
being hatched in the inside of the pouch. 
In Hippocampus the pouch is completely 
closed, with a narrow anterior opening. 
The genital organs of Ganoids show 
similar diversity of structure as those of 
Teleosteans, but on the whole they approach 


Fig. 76.—Sub-caudal 
pouch of Syngnathus 
acus, with the young, 
ready to leave the 
pouch. One side of 
the membrane of the 
pouch is pushed 
aside to admit of a 
view of its interior. 
(Natural size. ) 


164 FISHES. 


the Batrachian type. The ovaries are not closed, except in 
Lepidosiren ; all Ganoids possess oviducts. In the Sturgeons 
the oviduct as well as the vas deferens is represented by 
a funnel-shaped prolongation of the peritoneum, which com- 
municates with the wide ureter. The inner aperture of 
the funnel is on a level of the middle of the testicle or 
ovary, the outer within the ureter; and it is a noteworthy 
fact that only at certain periods of the life of the fish this 
outer aperture is found to be open,—at other times the peri- 
toneal funnel appears as a closed blind sae within the ureter. 
The mode of passage of the semen into the funnel is not known. 

In Polypterus and Anvia, proper oviducts, with abdominal 
apertures in about the middle of the abdominal cavity, are 
developed ; they coalesce with the ureters close to the com- 
mon urogenital aperture. 

In Ceratodus (Fig. 77), a long convoluted oviduct extends 
to the foremost limit of the abdominal cavity, where it opens 
by a slit at a considerable distance from the front end of the 
long ovary ; this aperture is closed in sexually immature speci- 
mens. The oviducts unite close to their common opening in 
the cloaca. During their passage through the oviduct the ova 
receive a gelatinous covering secreted by its mucous mem- 
brane. This is probably also the case in Lepidosiren, which 
possesses a convoluted oviduct with secretory glands in the 
middle of its length. The oviduct begins with a funnel- 
shaped dilatation, and terminates in a wide pouch, which 
posteriorly communicates with that of the other side, both 
opening by a common aperture behind the urinary bladder. 

The ova of Ganoids, as far as they are known at present, 
are small, but enveloped in a gelatinous substance. In the 
Sturgeon have been counted as many as 7,635,200. Those 
of Lepidosteus seem to be the largest, measuring 5 millimetres 
in diameter with their envelope, and 3 millimetres without 
it. They are deposited singly, like those of Newts. 


165 


ORGANS OF REPRODUCTION. 


‘JONPIAO 944 JO doy T1o yeuTUIOpay “ f 4y3It oY 


OJUL YonpIAo yor oq} Jo Sutuedo h FouerqMoW IOUT S}T JO SP[OF ot} MOS OF pouado st yonprao 


$ OAT] JO WOTJog {7 | doVJANS JayNO S}T Sulmoys 


‘Krvao 4JarT 


‘ 
( 


Summotoytzed ey} Aq poLeaod St Yor 


‘snpoyeray Jo solmwaQ—'L) ‘Bid 


‘ 


ayy Jo yaed somoy oy} ‘d ¢ yonplAad ‘0 


govjANs JaUUT oY} Woy UMOYs ArwAo 4 


ysty 


77) 


166 FISHES. 


In Chondropterygians (and Holocephali) the organs of re- 
production assume a more compact form, and are more free 
from a lengthened attachment to the back of the abdominal 
cavity. The ovaries of the majority are paired, single in 
the Carchariide and Seyllide, one remaining undeveloped. 
But the oviducts are always paired, beginning immediately 
behind the diaphragma with a common aperture. They 
consist of two divisions, separated by a circular valve; the 
upper is narrow, and provided within its coats with a gland 
which secretes the leathery envelope in which most of 
the Chondropterygian ova are enclosed; the lower forms 
the uterine dilatation, in which the embryoes of the vivi- 
parous species are developed. Generally the vitelline sac 
of the embryoes is free, and without connection with the 
uterus, which in these cases has merely the function of 
a protecting pouch; but in Carcharias and Mustelus levis a 
placenta uterina is formed, the vascular walls of the vitelline 
sac forming plaits fitting into those of the membrane of the 


Fig. 78.—Ventral fins and claspers of Chiloscyllium trispeculare. 


uterus. The ends of the uteri open by a common aperture 
behind the ureter into the cloaca. 


ORGANS OF REPRODUCTION. 167 


The testicles are always paired, rounded, and situated in 
the anterior part of the abdominal cavity, covered by the 
liver. Vasa efferentia pass the semen into a much-convoluted 
epididymis, which is continued into the vas deferens; this, 
at the commencement of its course, is spirally wound, but 
becomes straight behind, and has its end dilated into a 
seminal reservoir. It opens with the urethra in a papilla 
within the cloaca. 

The so-called claspers of Chondropterygians (Fig. 78) are 
characteristic of all male individuals. They are semi-ossified 
appendages of the pubic, with which they are movably joined, 
and special muscles serve to regulate their movements. Some- 
times they are armed with hook- 
like osseous excrescences (Selache). 
They are irregularly longitudinally 
convoluted, and, when closely ad- 
pressed to each other, form a canal 
open at their extremity. A gland, 


abundantly discharging a_ secre- 


tion during the season of pro- 
pagation, is situated at, and opens 
into, the base of the canal. It is 
still doubtful whether the generally- 
adopted opinion that their func- 


tion consists in holding the female 
during copulation is correct, or 


whether they are not rather an in- 
tromittent organ, the canal of which 
not only conducts the secretion of 
their proper gland but also the 
impregnating fluid. 


The ova of the oviparous Chon- 
3 . Fig. 79.—Egg of a Scyllium 
dropterygians are large and few in from Magelhan’s Straits (? Se. 


number ; they are successively im-  chilense). Natural size. 


168 FISHES, 


pregnated, and the impregnation must take place before they 
are invested with a tough leathery envelope which would be 


Fig. 80.—Egg-shell of Cestracion philippi, half natural size, linear. 
I. External view. II. Vertical section. 


a, One spiral ridge ; 6, The other spiral ridge ; c, Cavity for the ovum. 


impenetrable to the semen, that is, before they enter the uterus ; 
therefore, copulation must take place in all these fishes. The 
form of the ege-shell differs in the various genera; generally 
(Fig. 79) they are flattened, quadrangular, with each of the 
four corners produced, and frequently prolonged into long 
filaments which serve for the attachment of the ova to other 
fixed objects. In Notidanus the surfaces are crossed by 
numerous ridges. In Cestracion (Fig. 80) the egg is pyriform, 
with two broad ridges or plates, wound edgewise round it, 
the two ridges forming five spires. The eggs of Callorhynchus 


OVA OF CHONDROPTERYGIANS. 169 


(Fig. 81) have received a protective resemblance to a broad- 
leaved fucus, forming a long depressed ellipse, with a plicated 
and fringed margin. 


TO Ly “ites 
on = 
be aed 
SY at i : a 
x iy. Nu \\ va ‘ WAS 
SS yf OTH i N\A 
S iy ‘ ii ae i Z 
S “iff My) \ rN 
< A ; ‘ y’ , i 
Vr ee WE 
NS | Thy i ii ow MN 
\ ‘iil ai’ | \ 
tlw jill” WN 
Wi “il =—\\y ! N 
Ni | ==. \ iN 
: gg : ‘a i i \ 
a Hil \ 
; ‘NNN ii \ \ 
jf" 


\ SU \\ 
SQ" “lay 


DO 
wn 


a \\ 
S\C 


| I. & \\ 


: | 
i y ii j | 
ii: y \ 
Bie 


MT IH J 
| lil ff ‘\ 
il 


au 
Hl 


ee EBA 
= ZEA a 
Ba B&-AAA: 
BES ZA 


EZ 


ZB 


B.- 


Fig. 81.—Egg of Callorhynchus antarcticus. 
a, Cavity for the embryo. 


CHAPTER XIII. 


GROWTH AND VARIATION OF FISHES. 


CHANGES of form normally accompanying growth (after ab- 


sorption of the vitelline 


sac) are observed in all fishes ; 


but in the majority they affect only the proportional size 


of the various parts of the body. In 
young fishes the eyes are constantly larger 
than in adult relatively to the size of the 
head; and again, the head is larger rela- 
tively to that of the body. Changes amount- 


Fig, 82.—Mouth of 12g to metamorphosis have been hitherto 
Larva of Petromy- observed in Petromyzon only. In the lar- 


zon branchialis. 


val condition (Ammocetes) the head is 


very small, and the toothless buccal cavity is surrounded 


Fig. 83.—Mouth of Petromyzon 
fluviatilis. 
me, Maxillary tooth ; md, Mandi- 
bulary tooth ; 7, Lingual tooth ; 
s, Suctorial teeth. 


by a semicircular upper lip. The 
eyes are extremely small, hid- 
den in a shallow groove; and 
the vertical fins form a con- 
tinuous fringe. In the course of 
three or four years the teeth are 
developed, and the mouth changes 
into a_ perfect suctorial organ ; 
the eyes grow; and the dorsal 
fin is divided into two divisions. 
In Malacopterygians and Ana- 
canths the embryonal fringe from 


which the vertical fins are developed, is much longer per- 


GROWTH. 171 
sistent than in Acanthopterygians. A metamorphosis relating 
to the respiratory organs, as in Batrachians, is indicated in 
the class of Fishes by the external gills with which feetal 
Plagiostomes (Fig. 58, p. 136) and the young of some Ganoids, 
viz. the Protopterus and Polypterus, are provided. 

One of the most extraordinary changes by which, during 
erowth, the form and position of several important organs 
are affected, occurs in Flat-fishes (Pleuronectide) ; their young 
are symmetrically formed, with a symmetrical mouth, and 
with one eye on each side, and, therefore, keep their body in a 
vertical position when swimming. As they grow they live 
more on the bottom, and their body, during rest, assumes a 
horizontal position ; in consequence, the eye of the lower side 
moves towards the upper, which alone is coloured; and in 
many genera the mouth is twisted in the opposite direction, 
so that the bones, muscles, and teeth are much more developed 
on the blind side than on the coloured. In a great number of 
other Teleostei certain bones of the head show a very different 
form in the young state. Ossification proceeds in those 
bones in the direction of lines or radii which project in the 
form of spines or processes; as the interspaces between 


ie 


Fig. 84.—Armature of preoperculum of young Caranx ferdau. (Magnified.) 
I. Of an individual, 1} inch long. II. Of an individual, 2 inches long. 


these processes are filled with bone, the processes disap- 
pear entirely, or at least project much less in the older than 
in the younger individuals (Fig. 84). The young of some fishes 
may be armed with a long powerful preeopercular or scapular 
spine, or show a serrature of which nothing remains in the 


i772 FISHES. 


adult fish except some ridges or radiating lines. These pro- 
cesses seem to serve as weapons of defence during a period 
in the life of the fish in which it needs them most. In 
not a few instances a portion of this armature is so much 


Fig. 85.—Tholichthys osseus. Six times the natural size. 


developed that the disappearance of its most projecting parts 
with the growth of the fish is not only due to its being sur- 
rounded by other bone, but, partially 
at least, caused by absorption. The 
Carangide, Cyttide, Squamupinnes, 
AXiphiide, offer instances of such 
remarkable changes. A fish, de- 
scribed as Tholichthys osseus (Fig. 
85), is probably the young of a 
Cyttoid, the supra-scapula, humerus, 


Fig. 86.—Tholichthys-stage of and preeoperculum forming enor- 

Pa ohueNy): mously enlarged plates. In the fish 
Fig. 86 those bones appear still enlarged, and the frontals 
develop a remarkably long and curved horn above the orbit. 
In the Tholichthys-stage of Pomacanthus (specimens 10 milli- 
metres long, Fig. 87), the frontal bone is prolonged into a 
straight lancet-shaped process, nearly half as long as the 


body; the suprascapular and preeopercular processes cover 


GROWTH. 7s 


and hide the dorsal and ventral fins. The plates attached to 
the shoulder-girdle remain persistent until the young fish 


Fig. 87.—Tholichthys-stage of Pomacanthus (magn.) Atlantic. 


has assumed the form of the adult; thus they are still 
visible in young Chetodon citrinellus, 
30 millimetres long, in which the 
specific characters are already fully 
developed—The Sword-fishes with 
ventral fins (MHistiopharus) belong 
to the Teleosteans of the largest size ; 
in young individuals, 9 millimetres Fig. 88.—Young Chetodon 
: : citrinellus (30 mill. long). 

long (Fig. 89), both jaws are pro- 

duced, and armed with pointed teeth; the supra-orbital 
margin is ciliated; the parietal and preeoperculum are pro- 
longed into long spines; the dorsal and anal fins are a 
low fringe, and the ventrals make their appearance as a 
pair of short buds. When 14 millimetres long (Fig. 90) 
the young fish has still the same armature of the head, 
but the dorsal fin has become much higher, and the ventral 


174 FISHES. 


filaments have grown to a great length. At a third stage, 


Fig. 89.— Young Sword-fish (Histiophorus), 9 mill. long. 
Atlantic. (Magn. ) 


Fig. 90.—Young Sword-fish (Histiophorus), 14 mill. long. 
South Atlantic. (Magn. ) 


when the fish has attained to a length of 60 millimetres, 


Fig. 91.—Young Sword-fish (Histiophorus), 60 mill. long. Mid-Atlantic. 


the upper jaw is considerably prolonged beyond the lower, 


GROWTH. 175 


losing its teeth; the spines of the head are shortened, and the 
fins assume nearly the shape which they retain in mature indi- 
viduals. Young Sword-fishes without ventral fins (Yiphias) 
undergo similar changes; and, besides, their skin is covered 
with small rough excrescences longitudinally arranged, which 
continue to be visible after the young fish has assumed the 
form of the mature in other respects (Fig. 92). 


Fig. 92.—Xiphias gladius, young, about 8 inches long. 


The Plectognaths show no less extraordinary changes : 
an extraordinary form taken in the South Atlantic, and 
named Ostracion boops, is con- 
sidered by Liitken to be the 
young of a Sunfish (Orthago- 
riscus). In very young more 
advanced Sun-fishes (18 to 32 
millimetres) the vertical dia- 
meter of the body exceeds, 


or is not much less than, the Fig. 93.—‘ Ostracion boops” (much 
magnified). 


longitudinal; and small coni- 
cal spines are scattered over its various parts. The caudal 


Fig. 94.—Young of Orthagoriscus, 18 and 32 mill. long. (Natural size. ) 


fin is developed long after the other vertical fins. 


176 FISHES. 


Similar changes take place in a number of other fishes, 
and in many cases the young are so different that they were 
described as distinct genera: thus Priacantichthys has proved 
to be the young of Serranus, Rhynchichthys that of Holocen- 
trum, Cephalacanthus of Dactylopterus, Dicrotus of Thyrsites, 
Nauclerus of Naucrates, Porthmeus of Chorinemus, Lampugus 
of Coryphena, Acronurus of Acanthurus, Keris of Naseus, 
Porobronchus of Fierasfer, Couchia of Motella, Stomiasunculus 
of Stomias, ete. 

The fins are most frequently subject to changes; but, 
whilst in some fishes parts of them are prolonged into fila- 
ments with age, in others the filaments exist during the early 
life-periods only ; whilst in some a part of the dorsal or the 
ventral fins is normally developed in the young only, in 
others those very parts are peculiar to the mature age. The 
integuments are similarly altered : in some species the young 
only has asperities on the skin, in others the young are 
smooth and the old have a tubercular skin; in some the 
young only have a hard bony head; in others (some Silu- 
roids) the osseous carapace of the head and neck, as it appears 
in the adult, is more or less covered with soft skin whilst 
the fish is young. 

In not a few fishes the external changes are in relation 
to the sexual development (Callionymus, many Labyrinthici, 
Cyprinodonts). These secondary sexual differences show them- 
selves in the male individual, only when it commences to enter 
upon his sexual functions, and it may require two or more 
seasons before its external characteristics are fully developed. 
Immature males do not differ externally from the old female. 
The male secondary sexual characters consist principally in 
the prolongation of some of the fin-rays, or of entire fins ; and 
in Salmonide in the greater development of the jaw-bones. 
The coloration of the male is in many fishes much brighter 
and more variegated than that of the female, but in com- 


SEXUAL DIFFERENCES. i ba/g 


paratively few permanent (as in some Callionymus, Labrus 
mixtus); generally it is acquired immediately before and 
during the season of propagation only, and lost afterwards. 
Another periodical change in the integuments, also due -to 
sexual influence and peculiar to the male, is the excrescence 
of wart-like tubercles on the skin of many Cyprinoids ; they 
are developed chiefly on the head, but sometimes extend over 
the whole body and all the fins. 

With regard to size, it appears that in all Teleosteous fishes 
the female is larger than the male ; in many Cyprinodonts the 
male may be only one-sixth or even less of the bulk of the 
female. The observations on the relative size of the sexes 
are few in Paleichthyes, but such as have been made tend to 
show that, if a difference exists at all, the male is generally 
the larger (Lepidosteus). In the Rays (Raja) the sexes, after 
they have attained maturity, differ in the development of 
dermal spines and the form of the teeth, the female being 
frequently much rougher than the male. There is much 
variation in this respect in the different species; but the 
males are constantly distinguished by an oblong patch of 
erectile clawlike spines on each pectoral fin, and by having 
the teeth (all, or only a portion) pointed, and not obtuse, like 
those of the females. In Sharks no secondary sexual differ- 
ences have been observed; the male Chimeridwe (see Fig. 
96, p. 184), possess a singular comblike cartilaginous ap- 
pendage on the top of the head, which can be erected or 
depressed into a groove, both the appendage and the anterior 
part of the groove being armed with hooklets. The use of 
this singular organ is not known. 

The majority of Teleostei are mizogamous—that is, the 
males and females congregate on the spawning-beds, and 
the number of the former being in excess, several males 
attend to the same female, frequently changing from one 
female to another. The same habit has been observed in 

N 


178 FISHES. 


Lepidosteus. Gastrosteus is truly polygamous, several females 
depositing their ova into the same nest, guarded by one 
male only. Some Teleostei (Ophiocephalus), and probably all 
Chondropterygians, are monogamous ; and it is asserted that 
the connection between the pair is not merely temporary, but 
lasts until they are separated by accident. Monogamous are 
probably also all those Teleosteans which bring forth living 
young, and those, the males of which, for the attraction of 
the female, are provided with appendages, or ornamented 
with a bright coloration. 

Hybridism is another source of changes and variations 
within the limits of a species, and is by no means so scarce 
as has been believed hitherto; it is only apparently of ex- 
ceptional occurrence, because the life of fishes is more with- 
drawn from our direct observation than that of terrestrial 
animals. It has been observed among species of Serranus, 
Pleuronectide, Cyprinidae, Clupeide, and especially Salmonide. 
As in other animals, the more certain kinds of fishes are 
brought under domestication, the more readily do they inter- 
breed with other allied species. It is characteristic of hybrids 
that their characters are very variable, the degrees of affinity 
to one or the other of the parents being inconstant; and 
as these hybrids are known readily to breed with either of 
the parent race, the variations of form, structure, and colour 
are infinite. Of internal organs the dentition, gill-rakers, 
pyloric appendages, are those particularly affected by such 
mixture of species. 


Some fishes are known to grow rapidly (in the course of 
from one to three years) and regularly to a certain size, growth 
being definitely arrested after the standard has been attained. 
Such fishes may be called “ full-grown,” in the sense in which 
the term is applied to warm-blooded Vertebrates—the Stickle- 
backs, most Cyprinodonts, and many Clupeoids (Herring, 


= 


a 


IRREGULARITY OF GROWTH. 179 


Sprat, Pilchard) are examples of this regular kind of growth.’ 
But in the majority of fishes the rate of growth is extremely 
irregular, and it is hardly possible to know when growth 
is actually and definitely arrested. All seems to depend on 
the amount of food and the more or less favourable circum- 
stances under which the individual grows up. Fishes which 
rapidly grow to a definite size are short-lived, whilst those 
which steadily and slowly increase in size attain to a great 
age, Teleosteans as well as Chondropterygians. Carp and Pike 
have been ascertained to live beyond a hundred years. 

It is evident that such diversity and irregularity of 
growth in the same species is accompanied by considerable 
differences in the appearance and general development of 
the fish. No instance is more remarkable than that of the 
so-called ZLeptocephali, which for a long time have been 
regarded either as a distinct group of Fishes, or as the larval 
stages of various genera of fishes. 


Fig. 95.—Leptocephalus. 


The Leptocephali proper are small, narrow, elongate, more 
or less band-shaped fishes, pellucid in a fresh state, but assum- 


1 This applies to individuals only growing up under normal conditions. 
Dr. H.’A. Meyer has made observations on young Herrings. Individuals 
living in the sea had attained at the end of the third month a length of 
45 to 50 millimetres, whilst those reared from artificially-impregnated ova 
were only from 30 to 35 millimetres long. When the latter had been sup- 
plied with more abundant food, they grew proportionally more rapidly in 
the following months, so that at the end of the fifth month they had reached 
the same length as their brethren in the sea, viz. a length of 65 to 70 milli- 
metres. 


180 FISHES. 


ing a white colour when preserved in spirits, resembling a 
tapeworm, being quite as soft and flexible. The skeleton is 
entirely cartilaginous, or slight ossifications are only now and 
then visible, especially towards the end of the vertebral 
column. The latter is replaced by a chorda dorsalis which, 
in many specimens, is found to be divided into numerous 
segments. Neural arches are sometimes present in their 
rudimentary condition. The anterior end of the chorda 
passes into the cartilaginous base of the skull, the connec- 
tion not being by means of joint and hgaments. Hemal 
arches are found on the caudal portion. Ribs none. The 
skull, ike the vertebral column, is nearly entirely cartila- 
einous. The basi-sphenoid, frontal, and jaw-bones are the 
first which may be distinguished, and the mandible has 
generally ossifications. 

The muscles are generally not attached to the chorda, 
which is surrounded by a thick gelatinous mass, separating 
the lateral sets of muscles from each other. These muscles 
are attached to the external integument, each forming a thin 
flat angular band, the angle being directed forwards. How- 
ever, specimens are frequently found in which the muscles 
are more developed, evidently at the expense of the gela- 
tinous matter, which is diminished in quantity. They are 
attached to the chorda, and the entire fish has a more cylin- 
drical form of the body (Zelmichthys). 

The nervous, circulatory, and respiratory organs are well 
developed. In those with a sub-cylindrical body the blood 
is red, in those with a flat body the blood-corpuscles show 
but rarely a faint coloration. There are four branchial 
arches, and in some (Zilwrus) pseudobranchie have been 
found. The gill-openings are more or less narrow. The 
nostrils are double on each side, and the posterior is close 
to the eye. 

The stomach has a large blind sac, and in Leptocephalus 


LEPTOCEPHALI. 181 


two lateral ceca. The intestine is straight, running close to 
the abdominal profile, with a small appendix directed for- 
ward and a larger one directed backwards. The vent is 
nearly always very small, and, in preserved examples at 
least, cannot always be discovered. Its position is vari- 
able, even in examples entirely similar in other points. Air- 
bladder none. No trace of generative organs. 

The vertical fins, when present, are confluent, with more 
or less conspicuous traces of rays; sometimes they are merely 
a fold of the skin, without any rays. Pectoral fins some- 
times present, sometimes rudimentary, sometimes entirely 
absent. Ventrals none. 

Most examples have series of round black dots along 
each side of the abdominal profile, along the lateral line, and 
sometimes along the dorsal fin. They remind us of the lumi- 
nous organs of many Scopelidw, Stomiatide, and other pelagic 
fishes, but are composed entirely of pigmentary cells. 

These fishes are found floating in the sea, frequently at a 
ereat distance from land. Their movements are slow and 
languid. The largest specimen of Leptocephalus observed 
was 10 inches, but specimens of that size are very rare. 

[See Kolliker, Zeitschr. wiss. Zool. iv. 1852, p. 360; and Carus, Ueber 

die Leptocephaliden. Leipz. 1861. 4to.] 

Taking into account all the various facts mentioned, we 
must come to the conclusion that the Leptocephalids are 
the offspring of various kinds of marine fishes, representing, 
not a normal stage of development (larve), but an arrest 
of development at a very early period of their life; they con- 
tinue to grow to a certain size without corresponding develop- 
ment of their internal organs, and perish without having 
attained the characters of the perfect animal. The cause 
by which this abnormal condition is brought about is not 
known ; but it is quite within the limits of probability that 
fishes usually spawning in the vicinity of land sometimes 


182 FISHES. 


spawn in the open ocean, or that floating spawn is carried 
by currents to a great distance from land; and that such 
embryoes, which for their normal growth require the con- 
ditions afforded by the vicinity of the shore, if hatched in 
mid-ocean, grow into undeveloped hydropic creatures, such as 
the Leptocephales seem to be. 


Abundance or scarcity of food, and other circumstances 
connected with the localities inhabited by fishes, affect con- 
siderably the colour of their muscles and integuments; the 
periodical changes of colour in connection with their sexual 
functions have been referred to above (p. 176). The flesh 
of many Teleostei is colourless, or but shghtly tinged by the 
blood ; that of Scombridee, most Ganoids and Chondroptery- 
gians, is more or less red; but in badly-fed fishes, as well 
as In very young ones, the flesh is invariably white (anemic). 
Many fishes, ike the Salmonide, feed at times exclusively on 
Crustaceans, and the colouring substance of these Inverte- 
brates, which by boiling and by the stomachic secretion turns 
red, sees to pass into the flesh of the fishes, imparting to it 
the well-known “salmon” colour. Further, the coloration of 
the integuments of many marie fish is dependent on the 
nature of their surroundings. In those which habitually hide 
themselves on the bottom, in sand, between stones or sea- 
weeds, the colours of the body readily assimilate to those of 
the vicinity, and are thus an important element in the economy 
of their ife. The changes from one set or tinge of colours 
to another may be rapid and temporary, or more or less per- 


manent; in some fishes—as in the Pediculati, of which 
the Sea-Devil, or Lophius, and Antennarius are members— 
scarcely two individuals are found exactly alike in colora- 
tion, and only too frequently such differences in coloration are 
mistaken for specific characters. The changes of colours are 
produced in two ways : either by an increase or decrease of the 


—— 


VARIATION OF COLOUR. 183 


black, red, yellow, etc., pigment-cells, or chromatophors, in the 
skin of the fish; or by the rapid contraction or expansion 
of the chromatophors which happen to be developed. The 
former change is gradual, like every kind of growth or de- 
velopment; the latter rapid, owing to the great sensitive- 
ness of the cells, but certainly involuntary. In many bright- 
shining fishes—as Mackerels, Mullets—the colours appear 
to be brightest in the time intervening between the capture 
of the fish and its death : a phenomenon clearly due to the 
pressure of the convulsively-contracted muscles on the chro- 
matophors. External irritation readily excites the chroma- 
tophors to expand—a fact unconsciously utilised by fishermen, 
who, by scaling the Red Mullet immediately before its death, 
produce the desired intensity of the red colour of the skin, 
-without which the fish would not be saleable. However, it 
does not require such strong measures to prove the sensitive- 
ness of the chromatophors to external irritation, the mere 
change of darkness into light is sufficient to induce them to 
contract, the fish appearing paler, and vice versa. In Trout 
which are kept or live in dark places, the black chromatophors 
are expanded, and, consequently, such specimens are very 
dark-coloured ; when removed to the light they become paler 
almost instantaneously. 

Total absence of chromatophors in the skin, or AJdi- 
nism, 18 very rare among fishes; much more common is 
incipient Albinism, in Which the dark chromatophors are 
changed into cells with a more or less intense yellow pig- 
ment. Fishes in a state of domestication, like the Crucian 
Carp of China, the Carp, Tench, and the Ide, are particularly 
subject to this abnormal coloration, and are known as the 
common Goldfish, the Gold-Tench, and the Gold-Orfe. But 
it occurs also not rarely in fishes living in a wild state, and 
has been observed in the Haddock, Flounder, Plaice, Carp, 
Roach, and Eel. 


184 FISHES. 


It will be evident, from the foregoing remarks, that the 
amount of variation within the limits of the same species— 
either due to the natural growth and development, or to 
external physical conditions, or to abnormal accidental cir- 
cumstances—is greater in fishes than in any of the higher 
classes of Vertebrates. The amount of variation is greater 
in certain genera or families than in others, and it is much 
ereater in Teleosteans and Ganoids than in Chondroptery- 
gians. Naturally, it is greatest in the few species which 
have been domesticated, and which we shall mention in the 
succeeding chapter. 


Fig. 96.—Chimera colliei ¢, west coast of North America, A. Front view of 
head. B. Palate. a, Peritoneal aperture ; 6, Nostrils; c, Vomerine teeth ; 
d, Mandibular teeth ; e, Palatine teeth ; f, Claspers. 


CHAPTER XIV. 


DOMESTICATED AND ACCLIMATISED FISHES ; ARTIFICIAL IMPREG- 
NATION OF OVA—-TENACITY OF LIFE AND REPRODUCTION 
OF LOST PARTS—-HYBERNATION—-USEFUL AND POISONOUS 
FISHES. 


A FEW fishes only are thoroughly domesticated — that. is, 
bred in captivity, and capable of transportation within cer- 
tain climatic limits—viz. the Carp, Crucian Carp (European 
and Chinese varieties), Tench, Orfe or Ide, and the Goramy. 
The two former have accompanied civilised man almost to 
every place of the globe where he has effected a permanent 
settlement. 

Attempts to acclimatise particularly useful species in 
countries in which they were not indigenous have been made 
from time to time, but were permanently successful in a few 
instances only ; the failures being due partly to the choice of 
a species which did not yield the profitable return expected, 
partly to the utter disregard of the difference of the climatic and 
other physical conditions between the original and new homes 
of the fish. The first successful attempts of acclimatisation 
were made with domestic species, viz. the Carp and Gold- 
fish, which were transferred from Eastern Asia to Europe. 
Then, in the first third of the present century, the Javanese 
Goramy was acclimatised in Mauritius and Guiana, but no 
care seems to have been taken to insure permanent advan- 
tages from the successful execution of the experiment. In 
these cases fully developed individuals were transported to 


186 FISHES. 


the country in which they were to be acclimatised. The 
most successful attempt of recent years is the acclimatisation 
of the Trout and Sea-Trout, and probably also of the Salmon, 
in Tasmania and New Zealand, and of the Californian Salmon 
(Salmo quinnat ?), in Victoria, by means of artificially-im- 
pregnated ova. The ova were transported on ice, in order to 
retard their development generally, and thus to preserve them 
from destruction during the passage of the tropical zone. 

Artificial impregnation of fish-ova was first practised by 
J. L. JAcosi, a native of Westphalia, in the years 1757-63, 
who employed exactly the same method which is followed 
now; and there is no doubt that this able observer of nature 
conceived and carried out his idea with the distinct object 
of advantageously restocking water-courses which had become 
unproductive, and increasing production by fecundating and 
preserving all ova, of which a great proportion, in the ordi- 
nary course of propagation, would be left unfecundated or 
accidentally perish. Physiology soon turned to account 
Jacobi’s discovery, and artificial impregnation has proved to 
be one of the greatest helps to the student of embryology. 


Fishes differ i an extraordinary degree with regard to 
tenacity of life. Some will bear suspension of respiration— 
caused by removal from water, or by exposure to cold or 
heat—for a long time, whilst others succumb at once. Nearly 
all marine fishes are very sensitive to changes in the tem- 
perature of the water, and will not bear transportation from 
one climate to another. This seems to be much less the 
case with some freshwater fishes of the temperate zones: the 
Carp may survive after being frozen in a solid block of ice, 
and will thrive in the southern parts of the temperate zone. 
On the other hand, some freshwater fishes are so sensitive 
to a change in the water that they perish when transplanted 
from their native river into another apparently offermg the 


TENACITY OF LIFE. 187 


same physical conditions (Grayling, Salmo hucho). Some 
marine fishes may be abruptly transferred from salt ito 
fresh water, like Sticklebacks, some Blennies, and Cottus, etc.; 
others survive the change when gradually effected, as many 
migratory fishes ; whilst again, others cannot bear the least 
alteration in the composition of the salt water (all pelagic 
fishes), On the whole, instances of marine fishes voluntarily 
entering brackish or fresh water are very numerous, whilst 
freshwater fishes proper but rarely descend into salt water. 

Abstinence from food affects different fishes in a similarly 
different degree. Marine fishes can endure hunger less than 
freshwater fishes, at least in the temperate zones, no obser- 
vations having been made in this respect on tropical fishes. 
Goldfishes, Carps, Eels, are known to be able to subsist 
without food for months, without showing a visible decrease 
of bulk; whilst the Trigloids, Sparoids, and other marine 
fishes, survive abstinence from food for a few days only. In 
freshwater fishes the temperature of the water is of great 
influence on their vital functions generally, and consequently 
on their appetite——many cease to feed altogether in the course 
of the winter; a few, like the Pike, are less inclined to feed 
during the heat of the summer than when the temperature 
is lowered. 

Captivity is easily borne by most fishes, and the appl- 
ances introduced in our modern aquaria have rendered it 
possible to keep in confinement, and even to induce to 
propagate, fishes which formerly were considered to be in- 
tolerant of captivity. 

Wounds affect fishes generally much less than higher 
Vertebrates. A Greenland Shark continues to feed whilst his 
head is pierced by a harpoon or by the knife, as long as the 
nervous centre is not touched ; a Sea-perch or a Pike (Fig. 97) 
will survive the loss of a portion of its tail; a Carp that 
of half of its snout. However, some fishes are much more 


188 FISHES. 


sensitive, and perish even from the superficial abrasion caused 
by the meshes of the net during capture (Mullsn.) 

The power of reproduction of lost parts in Teleosteous 
fishes is limited to the delicate terminations of their fin-rays 
and the various tegumentary filaments with which some are 
provided. These filaments are sometimes developed in an 
extraordinary degree, mimicking the waving fronds of the sea- 
weed in which the fish hides. Both the ends of the fin-rays 


Fig, 97.—Pike caught in the Thames, which, when young, had lost part of the 
tail with the caudal fin. 

and the filaments are frequently lost, not only by accident, but 

merely by wear and tear; and as these organs are essential 

for the preservation of the fish, their reproduction is necessary. 

In Dipnoi, Ceratodus, and Protopterus, the terminal portion 

of the tail has been found to have been reproduced, but with- 
out the notochord. 


Hybernation has been observed in many Cyprinoids and 
Murenoids of the temperate zones. They do not fall into a 
condition of complete torpidity, as Reptiles and Mammals, 
but their vital functions are simply lowered, and they hide 
in sheltered holes, and cease to go abroad in search of their 
food. Between the tropics a great number of fishes (especi- 
ally Siluroids, Labyrinthici, Ophiocephaloids, the Dipnoi), 
are known to survive long-continued droughts by passing 
the dry season in a perfectly torpid state, imbedded in the 
hardened mud. Protopterus, and probably many of the other 
fishes mentioned, prepare for themselves a cavity large enough 
to hold them, and coated on the inside with a layer of 
hardened mucus, which preserves them from complete desic- 


POISONOUS FISHES. 189 


cation. It has been stated that in India fishes may survive 
in this condition for more than one season, and that ponds 
known to have been dry for several years, and to the depth 
of many feet, have swarmed with fishes as soon as the accu- 
mulation of water released them from their hardened bed. 


The principal wse derived by man from the class of Fishes 
consists in the abundance of wholesome and nourishing food 
which they yield. In the Polar regions especially, whole 
tribes are entirely dependent on this class for subsistence ; 
and in almost all nations fishes form a more or less essential 
part of food, many being, in a preserved condition, most im- 
portant articles of trade. The use derived by man from them 
in other respects is of but secondary importance. Cod- 
liver oil is prepared from the liver of some of the Gadoids 
of the Northern Hemisphere, and of Sharks; isinglass from 
the swim-bladder of Sturgeons, Scizenoids, and Polynemoids ; 
shagreen from the skin of Sharks and Rays. 


The flesh of some fishes is at times, or constantly, poison- 
ous. When eaten, it causes symptoms of more or less intense 
irritation of the stomach and intestines, inflammation of the 
mucous membranes, and not rarely death. The fishes, the 
flesh of which appears always to have poisonous properties, 
are Clupea thrissa, Clupea venenosa, and some species of 
Scarus, Tetrodon, and Diodon. There are many others which 
have occasionally or frequently caused symptoms of poison- 
ing Poey enumerates not less than seventy-two different 
kinds from Cuba; and various species of Sphyrena, Balistes, 
Ostracion, Caranx, Lachnolemus, Tetragonurus, Thynnus, have 
been found to be poisonous ‘in all seas between the tropics. 
All or nearly all these fishes acquire their poisonous proper- 
ties from their food which consists of poisonous Meduse, 
Corals, or decomposing substances. Frequently the fishes 


190 FISHES. 


are found to be eatable if the head and intestines be removed 
immediately after capture. In the West Indies it has been 
ascertained that all the fishes living and feeding on certain 
coral banks are poisonous. In other fishes the poisonous 
properties are developed at certain seasons of the year only, 
especially the season of propagation: as the Barbel, Pike, 
and Burbot, whose roe causes violent diarrhceas when eaten 
during the season of spawning. 


Poison-organs are more common in the class of Fishes than 
was formerly believed, but they seem to have exclusively the 
function of defence, and are not auxiliary in procuring food, as 
in venomous Snakes. Such organs are found in the Sting-rays, 
the tail of which is armed with one or more powerful barbed 


Fig. 98.—Portion of tail, with spines, of Aétobatis narinart, a Sting-ray 
from the Indian Ocean. a, nat. size. 


spines. Although they lack a special organ secreting poison, 
or a canal in or on the spine by which the venomous fluid is 
conducted, the symptoms caused by a wound from the spine 
of a Sting-ray are such as cannot be accounted for merely by 
the mechanical laceration, the pain being intense, and the 
subsequent inflammation and swelling of the wounded part 
terminating not rarely in gangrene. The mucus secreted 
from the surface of the fish and inoculated by the jagged 
spine evidently possesses venomous properties. This is also 
the case in many Scorpzenoids, and in the Weaver (7rachinus), 
in which the dorsal and opercular spines have the same 


POISON-ORGANS. 191 


function as the caudal spines of the Sting-rays ; however, in 
the Weavers the spines are deeply grooved, the groove 


Fig. 99.—A dorsal spine, with 
poison-bags, of Synanceia 
verrucosa. Indian Ocean. 


being charged with a 
fluid mucus. In Syn- 


anceva the poison-organ 
(Fig. 99,) is still more 


Fig. 100.—Opercular part of the Poison-apparatus 

developed : each dorsal of Thalassophryne (Panama). 

spine is in its terminal 1. Hinder half of the head, with the venom-sac* 
: , in situ. a, Lateral line and its branches ; 

half provided with a b, Gill-opening ; ce, Ventral fin; d, Base of 


deep groove on each Pectoral fin; ¢, Base of dorsal. 
2. Operculum with the perforated spine. 


side, at the lower end of 
which lies a pear-shaped bag containing the milky poison ; 
it is prolonged into a membranous duct, lying in the groove 
of the spine, and open at its point. The native fishermen, well 
acquainted with the dangerous nature of these fishes, care- 
fully avoid handling them; but it often happens that persons 
wading with naked feet in the sea, step upon the fish, which 
generally lies hidden in the sand. One or more of the erected 
spines penetrate the skin, and the poison is injected into the 
wound by the pressure of the foot on the poison-bags. Death 
has not rarely been the result. 


192 FISHES. 


The most perfect poison-organs hitherto discovered in 
fishes are those of Thalassophryne, a Batrachoid genus of fishes 
from the coasts of Central America. In these fishes the oper- 
culum again and the two dorsal spines are the weapons. The 
former (Fig. 100, *) is very narrow, vertically styliform and very 
mobile ; it is armed behind with a spine, eight lines long, and 
of the same form as the hollow venom-fang of a snake, being 
perforated at its base and at its extremity. A sac covering 
the base of the spine discharges its contents through the 
apertures and the canal in the interior of the spme. The 
structure of the dorsal spines is similar. There are no secre- 
tory glands imbedded in the membranes of the sacs; and the 
fluid must be secreted by their mucous membrane. The sacs 
are without an external muscular layer, and situated imme- 
diately below the thick loose skin which envelops the spines 
to their extremity; the ejection of the poison into a lving 
animal, therefore, can only be effected, as in Synanceia, by the 
pressure to which the sac is subjected the moment the spine 
enters another body. 

Finally, a singular apparatus found in many Siluroids 
may be mentioned in connection with the poison-organs, 
although its function is still problematical. Some of these 
fishes are armed with powerful pectoral spines and justly 
feared on account of the dangerous wounds they inflict; 
not a few of them possess, in addition to the pectoral spines, 
a sac with a more or less wide opening in the axil of the 
pectoral fin ; and it does not seem improbable that it contains 
a fluid which may be introduced into a wound by means of 
the pectoral spine, which would be covered with it, lke the 
barbed arrow-head of an Indian. However, whether this 
secretion is equally poisonous in all the species provided with 
that axillary sac, or whether it has poisonous qualities at all, 
is a question which can be decided by experiments only made 
with the living fishes. 


| 


CHARTER meV. 
DISTRIBUTION OF FISHES IN TIME, 


Or what kind the fishes were which were the first to make 
their appearance on the globe ; whether or not they were 
identical with, or similar to, any of the principal types exist- 
ing at present; are questions which probably will for ever 
remain hidden in mystery and uncertainty. The supposition 
that the Leptocardii and Cyclostomes, the lowest of the 
vertebrate series, must have preceded the other sub-classes, is 
an idea which has been held by many Zoologists : and as the 
horny teeth of the Cyclostomes are the only parts of their body 
which under favourable circumstances might have 

been preserved, Palzeontologists have ever been 8 
searching for this evidence. Fig. 101. 
Indeed, in deposits belonging to the Lower Right dental 


plate of Myx- 


Silurian and Devonian, in Russia, England, =, .. 
2 5 ine affinis. 


and North America, minute, slender, pointed 

horny bodies, bent like a hook, with sharp opposite mar- 
eins, have been found and described under the name of 
Conodonts. More frequently they possess an elongated 
basal portion, in which there is generally a larger tooth 
with rows of similar but smaller denticles on one or both 
sides of the larger tooth, according as this is central or at one 
end of the base. In other examples there is no prominent 
central tooth, but a series of more or less similar teeth is 
implanted on_a straight or curved base. Modifications of 
these arrangements are very numerous, and many Paleonto- 
logists entertain still doubts whether the origin of these 

O 


194 FISHES. 


remains ig not rather from Annelids and Mollusks than from 
Fishes. 
[See G. J. Hinde, in ‘‘ Quarterly Journal of the Geological Society,” 1879. ] 


The first undeniable evidence of a fish, or, indeed, of 
a vertebrate animal, occurs in the Upper Silurian Rocks, m 
a bone-bed of the Downton sandstone, near Ludlow. It con- 
sists of compressed, shghtly curved, ribbed spines, of less 
than two inches in leneth (Onchus) ; of small shagreen-scales 
(Thelodus) ; the fragment of a jaw-like bar with pluricuspid 
teeth (Plectrodus) ; the cephalic bucklers of what seems to be 
a species of Pleraspis ; and, finally, the coprolitic bodies of 
phosphate and carbonate of lime, including recognisable re- 
mains of the Mollusks and Crinoids inhabiting the same 
waters. But no vertebra or other part of the skeleton has 
been found. The spines and scales seem to have belonged 
to the same kind of fish, which probably was a Plagiostome. 
It is quite uncertain whether or not the jaw (if it be the 
jaw of a fish") belonged to the buckler-bearing Pteraspis, the 
position of which among Ganoids, with which it is gener- 
ally associated, is open to doubt. 

No detached undoubted tooth of a Plagiostome or Ganoid 
scale has been discovered in the Ludlow deposits: but so 
much is certain that those earliest remains in Paleozoic 
rocks belonged to fishes closely allied to forms occurring in 
greater abundance in the succeeding formation, the Devonian, 
where they are associated with undoubted Paleichthyes, 
Plagiostomes as well as Ganoids. 


These fish-remains of the Devonian or Old Red Sandstone, 
can be determined with greater certainty. They consist of 
spines or the so-called Jchthyodorulites, which show sufficiently 
distinctive characters to be referred to several genera, one of 


1 Ray Lankester considers it to be a portion of the long denticulated 
cornua of a genus Lukeraspis allied to Cephalaspis. 


GEOLOGICAL DISTRIBUTION, 195 


them, Onchus, still surviving from the Silurian epoch, All 
these spines are believed to be those of Chondropterygians, to 
which order some pluricuspid teeth (Cladodus) from the Old 
Red Sandstone in the vicinity of St. Petersburg have been 
referred likewise. 

The remains of the Ganoid fishes are in a much more 
perfect state of preservation, so that it is even possible to 
obtain a tolerably certain idea of the general appearance and 
habits of some of them, especially of such as were provided 
with hard carapaces, solid scales, and ordinary or bony fin- 
rays. A certain proportion of them, as might have been 
expected, remind us, with regard to external form, of Teleos- 
teous fishes rather than of any of the few still existing Ganoid 
types ; but it is contrary to all analogy and to all palonto- 
logical evidence to suppose that those fishes were, with regard 
to their internal structure, more nearly allied to Teleosteans 
than to Ganoids. If they were not true Ganoids, they may 
be justly supposed to have had the essential characters of 
Paleeichthyes. Other forms exhibit even at that remote geo- 
logical epoch so unmistakably the characteristics of existing 
Ganoids, that no one can entertain any doubt with regard to 
their place in the system. In none of these fishes is there 
any trace of vertebral segmentation. 

The Paleichthyes of the Old Red Saitdatone the syste- 
matic position of which is still obscure, are the Cephalaspide 
from the Lower Old Red Sandstone of Great Britain and 
Eastern Canada; Pterichthys, Coccosteus, and Dinichthys: 
genera which have been combined in one group—Placodermi ; 
and Acanthodes and allied genera, which combined numerous 
branchiostegals with chondropterygian spines and a shagreen- 
like dermal covering. 

Among the other Devonian fishes (and they formed the 
majority) two types may be recognised, both of which are 
unmistakably Ganoids, The first approaches the still living 


196 FISHES. 


Polypterus, with which some of the genera lke Diplopterus 
singularly agree in the form and armature of the head, 
the lepidosis of the body, the lobate pectoral fins, and 
the termination of the vertebral column. Other genera, as 
Holoptychius, have cycloid scales ; many have two dorsal fins 
(Holoptychius), and, instead of branchiostegals, jugular scutes ; 
others one long dorsal confluent with the caudal (Phanero- 
pleuron). 

In the second type the principal characters of the Dipnot 
are manifest, and some of them, for example Dipterus, Pale- 
daphus, Holodus, approach so closely the Dipnoi which still 
survive, that the differences existing between them warrant a 
separation into families only. 

Devonian fishes are frequently found under peculiar cir- 
cumstances, enclosed in the so-called nodules. These bodies 
are elliptical flattened pebbles, which have resisted the action 
of water in consequence of their greater hardness, whilst 
the surrounding rock has been reduced to detritus by that 
agency. Their greater density is due to the dispersion in 
their substance of the fat of the animal which decomposed in 
them. Frequently, on cleaving one of these nodules with 
the stroke of the hammer, a fish is found embedded in the 
centre. At certain localities of the Devonian, fossil fishes are 
so abundant that the whole of the stratum is affected by the 
decomposing remains emitting a pecular smell when newly 
opened, and acquiring a density and durability not possessed 
by strata without fishes. The flagstones of Caithness are a 
remarkable instance of this. 


The fish-remains of the Carboniferous formation show a 
ereat similarity to those of the preceding. They occur 
throughout the series, but are very irregularly distributed, 
being extremely scarce in some countries, whilst in others 
entire beds (the so-called bone-beds) are composed of ichthyo- 


GEOLOGICAL DISTRIBUTION, 197 


lites. In the ironstones they frequently form the nuclei of 
nodules, as in the Devonian. 

Of Chondropterygians the spines of Onchus and others 
still occur, with the addition of teeth indicative of the exist- 
ence of fishes allied to the Cestracion-type (Cochliodus, Psam- 
modus): a type which henceforth plays an important part in 
the composition of the extinct marine fish faune. Another 
extinct Selachian family, that of Hybodontes, makes its 
appearance, but is known from the teeth only. 

Of the Ganoid fishes, the family Palwoniscide (Traquair) is 
numerously represented ; others are Coelacanths (Calacanthus, 
Rhizodus), and Saurodipteride (Megalichthys). None of these 
fishes have an ossified vertebral column, but in some (Megal- 
ichthys) the outer surface of the vertebra is ossified mto a 
ring; the termination of their tail is heterocercal. The car- 
boniferous Uronemus and the Devonian Phaneropleuron are 
probably generically the same; and the Devonian Dipnoi are 
continued as, and well represented by, Ctenodus. 


The fishes of the Permian group are very similar to those 
of the Carboniferous. A type which in the latter was but 
very scantily represented, namely the Platysomide, is much 
developed. They were deep-bodied fish, covered with hard 
rhomboid scales possessing a stron® anterior rib, and provided 
with a heterocercal caudal, lone dorsal and anal, short non- 
lobate paired fins (when present), and branchiostegals. The 
Palwoniscide are represented by many species of Palawoniscus, 
Pygopterus and Acrolepis, and Cestracionts by Janassa and 
Strophodus. 


The passage from the Paleozoic into the Mesozoic era is 
not indicated by any marked change as far as fishes are con- 
cerned. The more remarkable forms of the Trias are Shark- 
like fishes represented by ichthyodorulithes like Vemacanthus, 
Inacanthus, and Hybodus; and Cestracionts represented by 


198 FISHES. 


species of Acrodus and Strophodus. Of the Ganoid genera 
Celacanthus, Amblypterus (Palewoniscide), Sawrichthys persist 
from the Carboniferous epoch. Ceratodus appears for the first 
time (Muschel-Kalk of Germany). 

Thanks to the researches of Agassiz, and especially Sir P. 
Egerton, the ichthyological fauna of the Lias is, perhaps, the 
best known of the Mesozoic era, 152 species having been 
described. Of the various localities, Lyme Regis has yielded 
more than any other, nearly all the Liassic genera being 
represented there by not less than seventy-nine species. The 
Hybodonts and Cestracionts continue in their fullest develop- 
ment. Holocephales (/schyodus), true Sharks (Palwoscylliwm), 
Rays (Squaloraja, Arthropterus), and Sturgeons (Chondrosteus) 
make their first appearance; but they are sufficiently distinct 
from living types to be classed in separate genera, or even 
familes. The Ganoids, especially Lepidosteoids, predominate 
over all the other fishes : Lepidotus, Semionotus, Pholidophorus, 
Pachycormus, Hugnathus, Tetragonolepis, are represented by 
numerous species; other remarkable genera are Aspido- 
rhynchus, Belonostomus, Saurostomus, Sauropsis, Thrissonotus, 
Conodus, Ptycholepis, Endactis, Centrolepis, Leqgnonotus, Oxygna- 
thus, Heterolepidotus, Isocolum, Osteorhachis, Mesodon. 'These 
genera offer evidence of a great change since the preceding 
period, the majority not being represented in older strata, 
whilst, on the other hand, many are continued into the suc- 
ceeding oolithic formations. The homocercal termination of 
the vertebral column commences to supersede the heterocercal, 
and many of the genera have well ossified and distinctly seg- 
mented spinal columns. Also the cycloid form of scales 
becomes more common: one genus (Leptolepis) beg, with 
regard to the preserved hard portions of its organisation, so 
similar to the Teleosteous type that some Paleontologists 
refer it (with much reason) to that sub-class. 


[See #. Sauvage, Essai sur la Faune Ichthyologique de la période Liasique. 
In ‘‘ Bibl. de Pécole des hautes études,” xiii. art. 5. Paris 1875. 8°.] 


GEOLOGICAL DISTRIBUTION. 199 


As already mentioned, the Oolithic formations show a 
great similarity of their fish-fauna to that of the Lias ; but 
still more apparent is its approach to the existing fauna. 
Teeth have been found which cannot even generically be 
distinguished from Notidanus. The Rays are represented by 
genera like Spathobatis, Belemnobatis, Thaumas ; the Holoce- 
phalv are more numerous than in the Lias Uschyodus, Gan- 
odus). The most common Ganoid genera are Caturus, 
Pycnodus, Pholidophorus Lepidotus, Leptolepis, all of which 
had been more or less fully represented in the Lias. Also 
Ceratodus is continued into it. 


The Cretaceous group offers clear evidence of the further 
advance towards the existing fauna. Teeth of Sharks of 
existing genera Carcharias (Corax), Scyllium, Notidanus, and 
Galeocerdo, are common in some of the marine strata, whilst 
Hybodonts and Cestracionts are represented by a small num- 
ber of species only; of the latter one new genus, Ptychodus, 
appears and disappears. A very characteristic Ganoid genus, 
Macropoma, comprises homocercal fishes with rounded ganoid 
scales sculptured externally and pierced by prominent mucous 
tubes. Catwrus becomes extinct. Teeth and scales of Lepi- 
dotus (with Sphwrodus as sub-genus), clearly a fresh-water 
fish, are widely distributed in the Wealden, and finally dis- 
appear in the chalk; its body was covered with large rhom- 
boidal ganoid scales. Gyrodus and Aspidorhynchus occur in 
the beds of Voirons, Coelodus and Amiopsis (allied to Amra), 
in those of Comen, in Istria. But the Palzichthyes are now 
in the minority ; undoubted Teleosteans have appeared, for 
the first time, on the stage of life in numerous genera, many 
of which are identical with still existing fishes. The majority 
are Acanthopterygians, but Physostomes and Plectognaths 
are likewise well represented, most of them being marine. 
Of Acanthopterygian families the first to appear are the Bery- 


200 FISHES. 


cidw, represented by several very distinct genera: Beryz ; 
Pseudoberyx with abdominal ventral fins ; Berycopsis with 
cycloid scales; Homonotus, Stenostoma, Sphenocephalus, Acanus, 
Hoplopteryx, Platycornus with granular scales; Podocys with 
a dorsal extending to the neck; <Acrogaster, Macrolepis, 
Rhacolepis from the chalk of Brazil. The position of Pyenos- 
terynx 18 uncertain, it approaches certain, Pharyngognaths. 
True Percide are absent, whilst the Carangidw, Sphyrende, 
Cataphracti, Gobude, Cottide, and Sparide are represented 
by one or more genera. Somewhat less diversified are 
the Physostomes, which belong principally to the Clupeide 
and Dercetide, most of the genera being extinct ; Clupea is 
abundant in some localities. Scopelide (Hemisaurida and 
Saurocephalus) occur in the chalk of Comen in Istria, and of 
Meestricht. Of all cretaceous deposits none surpass those 
of the Lebanon with regard to the number of genera, species, 
and individuals ; the forms are exclusively marine, and the 
remains in the most perfect condition. 


In the Zertiary epoch the Teleosteans have almost entirely 
replaced the Ganoids; a few species only of the latter make 
their appearance, and they belong to existing genera, or, at 
least, very closely allied forms (Lepidosteus, Amia, Hypamia, 
Acipenser). The Chondropterygians merge more and more 
into recent forms ; Holocephali continue, and still are better 
represented than in the present fauna. The Teleosteans 
show even in the Eocene a large proportion of existing 
genera, and the fauna of some localities of the Miocene 
(Oeningen) is almost wholly composed of them. On the 
whole, hitherto more than one-half have been found to belong 
to existing genera, and there is no doubt that the number 
of seemingly distinct extinct genera will be lessened as the 
fossils will be examined with a better knowledge of the living 
forms. The distribution of the fishes differed widely from 


GEOLOGICAL DISTRIBUTION. 201 


that of our period, many of our tropical genera occurring in 
localities which are now included within our temperate zone, 
and being mixed with others, which nowadays are restricted 
to a colder climate: a mixture which continues throughout 
the Pliocene. 


A. few families of fishes, hike the freshwater Salmonide, 
seem to have put in their appearance in Post-pliocene times ; 
however, not much attention has been paid to fish-remains of 
these deposits ; and such as have been incidentally examined 
offer evidence of the fact that the distribution of fishes has 
not undergone any further essential change down to the 
present period. 


[See £. Sauvage, Mémoire sur la Faune Ichthyologique de la période 
Tertiaire. Paris 1873. 8°.] 


Fig. 102.— Pycnodus rhombus, a Ganoid from the Upper Oolite. 


CHAPTER XVI. 


THE DISTRIBUTION OF EXISTING FISHES OVER THE 


EARTH'S SURFACE—GENERAL REMARKS. 


IN an account of the geographical distribution of fishes the 
Freshwater forms are to be kept separate from the Marine. 
However, when we attempt to draw a line between these two 
kinds of fishes, we meet with a great number of species and 
of facts which would seem to render that distinction very 
vague. There are not only species which can gradually accom- 
modate themselves to a sojourn in either salt or fresh water, but 
there are also such as seem to be quite indifferent to a rapid 
change from one into the other: so that individuals of one 
and the same species (Gastrosteus, Gobius, Blennius, Osmerus, 
Retropinna, Clupea, Syngnathus, etc.), may be found at some 
distance out at sea, whilst others live in rivers far beyond the 
influence of the tide, or even in inland fresh waters without 
outlet to the sea. The majority of these fishes belong to 
forms of the fauna of the brackish water, and as they are not 
an insignificant portion of the fauna of almost every coast, 
we shall have to treat of them in a separate chapter. 

Almost every large river offers instances of truly marine 
fishes (such as Serranus, Sciwnide, Plewronectes, Clupeide, 
Tetrodon, Carcharias, Trygonide), ascending for hundreds of 
miles of their course; and not periodically, or from any appa- 
rent physiological necessity, but sporadically throughout the 
year, just like the various kinds of marine Porpoises which 
are found all along the lower course of the Ganges, Yang-tse- 


GEOGRAPHICAL DISTRIBUTION. 203 


Kiang, the Amazons, the Congo, etc. This is evidently the 
commencement of a change in a fish’s habits, and, indeed, not 
a few of such fishes have actually taken up their permanent 
residence in fresh waters (as species of Ambassis, Apogon 
Dules, Therapon, Scizena, Blennius, Gobius, Atherina, Mueil, 
Myxus, Hemirhamphus, Clupea, Anguilla, Tetrodon, Trygon) : 
all forms originally marine. 

On the other hand, we find fishes belonging to fresh- 
water genera descending rivers and sojourning in the sea for 
a more or less limited period ; but these instances are much 
less in number than those in which the reverse obtains. We 
may mention species of Salmo (the Common Trout, the 
Northern Charr), and Siluroids (as Arius, Plotosus). Core- 
gonus, a genus so characteristic of the inland lakes of Europe, 
Northern Asia, and North America, nevertheless offers some 
instances of species wandering by the effluents into the sea, 
and taking up their residence in salt water, apparently by 
preference, as Coregonus oxyrhynchus. But of all the Fresh- 
water families none exhibit so great a capability of surviving 
the change from fresh into salt water, as the Gastrostewda 
(Stickle-backs), of the northern Hemisphere, and the equally 
diminutive Cyprinodontide of the tropics; not only do they 
enter into, and live freely in, the sea, but many species of the 
latter family inhabit inland waters, which, not having an 
outlet, have become briny, or impregnated with a larger pro- 
portion of salts than pure sea water. During the voyage of 
the “Challenger” a species of Fundulus, F. nigrofasciatus, 
which inhabits the fresh and brackish waters of the Atlantic 
States of North America, was obtained, with Scopelids and 
other pelagic forms, in the tow-net, midway between St. 
Thomas and Teneriffe. 

Some fishes annually or periodically ascend rivers for the 
purpose of spawning, passing the rest of the year in the sea, 
as Sturgeons, many Salmonoids, some Clupeoids, Lampreys, 


204: FISHES. 


etc. The two former evidently belonged originally to the 
freshwater series, and it was only in the course of their 
existence that they acquired the habit of descending to the 
sea, perhaps because their freshwater home did not offer a 
sufficient supply of food. These migrations of freshwater 
fishes have been compared with the migrations of birds; 
but they are much more limited in extent, and do not im- 
part an additional element to the fauna of the place to which 
they migrate, as is the case with the distant countries to 
which birds migrate. 

The distinction between freshwater and marine fishes is 
further obscured by geological changes, in consequence of 
which the salt water is gradually being changed into fresh, or 
vice versa. These changes are so gradual and spread over so 
long a time, that many of the fishes inhabiting such localities 
accommodate themselves to the new conditions. One of the 
most remarkable and best studied instances of such an altera- 
tion is the Baltic, which, during the second half of the Glacial 
period, was in open and wide communication with the Arctic 
Ocean, and evidently had the same marine fauna as the 
White Sea. Since then, by the rising of the land of Northern 
Scandinavia and Finland, this great gulf of the Arctic Ocean 
has become an inland sea, with a narrow outlet into the 
North Sea, and its water, in consequence of the excess of the 
fresh water pouring into it over the loss by evaporation, has 
been so much diluted as to be nearly fresh at its northern 
extremities: and yet nine species, the origin of which from the 
Arctic Ocean can be proved, have survived the changes, propa- 
eating their species, agreeing with their brethren in the Arctic 
Ocean in every point, but remaimine comparatively smaller. 
On the other hand, fishes which we must regard as true fresh- 
water fishes, like the Rudd, Roach, Pike, Perch, enter freely 
the brackish water of the Baltic.'| Instances of marine fishes 


1 Ekstrém, Fische in den Scheeren von Morko. 


GEOGRAPHICAL DISTRIBUTION, 205 


being permanently retained in fresh water in consequence of 
geological changes are well known: thus Cottus quadricornis 
in the large lakes of Scandinavia; species of Gobius, Blennius, 
and Atherina in the lakes of Northern Italy ; Comephorus, 
of the depths of the Lake of Baikal, which seems to be a 
dwarfed Gadoid. Carcharias gangeticus in inland lakes of the 
Fiji Islands, is another instance of a marine fish which has 
permanently established itself in fresh water. 

In the miocene formation of Licata in Sicily, in which 
fish remains abound, numerous Cyprinoids are mixed with 
littoral and pelagic forms. Sauvage found in 450 specimens 
from that localty, not less than 266, which were Leucisci, 
Alburni, or Rhodei. Now, although it is quite possible that 
in consequence of a sudden catastrophe the bodies of those 
Cyprinoids were carried by a freshwater current into, and 
deposited on the bottom of, the sea, the surmise that they 
lived together with the littoral fishes im the brackish water 
of a large estuary, which was not rarely entered by pelagic 
forms, is equally admissible. And, if confirmed by other 
similar observations, this instance of a mixture of forms 
which are now strictly freshwater or marine, may have an 
important bearimg on the question to what extent fishes 
have in time changed their original habitat. 

Thus there is a constant exchange of species in progress 
between the freshwater and marine faune, and in not a few 
cases it would seem almost arbitrary to refer a genus or even 
larger group of fishes to one or the other; yet there are cer- 
tain groups of fishes which entirely, or with but few excep- 
tions are, and, apparently, during the whole period of their 
existence have been, inhabitants either of the sea or of fresh 
water; and as the agencies operating upon the distribution of 
marine fishes differ greatly from those influencing the dis- 
persal of freshwater fishes, the two series must be treated 
separately, The most obvious fact that dry land, which 


206 FISHES. 


intervenes between river systems, offers to the rapid spread- 
ing of a freshwater fish an obstacle which can be surmounted 
only exceptionally or by a most circuitous route, whilst marine 
fishes may readily and voluntarily extend their original limits, 
could be illustrated by a great number of instances. With- 
out entering into details, it may suffice to state as the general 
result, that no species or genus of freshwater fishes has any- 
thing like the immense range of the corresponding categories 
of marine fishes ; and that, with the exception of the Siluroids, 
no other freshwater family is so widely spread as the families ~ 
of marine fishes. Surface temperature or climate which is, if 
not the most, one of the most important physical factors in the 
limitation of freshwater fishes, similarly affects the distribution 
of marine fishes, but in a less degree, and only those which 
live near to the shore or the surface of the ocean; whilst it 
ceases to exercise its influence in proportion to the depth, 
the true deep-sea forms being entirely exempt from its opera- 
tion. Light, which is pretty equally distributed over the 
localities inhabited by freshwater fishes, cannot be considered 
as an important factor in their distribution, but it contributes 
towards constituting the impassable barrier between the sur- 
face and abyssal forms of marine fishes. Altitude has stamped 
the fishes of the various Alpine provinces of the globe with a 
certain character, and limited their distribution; but the 
number of these Alpine forms is comparatively small, ichthyic 
life being extinguished at great elevations even before the 
mean temperature equals that of the high latitudes of the 
Arctic region, in which some freshwater fishes flourish. On 
the other hand, the depths of the ocean, far exceeding the 
altitude of the highest mountains, still swarm with forms 
specially adapted for abyssal life. That other physical con- 
ditions of minor and local importance, under which fresh 
water fishes live, and by which their dispersal is regulated, 
are more complicated than similar ones of the ocean, is 


GEOGRAPHICAL DISTRIBUTION, 207 


probable, though perhaps less so than is generally supposed : 
for the fact is that the former are more accessible to obser- 
vation than the latter, and are, therefore, more generally and 
more readily comprehended and acknowledged. Thus, not 
only because many of the most characteristic forms of the 
marine and freshwater series are found, on taking a broader 
view of the subject, to be sufficiently distinct, but also be- 
cause their distribution depends on causes different in their 
nature as well as the degree of their action, it will be 
necessary to treat of the two series separately. Whether the 
oceanic areas correspond in any way to the terrestrial will 
be seen in the sequel. 


Fig. 103.—Ganoid scales of Tetragonolepis. 


CHAPTER XVII- 
THE DISTRIBUTION OF FRESHWATER FISHES. 


HaAvine shown above that numerous marine fishes enter fresh 
waters, and that some of them have permanently established 
themselves therein, we have to eliminate from the category of 
freshwater fishes all such adventitious elements. They are 
derived from forms, the distribution of which is regulated by 
other agencies, and which, therefore, would obscure the rela- 
tions of the faunee of terrestrial regions if they were included 
in them. They will be mentioned with greater propriety 
along with the fishes constituting the fauna of the brackish 
water. 

True freshwater fishes are the following families and 
eroups only :— 


Dipnoi . . with 4 species.| Labyrinthici. with 30 species. 
Acipenseridee and Luciocephalide ,, 1 ,, 
Polyodontide _ ,, ‘5 Gastrosteus . 5° aOnaaes 
Amiidee ; ke Ophiocephalide, ,, 31 _,, 
Polypteridz . Fe - Mastacembelide ,, 13 _,, 


bo 


6 

1 

2 
Lepidosteidee . ” Sees Chromides . 3; LOSe ee 
Percina : ee 54163 3.5, Comephoridee as he 
Grystina ; Poe | See Gadopside . 52 oll ee 
Aphredoderide ,, 1 ,, Silurids  . 4, D2. ee 
Centrarchina . MELO. ozs, Characinide. ,, 261 _ ,, 
Dules . ; Soe aks. Haplochitonide ,, 3) 
Nandide ; oe ae Salmonidee (3 genera 


eo 


Polycentride. _,, excepted). ,, 135  ,, 


DISTRIBUTION OF FRESHWATER FISHES. 209 


Percopsidee . with 1 species.) Kneriide  . with 2 species. 
Galaxiide . ee Wy ©, ks Hyodontide . soi LTT eee 
Mormyride (and Osteoglossidee a ON Ges 
Gymnarchide) ,, 52 __,, Notopteride . ii, MS 
Esocidee ‘ Bs Sirs Gymnotide . 0 ere 
Umbride : SOP ED) 28 Symbranchide ,, 5 _,, 
Cyprinodontide ,, 112 ,, Petromyzontide ,, 12 ,, 
Geteropyel. 4, 2 ;; : Ra a 
Cyprinide . or Total 2269 species. 


As in every other class of animals, these freshwater 
genera and families vary greatly with regard to the extent 
of their geographical range; some extend over the greater 
half of the continental areas, whilst others are limited to 
one continent only, or even to a very small portion of it. 
As a general rule, a genus or family of freshwater fishes 
is regularly dispersed and most developed within a certain 
district, the species and individuals becoming scarcer towards 
the periphery as the type recedes more from its central 
home, some outposts being frequently pushed far beyond the 
outskirts of the area occupied by it. But there are not want- 
ing those remarkable instances of closely allied forms occur- 
ring, almost isolated, at most distant points, without being 
connected by allied species in the intervening space ; or of 
members of the same family, genus, or species inhabiting the 
opposite shores of an ocean, and separated by many degrees 
of abyssal depths. We mention of a multitude of such 
instances the following only :— 


A. Species identical in distant continents— 


1. A number of species inhabiting Europe and the tem- 
perate parts of eastern North America, as Perca fluviatilis, 
Gastrosteus pungitius, Lota vulgaris, Salmo salar, Hsox lucius, 
Acipenser sturio, Acipenser maculosus, and several Petromy- 


zonts. 


210 FISHES. 


2. Lates calcarifer is common in’ India as well as in 
Queensland. 

3. Galaxias attenuatus inhabits Tasmania, New Zealand, 
the Falkland Islands, and the southernmost part of the South 
American continent. 

4, Several Petromyzonts enter the fresh waters of Tas- 
mania, South Australia, New Zealand, and Chili. 


B. Genera identical in distant continents— 


1. The genus Umbra, so peculiar a form as to be the type 
of a distinct family consisting of two most closely allied 
species only, one of which is found in the Atlantic States 
of North America, the other in the system of the Danube. 

2. A very distinct genus of Sturgeons, Scaphirhynchus, 
consisting of two species only, one inhabiting fresh waters 
of Central Asia, the other the system of the Mississippi. 

3. A second most peculiar genus of Sturgeons, Polyodon, 
consists likewise of two species only, one inhabiting the 
Mississippi, the other the Yang-tse-kiang. 

4. Amiurus, a Siluroid, and Catostomus, a Cyprinoid genus, 
both well represented in North America, occur in a single 
species in temperate China. 

5. Lepidosiren is represented by one species in tropical 
America, and by the second in tropical Africa (Protopterus). 

6. Notopterus consists of three Indian and two West African 
species. 

7. Mastacembelus and Ophiocephalus, genera characteristic 
of the Indian region, emerge severally by a single species in 
West and Central Africa. 

8. Symbranchus has two Indian and one South American 
species. 

9. Prototroctes, the singular antarctic analogue of Core- 
gonus, consists of two species, one in the south of Australia 
the other in New Zealand. 


DISTRIBUTION OF FRESHWATER FISHES. Aba b 


10. Galaxias is equally represented in Southern Australia, — 
New Zealand, and the southern parts of South America. 


C. Families identical in distant continents— 


1. The Labyrinthici, represented in Africa by 5, and in 
India by 25 species. 

2. The Chromides, represented in Africa by 25, and in 
South America by 80 species. 

3. The Characinide, represented in Africa by 35, and in 
South America by 226 species. 

4, The Haplochitonide, represented in Southern Australia 
by one, in New Zealand by one, and in Patagonia by a third 
species. 

This list could be much increased from the families 
of Siluride and Cyprinide, but as these have a greater 
- range than the other Freshwater fishes, they do not illus- 
trate with equal force the object for which the lst has been 
composed, 


The ways in which the dispersal of Freshwater fishes has 
been effected were various ; they are probably all still in opera- 
tion, but most work so slowly and imperceptibly as to escape 
direct observation ; perhaps, they will be more conspicuous, 
after science and scientific inquiry shall have reached to a 
somewhat greater age. From the great number of fresh- 
water forms which we see at this present day acclimatised 
in, gradually acclimatising themselves in, or periodically or 
sporadically migrating into, the sea, we must conclude that, 
under certain circumstances, salt water may cease to be an 
impassable barrier at some period of the existence of fresh- 
water species, and that many of them have passed from one 
river through salt water into another. Secondly, the head- 
waters of some of the grandest rivers, the mouths of which 
are at opposite ends of the continents which they drain, are 


22, FISHES. 


sometimes distant from each other a few miles only ; the inter- 
vening space may have been easily bridged over for the 
passage of fishes by a slight geological change affecting the 
level of the watershed, or even by temporary floods ; and 
a communication of this kind, if existing for a limited period 
only, would afford the ready means of an exchange of a 
number of species previously peculiar to one or the other of 
those river or lake systems. Some fishes, provided with 
gill-openings so narrow that the water moistening the gills 
cannot readily evaporate; and endowed, besides, with an 
extraordinary degree of vitality, hke many Siluroids (Clarias, 
Callichthys), Eels, etc., are enabled to wander for some dis- 
tance over land, and may thus reach a watercourse leading 
them thousands of miles from their original home. Finally, 
fishes or their ova may be accidentally carried by water- 
spouts, by aquatic birds or insects, to considerable distances. 

Freshwater fishes of the present fauna were already in 
existence when the great changes of the distribution of land 
and water took place in the tertiary epoch; and having stated 
that salt water is not an absolute barrier to the spreading of 
Freshwater fishes, we can now more easily account for those 
instances of singular disconnection of certain families or 
genera. It is not necessary to assume that there was a con- 
tinuity of land stretching from the present coast of Africa to 
South America, or from South America to New Zealand and 
Australia, to explain the presence of identical forms at so dis- 
tant localities; it suffices to assume that the distances were 
lessened by intervening archipelagoes, or that an oscillation 
has taken place in the level of the land area. 

Dispersal of a type over several distant continental areas 
may be evidence of its great antiquity, but it does not prove 
that it is of greater antiquity than another limited to one 
region only. Geological evidence is the only proof of the 
antiquity of a type. Thus, although the Dipnoi occur on the 


DISTRIBUTION OF FRESHWATER FISHES. 213 


continents of Africa, South America, and Australia, and their 
present distribution is evidently the consequence of their 
wide range in paleozoic and secondary epochs; the proof of 
their high antiquity can be found in their fossil remains only. 
For, though the Siluroids have a still greater range, their wide 
distribution is of comparatively recent date, as the few fossil 
remains that have been found belong to the tertiary epoch. 
The rapidity of dispersal of a type depends entirely on its 
facility to accommodate itself to a variety of physical condi- 
tions, and on the degree of vitality by which it is enabled 
to survive more or less sudden changes under unfavourable 
conditions ; proof of this is afforded by the family of Silu- 
roids, many of which can suspend for some time the energy 
of their respiratory functions, and readily survive a change of 
water. 


To trace the geological sequence of the distribution of an 
ichthyic type, and to recognise the various laws which have 
governed, and are still governing its dispersal, is one of the 
ultimate tasks of Ichthyology. But the endeavour to establish 
by means of our present fragmentary geological knowledge 
the divisions of the fauna of the globe, leads us into a maze 
of conflicting evidence; or, as Mr. Wallace truly observes, 
“any attempt to exhibit the regions of former geological ages 
in combination with those of our own period must lead to 
confusion.” Nevertheless, as the different types of animals 
found at the present day within a particular area have 
made their appearance therein at distant periods, we should 
endeavour to decide as far as we can, in an account of 
the several zoo-geographical divisions, the following ques- 
tions :— 

1. Which of the fishes of an area should be considered to 
be the remnants of ancient types, probably spread over much 
larger areas in preceding epochs ? 


214 FISHES. 


2. Which of them are to be considered to be autochthont 
species, that is, forms which came in the tertiary epoch or 
later into existence within the area to which they are still 
limited, or from which they have since spread ? 

3. Which are the forms which must be considered to be 
ummigrants from some other region ? 

The mode of division of the earth’s surface into zoological 
regions or areas now generally adopted, is that proposed by 
Mr. Sclater, which recommends itself as most nearly agree- 
ing with the geographical divisions. These regions -are as 
follows :— 


I. PALAOGAA. 


1. The Palearctic region ; including Europe, temperate 
Asia, and North Africa. 

2. The Ethiopian region ; including Africa, south of the 
Sahara, Madagascar, and the Mascarene Islands ; 
also Southern Arabia. 


Co 


. The Jndian region ; including India south of the 

Himalayas, to Southern China, Borneo, and Java. 
4, The Australian region ; including Australia, the Pacific 
Islands, Celebes, and Lombock. 


II. NEoG@A. 


5. The Nearctic region; including North America to 
Northern Mexico. 

6. The Neotropical region ; including South America, the 
West Indies, and Southern Mexico. 


Comparatively few classes and orders of animals have 
been carefully studied with regard to their geographical 
distribution, but the majority of those which have been 
examined show that the difference of latitude is accompanied 
by a greater dissimilarity of indigenous species than that of 


DISTRIBUTION OF FRESHWATER FISHES. 215 


longitude, and that a main division into an old world and 
new world fauna is untenable. More especially the Fresh- 
water fishes, with which we are here solely concerned, have 
been spread in evrcwmpolar zones, and in a but limited degree 
from north to south. No family, much less a genus, ranges 
from the north to the south, whilst a number of families 
and genera make the entire circuit, and some species more 
than half of the circuit round the globe within the zone to 
which they belong. Not even the Cyprinoids and Siluroids, 
which. are most characteristic of the freshwater fauna of our 
period, are an exception to this. Temperature and climate, 
indeed, are the principal factors by which the character of the 
freshwater fauna is determined ; they form the barriers which 
interfere with the unlimited dispersal of an ichthyic type, 
much more than mountain ranges, deserts, or oceans. Hence 
the tropical zone is an impassable barrier to the northern 
Freshwater fish in its progress towards the south ; where a 
similarly temperate climate obtains in the southern hemi- 
sphere, fish-forms appear analogous to those of the north, but 
genetically and structurally distinct. 

The similarity which obtains in fishes at somewhat distant 
points of the same degree of longitude, rarely extends far, and 
is due to the natural tendency of every animal to spread as 
far as physical conditions will permit. Between two regions 
situated north and south of each other there is always a 
debateable border ground, in parts of which sometimes the 
fishes of the one, sometimes those of the other, predominate, 
and which is, in fact, a band of demarcation. Within this 
band the regions overlap each other; therefore, their border 
lines are rarely identical, and should be determined by the 
northern and southernmost extent of the most character- 
istic types of each region. Thus, for instance, in China, 
a broad band intervenes between temperate and tropical 
Asia, in which these two faunz mix, and the actual northern 


216 FISHES. 


border line of the tropical fauna is north of the southern 
border line of temperate Asia. 

It is the aim of every philosophical classification to indi- 
cate the degree of affinity which obtains between the various 
divisions ; but the mode of division into six equivalent 
regions, as given above, does not fulfil this aim with regard 
to Freshwater fishes, the distribution of which allows of further 
generalisation and subdivision. The two families, Cyprinidae 
and Siluridew, of which the former yields a contingent of 
one-third, and the latter of one-fourth of all the freshwater 
species known of our period, afford most valuable guidance 
for the valuation of the degrees of affinity between the various 
divisions. The Cyprinoids may be assumed to have taken their 
origin in the Alpine region, dividing the temperate and tropical 
parts of Asia; endowed with a greater capability of acclima- 
tising themselves in a temperate as well as tropical climate 
than any other family of freshwater fishes, they spread north 
and south as well as east and west; in the preglacial epoch 
they reached North America, but they have not had time to 
penetrate into South America, Austraha, or the islands of the 
Pacific. The Siluroids, principally fishes of the sluggish 
waters of the plains, and well adapted for surviving changes 
of the water in which they live, for living in mud or sea- 
water, flourish most in the tropical climate, in which this 
type evidently had its origin. They came into existence after 
the Cyprinoids, fossil remains being known only from tertiary 
deposits in India, none from Europe. They rapidly spread over 
the areas of land within the tropical zone, reaching northern 
Australia from India, and one species even immigrated 
into the Sandwich Islands, probably from South America. 
The Coral Islands of the Pacific still remain untenanted by 
them. Their progress into temperate regions was evidently 
slow, only very few species penetrating into the temperate 
parts of Asia and Europe; and the North American species, 


DISTRIBUTION OF FRESHWATER FISHES. 217 


although more numerous, showing no great variety of struc- 
ture, all belonging to the same group (Amiurina). Towards 
the south their progress was still slower, Tasmania, New 
Zealand, and Patagonia being without representatives, whilst 
the streams of the Andes of Chili are inhabited by a few 
dwarfed forms identical with such as are characteristic of 
similar localities in the more northern and warmer parts of 
the South American continent. 

After these preliminary remarks we propose the following 
division of the fauna of Freshwater fishes :— 


I. Tut NorrHerN ZONE.— Characterised by Acipenseride. 
Few Siluride. Numerous Cyprinide. Salmonide, 
Esocidee. 

1. Europo-Asiatic or Palearctic Region.—Chavracterised 
by absence of osseous Ganoidei ; Cobitide and 
Barbus numerous. 


2. North American Region.—Characterised by osseous 
Ganoidei, Amiurina, and Catostomina ; but no Cobi- 


tide or Barbus. 


II. Toe EquatoriAL ZoneE.—Characterised by the develop- 
ment of Siluride. 


A. Cyprinoid Division. — Characterised by presence of 
Cyprinidee and Labyrinthici. 
1. Indian Region.—Characterised by [absence of 
Dipnoi!] Ophiocephalidee, Mastacembelide. 
Cobitidze numerous. 
2. African Region—Characterised by presence 
of Dipnoi and Polypteridee. Chromides and 
Characinide numerous. Mormyride. Cobi- 
tide absent. 


1 Will probably be found. 


218 FISHES. 


B. Acyprinoid Division.— Characterised by absence of 
Cyprinide and Labyrinthici. 


1. Tropical American Region—Characterised by 
presence of Dipnoi. Chromides and Chara- 
cinide numerous. Gymnotidee. 


2. Tropical Pacific Region.— Characterised by 
presence of Dipnoi. Chromides and Chara- 
cinidee absent. 


Ill. Tue SouTHERN ZoNE.— Characterised by absence of 
Cyprinidee, and scarcity of Siluride. Haplochitonidee 
and Galaxidve represent the Salmonoids and Esoces of 
the Northern zone. One region only. 


1. Antarctic Region.—Characterised by the small number 
of species ; the fishes of— 


a. The Tasmanian sub-region ; 

b. The New Zealand sub-region ; 

e. The Patagonian sub-region ; 
being almost identical.! 


In the following detailed account we begin with a descrip- 
tion of the equatorial zone, this being the one from which the 
two principal families of freshwater fishes seem to have 
spread. 


I. EQUATORIAL ZONE. 


Roughly speaking, the borders of this zoological zone 
coincide with the geographical limits of the tropical zone, 
the tropics of the Cancer and Capricorn; its characteristic 
forms, however, extend in undulating lines several degrees 
north and southwards. Commencing from the west coast of 

1 We distinguish these sub-regions, because their distinction is justified by 


other classes of animals ; as regards freshwater fishes their distinctness is even 
less than that between Europe and Northern Asia. 


EQUATORIAL ZONE. 219 


Africa the desert of the Sahara forms a well-marked boundary 
between the equatorial and northern zones ; as the boundary 
approaches the Nile it makes a sudden sweep towards the 
north as far as Northern Syria (Mastacembelus, near Aleppo, 
and in the Tigris ; Claritas and Chromides, in the lake of 
Galilee) ; crosses through Persia and Afghanistan (Ophioce- 
phalus), to the southern ranges of the Himalayas, and follows 
the course of the Yang-tse-Kiang, which receives its con- 
tingent of equatorial fishes through its southern tributaries. 
Its continuation through the North Pacific may be considered 
to be indicated by the tropic which strikes the coast of 
Mexico at the southern end of the Gulf of California. Equa- 
torial types of South America are known to extend so far 
northwards ; and by following the same line the West India 
Islands are naturally included in this zone. 

Towards the south the equatorial zone embraces the 
whole of Africa and Madagascar, and seems to extend still 
farther south in Australia, its boundary probably following 
the southern coast of that continent; the detailed distribu- 
tion of the freshwater fishes of South-Western Australia has 
been but little studied, but the few facts which we know show 
that the tropical fishes of Queensland follow the principal 
water-course of that country, the Murray River, far towards 
the south and probably to its mouth. The boundary-line 
then stretches northwards of Tasmania and New Zealand, 
coinciding with the tropic until it strikes the western slope 
of the Andes, on the South American Continent, where it 
again bends southwards to embrace the system of the Rio de 
la Plata. 

The equatorial zone is divided into four regions :— 

A. The Indian region. 

B. The African region. 

C. The Tropical American region. 
D. The Tropical Pacific region. 


220 FISHES. 


These four regions diverge into two well-marked divisions, 
one of which is characterised by the presence of Cyprinoid 
fishes, combined with the development of Labyrinthici; whilst 
in the other both these types are absent. The boundary 
between the Cyprinoid and Acyprinoid division seems to 
follow Wallace’s line, a line drawn from the south of the 
Philippines between Borneo and Celebes, and farther south 
between Bal and Lombock. Borneo abounds in Cyprinoids ; 
from the Philippine Islands a few only are known at present, 
and in Bali two species have been found; but none are 
known from Celebes or Lombock, or from islands situated 
farther east of them.’ 

Taking into consideration the manner in which Cypri- 
noids and Siluroids have been dispersed, we are obliged to 
place the Indian region as the first in the order of our treat- 
ment ; and indeed the number of its freshwater fishes, which 
appear to have spread from it into the neighbouring regions, 
far exceeds that of the species which it has received from 
them. 

A. The INDIAN REGION comprises the whole continent 
of Asia south of the Himalayas and the Yang-tse-kiang ; 
it includes the islands to the west of Wallace’s line. To- 
wards the north-east the island of Formosa, which also by 
other parts of its fauna leans more towards the equa- 
torial zone, has received some characteristic Japanese 
Freshwater fishes, for instance, the singular Salmonoid 
Plecoglossus. Within the geographical boundaries of China 
the Freshwater fishes of the tropics pass gradually into 
those of the northern zone, both being separated by a broad 
debateable ground. The affluents of the great river tra- 


' Martens (Preuss. Exped. Ostas. Zool. i. p. 356), has already drawn atten- 
tion that a Barbel, said to have been obtained by Ida Pfeiffer in Amboyna 
(Gunth. Fish. vii. p. 123), cannot have come from that locality. 


INDIAN REGION. Dol 


versing this district are more numerous from the south 
than from the north, and carry the southern fishes far into 
the temperate zone. The boundary of this region towards 
the north-west is scarcely better defined. Before Persia 
passed through the geological changes by which its waters 
were converted into brine and finally dried up, it seems 
to have been inhabited by many characteristic Indian forms, 
of which a few still survive in the tract intervening be- 
tween Afghanistan and Syria; Ophiocephalus and Disco- 
gnathus have each at least one representative, Macrones has 
survived in the Tigris, and Mastacembelus has penetrated as 
far as Aleppo. Thus, Freshwater fishes belonging to India, 
Africa, and Europe, are intermingled in a district which 
forms the connecting lnk between the three continents. Of 
the freshwater fishes of Arabia we are perfectly ignorant ; 
so much only being known that the Indian Discognathus 
lamta occurs in the reservoirs of Aden, having, moreover, 
found its way to the opposite African coast ; and that the 
ubiquitous Cyprinodonts flourish in brackish pools of Northern 
Arabia. ' 

The following is the list of the forms of freshwater fishes 
inhabiting this region :!— 


Percina— 

Lates? [Africa, psa ; 1 species. 
Nandina : : : ‘ (ae 
Labyrinthici [Africa] . ; : aT Geo eae 
Luciocephalide : ? : Ton 
Ophiocephalide [1 species in nical : ron 5; 
Mastacembelide [3 species in Africa]. . , oe ae 
Chromides [ Africa, South America] 

Etroplus 2 7 


1 Jn the following and succeeding lists, those forms which are peculiar to 
and exclusively characteristic of, the region, are printed in italics ; the other 
regions, in which the non-peculiar forms occur, are mentioned within brackets 
le at 2 Lates calcarifer in India as well as Australia. 


2o2 FISHES. 


Siluridee— 
Clariina [Africa] ; , . 12 species. 
Chacina : ; 3 as 
Silurina [Africa, Baleares] : 3. 302 owes 
Bagrina [ Africa | 5 D0 
Ariina [Africa, Australia, South enero AQ 3 
Bagariina . ; : o 20) es, 
Rhinoglanina EAtrica] : bs ty 
Hypostomatina [South Aenea : Meads 
Cyprinodontidee— 
Carnivore [Palearct., North America, 
Africa, South America] ; 
Haplochilus | Africa, South America, 
North America, Japan] . ; 7 


Cyprinide [Palearct., N. America, Africa] 
Cyprinina [Palearct., N. America, Africa] 190 ,, 


tasborina | Africa, 1 species] ; . 20. 
Semiplotina : ' i ; : 
Danionina [Africa] ‘ 30st ae 
Abramidina [Palearct., N. hone sateen 50 ee 
Homalopterina. * : ‘ 10s: 
Cobitidina [Paleearct.] . : Oe Pe 

Osteoglossidee [ Africa, Australia, S. Meera 1 
Notopteride [Africa | : ‘ ; a 
Symbranchidee— 
Amplhipnous | ae 
Monopterus Ll ws 
Symbranchus [1 species in < (Sates) Li dias 


In analysing this list we find that out of 39 families or 
eroups of freshwater fishes 12 are represented in this region, 
and that 625 species are known to occur in it; a number 
equal to two-sevenths of the entire number of freshwater 
fishes known. This large proportion is principally due to 
the development of numerous local forms of Siluroids and 


INDIAN REGION. 223 


Cyprinoids, of which the former show a contingent of about 
200, and the latter of about 330 species. The combined 
development of those two families, and their undue pre- 
ponderance over the other freshwater types, is therefore the 
principal characteristic of the Indian region. The second 
important character of its fauna is the apparently total 
absence of Ganoid and Cyclostomous fishes. Every other 
region has representatives of either Ganoids or Cyclostomes, 
some of both. However, attention has been directed to the 
remarkable coincidence of the geographical distribution of 
the Sirenidw and Osteoglosside, and as the latter family is 
represented in Sumatra and Borneo, it may be reasonably 
expected that a Dipnoous form will be found to accom- 
pany it. The distribution of the Svrenide and Osteoglosside 
is as follows :— 
Tropical America. 


Lepidosiren paradoxa. | Osteoglossum bicirrhosum. 
Arapaima gigas. 
Tropical Australia. 
Ceratodus forsteri. | Osteoglossum leichardti. 
Ceratodus miolepis. 


East Indian Archipelago. 


2 | Osteoglossum formosum. 
Tropical Africa. 
Protopterus annectens, |  Heterotis niloticus. 


Not only are the corresponding species found within the 
same region, but also in the same river systems ; and although 
such a connection may and must be partly due to a similarity 
of habit, yet the identity of this singular distribution is so 
striking that it can only be accounted for by assuming that 
the Osteoglosside are one of the earliest Teleosteous types 
which have been contemporaries of and have accompanied 


DOA. FISHES. 


the present Dipnoi since or even before the beginning of the 
tertiary epoch. 

Of the autochthont freshwater fishes of the Indian region, 
some are still limited to it, viz., the Vandina, the Luciocepha- 
lide (of which one species only exists in the Archipelago), of 
Siluroids the Chacina and Bagariina, of Cyprinoids the Semi- 
plotina and Homalopterina ; others very nearly so, like the 
Labyrinthici, Ophiocephalide, Mastacembelide, of Siluroids 
the Silurina, of Cyprinoids the Rasborina and Danionina, and 
Symbranchide. 

The regions with which the Indian has least similarity 
are the North American and Antarctic, as they are the most 
distant. Its affinity to the other regions is of a very different 


degree : 

1. Its affinity to the Europo-Asiatic region is mdicated 
almost solely by three groups of Cyprinoids, viz., the Cypri- 
nina, Abramidina, and Cobitidina. The development of 
these groups north and south of the Himalayas is due to 
their common origin in the highlands of Asia; but the forms 
which descended into the tropical climate of the south are 
now so distinct from their northern brethren that most of 
them are referred to distinct genera. The genera which are 
still common to both regions are only the true Barbels 
(Barbus), a genus which, of all Cyprinoids, has the largest 
range over the old world, and of which some 160 species 
have been described; and, secondly, the Mountain Barbels 
(Schizothorax, ete.), which, peculiar to the Alpine waters of 
Central Asia, descend a short distance only towards the 
tropical plains, but extend farther into rivers within the 
northern temperate districts. The ongin and the laws 
of the distribution of the Cobitidina appear to have been 
identical with those of Barbus, but they have not spread into 
Africa. 

If, in determining the degree of affinity between two 


INDIAN REGION. 225 


regions, we take into consideration the extent in which an 
exchange has taken place of the faunze originally peculiar to 
each, we must estimate that obtaiimg between the fresh- 
water fishes of the Europo-Asiatic and Indian regions as very 
shght indeed. 

2. There exists a great affinity between the Indian and 
African regions; seventeen out of the twenty-six families or 
groups found in the former are represented by one or more 
species in Africa, and many of the African species are not 
even generically different from the Indian. As the majority 
of these groups have many more representatives in India than 
in Africa, we may reasonably assume that the African species 
have been derived from the Indian stock; but this is pro- 
bably not the case with the Siluroid group of Clarvina, which 
with regard to species is nearly equally distributed between 
the two regions, the African species being referable to three 
genera (Clarias, Heterobranchus, Gymnallabes, with the sub- 
genus Channallabes), whilst the Indian species belong to two 
genera only, viz. Clarias and Heterobranchus. On the other 
hand, the Indian region has derived from Africa one fresh- 
water form only, viz. Etroplus, a member of the family of 
Chromides, so well represented in tropical Africa and South 
America. Htroplus inhabits Southern and Western India and 
Ceylon, and has its nearest ally in a Madegasse Freshwater 
fish, Paretroplus. Considering that other African Chromides 
have acclimatised themselves at the present day in saline 
water, we think it more probable that Etroplus should have 
found its way to India through the ocean than over the 
connecting land area; where, besides, it does not occur. 

3. A closer affinity between the Indian and Tropical 
American regions than is indicated by the character of the 
equatorial zone generally, does not exist. No genus of Fresh- 
water fishes occurs in India and South America without being 
found in the intermediate African region, with two exceptions. 

Q 


226 FISHES. 


Four small Indian Siluroids (Sisor, Lrethistes, Pseudecheneis, and 
Exostoma) have been referred to the South American Hyposto- 
matina ; but it remains to be seen whether this combination 
is based upon a sufficient agreement of their internal structure, 
or whether it is not rather artificial. On the other hand, the 
occurrence and wide distribution in tropical America of a fish 
of the Indian family Symbranchide (Symbranchus marmo- 
ratus), which is not only congeneric with, but also most 
closely allied to, the Indian Symbranchus bengalensis, offers 
one of those extraordinary anomalies in the distribution of 
animals of which no satisfactory explanation can be given at 
present. 

4. The relation of the Indian region to the Tropical Pacific 
region consists only in its having contributed a few species 
to the poor fauna of the latter. This immigration must have 
taken place within a recent period, because some species 
now inhabit fresh waters of tropical Australia and the South 
Sea Islands without having in any way changed their specific 
characters, as Lates calcarifer, species of Dules, Plotosus 
anguillaris ; others (species of Arius) are but little different 
from Indian congeners. All these fishes must have migrated 
by the sea ; a supposition which is supported by what we know 
of their habits. We need not add that India has not received 
a single addition to its freshwater fish-fauna from the Pacific 
region. 

Before concluding these remarks on the Indian region, 
we must mention that peculiar genera of Cyprinoids and 
Siluroids inhabit the streams and lakes of its alpine ranges 
in the north. Some of them, like the Siluroid genera Glypto- 
sternum, Euglyptosternum, Pseudecheneis, have a folded disk 
on the thorax between their horizontally spread pectoral fins ; 
by means of this they adhere to stones at the bottom of 
the mountain torrents, and without it they would be swept 
away into the lower courses of the rivers. The Cypri- 


AFRICAN REGION. 227 


noid genera inhabiting similar localities, and the lakes into 
which the alpine rivers pass, such as Oreinus, Schizothoraa, 
Ptychobarbus, Schizopygopsis, Diptychus, Gymnocypris, are dis- 
tinguished by peculiarly enlarged scales near the vent, the 
physiological use of which has not yet been ascertained. 
These alpine genera extend far into the Europo-Asiatic 
region, where the climate is similar to that of their southern 
home. No observations have been made by which the alti- 
tudinal limits of fish life in the Himalayas can be fixed, 
but it is probable that it reaches the line of perpetual snow, 
as in the European Alps which are inhabited by Salmonoids. 
Griffith found an Oreinus and a Loach, the former in abun- 
dance, in the Helmund at Gridun Dewar, altitude 10,500 
feet ; and another Loach at Kaloo at 11,000 feet. 


B. The ArricAN REGION comprises the whole of the 
African continent south of the Atlas and the Sahara. It 
might have been conjectured that the more temperate climate 
of its southern extremity would have been accompanied by a 
conspicuous difference of the fish-fauna. But this is not the 
case ; the difference between the tropical and southern parts 
of Africa consists simply in the gradual disappearance of spe- 
cifically tropical forms, whilst Siluroids, Cyprinoids, and 
even Labyrinthici penetrate to its southern coast; no new 
form has entered to impart to South Africa a character dis- 
tinct from the central portion of the continent. In the north- 
east the African fauna passes the Isthmus of Suez and pene- 
trates into Syria; the system of the Jordan presenting so 
many African types that it has to be included in a description 
of the African region as well as of the Europo-Asiatic. This 
river is inhabited by three species of Chromis, one of Hem- 
chromis, and Clarias macracanthus, a common fish of the 
Upper Nile. This infusion of African forms cannot be ac- 
counted for by any one of those accidental means of dispersal, 


228 FISHES. 


as Hemichromis is not represented in the north-eastern parts of 
Africa proper, but chiefly on the west coast and in the Central 
African lakes. 

Madagascar clearly belongs to this region. Besides some 
Gobies and Dules, which are not true freshwater fishes, four 
Chromides are known. To judge from general accounts, its 
Freshwater fauna is poorer than might be expected; but, 
singular as it may appear, collectors have hitherto paid but 
little attention to the Freshwater fishes of this island. The 
fishes found in the freshwaters of the Seychelles and Masca- 
renes are brackish-water fishes, such as Mundulus, Hap- 
lochilus, Elops, Mugil, etc. 

The following is the lst of the forms of Freshwater fishes 
inhabiting this region :— 

Dipnoi [ Australia, Neotrop.]— 
Lepidosiren annectens : : ; 1 species. 
Polypteride : : : ; 2 


Percina (Cosmopol.)— 


Lates [India, Australia] Leer: 
Labyrinthici [India } Doves 
Ophiocephalidee {India} Ls ee; 
Mastacembelide [India] 37 oe. 
Chromides [South America ]— 

Chromis : : : : : De loss 

femichromis : ; ; f A 

Paretroplus ; : ; : a: 
Siluridzee— 

Clariina [India] : : : . 14° | 

Silurina [India, Palearct.]  . : . ‘Sipe 

Bagrina [India] , : ; Oh, ae 

Pimelodina [South America ] : : 2 


Ariina! [India, Australia, 8. Amer., Patagonia] 4 
Doradina [South America ]— 
Synodontis. : : : ts 


1 One species (Arius thalassinus) found in Indian and African rivers. 


AFRICAN REGION. 


Rhinoglanina [India] 
Malapterurina 


Characinide [South America ]— 
Citharimina . 
Nannocharacina 
Tetragonopterina— 

Alestes 
Crenuchina— 

Xenocharax 
Hydrocyonina— 

Hydrocyon 
Distichodontina 
Ichthyborina 

Mormyride (eae) 


Cyprinodontide— 
Carnivore [Palearct., India, 8. America 
Haplochilus [India, South America| 
Fundulus [Paleearct., Nearct. ] 


Cyprinide [Paleearct., India, North America] 


Cyprinina [Palearct., India, N. America— 
Labeo [India] 
Barynotus [India] 
A brostomus ; 
Discognathus lamta! [India] 
Barbus [Paleearct., India] 
Rasborina [India] 
Danionina [India ]— 
Barilius [India] 
Abramidina [Paleearct., India, N. Araetical 
Pelotrophus 
Kieriidee : 
Osteoglosside [| India, Agere South eres 
Heterotis . 
Pantodontide 
Notopteridz [India] 


1 This species extends from India into East Africa. 


229 


2 species. 


bo bo 


10 


51 


m— pp bo oO 


bt — = 


” 


255 species. 


230 FISHES. 


Out of the 39 families or groups of freshwater fishes 
15 are represented in the African region, or three more than 
in the Indian region ; however of two of them, viz., the Ophio- 
cephalide and Mastacembelide, a few species only have found 
their way into Africa. On the other hand, the number of 
species is much less, viz. 255, which is only two-fifths of that of 
the known Indian species. The small degree of specialisation 
and localisation is principally due to the greater uniformity of 
the physical conditions of this continent, and to the almost 
perfect continuity of the great river systems, which take their 
origin from the lakes in its centre. This is best shown 
by a comparison of the fauna of the Upper Nile with that 
of the West African rivers. The number of species known 
from the Upper Nile amounts to 56, and of these not 
less than 25 are absolutely identical with West African 
species. There is an uninterrupted continuity of the fish- 
fauna from west to the north-east, and the species known to 
be common to both extremities may be reasonably assumed 
to inhabit also the great reservoirs of water in the centre of 
the continent. A greater dissimilarity is noticeable between 
the west and north-east fauna on the one hand, and that of 
the Zambezi on the other; the aftinity between them is 
merely generic ; and all the fishes hitherto collected in Lake 
Nyassa have proved to be distinct from those of the Nile, and 
even from those of other parts of the system of the Zambezi. 

Africa, unlike India, does not possess either alpine ranges 
or outlying archipelagoes, the fresh waters of which would 
swell the number of its indigenous species ; but at a future 
time, when its fauna is better known than at present, it is 
possible that the great difference in the number of species be- 
tween this and the Indian regions may be somewhat lessened. 

The most numerously-represented families are the Silur- 
oids, with 61 species ; the Cyprinoids, with 52; the Mormy- 
ridee, with 51; the Characinide, with 35; and the Chromides, 


AFRICAN REGION. 2a 


with 29. There is not, therefore, that great preponderance 
of the two first families over the remaining, which we 
noticed in the Indian region; in Africa there is a compara- 
tively greater variety of distinct Freshwater types, imparting 
to the study of its fauna an unflagging pleasure such as is 
scarcely gained by the study of the other region. With the 
forms peculiar to it there are combined those of India as 
well as South America. 

In Tropical Africa there are still remnants of Ganoids : 
Protopterus (Lepidosiren) annectens and Polypterus bichir, with 
the singularly modified Calamoichthys. The two former 
range from east to west, and are accompanied by an Osteo- 
glossoid (/eterotis) which has hitherto been found in the Nile 
and on the West Coast only. 

Autochthont and lmited to this region are the Mormy- 
ride, Pantodontide, and Knerude, a singular type, somewhat 
akin to the Loaches. Of Siluroid genera the most character- 
istic are Synodontis, Rhinoglanis, and the electric Malap- 
terurus ; of Characinoids, Citharinus, Alestes, Xenocharaz, 
Hydrocyon, Distichodon, Ichthyborus. 

The regions with which Africa (like India) has least 
similarity are, again, the North American and Antarctic. 
Its affinity with the Europo-Asiatic region consists only in 
having received, like this latter, a branch of the Cyprinoids, 
the African Carps and Barbels resembling, on the whole, 
more Indian than Europo-Asiatic forms. Its similarity to 
Australia is limited to the two regions possessing Dipnoous 
and Osteoglossoid types. But its relations to the two other 
regions of the equatorial zone are near and of great interest. 

1. Africa has, in common with India, the Siluroid group 
of Clariina, the Silurina, and Bagrina ; and more especially 
the small but very natural family of Notopteridw, represented 
by three species in India, and by two on the west coast of 
Africa. It would be hazardous to state at present in which 


232 FISHES. 


of the two regions these fishes first made their appearance, 
but the discovery of remains of Notopteride and Silurina 
in tertiary deposits of Sumatra points to the Indian region 
as their original home. We can have less doubt about the 
other fishes common to both regions; they are clearly immi- 
grants into Africa from the East, and it is a remarkable fact 
that these immigrants have penetrated to the most distant 
limits of Africa in the west as well as in the south,—viz. the 
Labyrinthict, represented by two genera closely allied to the 
Indian Anabas; the Ophiocephalide and Mastacembelide, a 
few species of which have penetrated to the west coast, 
singularly enough being absent from the eastern rivers; the 
Arina, represented by several species, of which one or two 
are identical with Indian, having extended their range along 
the intervening coasts to the east coast of Africa. The 
Cyprinoids also afford an instance of an Indian species 
ranging into Africa, viz. Discognathus lamta, which seems 
to have crossed at the southern extremity of the Red Sea, 
as it 1s found in the reservoirs at Aden and the hill-streams 
of the opposite coast-region of Abyssinia. 

2. No such direct influx of species and ‘genera has 
occurred from South America into Africa. Yet the affinity 
of their Freshwater fishes is striking. Two of the most 
natural families of fishes, the Chromides and Characinidea, are 
peculiar, and (with the exception of Htroplus) restricted to 
them. The African and South American Dipnoi are closely 
allied to each other. The Pimelodina, so characteristic of 
Tropical America, have three representatives in Africa, viz., 
Pimelodus platychir, P. balayi, and Auchenoglanis biscutatus ; 
the Doradina are another Siluroid group restricted to these 
two continents.' Yet, with all these points of close resem- 


1 We have left out from these considerations the Ariina and Cyprinodonts, 
which can pass with impunity through salt water, and are spread over much 
larger areas. 


NEOTROPICAL REGION. 233 


blance, the African and South American series are, with the 
exception of the two species of Pimelodus, generically distinct ; 
which shows that the separation of the continents must have 
been of an old date. On the other hand, the existence of 
so many similar forms on both sides of the Atlantic affords 
much support to the supposition that at a former period the 
distance between the present Atlantic continents was much 
less, and that the fishes which have diverged towards the 
East and West are descendants of a common stock which 
had its home in a region now submerged under some inter- 
vening part of that ocean. Be this as it may, it is evident 
that the physical conditions of Africa and South America 
have remained unchanged for a considerable period, and are 
still sufficiently alike to preserve the identity of a number of 
peculiar freshwater forms on both sides of the Atlantic. 
Africa and South America are, moreover, the only conti- 
nents which have produced in F reshwater fishes, though in 
very different families, one of the most extraordinary modi- 
fications of an organ—the conversion, that is, of muscle into 


an apparatus creating electric force. 


C. The boundaries of the TroprcAL AMERICAN (Neotropical) 
Recion have been sufficiently indicated in the definition of 
the Equatorial zone. A broad and most irregular band of 
country, in which the South and North American forms are 
mixed, exists in the north; offering some peculiarities which 
deserve fuller attention in the subsequent description of the 
relations between the South and North American faune. 
The following Freshwater fishes inhabit this region :— 


Dipnoi [Australia, Africa |— 


Lepidosiren paradoxa : : : 1 species. 
Polycentride . : : : ; one 
Chromides [Africa ]— 

Heros, Acara, Cichla, ete. : i 80) 


(Lucifuga. ia ; 2) >) 


234 FISHES. 


Siluridee— 
Hypophthalmina . ; : : 5 species. 
Pimelodina [Africa, 2 species]. so ° Oe 
Ariina [ Africa, India, Australia, Fuegian | 30) ee 
Doradina [ Africa] : 2) 2600 ae 
Hypostomatina [India]. 3 . =“ 905 ee 
Aspredinina : 9 
Nematogenyina | Fuegian |— Zia 
Trichomycterina [Fuegian | 2 Rs 
Stegophilina 3 < 
Characinidee [Africa |— 
Erythrinina 165) “ 
Curimatina : ; ‘ : 40 = 
Anastomatina F ; : . 25 e 
Tetragonopterina ; ; ; 80 55 
Hydrocyonina . ‘ ; 5305 
Crenuchina 1 Hs 
Serrasalmonina . ; ey ey 
Cyprinodontide 
Carnivore [Europe, Asia, N. America, 
India, Africa] ; , , 30 AS 
Limnophage : : ‘ - 43:5 ies 
Osteoglossidee [Africa, India, Australia] Qi as 
Gymnotide  . : 5 ; : 20 af 
Symbranchidee [India] : : : 1 


672 species. 


Out of the 39 familes or groups of Freshwater fishes, 
9 only are represented in the Tropical American region. 
This may be accounted for by the fact that South America is 
too much isolated from the other regions of the Equatorial 
zone to have received recent additions to its fauna. On the 
other hand, the number of species exceeds that of every other 
region, even of the Indian, with which, in regard to the com- 
parative development of familes, the Neotropical region shows 
great analogy, as will be seen from the following Table :— 


NEOTROPICAL REGION. 


235 


INDIAN. NEOTROPICAL. 
Siluridee 200 sp. Siluridee 276 sp. 
Cyprinidee 330 sp. Characinide 226 sp. 
Labyrinthici . 25 sp. Chromides 80 sp. 
Ophiocephalidze 30 sp. Cyprinodontide 60 sp. 
Mastacembelide 10 sp. Gymnotide 20 sp. 


In both regions the great number of species is due to the 
development of numerous local forms of two families, the 
Characinide taking in the New World the place of the 
Cyprinide of the Old World. Thereto are added a few smaller 
families with a moderately large number of species, which, 
however, is only a fraction of that of the leading families, the 
remainder of the families being represented by a few species 
only. The number of genera within each of the two regions 
of the two principal families is also singularly alike; the 
Indian region having produced about 45 Siluroid and as 
many Cyprinoid genera, whilst the Neotropical region is 
tenanted by 54 Siluroid and 40 Characinoid genera. These 
points of similarity between the two regions cannot be acci- 
dental; they indicate that agreement in their physical and 
hydrographical features which in reality exists. 

Of Ganoids, we find in Tropical America one species only, 
Lepidosiren paradoxa, accompanied by two Osteoglossoids 
(Osteoglossum bicirrhosum and Arapaima gigas). 

Autochthont and limited to this region are the Polycen- 
tridw, all the non-African genera of Chromides and Chara- 
cinide ; of Siluroids, the Hypophthalmina, Aspredinina, and 
Stegophilina, and the majority of Pimelodina, Hypostomatina, 
and Doradina ; the herbivorous Cyprinodonts or Limnophage, 
and numerous insectivorous Cyprinodonts or Cariivore ; and 
the Gymnotide (Electric eel). 

The relations to the other regions are as follows :— 

1. The resemblances to the Indian and Tropical Pacific 
regions partly date from remote geological epochs, or are partly 


236 FISHES. 


due to that similarity of physical conditions to which we 
have already referred. We have again to draw attention to 
the unexplained presence in South America of a repre- 
sentative of a truly Indian type (not found in Africa), viz. 
Symbranchus marmoratus. On the other hand, a direct 
genetic affinity exists between the Neotropical and African 
regions, as has been noticed in the description of the latter, 
a creat part of their freshwater fauna consisting of descendants 
from a common stock. 

2. A comparison of the specifically Neotropical with the 
specifically North American types shows that no two regions 
can be more dissimilar. It is only in the intervening border- 
land, and in the large West Indian Islands, that the two 
faunze mix with each other. We need not enter into the 
details of the physical features of Central America and Mexico 
—the broken ground, the variety of climate (produced by dif- 
ferent altitudes) within limited districts, the hot and moist 
alluvial plains surrounding the Mexican Gulf, offer a diver- 
sity of conditions most favourable to the intermixture of the 
types from the north and the south. But yet the exchange 
of peculiar forms appears to be only beginning ; none have yet 
penetrated beyond the debateable ground, and it is evident that 
the land-connection between the two continents is of com- 
paratively recent date: a view which is confirmed by the 
identity of the marine fishes on both sides of Central America. 

Cuba—and this is the only island in the West Indies 
which has a number of freshwater fishes sufficient for the 
determination of its zoogeographical relations—is inhabited 
by several kinds of a perch (Centropomus), freshwater mullets, 
Cyprinodonts, one species of Chromid (an Acara), and Sym- 
branchus marmoratus. All these fishes are found in Central 


America, and as they belong to forms known to enter brack- 
ish water more or less freely, it is evident that they have 
crossed from the mainland of South America or from Central 


NEOTROPICAL REGION. 237 


America. But with them there came a remarkable North 
American type, Lepidosteus. Lepidosteus viridis, which is 
found in the United States, has penetrated on the mainland 
to the Pacific coast of Guatemala, where it is common at the 
mouth of the rivers and in brack-water lakes along the coast; 
it probably crossed into Cuba from Florida. <A perfectly iso- 
lated type of fishes inhabits the subterranean waters of the 
caves of Cuba (two species of Lucifuga). The eyes are absent 
or quite rudimentary, as in most other cave animals. Sineu- 
larly, it belongs to a family (Ophidiide), the members of 
which are strictly marie; and its nearest ally is a genus, 
Brotula, the species of which are distributed over the Indo- 
Pacific Ocean, one only occurring in the Caribbean Sea. This 
type must have witnessed all the geological changes which 
have taken place since Cuba rose above the surface of the sea. 

A similar mixture of forms of the Tropical and Temperate 
types of Freshwater fishes takes place in the south of South 
America; its details have not yet been so well studied as in 
the north; but this much is evident that, whilst in the East 
Tropical forms follow the Plate river far into the Temperate 
region, in the West the Temperate Fauna finds still a congenial 
climate in ranges of the Andes, situated close to, or even 
north of, the Tropic. 

Like the Indian region, the Tropical American has a pecu- 
liar Alpine Fauna, the Freshwater fishes of which, however, 
belong to the Siluroids and Cyprinodonts. The former are 
small, dwarfed forms (Arges, Stygogenes, Brontes, Astroblepus, 
Trichomycterus, Eremophilus), and have a perfectly naked 
body, whilst the representatives in the lowlands of, at least, 
the first four genera are mailed. The Alpine Cyprinodonts, 
on the other hand, (Orestias) exceed the usual small size of 
the other members of this family, are covered with thick 
scales, but have lost their ventral fins. Some of these Alpine 
forms, ike Z’richomycterus, follow the range of the Andes far 


238 FISHES. 


into the southern temperate region. The majority reach to 
a height of 15,000 feet above the level of the sea, and a few 
are found still higher. 


D. The TropicAL PActFIc REGION includes all the islands 
east of Wallace’s Line, New Guinea, Australia—with the ex- 


ception of its south-eastern portion,—and all the islands of 


the Tropical Pacific to the Sandwich group. Comparing the 
area of this region with that of the others, we find it to be 
not only the poorest in point of the number of its species 
generally, but also in that of the possession of peculiar forms, 
as will appear from the following list :— 

Dipnoi [Neotrop., Africa. | 


Ceratodus ; : , 2 species. 
Percidze [Cosmopol.]— 


Lates (calearifer) [India] Lt oes 

Nannoperca : : : : le ae 

Oligorus [New Zealand] . : : Le 

Dules [India]. 8 4, 

(Macquaria) | ae 
Labyrinthici— 

Anabas (scandens) [India | ; | es 
Ophiocephalidie 

Ophiocephalus (striatus) [India] . Lae 
Atherinide [Brack-water ]|— 

Atherinichthys . , ‘ . ie: 
Osteoglossidz [India, Africa, Neotrop. | 3 i Be 
Siluridee . 

Plotosina [India] : : : OPE, 

Ariina [India, Africa, Neotrop.] . (rec 
Symbranchidee 

Monopterus (javanicus) [India] . ; ie 


Total . 36 species. 


The paucity of freshwater fishes is due, in the first place, 
to the arid climate and the deficiency of water in the Aus- 


TROPICAL PACIFIC REGION. 239 


tralian continent, as well as to the insignificant size of the 
fresh-water courses in the smaller islands. Still this cannot 
be the only cause: the large island of Celebes, which, by its 
mountainous portions, as well as by its extensive plains and 
lowlands, would seem to offer a favourable variety of condi- 
tions for the development of a freshwater Fauna,is, as far as 
has been ascertained, tenanted by seven Freshwater fishes 
only, viz. 2 Arius, 2 Plotosus, 1 Anabas, 1 Ophiocephalus, 1 
Monopterus, all of which are the commonest species of the 
Indian region. New Guinea has not yet been explored, but, 
from the faunze nearest to this island, we expect its fresh- 
water fishes will prove to be equally few in number, and 
identical with those of Celebes and North Australia; a sup- 
position confirmed by the few small collections which have 
reached Europe. Finding, then, that even those parts of this 
region, which are favourable to the development of Fresh- 
water fishes, have not produced any distinct forms, and that 
the few species which inhabit them, are unchanged, or but 
slightly modified Indian species, we must conclude that the 
whole of this area has remained geologically isolated from 
the other regions of this zone since the commencement of the 
existence of Teleostei; and that, with the exception of Cera- 
todus and Osteoglossum, the immigration of the other species 
is of very recent date. 

Fossil remains of Ceratodus have been found in Liassic 
and Triassic formations of North America, England, Germany, 
and India; and it is, therefore, a type which was widely 
spread in the Mesozoic epoch. Although it would be rash 
to conclude that its occupation of Australia dates equally far 
back, for it may have reached that continent long afterwards ; 
yet it is evident that, as it is one of the most ancient of the 
existing types, so it 1s certainly the first of the Freshwater 
fishes which appeared in Australia. Osteoglossum, of which 
no fossil remains yet have been found, is proved by its distri- 


240 FISHES. 


bution to be one of the oldest Teleosteous types. There 
must have been a long gap of time before these ancient 
types were joimed by the other Teleostei. All of them 
migrated through the intervening parts of the ocean from 
India. Most of the Plotosina, some of the Ari, Dules, and 
the Atherinichthys, also Nannoperca (allied to Apogon), were 
among the earliest arrivals, being sufficiently differentiated 
to be specifically or even generically (Cnidoglanis, Nanno- 
perca) distinguished; but some others, like Anabas scandens, 
Lates calearifer, Dules marginatus, must have reached the 
Australian continent quite recently, for they are indistin- 
cuishable from Indian specimens. 

In South-western Australia a mingling of the scanty 
fauna with that of the southern temperate parts takes place. 
Oligorus macquariensis (The Murray Cod), which has a con- 
gener on the coast of New Zealand, ascends high up the 
Murray river, so that we cannot decide whether this Percoid 
should be located in the Tropical or Temperate part of Aus- 
tralia. Several Galaxias also extend to the confines of 
Queensland, and will probably some day be found members 
of this region. 

In the smaller Pacific islands the Freshwater fishes ex- 
hibit a remarkable sameness: two or three species of Dudes, 
several Eels, an Atherine, or some Gobies, Mullets, and other 
fishes which with equal readiness exchange fresh for salt 
water, and which would at once reach and occupy any streams 
or freshwater lakes that may be formed on an island. 

The Sandwich Islands are the only group among the 
smaller islands which are tenanted by a Siluroid, a species 
of Arius, which is closely allied to Central American species, 
and, therefore, probably immigrated from Tropical America. 


II. NoRTHERN ZONE. 


The boundaries of the Northern Zone coincide in the 


NORTHERN ZONE. 241 


main with the northern limit of the Equatorial Zone; but at 
three different points they overlap the latter, as has been 
already indicated. This happens in, and east of, Syria, where 
the mixed faunz of the Jordan and the rivers of Mesopotamia 
demand the inclusion of this territory into the Northern Zone 
as well as the Equatorial; in the island of Formosa, where a 
Salmonoid and several Japanese Cyprinoids flourish ; and in 
Central America, where a Lepidosteus, a Cyprinoid (Selerog- 
nathus meridionalis), and an Amiurus (A. meridionalis) repre- 
sent the North American fauna in the midst of a host of 
tropical forms. 

A separate Arctic Zone does not exist ‘for Freshwater 
fishes; ichthyic life becomes extinct towards the pole as 
soon as the fresh water remains frozen throughout the year, or 
thaws for a few weeks only ; and the few fishes which extend 
into high latitudes, in which lakes are open for two or three 
months in the year, belong to types in no wise differing from 
those of the more temperate south. The highest latitude at 
which fishes have been obtained is 82° lat. N., whence the 
late Arctic Expedition brought back specimens of Charr 
(Salmo arcturus and Salmo naresit). 

The ichthyological features of this zone are well marked : 
the Chondrosteous Ganoids or Sturgeons, and the families 
of Salmonide and Esocide are limited to, and characteristic 
of, it; Cyprinoids flourish with the Salmonoids, both families 
preponderating in numbers over the others, whilst the Silur- 
oids are few in number and in variety. 

The two regions in which this zone is divided are very 
closely related to one another, and their affinity is not unlike 
that which obtains between the sub-regions of the Southern 
Zone. The subjoined list will show their close agreement 
with regard to families as well as species. Several of the 
latter are common to both, viz.—Acipenser sturio, A. macu- 
latus, Perca fluviatilis, Gastrosteus pungitius, Salmo salar, 

R 


242 FISHES. 


Esox lucius, Lota vulgaris, Petromyzon marinus, P. fluviatilis, 
and P. branchialis ; and all recent investigations have resulted 
in giving additional evidence of the affinity, and not of the 
diversity of the two regions. 

In Europe and temperate Asia, as well as in North 
America, mountain ranges elevated beyond the line of per- 
petual snow would seem to offer physical conditions favour- 
able for the development of a distinct alpine fauna. But 
this is not the case, because the difference of climate be- 
tween the mountain districts and the lowlands is much 
less in this zone than in the Equatorial. Consequently the 
alpine freshwater fishes do not essentially differ from those of 
the plains; they are principally Salmonoids; and in Asia, 
besides, mountain-barbels and Loaches. Salmo orientalis was 
found by Griffith to abound in the tributaries of the Bamean 
river at an altitude of about 11,000 feet. 


Europo-Asiatic. N, American. 


A cipenserida— 

Acipenser : ; 9 species. 12 species. 

Scaphirhynchus re ss 1 ize. 

Polyodon 133; tw, 
Lepidosteide Oj ees 3a 
Amide : : : Os tmss Lyte 
Percina [Cosmopol. | : oy Oras 30 
Grystina [Australia, New Zealand] 0 ,, Dee 
Centrarchina ls 20 ae 
A phredoderidee Ole Se aoa 
Cottide [partly marine ]}— 

Cottus Sime oS 

Ptyonotus Ore; anes 2 
Gastrosteide Daan D> Lae 
Comephoride enue: Oinnes 
Gadide [marine ]— 

Lota : ; ‘ : Lae lb 


Siluridee— 
Silurina [India, Africa] . 5 ,, 4, 


NORTHERN ZONE. 243 


Europo-Asiatic. N. American. 


Bagrina . : ‘ 2 species. 0 species. 

Amiurina , : , i rs Seles 
Salmonide. ‘ : : : S07: LNB ack 
Percopside : ; ‘ We vows 1 eee 
Esocide . : : , : | te (ae 
Umbride Prat 28 1 ae 
Cyprinodontid Canty ore ean 

Africa, Neotrop.]  . : Seat 30: 
Heteropygii : : : OM 5, Dig re 
Cyprinidze— 

Catostomina . ; jks HAS) arp 

Cyprinina [India, Ne eS Oumar 30. 

Leuciscina : : : (Oe ee, Ol oe 

thodeina ; On” y.,3 Ora. 

Abramidina [India, hema AE a HORS 

Cobitidina [India]. : DOLE a. O1ass 
Hyodontide . : OM,.a by ls, 
Petromyzontide soutien Zone Les, Shas 


360 species. 339 species. 


A. The Europo-ASIATIc (PALHARCTIC) REGION.—Its western 
and southern boundaries coincide with those of the Northern 
Zone, so that only those which divide it from North America 
have to be indicated. Behring’s Strait and the Kamtschatka 
Sea have been conventionally taken as the boundary, but 
this is shown to be artificial by the fact that the animals of 
both coasts, as far as they are known at present, are not suf- 
ficiently distinct to be referred to two distinct regions. As 
to the freshwater fishes those of North-western America and 
of Kamtschatka are but imperfectly known, but there can 
be little doubt that the same agreement exists between them 
as is the case with other classes of animals. The Japanese 
islands exhibit a decided Palearctic fish-fauna, which includes 
Barbus and Cobitioids, forms strange to the North American 
fauna. A slight influx of tropical forms is perceived in the 


244 FISHES. 


south of Japan, where two Bagrina (Pseudobagrus aurantiacus 
and Liocassis longirostris) have established themselves for a 
considerable period, for both are peculiar to the island, and 
have not been found elsewhere. 

In the east, as well as in the west, the distinction between 
the Europo-Asiatic and North American regions disappears 
almost entirely the farther we advance towards the north. 
Of four species of the genus Salmo known from Iceland, one 
(S. salar) is common to both regions, two are European (S. 
fario and S. alpinus), and one is a peculiarly Icelandic race 
(S. nivalis). As far as we know the Salmonoids of Greenland 
and Baffin’s Land they are all most closely allied to European 
species, though they may be distinguished as local races. 

Finally, as we have seen above, the Europo-Asiatic fauna 
mingles with African and Indian forms in Syria, Persia, and 
Afghanistan. Capoéta, a Cyprinoid genus, is characteristic 
of this district, and well represented in the Jordan and rivers 
of Mesopotamia. 

Assuming that the distribution of Cyprinoids has taken 
its origin from the alpine tract of country dividing the Indian 
and Palearctic regions, we find that this type has found in the 
temperate region as equally favourable conditions for its devel- 
opment as in the tropical. Out of the 560 species known to 
exist in the Palearctic regions, no less than 215 are Cyprin- 
oids. In the countries and on the plateaus immediately 
joining the Himalayan ranges those mountain forms which 
we mentioned as peculiar to the Indian Alps abound and 
extend for a considerable distance towards the west and east, 
mixed with other Cyprinina and Cobitidina. The represent- 
atives of these two groups are more numerous in Central and 
Eastern Asia than in Europe and the northern parts of Asia, 
where the Leuciscina predominate. Abramidina or Breams 
are more numerous in the south and east of Asia, but they 
spread to the extreme north-western and northern limits, to 


EUROPO-ASIATIC REGION. 245 


which the Cyprinoid type reaches. The Rhodeina are a small 
family especially characteristic of the East, but with one or 
two off-shoots im Central Europe. Very significant is the 
appearance in China of a species of the Catostomina, a group 
otherwise limited to North America. 

The Cyprinoids, in their dispersal from the south north- 
wards, are met from the opposite direction by the Salmonoids. 
These fishes are, without doubt, one of the youngest families 
of Teleoster, for they did not appear before the Pliocene era; 
they flourished at any rate during the glacial period, and, 
as is testified by the remnants which we find in isolated 
elevated positions, like the Trout of the Atlas, of the moun- 
tains of Asia-Minor, and of the Hindu Kush, they spread to 
the extreme south of this region. At the present day they 
are most numerously represented in its northern temperate 
parts; towards the south they become scarcer, but increase 
again in numbers and species, wherever a great elevation offers 
them the snow-fed waters which they affect. In the rivers 
of the Mediterranean Salmonoids are by no means scarce, 
but they prefer the upper courses of those rivers, and do 
not migrate to the sea. 

The Pike, Umbra, several species of Perch and Stickle- 
back, are also clearly autochthont species of this region. 
Others belong to marine types, and seem to have been re- 
tained in fresh water at various epochs: thus the freshwater 
Cottus (Miller’s Thumb) ; Cottus quadricornis, which inhabits 
lakes of Seandinavia, whilst other individuals of the same 
species are strictly marine; the Burbot (Lota vulgaris) ; and 
the singular Comephorus, a dwarfed and much-changed Gadoid 
which inhabits the greatest depths of Lake Baikal. 

Remnants of the Palsichthyic fauna are the Stwrgeons 
and Lampreys. The former inhabit in abundance the great 
rivers of Eastern Europe and Asia, periodically ascending 
them from the sea; their southernmost limits are the Yang- 


246 FISHES. 


tse-kiang in the east, and rivers flowing into the Adriatic, 
Black and Caspian Seas, and Lake Aral, towards the centre 
of this region. None are known to have gone beyond the 
boundaries of the Northern Zone. If the Lampreys are 
justly reckoned among Freshwater fishes, their distribution 
is unique and exceptional. In the Paleearctic region some of 
the species descend periodically to the sea, whilst others 
remain stationary in the rivers; the same has been observed 
in the Lampreys of North America. They are entirely absent 
in the Equatorial Zone, but reappear in the Temperate Zone 
of the Southern Hemisphere. Many points of the organ- 
isation of the Cyclostomes indicate that they are a type of 
ereat antiquity. 

The remaining Palearctic fishes are clearly immigrants 
from neighbouring regions: thus Siluwrus, Macrones, and 
Pseudobagrus from the Indian region; Amiwrus (and, as 
mentioned above, Catostomus) from North America. The 
Cyprinodonts are restricted to the southern and warmer 
parts ; all belong to the carnivorous division. The facility 
with which these fishes accommodate themselves to a 
sojourn in fresh, brackish, or salt water, and even in thermal 
springs, renders their general distribution easily compre- 
hensible, but it is impossible to decide to which region 
they originally belonged; their remains in tertiary deposits 
round the Mediterranean are not rare. 


B. The boundaries of the NorrH AMERICAN or NEARCTIC 
REGION have been sufficiently indicated. The main features 
and the distribution of this fauna are identical with those of 
the preceding region, The proportion of Cyprinoid species 
to the total number of North-American fishes (135 :339) 
appears to be considerably less than in the Palzearctic region, 
but we cannot admit that these figures approach the truth, 
as the Cyprinoids of North America have been much less 


NORTH AMERICAN REGION, 247 


studied than those of Europe; of many scarcely more than 
the name is known. ‘This also applies in a great measure to 
the Salmonoids, of which only half as many as are found in 
the Palearctic region have been sufficiently described to be 
worthy of consideration. North America will, without doubt, 
in the end show as many distinct races as Europe and Asia. 

Cyprinoids, belonging to genera living as well as extinct, 
existed in North America in the tertiary period. At present, 
Cyprinina, Leuciscina, and Abramidina are well represented, 
but there is no representative of the Old World genus Barbus, 
or of the Cobitidina! ; Rhodeina are also absent. On the 
other hand, a well-marked Cyprinoid type is developed — 
the Catostomina, of which one species has, as it were, re- 
turned into Asia. Very characteristic is the group of Centrar- 
china, allied to the Perch, of which there are some thirty 
species; two Grystina. Of the Sticklebacks there are as 
many species as in Europe, and of Pike not less than seven 
species have been distinguished. Umbra appears to be 
as local as in Europe. Some very remarkable forms, types 
of distinct families, though represented by one or two species 
only, complete the number of North American autochthont 
fishes—viz., Aphredoderus, Percopsis, Hyodon, and the Heter- 
opygit (Amblyopsis and Chologaster). The last are allied to 
the Cyprinodonts, differing from them in some points of the 
structure of their intestines. The two genera are extremely 
sunilar, but Chologaster, which is found in ditches of the rice- 
fields of South Carolina, is provided with eyes, and lacks the 
ventral fins. Amblyopsis is the celebrated Blind Fish of the 
Mammoth Cave of Kentucky: colourless, eyeless, with rudi- 
mentary ventral fins, which may be occasionally entirely 
absent. 


1 Cope has discovered in a tertiary freshwater-deposit at Idaho an extinct 
genus of this group, Diastichus. He considers this interesting fact to be 
strongly suggestive of continuity of territory of Asia and North America. — 
**Proc. Am. Phil, Soc. 1873,” p. 55. 


248 FISHES. 


A peculiar feature of the North American Fish Fauna is 
that it has retained, besides the Sturgeons and Lampreys, 
representatives of two Ganoid families, Zepidosteus and Ama. 
Both these genera existed in tertiary times: the former occurs 
in tertiary deposits of Europe as well as North America, 
whilst fossil remains of Amia have been found in the 
Western Hemisphere only. 

It is difficult to account for the presence of the Amzurina 
in North America. They form a well-marked division of the 
Bagrina, which are well represented in Africa and the East 
Indies, but absent in South America; it is evident, therefore, 
they should not be regarded as immigrants from the south, 
as is the case with the Palearctic Siluroids. Nor, again, 
has the connection between South and North America been 
established sufficiently long to admit of the supposition that 
these Siluroids could have spread in the interval from the 
south to the northern parts of the continent, for some of the 
species are found as far north as Pine Islands Lake (54° 
lat. N.)? 


III. SouTHERN ZONE. 


The boundaries of this zone have been indicated in the 
description of the Equatorial Zone ; they overlap the southern 
boundaries of the latter in South Australia and South 
America, but we have not at present the means of exactly 
defining the limits to which southern types extend north- 
wards. This zone includes Tasmania with at least a por- 
tion of South-eastern Australia (Zasmanian sub-region), New 
Zealand and the Auckland Islands (New Zealand sub-region), 
and Chili, Patagonia, Terra del Fuego, and the Falkland 
Islands (Fuegian sub-region). No freshwater fishes are known 


1 Leidy describes a Siluroid (Pimelodus) from tertiary deposits of Wyoming 
Territory. ‘‘Contrib. to the Extinct Vert. Fauna of the Western Territ. 
1873,” p. 198. 


SOUTHERN ZONE. 249 


from Kerguelen’s Land, or from islands beyond 55° lat. 8. 
The southern extremity of Africa has to be excluded from 
this zone so far as Freshwater fishes are concerned. 

This zone is, with regard to its extent as well as to 
the number of species, the smallest of the three; yet its 
ichthyological features are well marked ; they consist in the 
presence of two peculiar families, each of which is analogous 
to a northern type, viz. the Haplochitonide, which represent 
the Salmonide, Haplochiton being the analogue of Salmo, and 
Prototroctes that of Coregonus; and the Galaxiude, which are 
the Pikes of the Southern Hemisphere. 

Although geographically widely separate from each other, 
the Freshwater fishes of the three divisions are nevertheless 
so closely allied that conclusions drawn from this group 
of animals alone would hardly justify us in regarding these 
divisions as sub-regions. One species of Galaxias (Gt. attenu- 
atus) and the three Lampreys are found in all three, or at 
least two, sub-regions. 


Freshwater Fishes of the Southern Zone. 


Tasmanian. N. Zealand. Fuegian. 


Percichthys : : : ws oe 3 
Siluridze— 
Diplomystax . : : ae ee 1 
Nematogenys . : ; wee a 1 
Trichomycterina [Neotrop.] ... 
Gadopside . 1 oe rf 
(Retropinna 1 Seo hy. 
Haplochitonide . 1 1 1 
Galaxude . 6 5 4 
Petromyzontide 3 1 3 
11 8 18 


But little remains to be added in explanation of this 
list ; Percichthys is in Chili the autochthont form of the cos- 


250 FISHES. 


mopolitan group of Percina.  Diplomystax, an Arioid fish of 
Chili, and Nematogenys seem to have crossed the Andes from - 
Tropical America at a comparatively early period, as these 
genera are not represented on the eastern side of South 
America; the Z'richomycterina occur on both sides of the 
Andes, which they ascend to a considerable height. Retvo- 
pinna is a true Salmonoid, allied to, and representing in the 
Southern Hemisphere the Northern Smelt, Osmerus. In 
both these genera a part of the specimens live in the sea, 
and ascend rivers periodically to spawn ; another part remain 
in rivers and lakes, where they propagate, never descending 
to the sea, this freshwater race being constantly smaller than 
their marine brethren. That this small Teleostean of the 
Northern Hemisphere should reappear, though in a generic- 
ally modified form, in New Zealand, without having spread 
over other parts of the Southern Zone, is one of the most 
remarkable, and at present inexplicable facts of the geo- 
graphical distribution of freshwater fishes. 


Fig. 104.—Haplochiton zebra, Straits of Magelhen. 


CHAPTER XVIII. 
THE FISHES OF THE BRACKISH WATER. 


ON such parts of a coast at which there is a mixture of fresh 
and salt water, either in consequence of some river empty- 
ing its water into the sea or from an accumulation of land 
surface water forming lagunes, which are in uninterrupted or 
temporary communication with the sea, there flourishes a 
peculiar brackish water fauna which is characterised by the 
presence of fishes found sometimes in sea-, sometimes in 
pure fresh-water. 

This fauna can be rather sharply defined if a limited 
district only is taken into consideration ; thus, the species of 
the brackish water fauna of Great Britain, the Pacific coast 
of Central America, of the larger East India Islands, ete., can 
be enumerated without much hesitation. But difficulties 
arise When we attempt to generalise in the enumeration of 
the forms referable to the brackish water fauna; because the 
genera and families enumerated include certain species and 
genera which have habituated themselves exclusively either 
to a freshwater or marine existence; and, besides, because 
a species of fish may be at one locality an inhabitant of 
brackish water, at another of the sea, and at a third of fresh 
water. The circumstance that these fishes can live in sea 
and fresh water has enabled them to spread readily over the 
globe, a few only being limited to particular regions; there- 
fore, for the purposes of dividing the earth’s surface into natural 
zoological regions the brackish water forms are useless. The 
following fishes may be referred to this Fauna :— 


bo 
On 
bo 


FISHES. 


1. Species of Rajidw (Raja, Trygon) prefer the mouths of 
rivers, probably because the muddy or sandy bottom offers 
the most suitable conditions for fishes which can feed on the 
bottom only; such brackish water species belong chiefly to 
the Equatorial Zone, some having taken up their abode 
entirely in fresh water (South American Trygons). 

2. Ambassis, a Percoid genus, consisting of numerous small 
species, inhabiting the shores of the tropical parts of the 
Indian Ocean- and the coasts of Tropical Australia. Many 
species enter, and all seek the neighbourhood of, fresh water ; 
hence they disappear in the islands of the Pacific, and are 
scarce in the Red Sea. 

3. Therapon, with the same distribution as the former. 

4, Numerous Sciwnide of the Equatorial Zone. 

5. The Polynemide, chiefly inhabitants of brackish water 
of the Equatorial Zone, most developed in the Indian 
region, and scarce in the Tropical Pacific. 

6. Numerous species of Caranxz (or Horse Mackerels) of 
the Equatorial Zone. 

7. Nearly all species of Gastrosteus enter brackish water, 
G. spinachia being almost exclusively confined to it: 
Northern Zone. 

8. The most important genera of the Gobies (Gobina) : 
Gobius (nearly cosmopolitan), Sieydiwm, Boleophthalmus, Peri- 
ophthalmus, Eleotris (equatorial). Many of the species are 
entirely confined to fresh water. 

9. The Amblyopina, similar to the Gobies, but with more 
elongated body : Tropical Indo-Pacific. 

10. The 7rypauchenina : Coasts of the Indian region. 

11. Many species of Blennius, of which several are found 
far inland in fresh waters—for instance in North Italy, in the 
Lake of Galilee, in the eastern parts of Asia Minor. 

12. The majority of Atherinide, and 


FISHES OF BRACKISH WATER. 253 


13. The Mugilide: both families being most numerous 
and abundant in brackish water, and almost cosmopolitan. 

14. Many Plewronectide prefer the mouths of rivers for 
the same reason as the Rays; some ascend rivers, as the 
Flounder, Cynoglossus, ete. 

15. Several Stluridw, as especially the genera Plotosus, 
Cnidoglanis, Arius, which attain their greatest development 
in brackish water. 

16. The Cyprinodontide are frequently found in brackish 
water. 

17. Species of Clupea, some of which ascend rivers, and 
become acclimatized in fresh water, as Clupea jfinta, which 
has established itself in the lakes of northern Italy. 

18. Chatoessus, a genus of Clupeoid fishes of the Equatorial 
Zone, of which some species have spread into the Northern 
Zone. 

19. Megalops : Equatorial Zone. 

20. Anguilla. The distribution, no less than the mode 
of propagation, and the habits generally, of the so-called 
Freshwater-eels still present us with many difficult prob- 
lems. As far as we know at present their birthplace seems 
to be the coast in the immediate neighbourhood of the 
mouths of rivers. They are much more frequently found 
in fresh water than in brackish water, but the distribution of 
some species proves that they at times migrate by sea as well 
as by land and river. Thus Anguilla mauritiana is found 
in almost all the fresh and brackish waters of the islands 
of the Tropical Indian Ocean and Western Pacific, from 
the Comoros to the South Sea; Anguilla vulgaris is spread 
over temperate Europe (exclusive of the system of the 
Danube, the Black and Caspian Seas), in the Mediterranean 
district (including the Nile and rivers of Syria), and on the 
Atlantic coast of North America; Anguilla bostoniensis, in 
Eastern North America, China, and Japan; Anguzlla lati- 


254 FISHES. 


rostris, in Temperate Europe, the whole Mediterranean dis- 
trict, the West Indies, China, and New Zealand. The other 
more local species are found, in addition to localities already 
mentioned, on the East Coast of Africa, South Africa, on 
the continent of India, various East Indian Islands, Australia, 
Tasmania, Auckland Islands ; but none have ever been found 
in South America, the West Coast of North America, and 
the West Coast of Africa: surely one of the most striking 
instances of irregular geographical distribution. 

21. Numerous Syngnathide have established themselves in 
the Northern Zone as well as in the Equatorial, in the vege- 
tation which flourishes in brackish water. 

This list could be considerably increased if an enumera- 
tion of species, especially of certain localities, were attempted ; 
but this is more a subject of local interest, and would carry 
us beyond the scope of a general account of the distribution 


of Fishes. 


Fig. 105.—Mugil octo-radiatus. Fig. 106.—Mugil auratus. 


Fig. 107.—Mugil septentrionalis. 


Heads of Grey Mullets, fishes of Brackish water. 


CHAPTER XIX. 
THE DISTRIBUTION OF MARINE FISHES. 


MARINvE fishes fall, with regard to their mode of life and dis- 
tribution, into three distinct categories :— 

1. Shore Fishes—That is, fishes which inhabit chiefly 
parts of the sea in the immediate neighbourhood of land 
either actually raised above, or at least but little submerged 
below, the surface of the water. They do not descend to 
any great depth,—very few to 300 fathoms, and the majority 
live close to the surface. The distribution of these fishes is 
determined not only by the temperature of the surface water 
but also by the nature of the adjacent land, and its animal 
and vegetable products ; some of these fishes being confined 
to flat coasts with soft or sandy bottoms, others to rocky and 
fissured coasts, others to living coral formations. If it were 
not for the frequent mechanical and involuntary removals to 
which these fishes are exposed, their distribution within cer- 
tain limits, as it no doubt originally existed, would resemble 
still more that of freshwater fishes than we find it actually 
does at the present period. 

2. Pelagic Fishes—that is, fishes which inhabit the sur- 
face and uppermost strata of the open ocean, which approach 
the shores only accidentally, or occasionally (in search of 
prey), or periodically (for the purpose of spawning). The 
majority spawn in the open sea, their ova and young being 
always found at great distance from the shore. With regard 
to their distribution, they are still subject to the influences of 
light and the temperature of the surface water; but they are 


256 FISHES. 


independent of the variable local conditions which tie the 
shore fish to its original home, and therefore roam freely 
over a space which would take a freshwater or shore fish 
thousands of years to cover in its gradual dispersal. Such 
as are devoid of rapidity of motion are dispersed over simi- 
larly large areas by the oceanic currents, more slowly than, 
but as surely as, the strong swimmers. Therefore, an accu- 
rate definition of their distribution within certain areas equi- 
valent to the terrestrial regions is much less feasible than in 
the case of shore fishes. 

3. Deep-sea Fishes—that is, fishes which mhabit such 
depths of the ocean as to be but little or not influenced by 
light or the surface temperature ; and which, by their organ- 
isation are prevented from reaching the surface stratum in a 
healthy condition. Living almost under identical tellurian 
conditions, the same type, the same species, may inhabit an 
abyssal depth under the equator as well as one near the 
arctic or antarctic circle; and all we know of these fishes 
points to the conclusion that no separate horizontal regions 
can be distinguished in the abyssal fauna, and that no 
division into bathymetrical strata can be attempted on the 
base of generic much less of family characters. 

It must not be imagined that these three categories are 
more sharply defined than Freshwater and Marine Fishes. 
They gradually pass into each other, and there are numerous 
fishes about which uncertainty exists whether they should 
be placed in the Shore or Pelagic series, or in the Pelagic or 
Deep-sea series ; nay, many facts favour the view that changes 
in the mode of life and distribution of fishes are still in 
progress. 

The change in habitat of numerous fishes is regulated by 
the distribution of their favourite food. At certain seasons 
the surface of the sea in the vicinity of land swarms with 
mollusks, larval Crustaceans, Medusze, attracting shoals of 


SHORE FISHES. 257 


fishes from the open ocean to the shores ; and these are again 
pursued by fishes of larger size and predacious habits, so that 
all these fishes might be included, with equal propriety, in 
the littoral or pelagic series. However, species which are 
known to normally spawn in the open ocean must be always 
referred to the latter division. 

Chondropterygu, Acanthopterygu, Anacanths, Myxinoids, 
and. Pharyngobranchi furnish the principal contingents to 
the Marine Fauna; whilst the majority of Malacopterygians, 
the Ganoids, and Cyclostomes are Freshwater Fishes. 


I.—DISTRIBUTION OF SHORE FISHES. 


The principal types of Shore-fishes are the following : — 


CHONDROPTERYGII— 
HOLOCEPHALA ; . ; 4 species. 
PLAGIOSTOMATA— 
Carcharuide (part.) ee ee 
Scylliide 30 ss 
Cestraciontide AS 55 
Spinacide (part.) Sil 5. 
Rhinide il 
Pristiophoride ae 
Pristide Bi as 
Rhinobatide Jay 
Torpedinide . i : 13) 
Rajide ; 5 : pie oy 
Trygonidee 47 55 
ACANTHOPTERYGII— 

Percide (part. incl. Pristipomatide) . 625 _,, 
Mullide . : A 3 3199 ss 
Sparide ‘ , ; Ae ENS OMe 
Squamipinnes . : : so lSOigss 
Cirrhitide ; : ‘ eee) 


258 FISHES. 


Psychrolutide . 
Centriscider 
Fistulariidee 


Heterolepidina . ; : . 12 species. 
Scorpenide  . ; ; « 1200 
Cottide (part.) : : » LOO 
Cataphracti (part.) ‘ , 2055 
Trachinide ‘ ‘ . 100s 
Scuenide : : . L0Ot 
Sphyrenide  . : ; » At Pee 
Trichiuride  . ; ; : ieee 
Elacate ‘ ; : : 1 3 
Nomeide (part.) bk: 
Cyttidee Saale 
Stromateus : : . 9. 4%; 
Mene . ; . : : | ie 
Carangide (part.) » oO 
Kurtide 1, 
Gobiodon : ; ieee 
Callionymina . : : : 30 ae: 
Discoboli : ; ; : 18! E 3 
Batrachide . 5 : ». « iA 
Pediculati (part.) ; 5 : iil _ 
Blenniidee as : : . 20 
Acanthoclinidee : : ; 1 
Teuthidide  . : ; ; SOE 
Acronuride . : : : 60 
FToplognathide. 5 an 
Malacanthide 3: es 
Plesiopina 4 
Trichonotide 2°93 
Cepolide (ero 
Gobiesocide. 21 

2 

7 

4 


ACANTHOPTERYGII PHARYNGOGNATHI— 


Pomacentride . f : > 1505 
Labride . : : « 400° 7 
Embiotocide : : ; eli 


SHORE FISHES. 259 


ANACANTHINI— 
Gadopside : : : ‘ 1 species. 
Lycodidee i j ' ; Lor 
Gadide (part.) . ; bh ; DOM ws 
Ophidiidee (part.) ; Ae 
Pleuronectide . : : , H6Ow <5, 
PHYSOSTOMI— 
Saurina (part.) . , : GE 43 
Salmonide. (part.) ‘ : ; i rr 
Clupeide (part.) . : ‘ : 130). ,, 
Chirocentride 2 ' : ; 1 - 
Chilobranchus . : ‘ 1 5 
Murenide (part.) ‘ : ; 200 =z 
Pegaside ; : : : Bee 
LOPHOBRANCHII : : ; ; L200, 
PLECTOGNATHI— 
Sclerodermi : : : : Dae ace 
Gymnodontes : ; 835.5 
CYCLOSTOMATA— 
MYXINID& , ; : ‘ 5 PP 
LEPTOCARDILI : ; : ; oe ie 


3587 species. 


These types of Shore fishes are divided among the fol- 
lowing oceanic are :— 


I. The Arctic Ocean. 
II. The Northern Temperate Zone. 


A. The Temperate North Atlantic. 
1. The British district. 
2. The Mediterranean district. 
3. The North American district. 


B. The Temperate North Pacific. 
1. The Kamtschatkan district. 
2. The Japanese district, 
3. The Californian district. 


260 FISHES 


III. The Equatorial Zone. 


A. The Tropical Atlantic. 
B. The Tropical Indo-Pacific. 
C. The Pacific Coast of Tropical America. 


1. The Central American district. 


2. The Galapagoes district. 
3. The Peruvian district. 


IV. The Southern Temperate Zone. 


1, The Cape of Good Hope district. 
2. The South Australian district. 

3. The Chilian district. 

4, The Patagonian district. 


V. The Antarctic Ocean. 


As with freshwater fishes, the main divisions of the Shore- 
fish faunee are determined by their distance from the equator, 
the equatorial zone of the Freshwater series corresponding 
entirely to that of the Shore-fish series. But as Marie fishes 
extend farther towards the Poles than Freshwater fishes, and 
as the polar types are more specialised, a distinct Aretic and 
Antarctic fauna may be separated from the faune of the 
temperate zones. The two subdivisions of the Northern 
temperate zone in the Freshwater series are quite analogous 
to the corresponding divisions in the Coast series. In the 
Southern Hemisphere the Shore-fishes of the extremity of 
Africa form a separate district of the temperate zone, whilst 
the Freshwater fishes of South Africa were found to be 
tropical types. The Marine series of the Southern temperate 
zone is also much more diversified than the Freshwater series, 
and admits of further subdivision, which, although in some 
degree indicated in the Freshwater series, does not entirely 
correspond to that proposed for the latter. 


ARCTIC SHORE FISHES. 261 


I. SHORE FISHES OF THE ARCTIC OCEAN. 


The Shore fishes clearly prove a continuity of the Arctic 
circumpolar fauna, as the southern limit of which we may 
indicate the southern extremity of Greenland and the Aleu- 
tian Archipelago, or 60° of lat. N. 

Towards the North, fishes become less in variety of species 
and fewer in number of individuals, and only very few genera 
are restricted to this fauna. 

The highest latitude at which Shore fishes have been 
observed is 83° N. lat. The late Arctic Expedition collected 
at and near that latitude specimens of Cottus quadricornis, 
Icelus hamatus, Cyclopterus spinosus, Liparis fabricir, Gymnelis 
viridis, and Gadus fabricii. This number probably would 
have been larger if the difficulties of collecting fishes in those 
high latitudes were not almost insuperable for the greater 
part of the year. 

As far as we know, the fishes north and south of Behring’s 
Straits belong to the same generic or family types as those 
of the corresponding latitudes of the Eastern Hemisphere, 
though the majority are specifically distinct. But the infor- 
mation we possess of the fishes of the northernmost extremity 
of the Pacific is extremely scanty and vague. Farther south, 
whence now and then a collection reaches Europe, we 
meet with some European species, as the Herring, Holibut, 
Hake. 

The Chondropterygians are very scarce, and it is doubtful 
whether another Chondropterygian, beside the pelagic Lwm- 
argus or Greenland Shark, crosses the Arctic circle. In the 
more temperate latitudes of South Greenland, Iceland, and 
Northern Scandinavia, Acanthias, Centroscyllium, and a species 
of Raja, also Chimera, are met with. 

Of Acanthopterygians the families of Cottidw, Cataphracta, 
Discoboli, and Blenniide are well represented, and several of the 


262 FISHES. 


genera are characteristic of the Arctic fauna: marine species 
of Cottus ; Centridermichthys, Icelus, Triglops ; Agonus, Aspi- 
dophoroides ; Anarrhichas, Centronotus, Sticheus ; Cyclopterus 
and Liparis. Two species of Sebastes are rather common. 

Characteristic is also the development of Gadoid fishes, of 
which some thirteen species, belonging to Gadus, Merluccius, 
and Molva, form one of the principal articles of food to the 
inhabitants of the coasts of the Arctic Ocean. The Blennioid 
Anacanthini or Lycodide, are limited to the Arctic and An- 
tarctic coasts. Ammodytes and a few Flat-fishes (Hippo- 
glossoides and Plewronectes) are common in the more temperate 
parts. 

Labroids only exceptionally penetrate so far towards the 
north. 

Physostomes are very scarce, and represented only by a few 
species of Clupea and by Mallotus; the latter is an ancient in- 
habitant of the Greenland coasts, fossil remains, indistinguish- 
able from the species of the present day, being frequently 
found in nodules of clay of comparatively recent formation. 

The Arctic climate is still less favourable to the existence 
of Lophobranchs, only a few Syngnathus and Nerophis bemg 
present in the more southern latitudes, to which they have 
been carried by oceanic currents from their more congenial 
home in the south. Scleroderms and Plectognaths are entirely 
absent. 

The Gadoids are accompanied by Myaxine, which parasiti- 
cally thrives in them. 


II. THE NorrHERN TEMPERATE ZONE. 
A. Shore Fishes of the Temperate North Atlantic. 


This part of the fauna may be subdivided into three 
districts :— 


TEMPERATE NORTH ATLANTIC. 263 


1. The fishes of the north-eastern shores, viz. of the 
British islands, of Scandinavia so far as it is not included in 
the Arctic fauna, and of the continent of Europe southwards 
to about 40° of lat. Ni— British district. 

2. The fishes of the Mediterranean shores and of the 
adjoming shores of the Atlantic, including the Azores, 
Madeira, and the Canary Islands—Mediterranean district. 

3. The fishes of the western shores, from 60° lat. N. to 
about 30° lat. Ni—the North American district. 


1. The British district shows scarcely any marked dis- 
tinctive features; the character of its fauna is simply 
intermediate between that of the Arctic Ocean and the 
Mediterranean district ; truly Arctic forms disappear, while 
such as are also found in the Mediterranean make their 
appearance. Also with regard to the abundance of individuals 
and variety of fishes this district forms a transition from the 
north towards the south. 

Besides the few Arctic Chondropterygians, all of which 
extend into this district, the small shore Dog-fishes are well 
represented (Mustelus, Galeus, Seyllwwm, Pristiwrus) ; the ubi- 
quitous Rhina or Monk-fish is common; of Rays, Raja pre- 
dominates in a variety of species over Torpedo and T'rygon, 
which are still scarce. 

Of Acanthopterygians, Centridermichthys, Icelus, Triglops, 
and Aspidophoroides, do not extend from the north into this 
district; and Cottus, Anarrhichas, Centronotus, Stichaus, the 
Discoboli disappear within its limits. Nearly all the remainder 
are genera which are also found in the Mediterranean districts. 
The following are the principal forms, and known to propagate 
on these shores: Labrax; Serranus, Polyprion, Dentex; Mullus ; 
Cantharus, Pagrus, Pagellus; Sebastes; Cottus, Trigla, Agonus ; 
Trachinus ; Sciena (?) ; Zeus; Trachurus, Capros ; Calliony- 
mus; Discoboli; Lophius; Anarrhichas, Centronotus, Stich- 


264 FISHES. 


wus; Blenniops, Zoarces (not in Mediterranean); Cepola ; 
Lepadogaster. 

Of the Anacanthini the Gadoids are as numerous as in 
the Arctic Ocean, most being common to both districts ; 
they are represented by Gadus, Gadiculus, Merluccius, Phycis, 
Molva, Motella, Raniceps, and Brosmius; but, whilst the 
majority show their northern origin by not extending into 
the Mediterranean, Ammodytes and most Plewronectide prove 
themselves to be the more southern representatives of this 
order. In the British district we find Hippoglossus, Huppo- 
glossoides, Rhombus, Phrynorhombus, Pleuronectes, Solea, and 
only the two first are not met with in the Mediterranean. 

Labroids are common; with the exception of the North 
American Tautoga, all the other genera are met with. 

Physostomes are not well represented, viz. by one species 
of Osmerus, one of Engraulis, one of Conger, and about five of 
Clupea. 

Syngnathus and Nerophis become more common as we 
proceed southwards; but the existence of Scleroderms and 
Plectognaths is indicated by single individuals only, stragglers 
from their southern home, and unable to establish them- 
selves in a climate ungenial to them. 

The Gadoids are accompanied by Myxine ; and Branchio- 
stoma may be found in all suitable localities. 


2. The Mediterranean district is distinguished by a great 
variety of forms; yet, with the exception of a few genera 
established for single species, none of the forms can be con- 
sidered peculiar to it; and even that small number of 
peculiar genera is more and more diminished as our know- 
ledge of the distribution of fishes advances. Some genera 
are identical with those found on the western coasts of the 
Atlantic and in the West Indies; but a most remarkable 
and unexpected affinity obtains with another very distant 


TEMPERATE NORTH ATLANTIC, 265 


fauna, viz. that of Japan. The number of genera common 
to the Mediterranean district and the Japanese coasts is 
larger than that of the genera common to the Mediterranean 
and the opposite American coasts. 

The Chondropterygians found in the British district con- 
tinue in the Mediterranean, their number being increased by 
Centrina, Spinax, Pteroplatea, and some species of Rhinobatus, 
a genus more numerously represented in the Tropics. Tor- 
pedo and Trygon are common. 

The greatest variety belong to the Acanthopterygians, as 
will be seen from the following list :—Labrax ; Anthias, 
Serranus, Polyprion, Apogon, Pomatomus, Pristipoma, Dia- 
gramma (an Indian genus with two Mediterranean species, 
and otherwise not represented in the Atlantic), Dentex, Mena, 
Smaris ; Mullus ; Cantharus, Box, Scatharzs, Oblata, Sargus, 
Pagrus, Pagellus, Chrysophrys ; Sebastes, Scorpena ; Hoplo- 
stethus, Beryx, Polymixia; Trigla, Lepidotrigla, Agonus, 
Peristethus ; Trachinus, Uranoscopus; Umbrina, Scienea ; 
Sphyrena; Aphanopus, Lepidopus, Nesiarchus, Trichiurus, 
Thyrsites ; Cubieeps ; Zeus, Cyttus ; Stromateus ; Trachurus, 
Caranx, Capros, Diretmus, Antigonia ; Callionymus ; Ba- 
trachus ; Lophius; Cristiceps, Tripterygium ; Cepola ; Lepa- 
dogaster ; Centriscus ; Notacanthus. 

The ZLabridw are as common as, or even more so 
than, in the British district, and represented by the same 
genera. But, besides, some other Pharyngognaths, properly 
belonging to the Tropical Atlantic, have fully established 
themselves, though only by a few species, viz. Glyphidodon 
and Heliastes ; Cossyphus, Novacula, Julis, Coris, and Scarus. 

The Gadoids show a marked decrease of development ; and 
the species of Gadus, Gadiculus, Mora, Strinsia, Phycis, and 
Molva, which are peculiar to the Mediterranean, seem: to 
inhabit rather the colder water of moderate depths, than the 
surface near the shore. Motella, however, proves to be a true 


266 FISHES. 


Shore fish also in the Mediterranean, at least in its adult 
state. Ophidiuwm and Fierasfer appear now besides Ammo- 
dytes. As the Gadoids decrease, so the Plewronectide increase, 
the genera of the Mediterranean district being Rhombus, 
Phrynorhombus, Arnoglossus, Citharus, Rhomboidichthys, Pleu- 
ronectes (a northern genus not extending farther southwards), 
Solea, Synaptura, and Ammoplewrops. 

The variety of Physostomes is small; the following only 
being superadded to those of the British district :—Sawrus (a 
tropical genus), Auwlopus ; Congromurena, Heteroconger, Myrus, 
Ophichthys, Murena. 

The Lophobranchs are more numerous in species and 
individuals than in the British district; and, besides Syngna- 
thus and Nerophis, several species of Hippocampus are common. 
Also a few species of Balistes occur. 

Myxine is lost in this district; whilst Branchiostoma is 
abundant. 


3. The shore fishes of the North American district con- 
sist, as on the eastern coasts of the North Atlantic, of northern 
and southern elements; but they are still more mixed with 
each other than on the European coasts, so that a boundary 
line cannot be drawn between them. The affinity to the fauna 
of the eastern shores is great, but almost entirely limited to 
the genera composing the fauna of the British district. 
British genera not found on the American coasts are — 
Galeus, Scylluum, Chimera, Mullus, Pagellus, Trigla, Tra- 
chinus, Zeus, Callionymus. The southern elements of North 
America are rather derived from the West Indies, and have 
no special affinity to Mediterranean forms; very few of the 
non-British Mediterranean forms extend across the Atlan- 
tic; instead of a Mediterranean we find a West Indian 
element. Many of the British species range across the Atlantic, 
and inhabit in an unchanged condition the northern parts of 


TEMPERATE NORTH ATLANTIC. 267 


this district; and from the frequent occurrence of isolated 
specimens of other British species on the North American 
coast, we may presume that many more occasionally cross the 
Atlantic, but without being able to obtain a permanent 
footing. 

The genera peculiar to this district are few in number, 
and composed of very few species, viz. Hemitripterus, Pam- 
melas, Chasmodes, Cryptacanthodes, and Tautoga. 

The close resemblance of what must be considered 
northern forms to those of Europe will be evident from the 
following list :— 

Mustelus, Rhina, Torpedo, Raja, Trygon. 

Labrax, Centropristis, Serranus; Pagrus, Chrysophrys ; 
Sebastes, Hemitripterus ; Cottus, Aspidophoroides ; Uranosco- 
pus ; Micropogon, Pogonias, Scena ; Trachurus, Pammelas ; 
Cyclopterus, Liparis; Lophius; Anarrhichas, Chasmodes, 
Sticheus, Centronotus, Cryptacanthodes, Zoarces. . 

Tautoga, Ctenolabrus. 

Gadus, Merluccius, Phycis, Molva, Motella, Brosinius ; 
Ophidium (one species, perhaps identical with a Mediterranean 
species) ; Ammodytes ; Hippoglossus, Hippoglossoides, Rhombus, 
Pleuronectes. 

Osmerus, Mallotus ; Engraulis, Clupea ; Conger. 

Syngnathus—Myxine—Branchiostoma. 

West Indian genera, or at least genera which are more 
developed within the tropics, and which extend more or less 
northwards in the North American district, are -— 

Pteroplatea (also in the Mediterranean). 

Gerres, Dules (auriga), Lobotes, Ephippus ; Sargus ; Priono- 
tus; Umbrina, Otolithus, Larimus ; Sphyrena (Mediterr.) ; 
Trichivrus (Mediterr.); Elacate; Cybium, Trachynotus; Stro- 
mateus (Mediterr.); Caranz ; Batrachus (Mediterr.) ; Malthe. 

Pseudorhombus, Solea (Mediterr.) 

Saurus (Mediterr.); Ltrumeus, Albula, Elops, Megalops. 


268 FISHES 


Hippocampus (Mediterr.) 
Balistes, Monacanthus, 


B. Shore Fishes of the Temperate North Pacifie. 


This fauna shows a great affinity to that of the temperate 
North Atlantic, not only in including a considerable proportion 
of identical genera, and even of species, but also in having its 
constituent parts similarly distributed. However, our know- 
ledge of the ichthyology of this fauna is by no means com- 
plete. Very few collections have been made in Northern 
Japan, and on the coasts farther north of it; and, again, the 
ichthyology of the coasts of Southern California is but little 
known. Southern Japan has been well searched, but very 
little attention has been paid to the extent of the northward 
range of the species. In collections made by Mr. Swinhoe at 
Chefoo, in lat. 37° N., the proportions of temperate and tropical 
fishes were found to be about equal. Thus, the details of the 
distribution of the fishes of these shores have still to be 
worked out; nevertheless, three divisions may be recognised 
which, for the present, may be defined as follows :— 

1. The fishes of the north-western shores, to about 37° 
lat. N., including the corresponding northern parts of Japan— 
Kamtschatkan (istrict ; this corresponds to the British district 
of the Atlantic. 

2. The fishes of Southern Japan and the corresponding 
shores of the continent of Asia, between 37° and 30° lat. 
N.—Japanese district, which corresponds to the Mediter- 
ranean. 

3. The fishes of the eastern shores southwards to the lati- 
tude of San Francisco—Californian district ; this corresponds 
to the North American district of the Atlantic. 

Too little is known of the shore fishes of the coasts between 
San Francisco and the tropic to enable us to treat of it as a 
separate division. 


TEMPERATE NORTH PACIFIC. 269 


The Shore fishes of the North Pacific generally are com- 
posed of the following elements :— 

a. Arctic forms which extend into the Arctic Ocean, and 
the majority of which are also found in the British district. 

b. Peculiar forms limited to the North Pacific, like the 
Heterolepidina, Embiotocide, and certain Cottoid and Blen- 
nioid genera. 

c. Forms identical with fishes of the Mediterranean. 

d. Peculiar forms limited to the southern parts of Japan. 

e. Tropical forms which have entered the North Pacific 
from the south. 


1. The small list of fishes which we can assign to the 
Kamtschatkan district is due rather to the imperfect manner 
in which its fauna has been explored than to its actual 
poverty of fishes ; thus, although we may be sure that sooner 
or later the small kinds of Dog-fishes of the British district 
will be found there also, at present we have positive know- 
ledge of the occurrence of only two Chondropterygians, viz. 
Chimera and Raja. The species of the latter genus seem to 
be much less numerous than in the Atlantic. 

Of Acanthopterygians the following are known :—Sebastes ; 
Chirus, Agrammus ; Podabrus, Blepsias, Cottus, Centridermich- 
thys, Hemilepidotus, Agonus ; Trichodon ; Callionymus; Liparis ; 
Dictyosoma, Sticheus, Centronotus. 

Labroids are absent; they are clearly a type unable to 
endure great cold; of the Embiotocoids which represent them 
in the Pacific, one species only (a species of Ditrema) is known 
from this district. 

The Gadoids are, so far as we know at present, sparsely 
represented, viz. by isolated species of Gadus, Motella, and 
Lotella, the latter being an inhabitant of moderate depths 
rather than of the surface. Aippoglossus, Plewronectes, and 
Parophrys, seem to occur everywhere at suitable localities. 


270 FISHES. 


The Physostomes are nearly the same as in the British 
district, viz. a Smelt (Hypomesus), probably also the Arctic 
Mallotus, an Anchovy, several species of Clupea, and the 
Conger-eel. A very singular Salmonoid fish, Salanxz, which 
is limited to the north-western Pacific, occurs in great abund- 
ance, 

Also, the Lophobranchs correspond in their development 
to those of the British district, Nerophis being replaced by 
Urocampus. 

Neither Myxinoids nor Branchiostoma have as yet been 
found, 


2. The Japanese district is, ike the Mediterranean, dis- 
tinguished by a great variety of forms ; some of them are 
peculiar to it (marked J. in the following list); others occur 
in the Mediterranean, though also in other districts (JL) 
The resemblance to the Mediterranean is even greater than 
would appear from the following list of genera, inasmuch as 
a considerable number of species are identical in both dis- 
tricts. Three of the Berycoid genera have hitherto been 
found in the Japanese and Mediterranean districts only, and 
nowhere else. Another very singular fact is that some of 
the most characteristic genera, like Mullus, Zeus, Calliony- 
mus, Centriscus, habit the Mediterranean and Japanese 
districts, but have never reached the opposite American coasts, 
either in the Atlantic or Pacific; although, at least in the 
latter, the oceanic currents would rather favour than ob- 
struct their dispersal in the direction towards America. Bold 
as the hypothesis may appear, we can only account for the 
singular distribution of these shore fishes by assuming that 
the Mediterranean and Japanese seas were in direct and 
open communication with each other within the period of 
the existence of the present Teleosteous Fauna. 

Gadoids have disappeared, or are represented by forms 


TEMPERATE NORTH PACIFIC. 271 


inhabiting moderate depths. Neither Myxine nor Branchio- 
stoma are known to have as yet been found. 


List of Japanese Shore Fishes. 


Chimera (M.) 

Galeus (M.), Mustelus (M.), Triacis, Scylliwm (M.), Cros- 
sorhinus, Pristiophorus, Cestracion ; Rhina (M.) ; Rhinobatus 
(M.), Narcine, Raja (M.), Trygon (M.), Pteroplatea (M.) 

Percalabraz (J.), Niphon (J.), Centropristis, Anthias (M.), 
Serranus (M.), Apogon (M.), Scombrops (J.), Acropoma, Ano- 
plus (J.), Pristipoma (M.), Hapalogenys (J.), Histiopterus, 
Velifer (J.), Dentex (M.), Erythrichthys—Mullide (M.)— 
Girella, Pagrus (M.), Chrysophrys (M.)— Chilodactylus — 
Sebastes (M.), Scorpena (M.), Aploactis, Trichopleura, Pelor— 
Monocentris (J.), Hoplostethus (M.), Beryx (M.), Polymixia (M.) 
— Platycephalus, Hoplichthys (J.), Bembras (J.), Prionotus, 
Lepidotrigla (M.), Trigla (M.), Peristethus (M.)—Uranoscopus 
(M.), Percis, Sillago, Latilus.— Sciena (M.), Otolithus — 
Sphyrena (M.)—Lepidopus (M.), Trichiurus (M.)\—Zeus (M.) 
—Caranx, Trachurus (M.)—Callionymus (M.)—Lophius (M.), 
Halieuthwa (J.)\—Hoplognathus—Cepola (M.)—Centriscus (M.), 
Fistularia. 

Heliastes (M.)—Labrichthys, Duymeria, Platyglossus, Nova- 
cula (M.), Julis (M.), Corzs (M.) 

Strembo (J.)—Motella (M.)—Ateleopus (J.) 

Pseudorhombus, Pleuronectes (M.), Solea (M.), Synap- 
tura (M.) 

Saurus (M.), Harpodon—Salanz (J.)\—Engraulis (M.), 
Clupea (M.), Etrumeus—Conger (M.), Congromurena (M.), 
Murenesox (M.), Oxyconger, Myrus (M.), Ophichthys (M.), 
Mureena (M.) 

Syngnathus (M.), Hippocampus (M.), Solenognathus. 

Triacanthus, Monacanthus, Ostracion. 


HAT FISHES. 


3. The Californian district includes a marked northern 
element, the principal constituents of which are identical with 
types occurring in the corresponding district of the Atlantic, 
viz. the North American, as exemplified by Discoboli, Anarr- 
hichas, Centronotus, Cottus, Hippoglossus, Clupea (harengus), etc. 
But it possesses also, in the greatest degree of development, 
some types almost peculiar to itself, as the Heterolepidina, 
some remarkable Cottoid and Blennioid genera, and more 
especially the Embiotocoids—viviparous Pharyngognaths — 
which replace the Labroids of the other hemisphere. Gadoids 
are much less numerous than in the North American district. 
The southern forms are but little known, but it may be anti- 
cipated that, owing to the partial identity of the Faun of the 
two coasts of the Isthmus of Panama, a fair proportion of 
West Indian forms will be found to have entered this district 
from the south. The following are the principal genera -— 

Chimera, Galeus, Mustelus, Triacis, Cestracion, Rhina, Raja. 

Serranus ; Chirus, Ophiodon, Zaniolepis ; Sebastes ; Nau- 
tichthys, Scorpenichthys, Cottus, Centridermichthys, Hemilept- 
dotus, Artedius, Prionotus, Agonus; Cyclopterus, Liparis ; 
Anarrhichas, Neoclinus, Cebidichthys, Sticheus, Centronotus, 
Apodichthys ; Psychrolutes ; Aulvscops. 

Embiotocide. 

Gadus. Hippoglossus, Psettichthys, Citharichthys, Para- 
lichthys, Pleuronectes, Parophrys. 

Osmerus, Thaleichthys, Hypomesus ; Engraulis, Clupea. 

Syngnathus. 


IIT.—THE EQUATORIAL ZONE. 


As we approach the Tropic from the north, the tribes 
characteristic of the Arctic and Temperate zones become 
scarcer, and disappear altogether: to be replaced by the 
ereater variety of Tropical types. Of Chondropterygians, the 
Chimeride, Spinacide, Mustelus, and Raja, do not pass the 


EQUATORIAL ZONE. 273 


Tropic, or appear in single species only; and of Teleosteans, 
the Berycide, Pagrus, the Heterolepidina, Cottus and allied 
genera, Lophius, Anarrhichas, Sticheus, Lepadogaster, Psy- 
chrolutes, Centriscus, Notacanthus,the Labride and Embiotocide, 
the Lycodidw, Gadide, and marine Salmonide disappear 
either entirely, or retire from the shores and surface into the 
depths of the ocean. 

With regard to variety of forms, as well as to number 
of individuals, this zone far surpasses either of the tem- 
perate zones; in this respect, the life in the sea is as that 
on the land. Coast fishes are not confined to the actual 
coast-line, but abound on the coral reefs, with which some 
parts of the Atlantic and Pacific are studded, and many of 
which are submerged below the water. The abundance of 
animal and vegetable life which flourishes on them renders 
them the favourite pasture-grounds for the endless variety of 
coral-fishes (Squamipinnes, Acronuride, Pomacentride, Julide, 
Plectognathi, etc.), and for the larger predatory kinds. The 
colours and grotesque forms of the Fishes of the Tropics have 
justly excited the admiration of the earliest observers. Scarlet, 
black, blue, pink, red, yellow, etc., are arranged in patterns 
of the most bizarre fashion, mingling in spots, lines, bands ; 
and reminding us of the words of Captain Cook when de- 
scribing the coral-reefs of Palmerston Island: “The glowing 
appearance of the Mollusks was still inferior to that of the 
multitude of fishes that glided gently alone, seemingly with 
the most perfect security. The colours of the different sorts 
were the most beautiful that can be imagined—the yellow, 
blue, red, black, etc., far exceeding anything that art can 
produce. Their various forms, also, contributed to increase 
the richness of this sub-marine grotto, which could not be 
surveyed without a pleasing transport.” 

Of Chondropterygians the Seylliidw, Pristis (Saw-tishes), 
Lhinobatide, and Trygonide attain to the greatest de- 

A 


274 . FISHES 


velopment. Of Acanthopterygians Centropristis, Serranus, 
Plectropoma, Mesoprion, Priacanthus, Apogon, Pristipoma, 
Hemulon, Diagramma, Gerres, Scolopsis, Synagris, Coesio, 
Mullide, Lethrinus, Squamipinnes, Cirrhites, some genera 
of Scorpenide, Platycephalus, Scienide, Sphyrena, Carana 
Equula, Callionymus, Teuthis, Acanthurus, Naseus, are re- 
presented by numerous species; and the majority of these 
genera and families are limited to this zone. Of Pharyn- 
goenaths the Pomacentride, Julidina, and Scarina, are met 
with near every coral formation in a living condition. 
Of Gadoids, a singular minute form, Bregmaceros, is almost 
the only representative, the other forms belonging to deep 
water, and rarely ascending to the surface. Flat-fishes (Plewro- 
nectide) are common on sandy coasts, and the majority of 
the genera are peculiar to the Tropics. Of Physostomi only 
the Saurina, Clupeide, and Murenide are represented, the 
Clupeide being exceedingly numerous in individuals, whilst 
the Murenide live more isolated, but show a still greater 
variety of species. Lophobranchi and Sclerodermi are gene- 
rally distributed. Branchiostoma has been found on several 
coasts. 

Geographically it is convenient to describe the Coast fauna 
of the tropical Atlantic separately from that of the Indo- 
Pacific ocean. The differences between them, however, are 
far less numerous and important than between the freshwater 
or terrestrial faunze of continental regions. The majority of 
the principal types are found in both, many of the species being 
even identical ; but the species are far more abundant in the 
Indo-Pacific than in the Atlantic, owing to the greater extent 
of the archipelagoes in the former. But for the broken and 
varied character of the coasts of the West Indies, the shores 
of the tropical Atlantic would, by their general uniformity, 
afford but a limited variety of conditions to the development 
of specific and generic forms, whilst the deep inlets of the 


EQUATORIAL ZONE. VM 6) 


Indian ocean, with the varying configuration of their coasts, 
and the different nature of their bottom, its long peninsulas, 
and its archipelagoes, and the scattered islands of the tropical 
Pacific, render this part of the globe the most perfect for the 
development of fish-life. The fishes of the Indian and Pacific 
oceans (between the Tropics) are almost identical, and the 
number of species ranging from the Red Sea and east coast 
of Africa to Polynesia, even to its westernmost islands, 
is very great indeed. However, this Indo-Pacific fauna does 
not reach the Pacific coast of South America. The wide 
space devoid of islands, east of the Sandwich Islands and 
the Marquesas group, together with the current of cold water 
which sweeps northwards along the South American coast, 
has proved to be a very effectual barrier to the eastward exten- 
sion of the Indo-Pacific fauna of coast fishes; and, conse- 
quently, we find an assemblage of fishes on the American 
coast and at the Galapagoes Islands, sufficiently distinct to 
constitute a distinct zoological division. 

The following list, which contains only the principal 
genera and groups of coast fishes, will give an idea of the 
affinity of the tropical Atlantic and Indo-Pacific :-—" 


Trop. -Atl. Indo-Pac. 


Scylliide . ; : —— 13 
Pristis F : : 3 4 
hinobatide 4 8 
Torpedinide L : 1 8 
Trygomde . : : 14 24 
Etelis 1 1 
Aprion : ; — 1 
Apsilus . ; : 1 cee 
Centropristis oa : 15 — 
Anthias . : : 4 5 
Serranus . ‘ : 30 85 
Plectropoma ‘ : 11 5 


1 The genera peculiar to the Equatorial zone are printed in italics. 


276 


FISHES. 


Grammistes 
Rhypticus . 
Diploprion . 
Myriodon . 
Mesoprion . 
Priacanthus 

Apogon and Chilodipterus 
Pristipoma . 
Hemulon . 
Diagramma 

Gerres 

Scolopsis . : 
Dentex and Symphorus 
Synagris and Pentapus 
Cesio 

Mullidee 

Sargus 

Lethrinus . 
Chrysophrys 
Pimelepterus 
Squamipinnes 
Toxotes 

Cirrhites 
Scorpzenidee 
Myripristis 
Holocentrum 
Platycephalus 
Prionotus . 

Trigla 

Peristethus 
Uranoscopina 
Champsodon 

Percis 

Sillago 

Latilus 
Opisthognathus 
Pseudochromis 


Cichlops and Pseudoplesiops 


Trop.-Atl. 


Indo-Pac. 


bo bo 
OU 1 


_ 
poownwpaqor=ooa -» 


EQUATORIAL ZONE, 


Scienide 
Sphyrena . 
Trichiuride 
Caranz 
Chorinemus 
Trachynotus 
Psettus 
Platax 
Zanclus 


Equula and Gazza . 


Teuthis 
Acanthurus 
Naseus 
Kurtide 
Gobiodon 
Callionymus 
Batrachide 
Tetrabrachium 
Malthe 
Petroscirtes 
Clinus 
Dactyloscopus 
Malacanthus 
Cepola 
Gobiesocidee 
Amphisile . 
Fistulariidee 
Pomacentride 
Lachnoleemus 
Julidina 
Pseudodax 
Scarina 
Pseudophycis 
Bregmaceros 
Ophidide . 
Fierasfer 
Pleuronectide 
Saurima 


Trop. Atl. 
44 
1 
6 
20 


Ind.-Pac. 
43 
10 


277 


278 FISHES. 


Trop.-Atl. Ind.-Pac. 


Clupeide . : : 33 84 
Chirocentrus : : — 1 
Murenidee : : AT 130 
Pegasus. : : — 3 
Solenostoma , , — 2 
Syngnathide : 2 i 4] 
Scleroderma : : 16 67 
Gymnodontes ; 23 40 


A. Shore Fishes of the Tropical Atlantic. 


The boundaries of the tropical Atlantic extend zoologi- 
cally a few degrees beyond the Northern and Southern 
Tropics, but as the mixture with the types of the temperate 
zone is very gradual, no distinct boundary line can be drawn 
between the tropical and temperate faune. 

Types, almost exclusively limited to it, and not found in 
the Indo-Pacific, are few in nmmber, as Centropristis, Rhyp- 
ticus, Homulon, Malthe. A few others preponderate with 
regard to the number of species, as Plectropoma, Sargus, 
Trachynotus, Batrachide, and Gobiesocidw. The Scixnoids are 
equally represented in both oceans. All the remainder are 
found in both; but in the minority in the Atlantic, where they 
are sometimes represented by one or two species only (for 
instance, Lethrinus). 


B. Shore Fishes of the Tropical Indo-Pacifie Ocean. 


The ichthyological boundaries of this part of the tropical 
zone may be approximately given as 30° of lat. N. and S.; 
on the Australian coasts it should probably be placed still 
farther south, viz., to 34°; it includes, as mentioned above, 
the Sandwich Islands, and all the islands of the South Sea, 
but not the American coasts. 

Some eighty genera of Shore fishes are peculiar to the 
Indo-Pacific, but the majority consists of one or a few species 


EQUATORIAL ZONE. 279 


only; comparatively few have a plurality of species, as 
Diagramma, Lethrinus, Equula, Teuthis, Amphiprion, Das- 
cyllus, Choerops, Chilinus, Anampses, Stethojulis, Coris, Coilia. 

The Sea-perches, large and small, which feed on Crusta- 
ceans and other small fishes, and the coral-feeding Pharyn- 
gogenaths are the types which show the greatest generic and 
specific variety in the Indo-Pacific. Then follow the 
Squamipinnes and Murewnide, the Clupeide and Carangide 
families in which the variety is more that of species than of 
genus. The Scorpenide, Pleuronectide, Acronuride, Scienide, 
Syngnathide, and Teuthyes, are those which contribute the 
next largest contingents. Of shore-loving Chondropterygians 
the Scylliide and Trygonide only are represented in moderate 
numbers, though they are more numerous in this ocean than 
in any other. 


C. Shore Fishes of the Pacific Coasts of Tropical America. 


As boundaries within which this fauna is comprised, may 
be indicated 30° Jat. N. and S., as in the Indo - Pacific. 
Its distinction from the Indo-Pacific les in the almost 
entire absence of coral-feeding fishes. There are scarcely any 
Squamipinnes, Pharyngognaths or Acronuride, and the 
Teuthyes are entirely absent. The genera that remain are 
such as are found in the tropical zone generally, but the 
species are entirely different from those of the Indo-Pacific. 
They are mixed with a sprinkling of peculiar genera, consist- 
ing of one or two species, like Discopyge, Hoplopagrus, Doy- 
dixodon, but they are too few in number to give a strikingly 
peculiar character to this fauna. 

Three districts are distinguishable -— 

a. The Central American district, in which we include, for 
the present, Lower California, shows so near an affinity to the 
tropical Atlantic that, if it were not separated from it by the 


280 FISHES. 


neck of land uniting the two American Continents, it would 
most assuredly be regarded as a portion of the Fauna of the 
tropical Atlantic. With scarcely any exceptions the genera 
are identical, and of the species found on the Pacific side 
nearly one-half have proved to be the same as those of. the 
Atlantic. The explanation of this fact has been found in 
the existence of communications between the two oceans by 
channels and straits which must have been open till within 
a recent period. The isthmus of Central America was then 
partially submerged, and appeared as a chain of islands simi- 
lar to that of the Antilles; but as the reef-building corals 
flourished chiefly north and east of those islands, and were 
absent south and west of them, reef-fishes were excluded from 
the Pacific shores when the communications were destroyed 
by the upheaval of the land. 

b. The Galapagoes district received its coast fauna princi- 
pally from the Central American district, a part of the species 
being absolutely the same as on the coast of the Isthmus of 
Panama, or as in the West Indies. Yet the isolation of this 
eroup has continued a sufficiently long period to allow of the 
development of a number of distinct species of either pecu- 
harly Atlantic genera (such as Centropristis, Rhypticus, 
Gobiesox, Prionotus), or at least tropical genera (such as 
Chrysophrys, Pristipoma, Holacanthus, Caranx, Balistes). A 
few other types from the Peruvian coast (Doydixodon), or 
even from Japan (Prionwrus), have established themselves in 
this group of islands. A species of Cestracion has also reached 
the Galapagoes, but whether from the south, north, or west, 
cannot be determined. 

The presence of the Atlantic fauna on the Pacific side is 
felt still farther west than the Galapagoes, some Atlantic 
species having reached the Sandwich Islands, as Chetodon 
humeralis and Blennius brevipinnis. 

ce. The Peruvian district possesses a very limited variety 


SOUTHERN TEMPERATE ZONE. 281 


of shore fishes, which belong, with few exceptions, like 
Inscopyge, Hoplognathus, Doydixzodon, to genera distributed 
throughout the tropical zone, or even beyond it. But the 
species, so far as they are known at present, are distinct from 
those of the Indo-Pacific, as well as of the tropical Atlantic ; 
and therefore this district cannot be joined either to the 
Central American or the Galapagoes. 


IV.—THE SOUTHERN TEMPERATE ZONE. 


This zone includes the coasts of the southern extremity 
of Africa, from about 30° lat. S., of the south of Australia 
with Tasmania, of New Zealand, and the Pacific and Atlantic 
coasts of South America between 30° and 50° lat. 8. 

The most striking character of this fauna is the reappear- 
ance of types inhabiting the corresponding latitudes of the 
Northern Hemisphere, and not found in the intervening tropi- 
cal zone. This interruption of the contimuity in the geo- 
eraphical distribution of Shore-fishes is exemplified by species 


as well as genera, for instance—Chimera monstrosa, Galeus 
canis, Acanthias vulgaris, Acanthias blainvillit, Rhina squatina, 
Zeus faber, Lophius piscatorius, Centriscus scolopax, Engraulis 
encrasicholus, Clupea sprattus, Conger vulgaris. Instances of 
genera are still more numerous—Cestracion, Spinax, Pristio- 
phorus, Raja; Callanthias, Polyprion, Histiopterus, Cantharus, 
Lox, Girella, Pagellus, Chilodactylus, Sebastes, -Aploactis, 
Agonus, Lepidopus, Cyttus, Psychrolutide, Notacanthus ; 
Lycodes, Merluccius, Lotella, Phycis, Motella ; Aulopus ; Uro- 
campus, Solenognathus ; Myxine. 

Naturally, where the coasts of the tropical zone are con- 
tinuous with those of the temperate, a number of tropical 
genera enter the latter, and genera which we have found 
between the tropics as well as in the temperate zone of the 
Northern Hemisphere, extend in a similar manner towards the 


28 


bo 


FISHES. 


south. But the truly tropical forms are absent; there are no 
Squamipinnes, scarcely any Mullide,no Acronuri, no Teuthyes, 
no Pomacentride (with a single exception on the coast of 
Chili), only one genus of Julidina, no Scarina, which are re- 
placed by another group of Pharyngognaths, the Odacina. 
The Labrina, so characteristic of the temperate zone of the 
Northern Hemisphere, reappear in a distinct genus (Malaco- 
pterus) on the coast of Juan Fernandez. 

The family of Berycide, equally interesting with regard to 
their distribution in time and in space, consists of temperate 
and tropical genera. The genus by which this family is 
represented in the southern temperate zone (7'rachichthys) 1s 
much more nearly allied to the northern than to the tropical 
genera, 

The true Cottina and Heterolepidina (forms with a bony 
stay of the preeoperculum, which is generally armed) have not 
crossed the tropical zone; they are replaced by fishes ex- 
tremely similar in general form, and having the same habits, 
but lacking that osteological peculiarity. Their southern 
analogues belong chiefly to the family 7rachinide, and are 
types of genera peculiar to the Southern Hemisphere. 

The Discoboli of the Northern Hemisphere have likewise 
not penetrated to the south, where they are represented by 
Gobiesocide. These two families replace each other in their 
distribution over the globe. 

Nearly all the Plewronectide (but they are not numerous) 
belong to distinct genera, some, however, being remarkably 
similar in general form to the northern Pleuronectes. 

With Gadoids Myxinide reappear, one species being ex- 
tremely similar to the European Myxine. Adellostoma is a 
genus peculiar to the southern temperate zone. 

As in the northern temperate zone, so in the southern, 
the number of individuals and the variety of forms is much 
less than between the tropics. This is especially apparent 


SOUTHERN TEMPERATE ZONE. 283 


on comparing the numbers of species constituting a genus. 
In this zone genera composed of more than ten species are the 
exception, the majority having only from one to five. 

The proportion of genera limited to this zone is rather 
high; they will be indicated under the several districts, 
which we distinguish on geographical rather than zoological 
grounds. 


1. The Cape of Good Hope district. 

The principal genera found in this district are the follow- 
ing (those limited to the entire zone being marked with a 
single (*) and those peculiar to this district with a double (**) 
asterisk) :— 

Chimera, *Callorhynchus, Galeus, ** Leptocarcharias, Scyl- 
lium, Acanthias, Rhinobatus, Torpedo, Narcine, Astrape, Raja. 

Serranus, Dentex, Pristipoma ; Cantharus, Box,** Dipterodon, 
Sagrus, Pagrus, Pagellus, Chrysophrys ; * Chilodactylus ; Sebastes, 
*Agriopus ; Trigla ; Sphyrena ; Lepidopus, Thyrsites ; Zeus ; 
Caranx ; Lophius ; Clinus (10 species), Cristiceps ; ** Choriso- 
chismus. 

** Halidesmus, *Genypterus, Motella. 

Syngnathus.—* Bdellostoma. 

This list contains many northern forms, which in conjunc- 
tion with the peculiarly southern types (Callorhynchus, Chilo- 
dactylus, Agriopus, Clinus, Genypterus, Bdellostoma) leave no 
doubt that this district belongs to the southern temperate 
zone, Whilst the Freshwater fishes of South Africa are mem- 
bers of the tropical fauna. Only a few (Rhinobatus, Nar- 
cine, Astrape, and Sphyrena) have entered from the neigh- 
bouring tropical coasts. The development of Sparoids is 
greater than in any of the other districts of this zone, and 
may be regarded as one of its distinguishing features. 


2. The South Australian district comprises the southern 
coasts of Australia (northwards, about to the latitude of 


284 FISHES. 


Sydney), Tasmania, and New Zealand. It is the richest in 
the southern temperate zone, partly im consequence of a 
considerable influx of tropical forms on the eastern coast of 
Australia, where they penetrate farther southwards than 
should have been expected from merely geographical con- 
siderations; partly in consequence of the thorough manner 
in which the ichthyology of New South Wales and New 
Zealand has been explored. On the other hand, the western 
half of the south coast of Australia is still almost a terra 
incognita. 

The shore-fishes of New Zealand are not so distinct from 
those of south-eastern Australia as to deserve to be placed 
in a separate district. Beside the genera which enter this 
zone from the Tropics, and which are more numerous on the 
Australian coast than on that of New Zealand, and beside a 
few very local genera, the remainder are identical. Many of 
the South Australian species, besides, are found also on the 
coasts of New Zealand. The principal points of difference 
are the extraordinary development of Monacanthus on the 
coast of South Australia, and the apparently total absence in 
Australia of Gadoids, which in the New Zealand Fauna are 
represented by six genera. 


Shore-fishes of the South Australian district. 


South Australia 
and Tasmania. 


*Callorhynchus (antarcticus) . 1 1 
Galeus (canis) 1 
Scyllium 

**Parascyllium 
Crossorhinus 
Cestracion . 
Mustelus (antarcticus) 
Acanthias (vulgaris and blainvillii) 
Rhina 


Pristiophorus 


New Zealand. 


pe Te Sy Te) ST Le ser t— 


SOUTHERN TEMPERATE ZONE. 285 


South Australia 
and Tasmania. 


New Zealand. 

**Trygonorhina (fasciata) 
Rhinobatus 
Torpedo 
Narcine 
Raja 
Trygon unglenbicy, 

** Enoplosus 
Anthias (Gomrdeon 
Callanthias 
Serranus 
Plectropoma 

**Lanioperca . 

** Arripis 
Histiopterus 
Erythrichthys 

*Haplodactylus 
Girella 

**Tephrxops . 

Pagrus 
*Scorpis 

** A typichthys 

**Trachichthys 

** Chironemus 

**Holoxenus . 
Chilodactylus 

** Nemadactylus 

**Latris 
Scorpzena 

**Glyptauchen 
Centropogon 

* A griopus 
* A ploactis 

**Pentaroge 
Platycephalus 
Lepidotrigla 
Trigla 


_ 


tears Se See re ee | Ee eg eee me ore > ES en | HS 


1 Number of species uncertain. 


86 


FISHES. 


** Anema 
**Crapatalus . 
**K athetostoma 
**Leptoscopus 
Percis 
* Aphritis 
Sillago 
*Bovichthys . 
*Notothenia . 
Sphyrena 
Lepidopus 
Trichiurus 
Thyrsites 
**Platystethus 
Zeus (faber) 
Cyttus ; 
Trachurus (trachurus) 
Caranx 
*Seriolella 
Pempheris . 
Callionymus 
Batrachus 
**Brachionichthys 
**Saccarius 
Clinus 
**Lepidoblennius 
Cristiceps and Tripterygium 
** Patzecus 
** A canthoclinus 
**Diplocrepis . 
**Crepidogaster 
**Tyrachelochismus 
**N eophrynichthys 
Centriscus 
Notacanthus (esau 
**Tabrichthys 
**Odax 


South Australia New Zealand. 


and Tasmania. 


oo leet aa eal eon set =r OnE, ogres gt bare Mee A ne recto we eel 


(ah oes a eee 


[havea pepe eke een a || Spee | 


eae Camere ate a | eal ee 


SOUTHERN TEMPERATE ZONE, 287 


South Australia 


j New Zealand. 
and Tasmania. 


** Coridodax = 

**Olistherops . : 1 

** Siphonognathus if 
Gadus wet 
Merluccius . ‘ : — 
Lotella : : ; — 

** Pseudophycis : — 
Motella 
Bregmaceros 

*Genypterus . 

** Lophonectes 

**Brachypleura 
Pseudorhombus 

** A mmotretis 

** Rhombosolea 

** Peltorhamphus 
Solea : 
Aulopus. ; 
Gonorhyncbus (grey1) 
Engraulis (encrasicholus) 
Clupea 

**Chilobranchus 
Conger (vulgaris) 
Ophichthys 
Murenichthys 
Congromurena 
Syngnathus 
Ichthyocampus 

** Nannocampus 
Urocampus 

**Stigmatophora 
Solenognathus 

** Phyllopteryx 
Monacanthus 
Ostracion 

*Bdellostoma 

Branchiostoma : ; i 


— 
oo Ov KS bt bt ee 


288 FISHES. 


3. The coast-line of the Chilian district extends over 20 
degrees of latitude only, and is nearly straight. In its nor- 
thern and warmer parts it is of a very uniform character, 
and exposed to high and irregular tides, and to remarkable 
and sudden changes of the levels of land and water, which 
must seriously interfere with fishes living and propagating 
near the shore. No river of considerable size interrupts 
the monotony of the physical conditions, to offer an addi- 
tional element in favour of the development of littoral 
animals. In the southern parts, where the coast is lined 
with archipelagoes, the climate is too severe for the majority 
of fishes. All these conditions combine to render this district 
comparatively poor as regards variety of Shore fishes, as will 
be seen from the following lst :— 

*Callorhynchus ; Scyllium, Acanthias, Spinax; Urolo- 
phus. 

Serranus, Plectropoma, Polyprion, Pristipoma, Erythrich- 
thys; *Haplodactylus; *Scorpis; Chilodactylus, **Mendo- 
soma; Sebastes, *Agriopus; Trigla, Agonus; *Aphritis, 
*Eleginus, Pinguipes, Latilus, Notothenia (1 sp.) Umbrina ; 
Thyrsites; Trachurus, Caranx, *Seriolella ; Porichthys ; **Myx- 
odes, Clinus; Sicyases, Gobiesox. 

Heliastes ; **Malacopterus ; *Labrichthys. 

Merluccius ; *Genypterus ; Pseudorhombus. 

Engraulis, Clupea; Ophichthys, Mureena. 

Synenathus.—* Bdellostoma. 

Of these genera six only are not found in other districts 
of this zone. Three are peculiar to the Chilian district ; 
Porichthys and Agonus have penetrated so far southwards 
from the Peruvian and Californian districts; and Polyprion 
is one of those extraordinary instances in which a very speci- 
alised form occurs at almost opposite points of the globe, 
without having left a trace of its previous existence in, or of 
its passage through, the intermediate space. 


ANTARCTIC SHORE FISHES. 289 


4, The Patagonian district is, with the exception of the 
neighbourhood of the mouth of the Rio de la Plata, almost 
unknown. In that estuary occur Mustelus vulgaris, two Raja, 
two Trygon, several Scienoids, Paropsis signata and Percophis 
brasilianus (two fishes pecuhar to this coast), Prionotus punc- 
tatus, Lemonema longifilis (a Gadoid), a Pseudorhombus, two 
Soles, Engraulis olidus, a Syngnathus, Conger vulgaris, and 
Ophichthys ocellatus ; and if we notice the occurrence of a 
Serranus and Caranz, of Aphritis and Pinguipes, and of 
two or three Clupea, we shall have enumerated all that is 
known of this fauna. The fishes of the southern part, viz. 
the coast of Patagonia proper, southwards to Magelhzn’s 
Straits, are unknown; which is the more to be regretted, as 
it is most probably the part in which the characteristic types 
of this district are most developed. 


V.—SHORE FISHES OF THE ANTARCTIC OCEAN. 


To this fauna we refer the shore fishes of the southern- 
most extremity of South America, from 50° lat. S., with 
Terra del Fuego and the Falkland Islands, and those of Ker- 
guelen’s Land, with Prince Edward’s Island. No fishes are 
known from the other oceanic islands of these latitudes. 

In the Southern Hemisphere surface fishes do not extend 
so far towards the Pole as in the Northern; none are known 
from beyond 60° lat. S., and the Antarctic Fauna, which is 
analogous to the Arctic Fauna, inhabits coasts more than ten 
degrees nearer to the equator. It is very probable that the 
shores between 60° and the Antarctic circle are inhabited 
by fishes sufficiently numerous to supply part of the means 
of subsistence for the large Seals which pass there at least 
some season of the year, but hitherto none have been ob- 
tained by naturalists; all that the present state of our know- 
ledge justifies us in saying is, that the general character of 

U 


290 FISHES. 


the Fauna of Magelheen’s Straits and Kerguelen’s Land is 
extremely similar to that of Iceland and Greenland. 

As in the arctic Fauna, Chondropterygians are scarce, 
and represented by Acanthias vulgaris and species of Raja. 
Holocephali have not yet been found so far south, but Cadlor- 
hynchus, which is not uncommon near the northern boundary 
of this fauna, will prove to extend into it. 

As to Acanthopterygians, Cataphractt and Scorpenida 
are represented as in the arctic Fauna, two of the genera 
(Sebastes and Agonus) being identical. The Cottide are re- 
placed by six genera of Tvrachinide, remarkably similar in 
form to arctic types; but Discoboli and the characteristic 
Arctic Blennioids are absent. 

Gadoid Fishes reappear, but are less developed; as usual 
they are accompanied by Myxine. The reappearance of so 
specialised a genus as Lycodes is most remarkable. Flat- 
fishes are scarce as in the North, and belong to peculiar 
genera. 

Physostomes are probably not entirely absent, but hitherto 
none have been met with so far south. Lophobranchs are 
scarce, as in the Arctic zone; however, it is noteworthy that 
a peculiar genus, with persistent embryonic characters (Proto- 
campus), is rather common on the shores of the Falkland 
Islands. 

The following are the genera known from this zone. 
Those with a single asterisk (*) are known to extend into 
the Temperate zone, but not beyond it; those with a double 
asterisk (**) are limited to the Antarctic shores :— 


Magelhzen’s and 2 
ae Kerguelen. 


Falkland. 
Acanthias vulgaris . : 1 a 
Raja 1 2 
Psammobatis : : 1 — 
Sebastes. 1 — 


**Zanclorhynchus _. — 1 


ANTARCTIC SHORE FISHES. 291 


Magelhen’s and 
Falkland. 


*Agriopus . ; : 1 
Agonus if 

* A phritis 1 
*Eleginus 1 
** Cheenichthys 1 
*Bovichthys . 2 
*Notothenia . 8 
**Harpagifer . 1 
Lycodes. : : 4 
1 

1 

1 

1 

1 

1 

if 


Kerguelen. 


** Magnea 
Lotella 
Merluccius . 

**Lepidopsetta 

**Thysanopsetta 
Syngnathus 

**Protocampus 
Myxine 


ka ee se 


Fig. 108.—Cheenichthys rhinoceratus, shores of the Antarctic Ocean. 


CH AVP TE exe 
DISTRIBUTION OF PELAGIC FISHES. 


PELAGIC Fishes,—that is, fishes inhabiting the surface of mid- 
ocean (see p. 255), belong to various orders, viz. Chondrop- 
terygians, Acanthopterygians, Physostomes, Lophobranchs, 
and Plectognaths. But neither Anacanths nor Pharyngog- 
naths contribute to this series of the Marine Fauna, The 
following genera and families are included in it :— 

CHONDROPTERYGI: Carcharias, Galeocerdo, Thalassorhinus, 
Zygena, Trienodon, Lamnidee, Rhinodon, Notidanidee, Leemar- 
gus, Euprotomicrus, Echinorhinus, Isistius ; Myliobatide. 

ACANTHOPTERYGH : Dactylopterus, Micropteryx, Scom- 
brina, Gastrochisma, Nomeus, Centrolophus, Coryphzenina, 
Seriola, Temnodon, Naucrates, Psenes, Xiphide, Antennarius. 

PHYSOSTOMI: Sternoptychidee, Scopelus, <Astronesthes, 
Scombresocide (majority). 

LopHoBRANCHI: Hippocampus. 

PLECTOGNATHI: Orthagoriscus, and some other Gymnodonts. 

Pelagic fishes differ much from one another in their mode 
of life. The majority are excellent swimmers, which not only 
can move with great rapidity, but also are possessed of great 
powers of endurance, and are thus enabled to continue their 
course for weeks, apparently without the necessity of rest: 
such are many Sharks, Scombroids, Dolphins, Pilot-fish, Sword- 
fishes. In some, as in Dactylopterus and Exocoetus, the ability 
of taking flying leaps out of the water is superadded to the 
power of swimming (Flying-fishes). But in others the power 


PELAGIC FISHES. 293 


of swimming is greatly reduced, as in Antennarius, Hippo- 
campus, and Gymnodonts; they frequent places in the ocean 
covered with floating seaweed, or drift on the surface without 
resistance, at the mercy of wind and current. The Zcheneis or 
Sucking-fishes attach themselves to other large fish, ships, or 
floating objects, and allow themselves to be carried about, 
unless change of climate or want of food obliges them to 
abandon their temporary carrier. Finally, another class of 
Pelagic fishes come to the surface of the ocean during the 
night only; in the day time they descend to some depth, 
where they are undisturbed by the rays of the sun or 
the agitation of the surface-water : such are Brama, the Ster- 
noptychide, Scopelus, Astronesthes ; fishes, the majority of 
which are provided with those extraordinary luminary organs 
that we find so much developed in the true Deep-sea fishes. 
Indeed, this last kind of Pelagic fishes forms a passage to the 
Deep-sea forms. 

Pelagic fishes, like shore fishes, are most numerous in the 
Tropical Zone ; and, with few exceptions (Echinorhinus, Psenes, 
Sternoptychide, Astronesthes), the same genera are repre- 
sented in the tropical Atlantic as well as in the Indo-Pacific. 
The number of identical species occurring in both these 
oceans is great, and probably still greater than would appear 
from systematic lists, in which there are retained many specific 
names that were given at a time when species were believed 
to have a very limited range. The Pelagic fauna of the 
tropics gradually passes into that of the temperate zones, 
only a few genera, like Cybiwm, Psenes, Antennarius, being 
almost entirely confined to the tropics. All the other tropi- 
cal genera range into the temperate zones, but their repre- 
sentatives become scarcer with the increasing distance from 
the equator. North of 40° lat. N. many genera have disap- 
peared, or are met with in isolated examples only, as Carcha- 
rias, Zygena, Notidanus, Myliobatide, Dactylopterus, Echeneis, 


294 FISHES. 


Nomeus, Coryphena, Schedophilus, Seriola, Temnodon, Anten- 
narius, Sternoptychide, Astronesthes, Exocoetus, Tetrodon, Dio- 
don ; and only one genus of Sharks, Galeocerdo, approaches 
the Arctic circle. Some few species, like Antennarius, 
Scopelus, are carried by currents near to the northern confines 
of the temperate zones; but such occurrences are accidental, 
and these fishes must be regarded as entirely foreign to the 
fauna of those latitudes. On the other hand, some Pelagic 
fishes inhabit the temperate zones, whilst their occurrence 
within the tropics is very problematical; thus, in the Atlan- 
tic, Thalassorhinus, Selache, Lemargus, Centrolophus, Diana, 
Ausonia, Lampris (all genera composed of one or two species 
only). Beside the Shark mentioned, no other Pelagic fishes 
are known from the Arctic Ocean. 

We possess very little information about the Pelagic fish- 
fauna of the Southern oceans. So much only is certain, 
that the tropical forms gradually disappear; but it would be 
hazardous, in the present state of our knowledge, to state 
even approximately, the mits of the southward range of a 
single genus. Scarcely more is known about the appearance 
of types peculiar to the Southern temperate zone; for in- 
stance, the gigantic Shark (Rhinodon), representing the 
Northern Selache, near the coasts of South Africa, and the 
Scombroid genus, Gastrochisma, in the South Pacific. 

The largest of marine fishes, Rhinodon, Selache, Carcharo- 
don, Myliobatide, Thynnus, Xiphiida, Orthagoriscus, belong to 
the Pelagic Fauna. Young fishes are frequently found in 
mid-ocean, which are the offspring of shore-fishes normally 
depositing their spawn near the coast. The manner, in which 
this fry passes into the open sea, is unknown; for it has 
not yet been ascertained whether it is carried by currents from 
the place where it was deposited originally, or whether shore- 
fishes sometimes spawn at a distance from the coast. We 
may remember that shore-fishes inhabit not only coasts but 


PELAGIC FISHES. 295 


also submerged banks with some depth of water above, and 
that, by the action of the water, spawn deposited on these 
latter localities is very lable to be dispersed over wide areas 
of the ocean. Embryoes of at least some shore-fishes hatched 
under abnormal conditions seem to have an abnormal growth 
up toa certain period of their life, when they perish. The 
Leptocephali must be regarded as such abnormally developed 
fish (see p. 179). Fishes of a similar condition are the so- 
called Pelagic Plagusiw, young Pleuronectoids, the origin of 
which is still unknown. As mentioned before, Flat-fishes, 
like all the other Anacanths, are otherwise not represented in 
the Pelagic fauna. 


Figs. 109 and 110.—Antennarius candimaculatus, a pelagic fish, j 
from the Indian Ocean. 


CHAPTER XXI. 
THE FISHES OF THE DEEP SEA. 


THE knowledge of the existence of deep-sea fishes is one 
of the recent discoveries of ichthyology. It is only about 
twenty years ago that, from the evidence afforded by the 
anatomical structure of a few singular fishes obtained in the 
North Atlantic, an opinion was expressed that these fishes 
inhabited great depths of the ocean, and that their organisa- 
tion was specially adapted for living under the physical 
abyssal conditions. These fishes agreed in the character of 
their connective tissue, which was so extremely weak as to 
yield to, and to break under, the slightest pressure, so that the 
greatest difficulty is experienced to preserve their body in 
its continuity. Another singular circumstance was, that some 
of the specimens were picked up floating on the surface of the 
water, having met their deaths whilst engaged in swallowing 
or digesting another fish not much inferior or even superior 
in size to themselves. 

The first pecularity was accounted for by the fact that, 
if those fishes really inhabited the great depths supposed, 
their removal from the enormous pressure under which 
they lived would be accompanied by such an expansion of 
gases within their tissues as to rupture them, and to cause 
a separation of the parts which had been held together by the 
pressure. The second circumstance was explained thus :— 
A raptatorial fish organised to live at a depth of between 500 
and 800 fathoms seizes another usually inhabiting a depth of 
between 300 and 500 fathoms. In its struggles to escape, 


DEEP-SEA FISHES. 297 


the fish seized, nearly as large or strong as the attacking fish, 
carries the latter out of its depth into a higher stratum, 
where the diminished pressure causes such an expansion of 
gases as to make the destroyer with its victim rise with in- 
creasing rapidity towards the surface, which they reach dead 
or in a dying condition. Specimens in this condition are not 
rarely picked up; and as, of course, comparatively few can 
by accident fall into the hands of naturalists, occurrences of 
the kind related must happen very often. 

Thus, the existence of fishes peculiarly adapted for the 
deep sea has been a fact maintained and admitted for some 
time in Ichthyology ; and as the same genera and species were 
found at very distant parts of the ocean, it was further stated 
that those Deep-sea fishes were not limited in their range, and 
that, consequently, the physical conditions of the depths of the 
ocean must be the same or nearly the same over the whole 
globe. That Deep-sea fishes were not of a peculiar order, but 
chiefly modified forms of surface types, was another conclusion 
arrived at from the sporadic evidence collected during the 
period which preceded systematic deep-sea dredging. 

However, nothing was positively known as to the exact 
depths inhabited by those fishes until observations were made 
during the voyage of H.M.S. “Challenger.” The results 
obtained by this expedition afforded a surer and more extended 
basis for our knowledge of Deep-sea fishes. 

The physical conditions of the deep sea, which must 
affect the organisation and distribution of fishes, are the 
following :— 

1. Absence of sunlight. Probably the rays of the sun do 
not penetrate to, and certainly do not extend beyond, a depth 
of 200 fathoms, therefore we may consider this to be the 
depth where the Deep-sea fauna commences. Absence of 
light is, of necessity, accompanied by modifications of the 
organs of vision and by simplification of colours. 


298 FISHES. 


2. The absence of sunlight is in some measure compen- 
sated for by the presence of phosphorescent light, produced by 
many marine animals, and also by numerous Deep-sea fishes. 

3. Depression and equality of the temperature. Ata depth 
of 500 fathoms the temperature of the water is already as 
low as 40° Fahr., and perfectly independent of the temperature 
of the surface-water ; and from the greatest depths upwards to 
about 1000 fathoms the temperature is uniformly but a few 
degrees above freezing-point. Temperature, therefore, ceases to 
offer an obstacle to the unlimited dispersal of Deep-sea fishes. 

4. The increased pressure by the water. The pressure of 
the atmosphere on the level of the sea amounts to fifteen 
pounds per square inch of the surface of the body of an 
animal; but the pressure amounts to a ton weight for every 
1000 fathoms of depth. 

5. With the sunlight, vegetable life ceases in the depths of 
the sea. All Deep-sea fishes are therefore carnivorous ; the 
most voracious feeding frequently on their own offspring, and 
the toothless kinds being nourished by the animalcules which 
live on the bottom, or which, “like a constant rain,” settle 
down from the upper strata towards the bottom of the sea. 

6. The perfect quiet of the water at great depths. The 
agitation of the water, caused by the disturbances of the air, 
does not extend beyond the depth of a few fathoms; below 
this surface-stratum there is no other movement except the 
quiet flow of ocean-currents, and near the bottom of the 
deep sea the water is probably in a state of almost entire 
quiescence. 

The effect upon fishes of the physical conditions described 
is clearly testified by the modification of one or more parts of 
their organisation, so that every Deep-sea fish may be recog- 
nised as such, without the accompanying positive evidence 
that it has been caught at a great depth; and vice versa, 
fishes reputed to have been obtained at a great depth, and not 


DEEP-SEA FISHES. 299 


having any of the characteristics of the dwellers of the deep 
sea, must be regarded as surface-fishes. 

The most striking characteristic, found in many Deep-sea 
fishes, is in relation to the tremendous pressure under which 
they live. Their osseous and muscular systems are, as com- 
pared with the same parts of surface-fishes, very feebly de- 
veloped. The bones have a fibrous, fissured, and cavernous 
texture; are light, with scarcely any calcareous matter, so 
that the point of a needle will readily penetrate them with- 
out breaking. The bones, especially the vertebra, appear to 
be most loosely connected with one another; and it requires 
the most careful handling to prevent the breaking of the 
connective ligaments. The muscles, especially the great 
lateral muscles of the trunk and tail, are thin, the fascicles 
being readily separated from one another or torn, the connec- 
tive tissue being extremely loose, feeble, or apparently absent. 
This peculiarity has been observed in the Tvachypteride, 
Plagyodus, Chiasmodus, Melanocetus, Saccopharynz. But we 
cannot assume that it actually obtains whilst those fishes 
exist under their natural conditions. Some of them are most 
rapacious creatures which must be able to execute rapid and 
powerful movements to catch and overpower their prey; and 
for that object their muscular system, thin as its layers may 
be, must be as firm, and the chain of the segments of their 
vertebral column as firmly linked together as in surface-fishes. 
Therefore, it is evident that the change which the body of 
those fishes has undergone on their withdrawal from the pres- 
sure under which they live is a much ageravated form of the 
affection that is experienced by persons reaching great. alti- 
tudes in their ascent of a mountain or in a balloon. In every 
living organism with an intestinal tract there are accumula- 
tions of free gases; and, moreover, the blood and_ other 
fluids, which permeate every part of the body, contain gases 
in solution. Under greatly diminished pressure these gases 


300 FISHES. 


expand, so that, if the withdrawal from a depth is not an 
extremely slow and gradual process, the various tissues must 
be distended, loosened, ruptured ; and what is a vigorous fish 
at a depth of 500 or more fathoms, appears at the surface as 
a loosely-jointed body which, if the skin is not of sufficient 
toughness, can only be kept together with difficulty. At 
ereat depths a fibrous osseous structure and a thin layer of 
muscles suffices to obtain the same results for which, at the 
surface, thickness of muscle and firm osseous or cartilaginous 
tissue are necessary. 

The muciferous system of many Deep-sea fishes is deve- 
loped in an extraordinary degree. We find already in fishes 
which are comparatively little removed from the surface 
(that is to depths of 100-200 fathoms), the lateral line much 
wider than in their congeners or nearest allies which live on 
the surface, asin Trachichthys, Hoplostethus, many Scorpenide. 
But in fishes inhabiting depths of 1000 and more fathoms, 
the whole muciferous system is dilated ; it is especially the 
surface of the skull which is occupied by large cavities 
(Macruride, deep-sea Ophidiide), and the whole body seems 
to be covered with a layer of mucus. These cavities collapse 
and shrink in specimens which have been preserved in spirit 
for some time, but a re-immersion in water for a short time 
generally suffices to show the immense quantity of mucus 
secreted by them. The physiological use of this secretion is 
unknown; it has been observed to have phosphorescent 
properties in perfectly fresh specimens. 

The colours of Deep-sea fishes are extremely simple, their 
bodies being either black or silvery; in a few only are some 
filaments or the fin-rays of a bright scarlet colour. Among 
the black forms albinoes are not scarce. 

The organ of sight is the first to be affected by a sojourn in 
deep water. Even in fishes which habitually live at a depth 
of only 80 fathoms, we find the eye of a proportionally larger 


DEEP-SEA FISHES. 301 


size than in their representatives at the surface. In such 
fishes the eyes increase in size with the depth inhabited by 
them, down to the depth of 200 fathoms, the large eyes being 
necessary to collect as many rays of light as possible. Beyond 
that depth small-eyed fishes as well as large-eyed occur, the 
former having their want of vision compensated for by tenta- 
cular organs of touch, whilst the latter have no such accessory 
organs, and evidently see only by the aid of phosphorescence. 
In the greatest depths blind fishes occur with rudimentary 
eyes and without special organs of touch. 

Many fishes of the deep sea are provided with more or less 
numerous, round, shining, mother-of-pearl-coloured bodies, im- 
bedded in the skin. These so-called phosphorescent or lumi- 
nous organs are either larger bodies of an oval or irregularly 
elliptical shape placed on the head, in the vicinity of the eye, 
or smaller round globular bodies arranged symmetrically in 
series along the side of the body and tail, especially near the 
abdominal profile, less frequently along the back. The former 
have not yet been anatomically examined. The number of 
pairs of the latter is in direct relation to that of the segments 
of the vertebral column, the muscular system, etc. (meta- 
meres); and two kinds may be distinguished differing from 
each other in theiranatomical structure. The organs of one kind 
consist of an anterior, biconvex, lens-like body, which is trans- 
parent during life, simple or composed of rods (Chauliodus) ; 
and of a posterior chamber which is filled with a transparent 
fluid, and coated with a dark membrane composed of hexa- 
gonal cells, or of rods arranged as in a retina. This structure 
is found in Astronesthes, Stomias, Chauliodus, ete. In the other 
kind the organ shows throughout a simply glandular structure, 
but apparently without an efferent duct (Gonostoma, Scopelus, 
Maurolicus, Argyropelecus). Branches of the spinal nerves 
run to each organ, and are distributed over the retina-like 
membrane or the glandular follicles. The former kind of 


302 FISHES. 


organs are considered by some naturalists true organs of 
vision (accessory eyes), the function of the latter being left 
unexplained by them. 

Although, thus, these organs morphologically differ from 
each other, there is no doubt that the functions of all have 
some relation to the peculiar conditions of light under which 
the fishes provided with them live; these fishes being either 
deep-sea forms or nocturnal pelagic kinds. There are three 
possible hypotheses as to the function of these organs :— 

1. All the different kinds of organs are sensory, or, in 
other words, accessory eyes. 

2. Only the organs with a lenticular body are sensory, 
and those with a glandular structure produce and emit 
phosphorescent light. 

3. All are producers of light. 

There are very serious objections to adopting the first 
view. Scopelus and Argyropelecus possess not only perfectly 
developed, but even large eyes, specially adapted for a 
nocturnal life; and therefore accessory organs of vision must 
appear to be quite superfluous to them. On the other hand, 
in Deep-sea fishes without external eyes, which would seem 
to especially require these metameric organs of sense, they 
are invariably absent. And, finally, it is quite inconceiv- 
able that the glandular structures should have the faculty 
of conveying impressions of light to the nervous centre. 
The second supposition seems therefore to be nearer the 
truth; and is supported by the fact that the glandular organs 
of Scopeli have actually been observed to gleam with phos- 
phorescent light, and by the obvious morphological similarity 
of the organs with a lenticular body and retina-like membrane 
to an organ of vision. We are, moreover, justified, from an 
& priori consideration, in supposing that in depths to which no 
sunlight descends, and which are illuminated by phosphores- 
cent light only, peculiar organs of vision would have been 


DEEP-SEA FISHES. 303 


developed. On the other hand, this supposition is opposed by 
the fact that many fishes which dwell in those abyssal depths 
are provided with large ordinary eyes (as the Z'rachyptert, the 
majority of Macruride), and, therefore, that the ordinary 
organ of vision is quite sufficient for seeing by phosphores- 
cent light. Thus, whilst we must admit that those compound 
organs may prove to be organs of sense, we maintain at the 
same time that their morphological nature is not opposed to 
the belief that they too, like the glandular organs, are pro- 
ducers of light. It may be produced at the bottom of the 
posterior chamber, and emitted through the lenticular body 
in particular directions, with the same effect as light is sent 
through the convex glass of a “bull’s eye.” This hypothesis 
seems to be less bold than the other, which would require us 
to believe that vertebrate animals, with a nervous centre 
specialised for the reception of the impressions of the higher 
senses, should receive them through the spinal chord. 


[See Ussow, ‘‘ Ueber den Bau der sogenannten augenaehnlichen Flecken 
einiger Knochenfische.” St. Petersburg, Bullet. 1879. ] 


Whenever we find in a fish long delicate filaments, de- 
veloped in connection with the fins or the extremity of the 
tail, we may conclude that it is an inhabitant of still water 
~and of quiet habits. Many deep-sea fishes (7rachypteridea, 
Macruride, Ophidiide, Bathypterois) are provided with such 
filamentous prolongations, the development of which is per- 
fectly im accordance with their sojourn in the absolutely 
quiet waters of abyssal depths. 

Some of the raptatorial Deep-sea fishes have a stomach 
so distensible and capacious that it can receive a fish of 
twice or thrice the bulk of the destroyer (Melanocetus, Chias- 
modus, Saccopharynx). Deglutition is performed in them 
not by means of the muscles of the pharynx, as in other 
fishes, but by the independent and alternate action of the 


304 FISHES. 


jaws, as in Snakes. These fishes cannot be said to swallow 
their food, but rather draw themselves over their victim, in 
the fashion of an Actinia. 

Before the voyage of H.M.S. “Challenger,” scarcely thirty 
Deep-sea fishes were known. ‘This number is now much 
increased by the discovery of many new species and genera ; 
but, singularly, no new types of families were discovered : 
nothing but what might have been expected from our pre- 
vious knowledge of this group of fishes. Modifications of 
certain organs, perfectly novel, and of the greatest interest, 
were found, as we shall see in the “ Systematic Part;” but 
the most important results of this voyage are that the general 
character of the abyssal fish-fauna, the abundance of fishes, 
and the exact depths to which fishes may descend, have been 
ascertained, 

However, the statements of the depths at which the 
fishes collected by the “ Challenger” were taken cannot be 
received without some critical examination of each individual 
species. No precaution was taken to keep the mouth of the 
dredge closed during its descent or ascent, and therefore it 1s 
quite within the hmits of probability that sometimes fishes 
were accidentally enclosed within the dredge, whilst it was 
traversing the surface strata. And this has happened more 
than once; for it is quite certain that common surface fishes 
hike Sternoptyz and Astronesthes, never ranged to a depth 
of 2500 fathoms. On the other hand, the majority of the 
fishes obtained offer sufficient evidence from their own organ- 
isation that they live on the bottom, and are unable to 
support themselves in the water at a certain distance from 
the bottom or surface ; and, consequently, that they actually 
were obtained at the depth to which the dredge descended. 

As far as the observations go at present, no distinct 
bathymetrical regions, which would be characterised by 
peculiar forms, can be defined. The depths from 200 to 


DEEP-SEA FISHES. 305 


600 fathoms are inhabited by numerous forms, still strongly 
reminding us of surface types. To this fauna belong the few 
Chondropterygians of the deep sea, a Sebastes and Setarches, 
a Beryx and Polymixia, a Cottus, etc.; but they are associ- 
ated with many others which descend to the greatest depths. 
And before anything like a division into bathymetrical zones 
can be attempted, the observations of the “Challenger” 
expedition must be confirmed and supplemented by other 
series of similar systematic observations. One of the most 
startling conclusions at which we would have to arrive from 
the “ Challenger” observations is, that some of the species of 
Deep-sea fishes would range from a depth of some 300 fathoms 
down to one of 2000 fathoms; or, in other words, that a fish 
which has once attained in its organisation to that modifi- 
cation by which it is enabled to exist under the pressure of 
half a ton, can easily accommodate itself to one of two tons 
or more,—a conclusion which is not in accordance with ana- 
tomical facts, and which must be confirmed by other obser- 
vations before we can adopt it. But if the vertical range of 
Deep-sea fishes is actually as it appears from the “ Challenger ” 
lists, then there is no more distinct vertical than horizontal 
distribution of Deep-sea fishes. 

The greatest depth reached hitherto by a dredge in which 
fishes were enclosed is 2900 fathoms. But the specimens 
thus obtained belong to a species (Gonostoma microdon), which 
seems to be extremely abundant in upper strata of the Atlantic 
and Pacific, and were therefore most likely caught by the 
dredge in its ascent. The next greatest depth, viz., 2750 
fathoms, must be accepted as one at which fishes undoubtedly 
do live; the fish obtained from this depth of the Atlantic, 
Lathyophis feroxz, showing by its whole habit that it is a form 
living on the bottom of the ocean. 

The fish-fauna of the deep sea is composed chiefly of 
forms or modifications of forms which we find represented at 

xe 


306 FISHES. 


the surface in the cold and temperate zones, or which appear 
as nocturnal pelagic forms. The Chondropterygians are few 
in number, not descending to a depth of more than 600 
fathoms. The Acanthopterygians, which form the majority 
of the coast and surface faunas, are also scantily represented ; 
genera identical with surface types are confined to the same 
inconsiderable depths as the Chondropterygians, whilst those 
Acanthopterygians which are so much specialised for the life 
in the deep sea as to deserve generic separation, range from 
200 to 2400 fathoms. Three distinct families of Acanthop- 
terygians belong to the deep-sea fauna, viz. Trachypterida, 
Lophotide, and Notacanthide ; they respectively consist of 
three, one, or two genera only. 

Gadide, Ophidude, and Macruride are very numerous, 
ranging through all depths; they constitute about one-fourth 
of the whole deep-sea fauna. 

Of Physostomi, the families of Sternoptychidaw, Scopelide, 
Stomiatide, Salmonide, Bathythrisside, Alepocephalide, Halo- 
sauride, and Murenide are represented. Of these the Scope- 
loids are the most numerous, constituting nearly another 
fourth of the fauna. Salmonide are scarce, with three small 
genera only. Bathythrissidw include one species only, which 
is probably confined in its vertical as well as horizontal range ; 
it occurs at a depth of about 350 fathoms in the sea of Japan. 
The <Alepocephalide and Halosawride, known before the 
“ Challenger ” expedition from isolated examples only, prove to 
be true, widely-spread, deep-sea types. Eels are well repre- 
sented, and seem to descend to the greatest depths. 

Myzxine has been obtained from a depth of 345 fathoms. 

It will be useful to append a complete list of Deep-sea 
fishes, with the depths as ascertained by the dredgings of 
the “ Challenger :”— 


DEEP-SEA FISHES. 307 


List of Deep-sea Fishes. 


Fathoms. 
CHONDROPTERYGIANS— 
Raja : : ; ; 565 
Scylium . ‘ : ; 400 
Centroscyllium : : : 245 
Centrophorus : . 345-500 
ACANTHOPTERYGIANS— 
Pomatomus . : . (2 down to) 200 
Sebastes ‘ : ‘ : 275 
Setarches. : : : 215 
Beryx : : i ; 345 
Melamphaes . : ; (t beyond) 200 
Polymixia . ; : . 345 
Nealotus : 
Nesiarchus 
Aphanopus 
Euoxymetopon : : 
Lepidopus. ; ; 345 
Gempylus 
Anomalops . 
? Antigonia 

Diretmus F : : 
Cottus : . ‘ : 565 
Bathydraco . : , : 1260 
Oneirodes : 
Melanocetus johnsonii : 4 1850 

a bispinosus : ; 360 
Himantolophus : 
Chaunax . : : : 215 
Ceratias : 5 . : 2400 
Halieutichthys 5 ; 
Dibranchus . : ; : 360 
Trachypteridze 
Lophotes : 
Notacanthus rissoanus : : 1875 


bonapartii ; : 400 


? 


FISHES. 


ANACANTHINI— 


Melanonus 

Halargyreus . 

Lotella marginata 

Physiculus 

Uraleptus 

Lzemonema . 

Haloporphyrus australis 
By lepidion 
ss rostratus 

Chiasmodus niger 

Sirembo grandis 


. macrops 
5 messierl 
FA ocellatus 
% brachysoma . 


Acanthonus armatus . 
Typhlonus nasus 
Aphyonus gelatinosus 
Rhinonus ater 
Bathynectes laticeps . 


. compressus 
i gracilis . 
Pteridium 


Macrurus (12 species) 
Coryphznoides norvegicus 


PP serratus 

oH nasutus 

i villosus 

a rudis 

7” eequalis 

<3 crassiceps 
53 microlepis 
si murrayl 
_ serrulatus 
a filicauda 
. variabilis 
8 affinis 


Fathoms. 


1975 


120-345 
345 


55-70 
345-600 
600-1375 
1500 
1875 
375 
345 
350 
350 
1075 
2440 
1400 
2150 
2500 


. 1075-2500 


1400 


120-700 


345-565 
345 
500-650 
600 
520-650 
215 
1100 
700 


. 1800-2650 
. 1375-2425 


1900 


DEEP-SEA FISHES, 


Coryphznoides carinatus 
i longifilis 
o altipinnis 
3 asper 
5 leptolepis 
. sclerorhynchus 
- denticulatus . 
Malacocephalus 
Bathygadus cottoides 
fs multifilis 
STERNOPTYCHIDA— 
Argyropelecus 
Sternoptyx . 
Polyipnus ‘ 
Gonostoma denudatum 
5 microdon . 
55 elongatum 
¥9 gracile 
Chauliodus . 
SCOPELIDA— 
Bathysaurus ferox 
a mollis 
Bathypterois longifilis 
ss longipes 
BA quadrifilis 
longicauda 
Chlorophthalmus agassizil 
$3 nigripinnis . 
es gracilis 
Scopelus engraulis 
- antarcticus . 
i mizolepis 
“a dumerilii 
»  macrolepidotus 
- crassiceps 
a macrostoma 
, microps 
Odontostomus hyalinus 


Fathoms. 


500 

565 
565-1875 
500-1875 
350-2050 
1090 
275-520 
350 
520-700 
500 


1127 [7] 
0-2500 [2] 


255 


500-2900 [2] 


360-800 
345-2425 
565-2560 


1100 


. 1875-2385 


520-630 
2650 
500-770 
2550 
215 
120 


. 1100-1425 


255 

1950 
800 

215 
520-630 
675-1550 


. 2350-2425 


1375 


310 


FISHES. 


Odontostomus humeralis 
Nannobrachium nigrum 
Ipnops murrayi 
Paralepis 

Sudis 

Plagyodus 


STOMIATIDA— 


Astronesthes niger 
Stomias boa 
», barbatus 
»  ferox 
Echiostoma barbatum 
zp micripnus 
a microdon 
Malacosteus niger 
5 indicus. 
Bathyophis ferox 
SALMONIDA— 
Argentina 
Microstoma . : 
Bathylagus antarcticus 
55 atlanticus 
BATHYTHRISSIDA— 
Bathythrissa dorsalis 
ALEPOCEPHALIDA— 
Alepocephalus rostratus 
i, niger 
Platytroctes apus 
Bathytroctes microlepis 


Ap rostratus 
ie macrolepis 
Xenodermichthys 
HALOSAURIDE— 

Halosaurus owenil 

3 affinis 

a macrochir 

5 mediorostris 


a rostratus . 


Fathoms. 
500 
500 


. 1600-2150 


2500 [2] 
450-1800 


2150 
2440 


500 
2750 


1950 
2040 


345 


1400 
1500 
1090 
675 
2150 
345 


565 


. 1090-1375 


700 
2750 


DEEP-SEA FISHES. 


MuraNIDE— 
Nemichthys scolopacea 
Be infans 
Cyema atrum 
Saccopharynx 
Synaphobranchus pinatus 
5 bathybius 
5 brevidorsalis 
a affinis 
Nettastoma parviceps 
CYCLOSTOMATA— 


Myxine australis 


Fathoms. 


500-2500 
. 1500-1800 


345-1200 

. 1875-2050 
. 1075-1375 
345 

345 


345 


oll 


Fig. 111.—Chiasmodus niger ; obtained in the North Atlantic at a depth of 
1500 fathoms ; the specimen has swallowed a large Scopelus (s) ; 0, ventral fin. 


SYSLEMATIC AND DESCRIPTIVE? PAkae 


—= = 


THE Class of Fishes is divided into four sub-classes :— 


I, PALmICHTHYES.—Heart with a contractile conus arte- 
riosus ; intestine with a spiral valve; optic nerves non-decus- 
sating, or only partially decussating. 


II. TeLEostet — Heart with a non-contractile bulbus 
arteriosus ; intestine without spiral valve ; optic nerves de- 
cussating. Skeleton ossified, with completely separated 
vertebree. 


III. CycLostomata.—Heart without bulbus arteriosus ; 
intestine simple. Skeleton cartilaginous and notochordal. 
One nasal aperture only. No jaws; mouth surrounded by a 
circular hp. 


IV. Leprocarpil.—Heart replaced by pulsating sinuses ; 
intestine simple. Skeleton membrano-cartilaginous and noto- 
chordal. No skull; no brain. 


FIRST SUB-CLASS: PALAICHTHYES. 


A A ‘ aes é é 
Heart with a contractile conus arteriosus; intestine with a 
spiral valve ;* optic nerves non-decussating, or only partially 


decussating ;° 


skeleton cartilaginous or osseous. 

This sub-class comprises the Sharks and Rays, and the 
Ganoid fishes. Although based upon a singular concurrence 
of most important characters, its members exhibit as great a 


diversity of form, and as manifold modifications in the re- 


1See p. 151, Fig. 67. 2 See p. 128, Fig. 55. 3 See p. 104. 


CHONDROPTERYGII—PLAGIOSTOMATA. 33 


mainder of their organisation as the Teleostei. The Palwich- 
thyes stand to the Teleostec in the same relation as the 
Marsupials to the Placentalia. Geologically, as a sub-class, 
they were the predecessors of Teleosteous fishes; and it is a 
remarkable fact that all those modifications which show an 
approach of the ichthyic type to the Batrachians are found 
in this sub-class. We divide it into two orders: Chondrop- 
terygu and Ganoider. 


FIRST ORDER: CHONDROPTERYGII. 


Skeleton cartilaginous. Body with medial and paired fins, 
the hinder pair abdominal. Vertebral column generally hetero- 
cercal, the upper lobe of the caudal fin produced. Gills attached 
to the skin by the outer margin, with several intervening gill- 
openings: rarely one external gill-opening only. No gill-cover. 
No air-bladder. Two, three, or more series of valves in the 
conus arteriosus. Ova large and few in number, impregnated 
and, in some species, developed within a uterine cavity. Embryo 
with deciduous external gills.” Males with intromittent organs 
attached to the ventral fins.’ 

This order, for which, also, the name Hlasmobranchit has 
been proposed (by Bonaparte), comprises the Sharks and 
Rays and Chimeras, and is divided into two sub-orders: 
Plagiostomata and Holocephala. 


FIRST SUB-ORDER : PLAGIOSTOMATA. 


From five to seven gill-openings. Skull with a suspensorium 
and the palatal apparatus detached. Teeth numerous. 

The Plagiostomes differ greatly among each other with 
regard to the general form of their body: in the Sharks or 
Selachoidei the body is elongate, more or less cylindrical, 
eradually passing into the tail ; their gill-openings are lateral. 
In the Rays, or Batoidei, the gill-openings are always placed 


1 See p. 167, Figs. 79,81. *See p. 186, Fig. 58. 3 See p. 167, Fig. 78. 


314 FISHES. 


on the abdominal aspect of the fish; the body is depressed, 
and the trunk, which is surrounded by the immensely 
developed pectoral fins, forms a broad flat disk, of which the 
tail appears as a thin and slender appendage. Spiracles are 
always present; the number of gill-openings is constantly five; 
no anal fin; dorsal fins, if present, situated on the tail. 
However, some of the Rays approach the Sharks in hav- 
ing the caudal portion less abruptly contracted behind the 
trunk. 

Fossil Plagiostomes are very numerous in all formations. 
Some of the earliest determinable fish remains are believed 
to be, or are, derived from Plagiostomes. Those which can 
be referred to any of the following families will be mentioned 
subsequently: but there are others, especially fin-spines, which 
leave us in doubt to which group of Plagiostomes their 
owners had any affinity, thus Onchus from the upper Silurian, 
continuing to carboniferous formations; Dimeracanthus, 
Homocanthus, from the Devonian; Oracanthus, Gryracanthus, 
Tristychius, Astroptychius, Ptychacanthus, Sphenacanthus, etc., 
from carboniferous formations; Leptacanthus, from the coal 
to the Oolite ; Cladacanthus, Cricacanthus, Gyropristis, and 
Lepracanthus, from the coal measures ; Nemacanthus, Liacan- 
thus, from the Trias; Astracanthus, Myriacanthus, Pristacan- 
thus, from the jurassic group. 


A. SELACHOIDEI: SHARKS. 


The elongate cylindrical body, generally terminating in a 
more or less pointed snout, and passing into a powerful and 
flexible tail, blade-like at its extremity, gives to the Sharks a 
most extraordinary power of swimming, with regard to en- 
durance as well as rapidity of motion. Many, especially the 
larger kinds, inhabit the open ocean, following ships for weeks, 
or pursuing shoals of fishes in their periodical migrations. 
Other large-sized sharks frequent such parts of the coast as 


SELACHOIDEI. 315 


offer them abundance of food; whilst the majority of the 
smaller kinds are shore fishes, rarely leaving the bottom, and 
sometimes congregating in immense numbers. The move- 
ments of sharks resemble in some measure those of snakes, 
their flexible body being bent in more than one curve when 
moving. 

Sharks are most numerous in the seas between the 
Tropics, and become scarcer beyond, a few only reaching the 
Arctic circle; it is not known how far they advance south- 
wards towards the Antarctic region. Some species enter fresh 
waters, and ascend large rivers, like the Tigris or Ganges, to 
a considerable distance. ‘The pelagic as well as the shore 
species have a wide geographical range. Very few descend 
to a considerable depth, probably not exceeding 500 fathoms. 
There are about 140 different species known. 

Sharks have no scales like those of other fishes; their 
integuments are covered with calcified papille which, under 
the microscope, show a structure similar to that of teeth. If 
the papille are small, pointed, and close set, the skin is 


? 


called “shagreen ;” rarely they are larger, appearing as 
bucklers or spines, of various sizes. 

These fishes are exclusively carnivorous, and those armed 
with powerful cutting teeth are the most formidable tyrants of 
the ocean. They have been known to divide the body of a 
man in two at one bite, as if by the sweep of a sword. 
Some of the largest sharks, however, which are provided 
with very small teeth, are almost harmless, feeding on small 
fishes only or marine invertebrates. Others, particularly of 
the smaller kinds, commonly called “ Dog-fishes,” have short 
or obtuse teeth, and feed on shells or any other animal sub- 
stance. Sharks scent their food from a distance, being readily 
attracted by the smell of blood or decomposing bodies. 

In China and Japan, and many other eastern countries, 
the smaller kinds of sharks are eaten. Sharks’ fins form in 


316 FISHES. 


India and China a very important article of trade, the 
Chinese preparing from them gelatine, and using the better 
sorts for culinary purposes. The fins are obtained not ex- 
clusively from Sharks but also from Rays, and assorted in 
two kinds, viz. “ white and black.” The white consist ex- 
clusively of the dorsal fins, which are on both sides of the 
same uniform light colour, and reputed to yield more gelatine 
than the other fins. The pectoral, ventral, and anal fins pass 
under the denomination of black fins; the caudal fin is not 
used. One of the principal places where shark fishery is 
practised as a profession is Kurrachee. Dr. Buist, writing in 
1850 (“ Proc. Zool. Soe.” 1850, p. 100), states that there are 
thirteen large boats, with crews of twelve men each, con- 
stantly employed in this pursuit; that the value of the fins 
sent to the market varies from 15,000 to 18,000 rupees ; 
that one boat will sometimes capture at a draught as many 
as one hundred sharks of various sizes; and that the number 
total of sharks captured during the year amounts probably to 
not less than 40,000. Large quantities are imported from 
the African coast and the Arabian Gulf, and various ports on 
the coast of India. In the year 1845-46, 8770 ewt. of sharks’ 
fins were exported from Bombay to China. 


First FAMILY—CARCHARIID&. 


Eye with a nictitating membrane. Mouth crescent-shaped, 
inferior. Anal fin present. Two dorsal fins, the first opposite 
to the space between pectoral and ventral fins, without spine in 
front. 

CARCHARIAS.—Snout produced in the longitudinal axis of the 
body ; mouth armed with a series of large flat triangular teeth, 
which have a smooth cutting or serrated edge. Spiracles absent. 
A transverse pit on the back of the tail, at the root of the 
caudal fin. 


This genus comprises the true Sharks, common in the 


SELACHOIDEL. 317 


tropical, but less so in the temperate seas. Between thirty 
and forty different species have been distinguished, of which 


Fig. 112.—Dentition of the Blue Shark (Carcharias glaucus) ; 
the single teeth are of the natural size. 


one of the most common is the “Blue Shark” (Carcharias 
glaucus). Individuals of from twelve to fifteen feet are of 
very common occurrence, but some of the species attain a 
much larger size, and a length of 25 and more feet. Fishes 
of this genus or of closely allied genera (Corax, Hemipristis) 
are not uncommon in the chalk and tertiary formations. 


GaLEocerpo.—Teeth large, flat, triangular, oblique, serrated 
on both edges, with a deep notch on the outer margin. Spiracles 
small. A pit on the tail, above and below, at the root of the 
caudal fin. Two notches on the under caudal border, one of 
them at the end of the spine. 


Three species, of which one (G. arcticus) is confined to 


318 FISHES. 


the arctic and sub-arctic oceans. The others inhabit tem- 
perate and tropical seas, and all attain to a very large size. 

Gateus.—Snout produced in the longitudinal axis of the 
body ; teeth equal in both jaws, rather small, flat, triangular, 
oblique, serrated and with a notch. Spiracles small. No pit at 
the commencement of the caudal fin, which has a single notch 
on its lower margin. 

These are small sharks, commonly called “Tope.” The 
species found on the British coast is spread over nearly all 
the temperate and tropical seas, and is common in Cali- 
fornia and Tasmania. It lives on the bottom, and is very 
troublesome to fishermen by constantly taking away bait or 
driving away the fishes which they desire to catch. 

ZycuNA.—The anterior part of the head is broad, flattened, 
and produced into a lobe on each side, the extremity of which is 
occupied by the eye. Caudal fin with a single notch at its lower 
margin. <A pit at the root of the caudal fin. Spiracles none. 
Nostrils situated on the front edge of the head. 

The “Hammerheads,” or Hammerheaded Sharks, have a 
dentition very similar to that of Carcharias, and although 
they do not attain to the same large size, they belong 
to the most formidable fishes of the ocean. The peculiar 
form of their head is quite unique among fishes; young 
examples have the lateral extension of the skull much less 
developed than adults. Five species are known, which are 
most abundant in the tropics. By far the most common is 
Zygena malleus, which occurs in nearly all tropical and sub- 
tropical seas. Specimens of this species may be often seen 
ascending from the clear blue depths of the ocean like a 
great cloud. | Cantor found in a female, nearly 11 feet long, 
thirty-seven embryons.—Hammerheads have lived from the 
cretaceous epoch, 

Musretus.—The second dorsal fin is not much smaller than 
the first. No pit at the root of the caudal, which is without 
distinct lower lobe. Snout produced in the longitudinal axis 


SELACHOIDEI. 319 


of the body. Spiracles small, behind the eyes. Teeth small, 
numerous, similar in both jaws, obtuse, or with very indistinct 
cusps, arranged like pavement. 


The “ Hounds” are small Sharks, abundant on the coasts 
of all the temperate and tropical seas; two of the five species 
known occur on the coasts of Europe, viz. JZ levis and 
M. vulgaris. Closely allied as these two species are, they yet 
show a most singular difference, viz. that a placenta is de- 
veloped in the uterus for the attachment of the embryo in 
M. levis (the Tanreds Xetos of Aristotle, to whom this fact 
was already known); whilst the embryons of J/. vulgaris are 
developed without such placenta (see J. Miiller, “ Abhandl. 
Ak. Wiss.” Berl. 1840). The Hounds are bottom fish, which 
feed principally on shells, crustaceans, and decomposing 
animal substances. 


Several other genera belong to the family Carchariida, 
but it will be sufficient to mention their names -—Hemz- 
galeus, Loxodon, Thalassorhinus, Triceenodon, Leptocarcharias, 
and Triacis. 


SECOND FAMILY—LAMNIDA. 


Eye without nictitating membrane. Anal fin present. Two 
dorsal fins; the first opposite to the space between pectoral and 
ventral fins, without spine in front.  Nostrils not confluent 
with the mouth which is inferior. Spiracles absent or minute. 

All_the fishes of this family attain to a very large size, and 
are pelagic. But little is known of their reproduction. The 
first appearance of this family is indicated by Carcharopsis, 
a genus from carboniferous formations, the teeth of which 
differ from those of Carcharodon only by having a broad fold 
at the base. In the chalk and tertiary formations almost 
all the existing genera are represented; and, besides, Oxytes, 
Sphenodus, Gomphodus, and Ancistrodon, which are known 


320 FISHES. 


from teeth only, have been considered generically distinct 
from the living Porbeagles. 


Lamna (Oxyruina).—The second dorsal and anal are very small. 
A pit at the root of the caudal, which has the lower lobe much 
developed. Side of the tail with a prominent 
longitudinal keel. Mouth wide. Teeth large, 
lanceolate, not serrated, sometimes with addi- 
tional basal cusps. On each side of the upper 
Fig. 113.—Upper and jaw, at some distance from the symphysis, there 
lower tooth of Lamna. i; one or two teeth conspicuously smaller 


than the others. Gill-openings very wide. Spiracles minute. 


Of the “ Porbeagles,” three species have been described, 
of which the one occurring in the North Atlantic, and fre- 
quently straying to the British coasts (Z. cornubiea), is best 
known. It attains to a length of ten feet, and feeds chiefly 
on fishes; its lanceolate teeth are not adapted for cutting, 
but rather for seizing and holding its prey, which it appears 
to swallow whole. According to Pennant it is viviparous ; 
only two embryoes were found in the female which came 
under his observation. Haast has found this species also off 
the coast of New Zealand. 


Carcuaropon.—The second dorsal and anal are very small. 
Pit at the root of the caudal, which has the lower lobe well de- 
veloped. Side of the tail with a prominent: longitudinal keel. 
Mouth wide. Teeth large, flat, erect, regularly triangular, ser- 
rated. On each side of the upper jaw, at some distance from the 
symphysis, there is one or two teeth conspicuously smaller than 
the others. Gill-openings wide. 

One species only is known (C. rondeletii), which is the 
most formidable of all Sharks. It is strictly pelagic; and 
appears to occur in all tropical and sub-tropical seas. It 
is known to attain to a length of 40 feet. The tooth figured 
here, of the natural size, is taken from a jaw 20 inches wide 
in its transverse diameter (inside measure), each half of the 


SELACHOIDEI. 321 


mandible measuring 22 inches." The whole length of the 
fish was 564 feet. 

Carcharodon teeth are of very common occurrence in 
various tertiary strata, and 
have been referred to several 
species, affording ample evi- 
dence that this type was much 
more numerously represented 
in that geological epoch than 
in the recent fauna. Some 
individuals attaimed to an 
immense size, aS We may 
judge from teeth found in 
the Crag, which are 4 inches 
wide at the base, and 5 inches 
long, measured along their 


lateral margin. The natural- 


: a rie Fig. 114.—Tooth of Carcharodon 
ists of the “Challenger” expe- wandeleui: 


dition have made the highly interesting discovery that teeth 
of similar size are of common occurrence in the ooze of the 
Pacific, between Polynesia and the west coast of America. 
As we have no record of living individuals of that bulk hay- 
ing been observed, the gigantic species to which these teeth 
belonged must have become extinct within a comparatively 
recent period. Nothing is known of the anatomy, habits, 
and reproduction of the surviving species, and no oppor- 
tunity should be lost of obtaining information on this Shark. 

Opontaspis.—The second dorsal and anal are not much smaller 
than the first dorsal. No pit at the root of the caudal. Side of 
the tail without keel. Mouth wide. ‘Teeth large, awl-shaped, 


with one or two small cusps at the base. Gill-openings of mode- 
rate width. 


Large Sharks from tropical and temperate seas; two species. 


1 The cartilaginous jaws of Sharks shrink at least a third in drying, and, 
therefore, cannot be kept at full stretch without tearing. 


Y 


S22 FISHES. 


Atoprctas.—The second dorsal and anal very small. Caudal 
fin of extraordinary length, with a pit at its root. No keel on 
the side of the tail. Mouth and gill-openings of moderate width. 
Teeth equal in both jaws, of moderate size, flat, triangular, not 
serrated. 

This genus consists of one species only, which is known 
by the name of “Fox-shark” or “Thresher.” It is the most 
common of the larger kinds of Sharks which occur on the 
British coasts; and seems to be equally common in other 
parts of the Atlantic and Mediterranean, as well as on the 
coasts of California and New Zealand. It attains to a length 
of fifteen feet, of which the tail takes more than one half; 
and is quite harmless to man. It follows the shoals of Her- 
rings, Pilchards, and Sprats in their migrations, destroying 
incredible numbers. When feeding it uses the long tail in 
splashing the surface of the water, whilst it swims in gradu- 
ally decreasing circles round a shoal of fishes, which are thus 
kept crowded together, falivg an easy prey to their enemy. 
Statements that it has been seen to attack Whales and other 
large Cetaceans, rest upon erroneous observations. 


SeLAcHE.—The second dorsal and anal very small. A pit at 
the root of the caudal fin, which is provided with a lower lobe. 
Side of the tail with a keel. Gull-openings extremely wide. Teeth 
very small, numerous, conical, without serrature or lateral cusps. 


Also this genus consists of one species only, the “ Basking 
Shark” (Pélerin of the French). It is the largest Shark of 
the North Atlantic, growing to a leneth of more than thirty 
feet. It is quite harmless if not attacked ; its food consisting 
of small fishes, and other small marine animals swimming in 
shoals. On the west coast of Ireland it is chased for the sake 
of the oil which is extracted from the liver, one fish yielding 
from a ton to a ton and a-half. Its capture is not unattended 
with danger, as one blow from the enormously strong tail is 
sufficient to stave in the sides of a large boat. At certain 


SELACHOIDEI. ole 


seasons it is gregarious, and many specimens may be seen in 
calm weather lying together motionless, with the upper part 
of the back raised above the surface of the water; a habit 
from which this Shark has derived its name. The buccal and 
branchial cavities are of extraordinary width, and, in conse- 
quence of the flabby condition of those parts, the head pre- 
sents a variable and singular appearance in specimens lying 
dead on the ground, This peculiarity, as well as the circum- 
stance that young specimens have a much longer and more 
pointed snout than adult ones, has led to the erroneous opinion 
that several different genera and species of Basking Shark 
occur in the European seas. The branchial arches of Selache 
are provided with a very broad fringe of long (five to six inches) 
and thin gill-rakers, possessing the same microscopical struc- 
ture as the teeth and dermal productions of Sharks. Similar 
gill-rakers have been found in a fossil state in the Crag of 
Anvers in Belgium, proving the existence of this Selachian 
type in the tertiary epoch. Nothing is known of the repro- 
duction of this fish. The latest contributions to its history 
are by Steenstrup in “Overs. Dansk. Vidensk. Selsk., For- 
handl.” 1873, and by Pavest in “ Annal. Mus. Civ. Genova,” 
1874 and 1878. 


THIRD FAMILY—RHINODONTIDA. 


No nictitating membrane. Anal fin present. Two dorsal 
fins, the first nearly opposite to the ventrals, without spine in 
JSront. Mouth and nostril near the extremity of the snout. 

This small family comprises one species only, Rhinodon 
typicus, a gigantic Shark, which is known to exceed a length 
of fifty feet, but is stated to attain that of seventy. It does 
not appear to be rare in the western parts of the Indian 
Ocean, and possibly occurs also in the Pacific. It is one 
of the most interesting forms, not unlike the Basking Shark 
of the Northern Seas, having gill-rakers like that species ; 


324 FISHES. 


but very little is known of its structure and mode of life. 
It is perfectly harmless, its teeth bemg extremely small and 
numerous, placed in broad bands; it has been stated to feed 


on tang, an observation which requires confirmation. The 


g 
snout 1s very broad, short, and flat; the eyes are very small. 
A pit at the root of the caudal fin which has the lower 
lobe well developed; side of the tail with a keel. A charac- 
teristic figure of this fish has been given by A. Smith in his 
“ Tllustrations of the Zoology of South Africa,” Plate 26, from 


a specimen which came ashore at the Cape of Good Hope. 


FourtH FAMILY—NOTIDANIDA. 


No nietitating membrane. One dorsal fin only, without 
spine, opposite to the anal. 


Fig. 115.—Dentition of Notidanus indicus. a, teeth in function; 0, teeth in 
reserve ; u, upper, and Z, lower, tooth, of natural size. 


SELACHOIDEI, - 325 


Noripanus.—Dentition unequal in the jaws: in the upper 
jaw one or two pairs of awl-shaped teeth, the following six being 
broader, and provided with several cusps, one of which is much 
the strongest. Lower jaw with six large comb-like teeth on each 
side, beside the smaller posterior teeth. Spiracles small, on the 
side of the neck. No pit at the root of the caudal fin.  Gill- 
openings wide, six in number in Hevanchus, seven in Heptan- 
chus. 


Four species are known, distributed over nearly all the 
tropical and sub-tropical seas; they attain to a length of 
about fifteen feet. Fossil teeth belonging to this type have 
been found in jurassic and later formations (Wotidanus and 
Aellopos). 

FirtH FAMILY—ScCYLLUD&. 


Two dorsal fins, without spine: the first above or behind 
the ventrals; anal fin present. No nictitating membrane. 
Spiracle always distinct. Mouth inferior. Teeth small, several 
series generally being in function. 

Scytiium.—The origin of the anal fin is always in advance 
of that of the second dorsal. Nasal cavity separate from the 
mouth. Teeth small, with a middle longer cusp, and generally 
one or two small lateral cusps arranged in numerous series. Eggs 
similar to those of the Rays (Fig. 79, p. 167). 


The fishes of this genus are of small size, and commonly 
called “ Dog-fishes.” They are coast fishes, living on the 
bottom, and feeding on Crustaceans, dead fishes, ete. None 
of the eight species known have a very wide distribution, but 
where they occur they are generally sufficiently abundant to 
prove troublesome to fishermen. They inhabit most parts of 
the temperate and tropical seas. On the British coasts two 
species are found, the “ Larger” and “ Lesser spotted Dog-fish,” 
Scyllium canicula and Seyllium catulus, which are said to be 
more plentiful among the Orkney Islands than elsewhere. 
They are scarcely ever brought to market ; but the fishermen 
of some localities do not disdain to eat them. Their flesh is 


326 FISHES. 


remarkably white, a little fibrous, and dry. In the Orkneys 
they are skinned, split up, cleaned, and then spread out on 
the rocks to dry for home consumption. The skins are used 
for smoothing down cabinet-work. It would be worth while 
to apply the fins of these and other Sharks, which are so 
extensively used in China for making gelatine soups, to the 
same purpose in this country, or to dry them for exportation 
to the East. Most of the species of Dog-fishes are spotted, 
and those of the allied genera, Parascyllium and Chiloscyllium, 
very handsomely ornamented. 

Closely allied to Seyllium is Pristiurus, from the coasts 
of Europe, which is provided with a series of small flat spines 
on each side of the upper edge of the caudal fin. 

Fossil forms of Dog-fishes are not scarce in the Lias and 
Chalk : Scylliodus, Palwoseyllium, Thyellina, Pristiwrus. 


Ginetymostoma.—The second dorsal fin opposite to, and 
somewhat in advance of, the anal. Eyes very small; spiracle 
minute and behind the eye. Nasal and buccal cavities confluent. 
The nasal valves of both sides form one quadrangular flap in 
front of the mouth, each being provided with a free cylindrical 
cirrhus. The fourth and fifth gill-openings are close together. 
The teeth stand either in many series, each having a strong 
median cusp and one or two smaller ones on each side (Gingly- 
mostoma), or they stand in a few (three) series only, the fore- 
most only being in function, and each tooth having a convex, 
finely and equally serrated margin (Nedrius). 

Four species from the tropical parts of the Atlantic and 
Indian Oceans, attaining to a length of some 12 feet. 
Pelagic. 


Srrcostoma.—The first dorsal above the ventrals, the second 
in advance of the anal, which is very close to the caudal. Tail, 
with the caudal fin, exceedingly long, measuring one-half of the 
total length. Eyes very small, spiracle as wide as, and situated 
behind, the orbit. Nasal and buccal cavities confluent. Snout 
very obtuse ; upper lip very thick, like a pad, bent downwards 


SELACHOIDEI. 327 


over the mouth, with a free cylindrical cirrhus on each side. 
Teeth small, trilobed, in many series, occupying in both jaws a 
transverse flat sub-quadrangular patch. The fourth and fifth 
gill-openings are close together. 

The single species (S¢. tigrinum) for which this genus has 
been formed, is one of the commonest and handsomest sharks 
of the Indian Ocean. Young individuals keep generally close 
to the coasts, whilst the adult, which are from 10 to 15 feet 
long, are not rarely met in the open ocean. The colour is a 
brownish yellow, ornamented with black or brown transverse 
bands, or with snuff-coloured rounded spots ; hence this shark 
is frequently mentioned by the names o1 “ Zebra-Shark ” or 
“ Tiger-Shark.” 


CHILOscYLLium.—tLhe first dorsal fin above or behind the ven- 


Fig. 116.—Chiloscyllium trispeculare, from North-western Australia. ; 


trals. Anal fin placed far behind the second dorsal, and very 
close to the caudal. Spiracle very 
distinct, below the eye. Nasal 
and buccal cavities confluent. 
Nasal valve folded, with a cirrhus. 
Teeth small, triangular, with or 
without lateral cusps. The two 
last gill-openings close together. 


“ Dog-fishes,” from the In- 
dian Ocean, of small size. Four 


species are known, of which 
one, Ch, indicum, is one of the Fig. 117.—Confluent nasal and buccal 
commonest shore-fishes on the Covet GE ath > 
coasts of this region, extending from the southern extremity 
of the African Continent to Japan. 


328 FISHES. 


CrossorHinus.—The first dorsal behind the ventrals, the second 
in advance of the anal, which is very close to the caudal. Tail 
rather short. Eyes small. Spiracle a wide oblique slit, behind 
and below the eye. Nasal and buccal cavities confluent. Head 
broad, flat, with the snout very obtuse; mouth wide, nearly 
anterior. <A free nasal cirrhus; sides of the head with skinny 
appendages. Anterior teeth rather large, long and_ slender, 
without lateral lobes, the lateral tricuspid, smaller, forming a few 
series only. The fourth and fifth gill-openings close together. 

Three species are known from the Australian and Japanese 
coasts. They are evidently ground-sharks, which he concealed 
on the bottom watching for their prey. In 


‘ 

i4\ ; e ° . 

aN accordance with this habit their colour closely 
4 assunilates that of a rock or stone covered 


aS 


with short vegetable and coralline growth—a 
resemblance increased by the frond-like ten- 
tacles on the side of the head. This peculi- 


arity of the integuments, which is developed 


in a yet higher degree in Pediculati and 


SSS 


= 


Lophobranchs, is not met with in any other 
Selachian. These Sharks grow to a length of 
10 feet. 


SixtH FAMILY—HYBODONTID. 


Two dorsal fins, each with a serrated spine. 


Teeth rounded, longitudinally striated, with one 


larger, and from two to four smaller lateral 


cusps. Skin covered with shagreen. 


Extinct. From carboniferous, liassic, and 


triassic formations. Several genera have been 


distinguished ; and if Cladodus belongs to this 


family, it would have been represented even 


5 _ in the Devonian. 
Fig. 118.— Spine 
of Hybodus sub- 
carinatus. SEVENTH FAMILY—CESTRACIONTIDA. 


No nictitating membrane. Two dorsal fins, the first 


SELACHOIDEI. 329 


© 


opposite to the space between pectoral and ventral fins ; anal fin 
present. Nasal and buceal cavities confluent. Teeth obtuse, 
several series being im function. 

This family is one of particular interest, because re- 
presentatives of it occur in. 
numerous modifications in 


primary and secondary strata. 


Their dentition is uniformly / / ia 
adapted for the prehension | { 
and mastication of crusta- 
ceous and hard-shelled ani- 
mals. The fossil forms far 


exceeded in size the species L- 
Fig. 119.—Jaws of Port Jackson Shark, 


of the only surviving genus ; ilippi 
Cestracion philippi. 


they make their appearance 
with Ctenoptychius in the Devonian; this is succeeded in 


KK 


Fig. 120.—Upper jaw of the same, half natural size. 


the coal-measures by Psammodus, Chomatodus, Petrodus, Coch- 


330 FISHES. 


liodus, Polyrhizodus, etc.; in the Trias and Chalk by Stroph- 
odus, Acrodus, Thectodus, and Ptycho- 
dus. Of the 25 genera known, 22 have 
lived in the periods preceding the 
Oolitic. 


Crstracion (Heteropontus). — Each 
Fig. 121.—Cochliodus —_ dorsal fin armed with a spine in front ; the 

comp runs. second in advance of the anal. Mouth 
rather narrow. Spiracles small, below the posterior part of the 
eye. Gill-openings rather narrow. Dentition similar in both 
jaws, viz. small obtuse teeth in front, which in young individuals 


Fig. 122.—Cestracion galeatus, Australia. 


are pointed and provided with from three to five cusps. The 
lateral teeth are large, padlike, twice as broad as long, arranged 
in oblique series, one series being formed by much larger teeth 
than those in the other series. 


Four species are known from Japan, Amboyna, Australia, 
the Galapagoes Islands, and California ; none exceed a length 
of 5 feet. The ege has been figured on p. 168 (Fig. 80). 


EIGHTH FAMILY—SPINACIDA. 


No membrana nictitans. Two dorsal fins ; no anal. Mouth 


but slightly arched ; a long, deep, straight, oblique groove on - 


each side of the mouth. Spiracles present ; gill-openings narrow. 
Pectoral fins not notched at their origin. 
The oldest representative of this family (Palawospinax) 


SELACHOIDEI. Sol 


occurs at Lyme Regis; its skin is granular; each dorsal fin 
possesses a spine; the teeth im the jaws are dissimilar—the 
upper being multicuspid, longitudinally ribbed as in Hybodus, 
the lower smooth and tricuspid. Drepanophorus and Spinaz 
primevus occur in Cretaceous formations of England and the 
Lebanon. 


Crntrina.—Each dorsal fin with a strong spine. Trunk rather 
elevated, trihedral, with a fold of the skin running along each 
side of the belly. Teeth of the lower jaw erect, triangular, finely 
serrated ; those of the upper slender, conical, forming a group in 
front of the jaw. Spiracles wide, behind the eye. 

One species, Centrina salviani, from the Mediterranean 
and neighbouring parts of the Atlantic; of small size. 


Acantutas.—Each dorsal fin with a spine. Teeth equal in 
both jaws, rather small; their point is so much turned aside 
that the inner margin of the tooth forms the cutting edge. 
Spiracles rather wide, immediately behind the eye. 

The two species of “Spiny Doe-fishes,” A. vulgaris and 
A. dlainvillii, have a very remarkable distribution, being 
found in the temperate seas of the Northern and Southern 
Hemispheres, but not in the intermediate tropical zone. 
They are of small size, but occur at times in incredible 
numbers, 20,000 having been taken in one sean .on the 
Cornish coast. They do much injury to the fishermen by 
cutting their lines and carrying off their hooks. 


CrentTropHorus.—FEach dorsal fin with a spine which, however, 
is sometimes so small as to be hidden below the skin. Mouth 
wide. Teeth of the lower jaw with the point more or less in- 
clined backwards and outwards. Upper teeth erect, triangular, 
or narrow, lanceolate, with a single cusp. Spiracles wide, behind 
the eye. 

Eight species are known from the southern parts of the 
European seas, and one from the Moluccas; they do not 
appear to exceed a length of five feet. According to the 


302 FISHES. 

observations of E. P. Wright, some of the species at least live 
at a considerable depth, perhaps at a greater depth than any 
of the other known Sharks. The Portuguese fishermen fish 
for them in 400 or 500 fathoms with a line of some 600 
fathoms in length. The Sharks caught were specimens of 
Centrophorus coelolepis, from three to four feet long. “These 
sharks, as they were hauled into the boat, fell down into it 
like so many dead pigs; there was not the smallest motion of 
their bodies. There can be no reasonable doubt that they 
were inhabitants of the same great depth as Hyalonema,” and 
that, in fact, they were killed by being dragged to the surface 
from the pressure of water under which they lived. The 
dermal productions of some of the species have a very peculiar 
form, being leaf-shaped, pedunculate, or ribbed, or provided 
with an impression. 


Sprxax.—Each dorsal fin with a spine. Teeth of the lower 
jaw with the point so much turned aside that the inner margin 
of the tooth forms the cutting edge. Upper teeth erect, each 
with a long-pointed cusp and one or two small ones on each side. 
Spiracles wide, superior, behind the eye. 

Three small species from the Atlantic and the southern 
extremity of America. Centroscyllium is an allied genus 
from the coast of Greenland. 


Scymnus.—Two short dorsal fins without spine, the first at a 
considerable distance from the ventrals. Dermal productions 
uniformly small. Nostrils at the extremity of the snout. Upper 
teeth small, pointed ; lower much larger, dilated, erect, triangular, 
not very numerous. Spiracles wide. 

A single species, S. /ichia, is rather common in the 
Mediterranean and the neighbouring parts of the Atlantic. 


Lamarcus.—All the fins small; two dorsal fins, without 
spine, the first at a considerable distance from the ventrals. 
Skin unifcrmly covered with minute tubercles. Nostrils near 
the extremity of the snout. The upper teeth small, narrow, 


SELACHOIDEI. ooo 


conical ; the lower teeth numerous, in several series, the point 


Fig. 123.—Dentition of the Greenland Shark. Some teeth are represented 
of the natural size; those of the lower jaw in three series, 


so much turned aside that the inner mai gin forms a cutting, non- 
serrated edge. Jaws feeble. Spiracles of moderate width. 

The “Greenland Shark” is an inhabitant of the Arctic 
regions, but rarely straying to the latitudes of great Britain ; 
it grows to a length of about 15 feet, and, although it never 
or but rarely attacks man, is one of the greatest enemies of 
the whale, which is often found with large pieces bitten out 


Fig. 124.—Lemargus borealis, Greenland Shark. 


of the tail by this Shark. Its voracity is so great that, 
according to Scoresby, it is absolutely fearless of the presence 
of man whilst engaged in feeding on the carcase of a whale, 
so that it can be pierced through with a spear or knife with- 
out being driven away. It is stated to be viviparous, and to 
produce about four young at a birth. 


Ecuinoruinus. —Two very small dorsal fins, without spine, 


334 FISHES. 


the first opposite to the ventrals. Skin with scattered large 
round tubercles. Nostrils midway between the mouth and the 
end of the snout. Teeth equal in both jaws, very oblique, the 
point being turned outwards ; several strong denticulations on 
each side of the pringipal point. Spiracles small. 


The “Spinous Shark” is readily recognised by the short 
bulky form of its body, short tail, and large spinous tubercles. 
It is evidently a ground-shark, which probably lives at some 
depth and but accidentally comes to the surface. More 
frequently met with in the Mediterranean, it has been found 
several times on the south coast of England, and near the 
Cape of Good Hope. 

Euprotomicrus and Isistius are two other genera of this 
family ; they are pelagic and but little known. 


NINTH FAMILY—RHINIDA. 


No anal fin ; two dorsal fins. Spiracles present. Pectoral 
Jins large, with the basal portion prolonged forwards, but not 
grown to the head. 

Ruina.—Head and body depressed, flat ; mouth anterior. 
Gill-openings rather wide, lateral, partly covered by the base of 


the pectoral. Spiracles wide, behind the eyes. Teeth conical, 
pointed, distant. Dorsal fins on the tail. 


The “Angel-fish,” or “Monk-fish” (2h. squatina), ap- 
proaches the Rays as regards general form and habits. With- 
in the temperate and tropical zones it is almost cosmopolitan, 
being well known on the coasts of Europe, eastern North 
America, California, Japan, South Australia, etc.; 1t does not 
seem to exceed a length of five feet ; it 1s viviparous, produc- 
ing about twenty young at a birth. 

Extinct forms, closely allied to the “ Angel-fish,” are 
found in the Oolite, and have been described as Thawmas. 
The carboniferous genus, Orthacanthus, may have been allied 
to this family, but it was armed with a spine immediately 
behind the head. 


a 


RAYS. 300 


TENTH FAMILY—PRISTIOPHORID &. 


The rostral cartilage is produced into an exceedingly long, 
flat lamina, armed along each edge with a series of teeth (saw). 


These Sharks resemble so much the°common Saw-fishes 
as to be easily confounded with them, but their gill-openings 
are lateral, and not inferior. They are also much smaller in 
size, and a pair of long tentacles are inserted at the lower 
side of the saw. The four species known (Pristiophorus) occur 
in the Australian and Japanese seas. 

Squaloraja, from the Lias, is supposed to have its nearest 
affinities to this family. 


B. BATOIDEI—RAYS. 


In the typical Rays the body is excessively depressed, 
and forms, with the expanded pectoral fins, a circular or 
sub-rhomboidal disk, of which the slender tail appears as a 
more or less long appendage. In the two families which we 
shall place first (Pristide and Rhinobatide), the general habit 
of the body still resembles that of the Sharks, but the gill-open- 
ings are ventral, asin the true Rays; the anal fin is invariably 
absent, and the dorsal fins, if developed, are placed on the 
tail. The mode of life of those fishes is quite in accordance 
with the form of their body. Whilst the species with a 
shark-like body and muscular tail swim freely through the 
water, and are capable of executing rapid and sustained 
motions, the true Rays lead a sedentary life, moving slowly 
on the bottom, rarely ascending to the surface. Their tail 
has almost entirely lost the function of an organ of locomo- 
tion, acting in some merely as arudder. They progress solely 
by means of the pectoral fins, the broad and thin margins of 
which are set in an undulating motion, entirely identical 
with that of the dorsal and anal fins of the Plewronectide. 
They are exclusively carnivorous, ike the Sharks, but unable 


336 FISHES. 


to pursue and catch rapidly-moving animals; therefore they 
feed chiefly on molluscous and crustaceous animals. How- 
ever, the colour of their integuments assimilates so closely 
that of their surroundings, that other fishes approach them 
near enough to be captured by them. The mouth of Rays 
being entirely at the lower surface of the head, the prey is 
not directly seized with the jaws; but the fish darts over its 
victim so as to cover and hold it down with its body, when it 
is conveyed by some rapid motions to the mouth. 

Rays do not descend to the same depth as Sharks ; with one 
exception,’ at least,none have been known to have been caught 
by a dredge worked in more than 100 fathoms. The majority 
are coast fishes, and have a comparatively limited geographical 
range, none extending from the northern temperate zone into 
the southern. However, some, if not all the species of the 
family Myliobatide, which includes the giants of this division 
of Plagiostomes, have a claim of being included among the 
Pelagic fishes, as they are frequently met with in the open 
ocean at a great distance from the shore. It is probable 
that the occurrence of such individuals in the open sea indi- 
cates the neighbourhood of some bank or other comparatively 
shallow locality. Many species are exclusively confined to 
fresh water, and occur far inland, especially in tropical 
America. 

The majority are oviparous. All have five pairs of gill- 
openings. The number of known species is about the same 
as that of Sharks, viz. 140. 


First FAMILY—PRISTIDZ. 


The snout ts produced into an exceedingly long flat lamina, 
armed with a series of strong teeth along each edge (saw). 


1 This exception is a Ray obtained during the ‘ Challenger” expedition, 
and said to have been dredged in 565 fathoms. 


RAYS. 337 


Pristis.—Body depressed and elongate, gradually passing into 
the strong and muscular tail. Pectoral fins, with the front 
margins quite free, not extending to the head. No tentacles 
below the saw. Teeth in the jaws minute, obtuse. Dorsal fins 
without spine, the first opposite or close to the base of the 
ventrals, 


“Saw-fishes.” Abundant in tropical, less so in sub-tropi- 
cal seas. They attain to a considerable size, specimens with 
a saw 6 feet long and 1 foot broad at the base not being of 
uncommon occurrence. The saw, which is their weapon of 
attack, renders them most dangerous to almost all the other 
large inhabitants of the ocean. Its endo-skeleton consists 
of three, sometimes five, rarely four, hollow cylindrical tubes, 
placed side by side, tapermg towards the end, and incrusted 
with an osseous deposit. These tubes are the rostral processes 
of the cranial cartilage, and exist in all Rays, though in them 
they are shorter and much less developed. The teeth of the 
saw are implanted in deep sockets of the hardened integu- 
ment. The teeth proper, with which the jaws are armed, are 
much too small for inflicting wounds or seizing other animals. 
Saw-fishes use this weapon in tearing pieces of flesh off an 
animal’s body or ripping open its abdomen. The detached 
fragments or protruding soft parts are then seized by them 
and swallowed. Five distinct species of Saw-fishes are known. 

Saws of extinct species have been found in the London 
clay of Sheppey and in the Bagshot sands. 


SECOND FAMILY—RHINOBATID. 


Tail strong and long, with two well-developed dorsal fins, 
and a longitudinal fold on each side ; caudal developed. Disk 
not excessively dilated, the rayed portion of the pectoral fins 
not being continued to the snout. 


RHYNCHOBATUS.— Dorsal fins without spine, the first opposite 
to the ventrals. Caudal fin with the lower lobe well developed. 
Z 


338 FISHES. 


Teeth obtuse, granular, the dental surfaces of the jaws being 
undulated. 


Fig. 125.—Dentition of Rhynchobatus. 


Two species, Li. ancylostomus and Rh. djeddensis, are very 
common on the tropical coasts of the Indian Ocean. They 
feed on hard-shelled animals, and attain scarcely a length of 
8 feet. 


RHINOBATUS.—Cranial cartilage produced into a long rostral 
process, the space between the process and pectoral fin being 
filled by a membrane. Teeth obtuse, with an indistinct trans- 
verse ridge. Dorsal fins without spine, both at a great distance 
behind the ventral fins. Caudal fin without lower lobe. 

Numerous on the coasts of tropical and sub-tropical seas ; 
about twelve species. Zrygonorhina is an allied genus from 
South Australia. 

The oolitic genus Spathobatis is scarcely distinct from 
Rhinobatus ; and another fossil from Mount Lebanon has 
been actually referred to this latter genus. Zrigorhina from 
Monte Postale must be placed here. 


THIRD FAMILY—TORPEDINID®. 


The trunk is a broad, smooth disk. Tail with a longitudi- 
nal fold on each side; a rayed dorsal fin is generally, and a 


RAYS. 339 


caudal always, present. Anterior nasal valves confluent into a 
quadrangular lobe. An electric organ composed of vertical 
hexagonal prisms between the pectoral fins and the head. 
“Electric Rays.” The electric organs with which these 
fishes are armed are large, flat, uniform bodies, lying one on 
each side of the head, bounded behind by the scapular arch, and 
laterally by the anterior crescentic tips of the pectoral fins. 
They consist of an assemblage of vertical hexagonal prisms, 
whose ends are in contact with the integuments above and 
below; and each prism is subdivided by delicate transverse 
septa, forming cells, filled with a clear, trembling, jelly-like 
fluid, and lined within by an epithelium of nucleated cor- 
puscles. Between this epithelium and the transverse septa 
and walls of the prism there is a layer of tissue on which the 
terminations of the nerves and vessels ramify. Hunter 
counted 470 prisms in each battery of Torpedo marmorata, 
and demonstrated the enormous supply of nervous matter 
which they receive. Each organ receives one branch of the 
Trigeminal nerve and four branches of the Vagus, the former, 
and the three anterior branches of the latter, being each as 
thick as the spinal chord (electric lobes). The fish gives the 
electric shock voluntarily, when it is excited to do so in self- 
defence or intends to stun or to kill its prey; but to receive 
the shock the object must complete the galvanic circuit by 
communicating with the fish at two distinct points, either 
directly or through the medium of some conducting body. 
If an insulated frog’s leg touches the fish by the end of the 
nerve only, no muscular contractions ensue on the discharge 
of the battery, but a second point of contact immediately 
produces them. It is said that a painful sensation may be 
produced by a discharge conveyed through the medium of a 
stream of water. The electric currents created in these fishes 
exercise all the other known powers of electricity: they 
render the needle magnetic, decompose chemical compounds, 


340 FISHES. 


and emit the spark. The dorsal surface of the electric organ 
is positive, the ventral surface negative. 


[The literature on the electric organ of Torpedo is very extensive. 
Here may be mentioned Lorenzini, ‘‘Osservazioni intorno alle 
Torpedini (1678) ; Walsh, ‘‘On the Electric Property of the Tor- 
pedo,” in Philos. Trans., 1773 ; Hunter, ‘‘ Anatomical Observa- 
tions on the Torpedo,” ibid.; Davy, ‘‘ Observations on the 
Torpedo,” in Philos. Trans., 1834 ; Matteucci and Savi, ‘ Traité 
des Phénomeénes Electro-Physiologiques,” 1844.] 


Of the genus Zorpedo six species are known, distributed 
over the Atlantic and Indian Oceans; three of them are rather 
common in the Mediterranean, and one (7" hebetans) reaches 
the south coast of England. They attain to a width of from 
two to three feet, and specimens of that size are able to dis- 
able by a single discharge a full-grown man, and, therefore, 
may prove dangerous to bathing persons. Other genera, 
differing from Yorpedo in the position and structure of some 
of the fins, ate found in other tropical and sub-tropical seas, 
viz. Narcine, Hypnos, Discopyge (Peru), Astrape, and Temera. 
All, like electric fishes generally, have a naked body. 

A large fish, of the general appearance of a Torpedo, has 
been found at Monte Bolca; and Cyclobatis, from the upper 
cretaceous limestone of Lebanon, is probably another extinct 
representative of this family. 


FourtTH FAMILY—RAJIDA. 


Disk broad, rhombic, generally with asperities or spines ; 
tal with a longitudinal fold on each side. The pectoral fins 
extend to the snout. No electric organ; no serrated caudal 
spine. 

RasA.—Two dorsal fins on the tail, without spine ; tail with 
a rudimentary caudal fin, or without caudal. Each ventral fin 
divided into two by a deep notch. Teeth small, obtuse, or 
pointed, Pectoral fins not extending forwards to the extremity 
of the snout. Nasal valves separated in the middle, where they 
are without a free margin (see Fig. J, p. 34). 


RAYS. 341 


Of all the genera of Batoidei, Rays have the widest 
geographical range ; they are chiefly inhabitants of temperate 


Fig. 126.—Raja lemprieri, from Tasmania. 


seas, and much more numerous in those of the Northern than 
of the Southern Hemisphere. They advance more closely to 
the Arctic and Antarctic circles than any other member of 
this group. More than thirty species are 
known, of which the following are found on 
the British coast:—The Thornback (A. ela-  , 
vata), the Homelyn Ray (R. maculata), the < 
Starry Ray (&. radiata), the Sandy Ray (2. 
circularis), the common Skate (A. batis), the 
Burton Skate (2. marginata), and the Shagreen Le 


Skate (R. fullonica). Some of these species, “22” 
Fig. 127.—Dermal 

spines of a male 
the disk measuring six and even seven feet Thomback, Raja 


across. All are eatable, and some of them °!@vata. 


especially the Skates, attain a considerable size, 


regularly brought to market. In the majority of the species 
peculiar sexual differences have been observed. In some, 
as in the Thornback, all or some of the teeth are pointed in 
the male sex, whilst they are obtuse and flat in the female. 
The males of all are armed with patches of claw-like spines, 
retractile in grooves of the integument, and serially arranged 
occupying a space on the upper side of the pectoral fin 


342 FISHES. 


near the angle of the disk, and frequently also the sides 
of the head. In species which are armed with bucklers or 
asperities it 1s the female which is principally provided with 
these dermal productions, the male being entirely or nearly 
smooth. Also the colour is frequently different in the two sexes. 

Other genera of this family are Psammobatis, Syinpterygia, 
and Platyrhina. Although probably this family was well re- 
presented in cretaceous and tertiary formations, the remains 
found hitherto are comparatively few. Arthropterus, from the 
Lias, seems to have been a true Ray; and dermal spines of a 
species allied to the Thornback (Raja antiqua) are abundant 
in the crag deposits of Suffolk and Norfolk. 


FirtH FAMILY—TRYGONIDA. 


The pectoral fins are uninterruptedly continued to, and con- 
fluent at, the extremity of the snout. Tail long and slender, 
without lateral longitudinal folds ; vertical fins none, or im- 
perfectly developed, often replaced by a strong serrated spine. 

The “Sting-Rays” are as numerous as the Rays proper, 
but they inhabit rather tropical than temperate seas. The 
species armed with a spine use it as a weapon of defence, 
and the wounds inflicted by it are, to man, extremely painful, 
and have frequently occasioned the loss of a limb. We have 
mentioned above (p. 190) that the danger arises from the 
lacerated nature of the wound as well as from the poisonous 
property of the mucus inoculated. The spines (Fig. 98, p. 
190) are always barbed on the sides, and may be eight or nine 
inches long in the larger species. They are shed from time 
to time, and replaced by others growing behind the one in 
function, as the teeth of the fishes of this order, or as the 
fangs of a poisonous snake. Fossil species of Zrygon and 
Urolophus occur in the tertiary strata of Monte Bolea and 
Monte Postale. The genera into which the various species 
have been divided are the following :— 


RAYS. ote 


UroGymNnus.—Tail long, without fin or spine, sometimes with 
a narrow cutaneous fold below. Body densely covered with 
osseous tubercles. Teeth flattened. 


Only one species is known (U. asperrinvus), common in 
the Indian Ocean, and with a body from 4 to 5 feet long; 
the skin is frequently used for covering shields and the handles 
of swords and other weapons, its rough surface offering a 
firm hold to the hand. 

TryGON.—Tail very long, tapering, armed with a long arrow- 


shaped barbed spine. Body smooth or with tubercles. Nasal 
valves coalescent into a quadrangular flap. Teeth flattened. 


Some twenty-five species are known, one of which (Z. 
pastinaca) extends from the south coast of England and the 
east coast of North America through the Atlantic and Indian 
Ocean to Japan. The majority of the species belong to the 
tropical parts of the Indian and Atlantic Oceans; some 
inhabit exclusively fresh-waters of eastern tropical America. 
A closely allied genus is Zweniwra, with six species. 


UroLopuus.—Tail of moderate length, with a distinct rayed 


Fig. 128.—Urolophus cruciatus, from Australia. 


terminal fin, armed with a barbed spine, without or with a 
rudimentary dorsal fin. Teeth flattened. 


Seven species from tropical seas, apparently of small size. 


344 FISHES. 


PTEROPLATEA.—Body at least twice as broad as long; tail very 
short and thin, without or with a rudimentary fin, and with a 
serrated spine. Teeth very small, uni- or tri-cuspid. 

Six species from temperate and tropical seas. 


SIXTH FAMILY—MYLIOBATID. 

The disk is very broad, in consequence of the great develop- 
ment of the pectoral fins, which, however, leave the sides of the 
head free, and reappear at the extremity of the snout as a 
pair of detached (cephalic) fins. Viviparous. 

“ Devil-fishes,” “Sea-devils,” or “ Eagle-rays.” Generally 
of large size, inhabiting temperate and tropical seas. Some 
genera possess a pair of singular cephalic processes, which 
generally project in a direction parallel to the longitudinal axis 
of the body, but are said to be flexible in the living fish, and 
used for scooping food from the bottom and conveying it to the 
mouth. In all the species the dentition consists of perfectly 
flat molars, forming a kind of mosaic pavement in both the 
upper and lower jaws: a most perfect mechanical arrange- 
ment for crushing alimentary substances. 


MYLIopaAtis.—Teeth sexangular, large, flat, tessellated, those 
in the middle much broader than long ; several narrower series on 


Fig. 129.—Jaws of an Eagle-Ray, Myliobatis aquila. 


RAYS. 345 


each side. Tail very long and thin, with a dorsal fin near its 
root ; generally a serrated spine behind the fin. 


Seven species are known, two of which are European, one 
(M. aquila) being almost cosmopolitan, and occasionally 
found on the British coast. The young differ much from 
the adult, having no median series of larger teeth, but all the 
teeth of equal size and regularly sexangular. Also the tail is 
much longer in young examples than in old ones, and the 
coloration more ornamental. Teeth of species very closely 
allied to, or perhaps even identical with, existing species, are 
found in tertiary formations. 


A&ETOBATIS.—Form of the head, body, and tail as in Myliobatis. 
The nasal valves remain separate, each forming a long flap. The 
lower dental lamina projects beyond the upper. Teeth flat, 
broad, forming a single series, equivalent to the median series of 
Myliobatis, there being no small lateral teeth. 


Fig. 130.—Aétobatis narinari. 


One species only (4. narinari) which is found in almost 


346 FISHES. 


all tropical seas, and of exceedingly common occurrence in 
the Atlantic and Indian Oceans; it 
does not seem to grow to a very large 
size (perhaps not exceeding 5 feet in 
width), and is readily recognised by 
numerous round bluish-white spots, 
with which the back is ornamented. 
Fossils of this genus occur in the 


Fic, 131.—Aétobatis subar- English Eocenes and the Swiss Molasse. 


cuatus, from Bracklesham. , 
RHINOPTERA.—The cephalic appen- 


dages are bent inwards, and situated at the lower side of the snout. 
Nasal valves confluent into a broad flap, with free margin. Teeth 
broad, flat, tessellated, in five or more series, the middle being the 
broadest, and the others decreasing in width outwards. Tail 
very slender, with a dorsal fin before the serrated spine. 


Seven species from tropical and sub-tropical seas are 


known; of Rhinoptera (os, Upper Jaw. 
polyodon nothingisknown [_ <= 
except the jaws; and 
as its dentition is very 
pecuhar, no  opportu- 


nity should be lost of Gon 
obtaining and preserving Fironk. 
entire animals. Teeth ae 


very similar to those of 
existing species, and de- 
scribed as Zygobatis, oc- 


: : Lower Jaw. 
Fig. 132. —Rhinoptera 


woodwardi ; fossil. Fig. 133.—Rhinoptera polyodon. 


9 


RAYS. 347 


cur in the Norwich Crag and in Miocene formations of 
Switzerland. 


DICEROBATIS (CEPHALOPTERA).—Cephalic appendages point- 
ing straight forwards or inwards. Nostrils widely separated from 
each other. Mouth inferior, wide. Both jaws with very nume- 
rous and very small flat or tubercular teeth. Tail very slender, 
with a dorsal fin between the ventrals, and with or without a 
serrated spine. 

CERATOPTERA.—Cephalic appendages pointing forwards or in- 
wards. Mouth anterior; wide. Teeth in the lower jaw only, 
very small. Tail very slender, with a dorsal fin between the 
ventrals and without spine. 

The species of these two last genera are not yet well dis- 


tinguished; about five of Dicerobatis and two of Ceratoptera 


Fig. 154.—Dicerobatis draco, from Misol. 


are known from tropical and temperate seas, but their occur- 
rence in the latter is rather sporadic. Some of them, if not 
all, attain an enormous size. One mentioned by Risso, taken 
off Messina, weighed 1250 pounds. Several observers speak 
of having seen them in pairs, the male being usually the 
smaller. Of a pair mentioned by Risso the female was first 
taken, and the male remained hovering about the boat for 


348 FISHES. 


three days, and was afterwards found floating dead on the 
surface. Still larger individuals, but of uncertain species, 
are mentioned by Lacépede, who says that one taken at Bar- 
badoes required seven yoke of oxen to draw it. A sketch of 
another, which was said to be twenty feet long, was sent to 
Lacépéde ; and Sonnini speaks of one which appeared to him 
to be longer and wider than the ship in which he was sailing. 
A feetus taken from the uterus of the mother captured at 
Jamaica, and preserved in the British Museum, is five feet 
broad, and weighed twenty pounds. The mother measured 
fifteen feet in width as well as in length, and was between 
three and four feet thick. The capture of “ Devil-fishes” of 
such large size is attended with danger, as they not rarely 
attack and capsize the boat. They are said to be especially 
dangerous when they accompany their young, of which they 
bring forth one only at a time. 


SECOND SUB-ORDER—HOLOCEPHALA. 


One external gill-opening only, covered by a fold of the skin, 
which encloses a rudimentary cartilaginous gill-cover ; four 
branchial clefts within the gill-cavity. The maxillary and 
palatal apparatus coalescent with the skull. 


This sub-order is represented in the living fauna by one 
family only, Chimeride ; it forms a passage to the following 
order of fishes, the Ganoids. In external appearance, and 
with regard to the structure of their organs of propagation, 
the Chimeras are Sharks (See Fig. 96, p. 184). The males 
are provided with “claspers” in connection with the ventral 
fins, and the ova are large, encased in a horny capsule, and 
few in number; and there is no doubt that they are impreg- 
nated within the oviduct, as in Sharks. Chimeras are naked, 
but, as in Seylliide, very young individuals possess a series of 


HOLOCEPHALA. 349 


small “placoid” spines, which occupy the median line of the 
back, and remind us of similar dermal productions in the 
Rays. The males, besides, are provided with a singular erectile 
appendage, spiny at its extremity, and received in a groove 
on the top of the head. On the other hand, the relations of 
the Chimeras to the Ganoid, and, more especially, Dipnoous 
type become manifest in their notochordal skeleton and con- 
tinuity of cranial cartilage. The spine in front of the first 
dorsal fin is articulated to the neural apophysis, and not merely 
implanted in the soft parts, and immovable as in Sharks. A 
cartilaginous operculum makes its appearance, and the 
external gill-opening is single. The dentition is that of a 
Dipnoid, each “jaw” being armed with a pair of broad dental 
plates, with the addition of a pair of smaller cutting teeth in 
the upper “jaw.” Fossils of similar dental combination are not 
rare in strata, commencing from the Lias and the bottom of 
the Oolitic series ; but it is impossible to decide in every case 
whether the fossil should be referred to the Holocephalous or 
Dipnoous type. According to Newberry, Chimeroid fishes 
commence in the Devonian with Rhynchodus, the remains 
of which were discovered by him in Devonian rocks of Ohio. 
Undoubted Chimeeroids are Hlasmodus, Psaliodus, Ganodus, 
Ischyodus, Edaphodon, and Hlasmognathus, principally from 
mesozoic and tertiary formations. Very similar fossils occur 
in the corresponding strata of North America. A single 
species of Callorhynchus has been discovered by H. Hector 
in the Lower Greensand of New Zealand. 

The living Chimeras are few in number, and remain 
within very moderate dimensions, probably not exceeding a 
length of five feet, inclusive of their lone filamentous, diphy- 
cercal tail. They are referred to two genera. 

CHIMZRA.—Snout soft, prominent, without appendage. The 


dorsal fins occupying the greater part of the back, anterior with 
a very strong and long spine. Longitudinal axis of the tail nearly 


350 FISHES. 


the same as that of the trunk, its extremity being provided with 
a low fin above and below, similar in form to a dorsal and anal 
fin. Anal fin very low. 

Three species are known: Ch. monstrosa, from the coasts 
of Europe and Japan and the Cape of Good Hope; Ch. colliet 
from the west coast of North America; and Ch. affinis from 
the coast of Portugal. (See Fig. 96, p. 184.) 

CALLORHYNCHUS.—Snout with a cartilaginous prominence, 
terminating in a cutaneous flap. Two dorsal fins, the anterior with 
a very strong and long spine. Extremity of the tail distinctly 
turned upwards, with a fin along its lower edge, but without one 
above. Anal fin close to the caudal, short and deep. 

One species (C. antarcticus) is common in the Southern 
temperate zone. Cunningham describes the egg (see Fig. 81, 
p- 169), as being of a dark greenish-black colour, and, in 
general, measuring from eight to nine or even ten inches in 
length, by about three in breadth. It consists of a central, 
somewhat spindle-shaped convex area (between the horny 
» fish lies), surrounded by a broad 


walls of which the young 
plicated margin, which is fringed at the edge, and covered on 


the under surface with fine light brownish-yellow hairs. 


SECOND ORDER—GANOIDEI. 


Skeleton cartilaginous or ossified. Body with medial and 
paired fins, the hinder pair abdominal. Gills free, rarely 
partially attached to the walls of the gill-cavity. One external 
gill-opening only on each side; a gill-cover. Arr-bladder with 
a pneumatic duct. Ova small, impregnated after exclusion. 
Embryo sometimes with external gulls. 


To this order belong the majority of the fossil fish re- 
mains of paleozoic and mesozoic age, whilst it is very 
scantily represented in the recent fauna, and evidently verging 
towards total extinction. The knowledge of the fossil forms, 
based on mere fragments of the hard parts of the body only, 


eee.” 


GANOIDEI. oo 


is very incomplete, and therefore their classification is in a 
most unsatisfactory state. In the following pages only the 
most important groups will be mentioned. 


[For a study of details we have to refer to Agassiz, “ Poissons Fossiles :” 


Owen, “ Paleontology,” Edinb. 1861, 8vo ; Hualey, ‘‘ Preliminary 
Essay upon the Systematic Arrangement of the Fishes of the 
Devonian Epoch,” in Mem. Geolog. Survey, Dec. 10 ; Lond. 1861, 
and ‘‘ Illustrations of the Structure of Crossopterygian Ganoids,” 
ibid. December 12, 1866 ; Traquair, ‘‘ The Ganoids of the British 
Carboniferous Formations,” part I. ‘‘ Paleoniscide.” Palontogr. 
Soc. Lond. 1877.] 


Eight sub-orders may be distinguished at present. 


FIRST SUB-ORDER—PLACODERMI. 


Extinct. The head and pectoral region of the body encased 
in great bony, sculptured plates, with dots of enamel ; the re- 
mainder of the body naked, or with ganoid scales ; skeleton 
notochordal. 


Comprises the oldest vertebrate remains, from Devonian 
and Carboniferous formations. Pterichthys: (Figs. 135 and 
136), tail tapering, covered with small ganoid scales, without 
caudal fin; the cephalic shield was probably moveably joined 
to the cuirass of the trunk, and both were composed of several 
pieces; the abdominal shield consisted of one single median 
plate, and two pairs of lateral plates, a third small pair being 
sometimes observed detached in front of the anterior pair; 
pectoral exceedingly long, consisting of two pieces movably 
connected with each other; tail scaly, and short; a small 
dorsal fin placed on the tail; a pair of small ventrals; 
jaws small, with confluent denticles. Several species have 
been distinguished in remains found in the strata of Caith- 
ness and other localities in Scotland.  Coccosteus (Fig. 137, 
p. 354): all the bony plates are firmly united, no pectoral 


spines ; tail naked and long; 


g; a dorsal and anal fin sup- 


ported by interneural and interhemal spines. Dentition 


352 FISHES. 


unknown. Dinichthys: a gigantic fish from the Devonian 
of North America (estimated at from 15 to 18 feet in length), 


Fig. 135.—Dorsal surface of Pterichthys, after Pander. d, Dorsal fin; ¢, 
pectoral member ; 2-10, head-bucklers ; 11-13, dorsal bucklers. 


with the dermal covering very similar to that of Cocco- 


y 
Hi 


GANOIDEI. 353 


steus, but with a simple arched dorsal shield. As in this 
latter genus the caudal extremity does not possess external 
or internal bony parts, and the ventral plastron of both 
genera corresponds in every particular; the dentition is so 


Fig. 136.—Ventral aspect of Pterichthys, after Pander. 15, mandible (?) ; 
16-21, ventral bucklers. 


singularly like that of Lepidosiren, that Newberry (Geolog. 

Survey of Ohio, vol. ii. part 2) considers this genus to be in 

genetic relation to the Dipnoi. The following genera have 

been united in a separate family, Cephalaspide ; viz. Cephal- 
2A 


354 FISHES. 


aspis: head covered by a continuous shield with tubercular 
surface, produced into a 
horn at each posterior 
corner; a median dorsal 
backward prolongation 
bears a spine; _hetero- 
cereal. Auchenaspis and 
Didymaspis: allied to the 
preceding, but with the 
cephalic shield divided 
into a larger anterior and 
smaller posterior piece. 
Pteraspis: with the ceph- 
alic shield finely striated 
or grooved, composed of 
seven pieces. Scaphaspis 
and Cyathaspis: with the 
surface of the head-shield 


D, Dorsal fin; C, Heterocercal tail ; ¢, notochord ; 


. 
’ 


similarly sculptured as in 
Pteraspis, but simple in 
the former, and composed 


A, Anal fin 


of four pieces in the latter. 


m, neurals; h, hemals; 6-24, bucklers. 


Astrolepis: attained to the 
gigantic size of between 
twenty and thirty feet ; 
its mouth was furnished 
with two rows of teeth, 
of which the outer ones 
were small, the inner 


Fig. 187.—Coccosteus, after Pander. 


\ much larger. 

¢ [See Ray Lankester, <A. 

\ Monograph of the Fishes 
a \ of the Old Red Sandstone 
Z N of Britain. Part I. Ceph- 
y \ alaspide. Lond. 1868 
e N& and 1870. 4to.] 

: Ay 


ps 


———- 


GANOIDEI. 355 


SECOND SUB-ORDER—ACANTHODINI. 


Extinct. Body oblong, compressed, covered with shagreen ; 
skull not ossified ; caudal heterocercal. Large spines, similar 
to those of Chondropterygians, in front of some of the median 
and paired fins. The spines are imbedded between the muscles, 
and not provided with a proximal joint. 

Acanthodes, Chiracanthus, from Devonian and Carbonifer- 
ous formations. 


THIRD SUB-ORDER—DIPNOI. 


Nostrils two pairs, more or less within the mouth ; limbs 
with an axial skeleton. Lungs and gills. Skeleton noto- 
chordal. No branchiostegals." 


First FAMILY—SIRENIDA. 


Caudal fin diphycercal ; no gular plates ; scales cycloid. A 
pair of molars, above and below, and one pair of vomerine teeth. 


LeprposirEN.—Body eel-shaped, with one continuous vertical 
fin. Limbs reduced to cylindrical filaments, without fringe. 
Vomerine teeth conical, pointed. Each dental lamina or molar 
with strong cusps, supported by vertical ridges. No external 
branchial appendages ; five branchial arches, with four interven- 
ing clefts. Conus arteriosus with two longitudinal valves. 
Ovaries closed sacs. 


One species only is known from the system of the River 
Amazons (LZ. paradoza). It must be very locally distributed, 
as but a few specimens have been brought to Europe, and all 
recent endeavours to obtain others have been unsuccessful. 
Natterer, by whom this most interesting fish was discovered, 
states that he obtained two specimens, one on the Madeira 
River, near Borba; the other in a backwater of the Amazons, 
above Villa Nova. The natives of the former place called it 
Caramuru, and considered it very scarce. The larger indivi- 


' See pp. 73 and 74, Figs. 35 and 36, 


356 FISHES. 


dual was nearly four feet long. It is said to produce a sound 
not unlike that of a cat, and to feed on the roots of mandioca 
and other vegetables. But, to judge from the dentition, this 
fish is much more likely to be carnivorous, like the following. 
It is one of the greatest desiderata of Natural History Col- 
lections. 


[Natterer, ‘“Annalen des Wiener Museum’s,” 1839, ii. ; Bischoff. “ Annales 
des Sciences Naturelles,” 1840. xiv. ]} 
_Protoprerus.—Very similar in the general form of the body 
and dentition to Lepidosiren. Pectoral and ventral filaments with 
a fringe containing rays. Three small branchial appendages above 
the small gill-opening ; six branchial arches, with five intervening 
clefts. Conus arteriosus with two longitudinal valves. Ovaries 
closed sacs. 
Protopterus annectens is the “ Lepidosiren” which is com- 
monly found in Zoological collections, It is usually imported 


Wider a se 
(eg Sealey A 
CU 


peti 


Fig. 138.—Protopterus annectens. g, Branchial filaments ; 7, vent. 


from the west coast of Africa, where it abounds in many 
localities; but it is spread over the whole of tropical Africa, 
and forms in many districts of the central parts a regular 
article of food. 

During the dry season, specimens living in shallow 
waters which periodically dry up, form a cavity in the mud, 
the inside of which they line with a protecting capsule of 
mucus, and from which they emerge again when the rains 
refill the pools inhabited by them. Whilst they remain in 
this torpid state of existence, the clay-balls containing them 
are frequently dug out, and if the capsules are not broken, 
the fishes imbedded in them can be transported to Europe, 


GANOIDEI. 357 


and released by being immersed in slightly tepid water. 
Protopterus is exclusively carnivorous, feeding on water- 
insects, frogs, and fishes, and attains a length of six feet. 


[Owen, “ Trans. Linn. Soc.” 1841, xviii. ] 


Crratopus.—Body elongate, compressed, with one continuous 
vertical fin. Limbs paddle-shaped, with broad, rayed fringe. 
Vomerine teeth incisor-like ; molars with flat, undulated surface, 
and lateral prongs. No external branchial appendages. Conus 
arteriosus with transverse series of valves. Ovaries transversely 
lamellated.1 


Fig. 139.—Ceratodus miolepis. 


Two species, C. forsteri and C. miolepis, are known from 
fresh waters of Queensland. The specimens hitherto obtained 
have come from the Burnett, Dawson, and Mary rivers, some 
from the fresh waters of the upper parts, others from the lower 
brackish portions. The fish is said to attain to a weight of 
twenty pounds and to a length of 6 feet. Locally, the settlers 
call it “Flat-head,” “Burnett- or Dawson-Salmon,” and the 
aborigines “ Barramunda,” a name which they appear to apply 
also to other large-scaled freshwater fishes, as the Osteoglos- 
sum leichardti. In the stomach there is generally found an 
enormous quantity of the leaves of plants growing on the 
banks of rivers, evidently eaten after they had fallen into 
the water and when in a decomposing condition. The flesh 
of the fish is salmon-coloured, and much esteemed as food. 

The Barramunda is said to be in the habit of going on 
land, or at least on mud-flats; and this assertion appears to 

' For other illustrations see p. 73, Fig. 35 (palatal view of head) ; p. 74, 


Fig. 36 (pectoral skeleton); p. 141, Fig. 60 (gills) ; p. 148, Fig. 65 (lung) ; 
p. 151, Fig. 67 (heart) ; p. 134, Fig. 57 (intestine) ; p. 165, Fig. 77 (ovary). 


358 FISHES. 


be borne out by the fact that it is provided with a lung. 
However, it is much more probable that it rises now and 
then to the surface of the water in order to fill its lung with 
air, and then descends again until the air is so much deoxy- 
genised as to render a renewal of it necessary. It is also 
said to make a grunting noise, which may be heard at night 
for some distance. This noise is probably produced by the 
passage of the air through the cesophagus when it is expelled 
for the purpose of renewal. As the Barramunda has per- 


fectly developed gills, beside the lung, we can hardly doubt - 


that, when it is in water of normal composition, and suffi- 
ciently pure to yield the necessary supply of oxygen, these 
organs are sufficient for the purpose of breathing, and that 
the respiratory function rests with them alone. But when 
the fish is compelled to sojourn in thick muddy water 
charged with gases, which are the products of decomposing 
organic matter (and this must be the case very frequently 
during the droughts which annually exhaust the creeks of 
tropical Australia), it commences to breathe air with its lung 
in the way indicated above. If the medium in which it 
happens to be is perfectly unfit for breathing the gills cease 
to have any function; if only in a less degree the gills may 
still continue to assist in respiration. The Barramunda, in 
fact, can breathe by either gills or lungs alone, or by both 
simultaneously. It is not probable that it lives freely out of 
the water, its limbs being much too flexible for supporting 
the heavy and unwieldy body, and too feeble generally to be 
of much use in locomotion on land. However, it is quite 
possible that it is occasionally compelled to leave the water, 
although we cannot believe that it can exist without it ina 
lively condition for any length of time. 

Of its propagation or development we know nothing, 
except that it deposits a great number of eggs of the size of 
those of a newt, and enveloped in a gelatinous case. We 


citi 


GANOIDEI, 359 


may infer that the young are provided with external gills, as 
in Protopterus and Polypterus. 

The discovery of Ceratodus does not date farther back 
than the year 1870, and proved to be of the greatest interest, 
not only on account of the relation of this creature to the other 


Fig. 140.—Tooth of fossil Ceratodus from Aust, near Bristol, natural size. 


living Dipnoi and Ganoidei, but also because it threw fresh 
light on those singular fossil teeth which are found in strata 
of Triassic and Jurassic formations in various parts of Europe, 
India, and America. These teeth, of which there is a great 
variety with regard to general shape and size, are sometimes 
two inches long, much longer than broad, depressed, with 
a flat or slightly undulated, always punctated crown, with 
one margin convex, and with from three to seven prongs pro- 
jecting on the opposite margin. 


SECOND FAMILY—CTENODODIPTERID. 


Caudal fin heterocercal. Gular plates. Scales cycloid. Two 
pairs of molars and one parr of vomerine teeth. 


Fig. 141.—Dipterus macrolepidotus. 


Extinct. Dipterus(Ctenodus), Heliodus from Devonian strata. 


360 FISHES. 


THIRD FAMILY—PHANEROPLEURIDA. 


Caudal fin diphycercal ; vertical fin continuous. Gular 
plates. Scales cycloid. Jaws with a series of minute conical 
teeth on the margin. 

Extinct. Phaneroplewron from Devonian formations, and 
the carboniferous Uronemus are probably generically identical. 


FOURTH SUB-CORDER—CHONDROSTEL 
Skeleton notochordal ; skull cartilaginous, with dermal 
osstfications ; branchiostegals few in number or absent. Teeth 
minute or absent. Integuments naked or with bucklers. Caudal 
fin heterocercal, with fulera. Nostrils double, in front of the eyes. 


First FAMILY—ACIPENSERIDA. 


Body elongate, sub-cylindrical, with five rows of osseous 
bucklers. Snout produced, subspatulate or conical, with the 
mouth at its lower surface, small, transverse, protractile, tooth- 
less. Four barbels in a transverse series on the lower side of the 
snout. Vertical fins with a single series of fulera im front. 
Dorsal and anal fins approximate to the caudal. Gill- 
membranes confluent at the throat and attached to the isthmus. 
Branchiostegals none. Gills four ; two accessory gills. Auzr- 
bladder large, simple, communicating with the dorsal wall of 
the esophagus. 


Fig. 142. 


Tail of Acipenser. «@, Fulcra; 0, osseous bucklers. 


GANOIDEI,. 361 


Sturgeons are, perhaps, the geologically youngest Ganoids, 
evidence of their existence not having been met with hitherto 
in formations of older date than the Eocene clay of Sheppey. 
They are exclusively inhabitants of the temperate zone of the 
Northern Hemisphere, being either entirely confined to fresh 
water, or passing, for the purpose of spawning, a part of the 
year in rivers. They grow to a large size, and are the largest 
fishes of the fresh waters of the Northern Hemisphere, speci- 
mens 10 feet long being of common occurrence. The ova are 
very small, and so numerous that one female has been caleu- 
lated to produce about three millions at one season; therefore 
their propagation, as well as their growth, must be very rapid ; 
and although in many rivers their number is annually con- 
siderably thinned by the systematic manner in which they 
are caught when they ascend the rivers in shoals from the 
sea, no diminution has been observed. Wherever they occur 
they prove to be most valuable on account of their wholesome 
flesh. In Russia, besides, two not unimportant articles of 
trade are obtained from them, viz. Caviare, which is prepared 
from their ovaries, and Isinglass, which is made from the 
inner coats of their air-bladder. True Sturgeons are divided 
into two genera, Acipenser and Scaphirhynchus. 

AcIPENSER.—The rows of osseous bucklers are not confluent 
on the tail. Spiracles present. Caudal rays surrounding the 
extremity of the tail. 

About twenty different species of Sturgeons may be dis- 
tinguished from European, Asiatic, and American rivers. The 
best known are the Sterlet (4. ruthenus) from Russian rivers, 
celebrated for the excellency of its flesh, but rarely exceeding 
a length of three feet ; the Californian Short-snouted Sturgeon 
(A. brachyrhynchus); the Hausen (A. huso), from rivers, 
falling into the Black Sea and the Sea of Azow (rare in 
Mediterranean), sometimes 12 feet long, and yielding an in- 
ferior kind of isinglass; the Chinese Sturgeon (A. sinensis) ; 


362 FISHES. 


the Common Sturgeon of the United States (4. maculosus), 
which sometimes crosses the Atlantic to the coasts of Great 
Britain ; Giildensteedt’s Sturgeon (A. giildenstedtii), common 
in European and Asiatic rivers, which yields more than one- 
fourth of the caviare and isinglass exported from Russia ; 
the Common Sturgeon of Western Europe (A. stwrio), which 
attains to a length of 18 feet, and has established itself also 
on the coasts of Eastern North America. 


ScaPpHIRHYNCHUs.—Snout spatulate ; posterior part of the tail 
attenuated and depressed, so that it is entirely enveloped by the 
osseous scutes. Spiracles none. The caudal rays do not extend 
to the extremity of the tail, which terminates in a filament. 


Four species are known: one (S. platyrhynchus) from the 
river-system of the Mississippi, and the three others from 
Central Asia; all are exclusively freshwater fishes; their 
occurrence in so widely distant rivers is one of the most 
striking instances by which the close affinity of the North 
American and North Asiatic faunas is proved. 


SECOND FAMILY—POLYODONTIDA. 


Body naked, or with minute stellate ossifications. Mouth 
lateral, very wide, with minute teeth in both jaws. Barbels 
none, Caudal fin with fulera. Dorsal and anal fins approxi- 
mate to the caudal. Four gills and a half; no opercular gill 
or pseudobranchia. 


Potyopon (SpaTuLaria).—The snout is produced into an ex- 
ceedingly long, shovel-like process, thin and flexible on the sides. 
Spiracles present. Gull-cover terminating in a very long tapering 
flap. One broad branchiostegal. Each branchial arch with a 
double series of very long, fine, and numerous gill-rakers, the two 
series being divided by a broad membrane. Air-bladder cellular. 
Upper caudal fulcra narrow, numerous. 


The single species, P. foliwm, occurs in the Mississippi, 


—s.° = 


GANOIDEI. 363 


and grows to a length of about six feet, of which the rostral 
shovel takes about one-fourth ; in young examples it is com- 
paratively still longer. 


Pseruurvs differs from Polyodon in having the rostral 
process less depressed and more conical. The gill-rakers are 
comparatively short, in moderate number, and distant from one 
another. Upper caudal fulcra enormously developed, and in 
small number (six). 

Psephurus gladius inhabits the Yan-tse-Kiang and Hoangho, 
the distribution of the Polyodontide being perfectly analogous 
to that of Scaphirhynchus. It grows to an immense size, 


Fig. 143.—Psephurus gladius. 


specimens of 20 feet in length being mentioned by Basilewsky. 
The function of the rostral process in the economy of these 
fishes is not yet sufficiently explained. Martens believes that 
it serves as an organ of feeling, the water of those large Asiatic 
and American rivers being too turbid to admit of the Sturgeon 
seeing its prey, which consists of other fishes. The eyes of 
Psephurus, as well as Polyodon, are remarkably small. Both 
fishes are used as food. 

Allied to the Polyodontide, and likewise provided with a 
paddle-shaped production of the fore part of the head, is the 
fossil genus Chondrosteus, remains of which occur in the Lias. 


FIFTH SUB-ORDER—POLYPTEROIDEI 


Paired fins with axial skeleton, fringed ; dorsal fins two or 
more. Branchiostegals absent, but generally gular plates.  Ver- 
tebral column diphycercal or heterocercal. Body scaly. 


364 FISHES. 


First FAMILY—POLYPTERID~. 


Scales ganoid ; fins without fulera. A series of dorsal 
spines, to each of which an articulated finlet is attached ; anal 
placed close to the caudal fin, the vent being near the end of the 
tail. Abdominal portion of the vertebral column much longer 


than the caudal. 


Potyptervus.—Teeth rasp-like, in broad bands in the jaws, 
on the vomer and palatine bones ; jaws with an outer series of 
closely-set, larger, pointed teeth, Caudal fin surrounding the 
extremity of the vertebral column ; ventral fins well developed. 
A spiracle on each side of the parietal, covered with an osseous 
plate. A single large gular plate. Air-bladder double, commu- 
nicating with the ventral wall of the pharynx. 


Fig. 144.—Polypterus bichir. 


This Ganoid is confined to tropical Africa, occurring in 
abundance in the rivers of the west coast and in the Upper 
Nile ; but it has not been found in the river-systems belonging 
to the Indian Ocean. It is scarce in the Middle and Lower 
Nile, and the specimens found below the Cataracts have 
been carried down, from southern latitudes, and do not pro- 
pagate their species in that part of the river. There is only: 
one species known, Polypterus bichir (“Bichir” being its 
vernacular name in Egypt), which varies in the number of 
the dorsal finlets, the lowest being eight, the highest eighteen. 
It attains to a length of four feet. Nothing is known of its 
mode of life, and observations thereon are very desirable. 

CaLamorcuTuys.—Distinguished from Polypterus by its greatly 
elongate form, and the absence of ventral fins. 


C. calabaricus, a dwarf form from Old Calabar. 


GANOIDEI. 365 


SECOND FAMILY—SAURODIPTERIDA. 


Scales ganoid, smooth like the surface of the skull. Two 
dorsal fins; paired fins obtusely lobate. Teeth conical. Caudal 
heterocercal. 

Extinct. Diplopterus, Megalichthys, and Osteolepis from 
Devonian and Carboniferous formations. 


THIRD FAMILY—COELACANTHID. 


Scales cycloid. Two dorsal fins, each supported by a single 
two-pronged winterspinous bone ; paired fins obtusely lobate. 
Air-bladder ossified ; notochord persistent, diphycercal. 

Extinct. Coelacanthus from carboniferous strata; several 
other genera, from the coal formations to the chalk, have been 
associated with it—Undina, Graphiurus, Macropoma, Holo- 
phagus, Hoplopygus, Rhizodus. | 


FourtH FAMILY—HOLOPTYCHIID. 


Scales cycloid or ganoid, sculptured. Two dorsal fins ; pec- 
torals narrow, acutely lobate ; dentition dendrodont. 


Extinct. In this family a pecuhar type of dentition is 
found—the jaws are armed with two kinds of teeth, small ones 
serially arranged, and much larger fang-like teeth disposed at 
long intervals. Both kinds show at their base in transverse 
sections a labyrinthic complexity of structure, numerous 
fissures radiating from the central mass of vasodentine 
which fills up the pulp cavity, and sending off small rami- 
fying branches. Genera belonging to this family are Holo- 
ptychius, Saurichthys, Glyptolepis, Dendrodus, Glyptolaemus, 
Glyptopomus, Tristichopterus, Gyroptychius, Strepsodus, from 
Devonian and Carboniferous strata. 


366 FISHES. 


SIXTH SUB-CORDER—PYCNODONTOIDEI. 


Body compressed, high and short or oval, covered with rhombie 
scales arranged in decussating pleurolepidal lines. Notochord 
persistent. Paired fins without axial skeleton. Teeth on the 
palate and hinder part of the lower jaw molar-like. Branchi- 
ostegals, but no gular plates. 

Extinct. The regular lozenge-shaped pattern of the im- 
teguments of these fishes is described by Sir P. Egerton thus : 
“Each scale bears upon its inner anterior margin a thick 
solid bony rib, extending upwards beyond the margin of the 
scale, and sliced off obliquely, above and below, on opposite 
sides, for forming splices with the corresponding processes of 
the adjoining scales. These splices are so closely adjusted 
that, without a magnifying power or an accidental dislocation, 
they are not perceptible. When im stu, and seen internally, 
these continuous lines decussate with the true vertebral 
apophyses.” In some genera the “pleurolepidal” lines are 
confined to the anterior part of the side. 


First FAMILY—PLEUROLEPIDA. 


Homocercal. Body less high. Fins with fulera. 
Pleurolepis and Homocolepis from the Lias. 


SECOND FAMILY—PYCNODONTIDA. 


Homocercal. The newral arches and ribs are ossified ; the 
roots of the ribs are but little expanded in the older genera, but 
enlarged in the tertiary forms, so as to simulate vertebre. 
Paired fins not lobate. Obtuse teeth on the palate and the sides 
of the mandible ; maxilla toothless ; incisor-like teeth in the 
intermaxulary and front of the mandible. Fulera absent in 
all the fins. 

These fishes abound in Mesozoic and Tertiary formations. 


—= 


GANOIDEI. 367 


Gyrodus, Mesturus, Microdon, Coclodus, Pyenodus, Mesodon, are 
some of the genera distinguished by paleontologists. (See 
Fig. 102, p. 201.) 


SEVENTH SUB-ORDER—LEPIDOSTEOIDEL 


Scales ganoid, rhombic ; fins generally with fulera ; paired 
Jins not lobate. Pree- and inter- operculum developed ; generally 
numerous branchiostegals, but no gular plate. 


First FAMILY—LEPIDOSTEID. 


Scales ganoid, lozenge-shaped. Skeleton completely ossified ; 
vertebra convex in front and concave behind. Fins with fulcra ; 
dorsal and anal composed of articulated rays only, placed far 
backwards, close to the caudal. Abdominal part of the vertebral 
column much longer than caudal. Branchiostegals not numer- 
ous, without enamelled surface. Heterocercal. 

Lepidosteus.—Body elongate, sub-cylindrical ; snout elongate, 
spatulate, or beak-shaped ; cleft of the mouth wide; both jaws 
and palate armed with bands of rasp-like teeth and series of 
larger conical teeth. Four gills; no spiracles ; three branchio- 
stegals. Air-bladder cellular, communicating with the pharynx. 


Fig. 145.—Lepidosteus viridis. 


Fishes of this genus existed already in Tertiary times; 
their remains have been found in Europe as well as North 
America. In our period they are limited to the temperate 
parts of North America, Central America, and Cuba. Three 
species can be distinguished which attain to a length of about 
six feet. They feed on other fishes, and their general resem- 
blance to a pike has given to them the vernacular names of 
“ Gar-Pike,” or “ Bony Pike.” 


368 FISHES. 


SECOND FAMILY—SAURID. 


Body oblong, with ganoid scales; vertebre not completely 
ossified ; termination of the vertebral column homocercal ; fins 
generally with fulera. Maxillary composed of a single piece ; 
jaws with a single series of conical pointed teeth. Branchioste- 
gals numerous, enamelled, the anterior broad gular plates. 


Extinct. Numerous genera occur in Mesozoic formations ; 
one with the widest range is Semzonotus, with distichous 
fulera, from the Lias and Jura; Hugnathus, with large 
posteriorly serrated scales, and fulcra on nearly all fins; 
Cephenoplosus from the Upper Lias; Macrosemius from the 
Oolite; Propterus, Ophiopsis, Pholidophorus, Plewropholis, 
Pachycormus, Oxygnathus, Ptycholepis, Conodus, Hulepidotus, 
Lophiostomus, ete. 


THIRD FAMILY—STYLODONTIDA. 


Body rhombic or ovate, with ganoid scales; vertebre not 
conupletely ossified ; termination of the vertebral column homo- 
cercal ; fins with fulcra. Maxillary composed of a single piece ; 
jaws with several series of teeth, the outer ones equal, styliform. 
Dorsal fin very long, extending to the caudal. Branchiostegals 
NUMETOUS. 

Extinct. Zetragonolepis from the Lias (see Fig. 103, p. 
207). 


FourtH FAMILY—SPHARODONTIDA. 


Body obtong, with rhombic ganoid scales ; vertebree ossified, 
but not completely closed ; homocercal ; fins with fulera. 
Maxillary composed of a single piece ; teeth in several series, 
obtuse ; those on the palate globular. Dorsal and anal fins short. 
Branchiostegals. 

Extinct. The type genus of this family is Lepidotus, so 
named from its large rhombic, dense, and polished scales. 


GANOIDEI, 369 


The dorsal is opposite to the anal, and all the fins are pro- 
vided with a double row of fulcra. This genus ranges from 
the Lias to the Chalk; one species would seem to have 
survived into tertiary times, if it should not prove to be a 
Lepidosteus. 


FirtH FAMILY—ASPIDORHYNCHID. 


Body elongate, with ganoid scales ; jaws prolonged into a 
beak ; termination of the vertebral column homocercal. Fins 
with fulera ; a serves of enlarged scales along the side of the body. 
Dorsal fin opposite to the anal, 


u 


Fig. 146.—Aspidorhynchus fisheri, from the Purbeck beds ; m, mandible ; 
a, presymphyseal bone. 

Extinct; mesozoic. Aspidorhynchus has the upper jaw 
longer than the lower; very peculiar is the occurrence of a 
single, solid, conical bone, situated in front of the symphysis 
of the lower jaw, to which it is jomed by a suture. Belo- 
nostomus with both jaws of equal length. 


SrxtH FAMILY—PALAONISCIDA. 


Body fusiform, with rhombic ganoid scales. Notochord 
persistent, with the vertebral arches ossified. Heterocercal. All 
the fins with fulcra ; dorsal short. Branchiostegals numerous, 
the foremost pair forming broad gulars. Teeth small, conical, 
or cylindrical. 

Extinct. Many genera are known; from the Old Red 

2B 


370 FISHES. 


Sandstone—Chirolepis and <Acrolepis ; from Carboniferous 
rocks—Cosmoptychius, Elonichthys, Nematoptychius, Cyclopty- 
chius, Microconodus, Gonatodus, Rhadinichthys, Myriolepis, 
Urosthenes ; from the Permian—Lhabdolepis, Paleoniscus, 
Amblypterus and Pygopterus ; from the Lias— Centrolepis, 
Oxygnathus, Cosmolepis, and Thrissonotus. 


[See Traquair, “The Ganoid Fishes of the British Carboniferous Forma- 
tions.” Part I. Paleoniscide.] 


SEVENTH FAMILY—PLATYSOMID&. 

Body generally high, compressed, covered with rhombic ganoid 
scales arranged in dorso-ventral bands. Notochord persistent, 
with the vertebral arches ossified. Heterocercal; fins with 
fulcra; dorsal fin long, occupying the posterior half of the 
back. Branchiostegals numerous. Teeth tubercular or obtuse. 


Fig. 147.—Platysomus gibbosus, 


Extinct. From Carboniferous and Permian formations— 
Hurynotus, Benedenius, Mesolepis, Eurysomus, Wardichthys, 
Chirodus (M‘Coy), Platysomus. 


[See Traquair, ‘‘ On the Structure and Affinities of the Platysomide, in 
“Trans. Roy. Soc.,” Edinb., vol. xxix. ] 


EIGHTH SUB-ORDER—AMIOIDEI. 


Vertebral column more or less completely ossified, hetero- 
cercal. Body covered with cycloid scales.  Branchiostegals 


present. 


GANOIDEI. all 


First FAMILY—CATURID&. 


Notochord persistent, with partially ossified vertebre ; homo- 
cercal ; fins with fulera. Teeth in a single series, small, pointed. 


= ——— 


See "=p DAMM 


. ITS 


a eft 


Fig. 148.—Caturus furcatus (Solenhofen). 


Extinct. Caturus from the Oolite to the Chalk. 


SrEconp FAMILY—LEPTOLEPIDA. 


Scales cycloid. Vertebree ossified ; homocercal ; fins without 
Sulera ; dorsal short. Teeth minute, in bands, with canines in 
front. 

Extinct, and leading to the living representative of this 
suborder. Zhrissops with the dorsal fin placed far backwards, 
and opposite to the long anal. Leptolepis with the dorsal fin 


Fig. 149,—Leptolepis sprattiformis. 


opposite to the ventrals, from the Lias and Oolite. These 
fishes, as far as the preserved parts are concerned, cannot be 
distinguished from Teleosteous fishes, to which they are 
referred by some Palzeontologists. 


THIRD FAMILY—AMIID/. 


Skeleton entirely ossified ; a single large gular plate ; homo- 


372 FISHES. 


cercal ; fins without fulcra ; a long soft dorsal fin. Abdominal 
and caudal parts of the vertebral column subequal in extent. 
Branchiostegals numerous, 


Amta.—Body rather elongate, sub-cylindrical, compressed be- 
hind. Snout short, cleft of the mouth of moderate width. Jaws- 


Fig. 150.—Amia calva ; g, gular plate. 


with an outer series of closely-set pointed teeth, and with a band 
of rasp-like teeth; similar teeth on the vomer, palatine, and 
pterygoid bones. Anal short; caudal fin rounded. Gills four ; 
air-bladder bifurcate in front, cellular, communicating with the 
pharynx. 


The “ Bow-fin” or “ Mud-fish” (4. calva) is not uncommon 
in many of the fresh waters of the United States; it grows 
to a length of two feet. Little is known about its habits; small 
fish, crustaceans, and aquatic insects, have been found in its 
stomach. Wilder has observed its respiratory actions; it 
rises to the surface, and, without emitting any air-bubble 
whatever, opens the jaws widely, and apparently gulps in 
a large quantity of air; these acts of respiration are more 
frequently performed when the water is foul or has not been 
changed ; and there is no doubt that an exchange of oxygen 
and carbonic acid is effected, as in the lungs of aérial 
vertebrates. The flesh of this fish is not esteemed. 

Fossil remains occur in tertiary deposits of North America, 
for instance in the Wyoming territory; they have been dis- 
tinguished as Protamia and Hypamia. 


SECOND SUB-CLASS—TELEOSTEI. 


Heart with a non-contractile bulbus arteriosus ; intestine 
without spiral valve ; optic nerves decussating ; skeleton ossified, 
with completely formed vertebre: ; vertebral column diphycercal 
or homocercal ; branchie free 


The Teleostei form the majority of the fishes of the present 
fauna, and are the geological successors of the Palsichthyes, 
undoubted Teleostei not ranging farther back than the 
Chalk. This sub-class comprises an infinite variety of 
forms; and as, naturally, many Ganoid fishes lived under 
similar external conditions, and led a similar mode of life 
as certain Teleostei, we find not a few analogous forms in 
both series: some Ganoids resembling externally the Teleos- 
teous Siluroids, others the Clupeoids, others the Cheetodonts, 
others the Scombresoces, etc. But there is no direct genetic 
relation between those fishes, as some Naturalists were in- 
clined to believe. 

The Teleostei are divided into six orders :— 

A. ACANTHOPTERYGIL—Part of the rays of the dorsal, anal, 
and ventral fins not articulated, spmes. The lower pharyngeals 
separate. Air-bladder, if present, without pneumatic duct in the 
adult. 

B. ACANTHOPTERYGII PHARYNGOGNATHI.—Part of the rays 


of the dorsal, anal, and ventral fins not articulated, spines. The 
lower pharyngeals coalesced. Air-bladder without pneumatic duct. 


1 See p. 97, Fig. 41; and p: 152, Figo. 68. 


374 FISHES, 


C. ANACANTHINI.—Vertical and ventral fins without spimous 
rays. Ventral fins, if present, jugular or thoracic. Air-bladder, 
if present, without pneumatic duct. Lower pharyngeals separate. 

D. Puysostomr.—All the fin rays articulated ; only the first 
of the dorsal and pectoral fins is sometimes ossified. Ventral fins, 
if present, abdominal, without eee Air-bladder, if present, 
with a pneumatic duct. 

E. LopHoprancuit.—Gills not laminated, but composed of 
small rounded lobes, attached to the branchial arches. Gull-cover 
reduced to a large simple plate. A dermal skeleton replaces 
more or less soft integuments. 

F, PLECTOGNATHI.—A soft dorsal fin opposite to the anal ; 
sometimes elements of a spinous dorsal. Ventral fins none, or 
reduced to spines. Gulls pectinate ; air-bladder without pneu- 
matic duct. Skin with rough scutes, or with spines, or naked. 


FIRST ORDER—ACANTHOPTERYGII. 


Part of the rays of the dorsal, anal, and ventral fins are not 
articulated, more or less pungent spines. The lower pharyngeals 
are generally separate. Atr-bladder, if present, without pneu- 
matic duct in the adult.’ 


II PERCIFORMES. 


First DIVISION 


Body more or less compressed, elevated or oblong, but not elon- 
gate ; the vent is remote from the extremity of the tail, behind 
the ventral fins of they are present. No prominent anal papilla. 
No superbranchial organ. Dorsal fin or fins occupying the 


1 The Acanthopterygians do not form a perfectly natural group, some 
heterogeneous elements being mixed up with it. Neither are the characters, 
by which it is circumscribed, absolutely distinctive. In some forms (certain 
Blennioids) the structure of the fins is almost the same as in Anacanths; there 
are some Acanthopterygians, as Gerres, Pogonias, which possess coalesced 
pharyngeals ; and, finally, the presence or absence of a pneumatic duct loses 
much of its value as a taxonomic character when we consider that probably 
in all fishes a communication between pharynx and air-bladder exists at an 
early stage of development. 


PERCID A, 375 


greater portion of the back ; spinous dorsal well developed, gener- 
ally with stiff spines, of moderate extent, rather longer than, or 
as long as, the soft ; the soft anal similar to the soft dorsal, of 
moderate extent or rather short. Ventrals thoracic, with one 
spine and with four or five rays. 


First FAMILY—PERCIDA. 


The scales extend but rarely over the vertical fins, and the 
lateral line is generally present, continuous from the head to the 
caudal fin. All the teeth simple and conical ; no barbels. No 
bony stay for the preoperculum. 


A large family, represented by numerous genera and species 
in fresh waters, and on all the coasts of the temperate and 
tropical regions. Carnivorous. 

Fossil Pereoids abound in some formations, for instance, 
at Monte Bolca, where species of Labrax, Lates, Smerdis and 
Cyclopoma (both extinct), Dules, Serranus, Apogon, Therapon, 
and Pristipoma have been recognised. Paraperca is a genus 
recently discovered in the Marles of Aix-en-Provence. <A 
species of Perca is known from the freshwater deposit of 
Oeningen. 

Prerca.—All the teeth are villiform, without canines ; teeth 
on the palatine bones and vomer ; tongue toothless. Two dorsal 
fins, the first with thirteen or fourteen spines ; anal fin with two 
spines. Preeoperculum and preorbital serrated. Scales small ; 
head naked above. Branchiostegals seven. Vertebree more than 
twenty-four. 

The “Freshwater Perch” (Perca fluviatilis) is too familiarly 
known to require description. It is generally distributed 
over Europe and Northern Asia; and equally common in 
North America, there being no sufficient ground for separat- 
ing specifically the specimens of the Western Hemisphere. 
It frequents especially still waters, and sometimes descends 
into brackish water. Its weight does not seem to exceed 


376 FISHES. 


5 lbs. The female deposits her ova, united together by a 
viscid matter, in lengthened or net-shaped bands, on water- 
plants. The number of the eggs of one spawn may exceed a 


oe ST 


Fig. 151.—Perca fluviatilis, the Perch. 


million. Two other species, P. gracilis, from Canada, and P. 
schrenchii, from Turkestan, have been distinguished, but they 
are very imperfectly known, An allied genus is Siniperea, 
from Northern China. 

Percicutays.—Differing from Perca especially in the number 


of the fin-spines, which are nine or ten in the first dorsal, and 
three in the anal fin. The upper surface of the head scaly. 


These fishes represent the Freshwater Perches of the 
Northern Hemisphere in the fresh waters of the temperate 
parts of South America. Two species have been described 
from Patagonia, and one or two from Chili and Peru. 


Laprax.—All the teeth are villiform, without canines ; teeth 
on the palatine bones, vomer, and the tongue. Two dorsal fins, 
the first with nine spines; anal fin generally with three. Prz- 
operculum serrated, and with denticulations along its lower limb ; 
preorbital with the margin entire. Scales rather small. Branchi- 
ostegals seven ; well developed pseudobranchie. 

The “ Bass” are fishes common on the coasts of Europe 
and the Atlantic coasts,and in the fresh waters of the United 
States and Canada. The three European species are almost 
exclusively inhabitants of the sea, entering brackish, but 
never fresh waters, whilst the American species, the number 


PERCIDA. OUT 


of which is still uncertain, seem to affect principally fresh 
water, although some are also found in the sea. The best 
known European species is Labrax lupus (see p. 41, Fig. 4), 
common on the British coasts. It is a voracious fish, with a 
remarkably large stomach, and received from the ancient 
tomans the appropriate name of lupus. By the Greeks it 
was so highly esteemed that Archestratus termed this or one 
of the two other closely-allied species, taken near Milet, 
“offspring of the gods.” They attributed to it a tender regard 
for its own safety; and Aristotle says that it is the most 
cunning of fishes; and that, when surrounded by the net, it 
digs for itself a channel of escape through the sand. Speci- 
mens of from two to three feet are not scarce, but its 
flesh is nowadays much less esteemed than in ancient times. 
Of the North American species Zabrax lineatus and Labrax 
rufus are the most common. 


Lates.—All the teeth are villiform, without canines ; teeth 
on the palatine bones and vomer, but none on the tongue. ‘Two 
dorsal fins—the first with seven or eight, the anal fin with two 
or three, spines. Praoperculum with strong spines at the angle 
and the lower limb; also the preorbital is strongly serrated. 
Scales of moderate size. Branchiostegals seven ; pseudobranchie 
present. 

Three well-known species belong to this genus. The 
Perch of the Nile and other rivers of tropical Africa (Lates 
niloticus) ; the Perch of the Ganges and other East Indian 
rivers, Which enters freely brackish water, and extends to the 
rivers of Queensland (Lates calcarifer). These two species 
attain to a large size, the Indian species to a length of five 
feet. Hamilton says that “the vulgar English in Calcutta 
eall it ‘Cockup,’ and that it is one of the lightest and most 
esteemed foods brought to table in that city.” Specimens 
two feet in length and caught in salt water are by far the 
best quality. The third species (ates colonorwm) is found in 


378 FISHES. 


Australia only, and does not appear to grow to the same 
large size as its congeners. 


Alhed to Lates is Psammoperca from Australia. 


Percaraprax.—All the teeth villiform, without canines ; 
teeth on the palatine bones and vomer, but none on the tongue. 
Two dorsal fins—the first with eleven, the anal fin with three 
spines. Preeoperculum serrated along its hinder margin, and with 
strong spinous teeth below ; preorbital not serrated. Scales 
rather small. Branchiostegals seven ; pseudobranchiz present. 

This Perch (Percalabrax japonicus) is one of the most 
common fishes on the coasts of China, Japan, and Formosa ; 
the Japanese name it “ Zuzuki,” or “ Seengo.” 


Acertna,—All the teeth villiform, without canines ; teeth on 
the vomer, but none on the palatine bones or the tongue. One 
continuous dorsal fin, of which the spinous portion consists of 
from thirteen to nineteen spines; two anal spines. Body rather 
low, with rather small scales. Bones of the skull with wide 
muciferous cavities ; preoperculum denticulated. 

Small freshwater perches, of which A. cernua, named 
“ Pope” in England, is the most common, and has the widest 
distribution in Central Europe and Siberia. The two other 
species have a more restricted range, A. schretzer being con- 
fined to the Danube and other rivers emptying into the 
Black Sea; and 4. czekanowskit to Siberian rivers. This 
genus is not represented in the Western Hemisphere. 


Lucroperca,—Teeth in villiform bands, those in the jaws with 
additional canines ; palatine bones toothed. Two dorsal fins— 
the first with from twelve to fourteen, the anal fin with two 
spies. Przeoperculum serrated ; scales small. 

The “ Pike-Perches” are inhabitants of many lakes and 
rivers of the temperate northern zone. The European species 
is confined to the eastern two-thirds of the continent, and one 
of the most esteemed freshwater fishes; it attains to a length 
of three or four feet, and to a weight of from 25 to 30 Ibs. 


PERCID A. 379 


It has been recommended for acclimatisation in England, and 
there is no doubt that in certain localities it might prove a 
valuable addition to the native fauna; but hke all its con- 
geners it 1s very voracious and destructive to smaller fishes. 
Two other species inhabit rivers of European and Asiatic 
Russia, and two or three the fresh waters of North America. 


Pitroma.—All the teeth minute, villiform, without canines ; 
teeth on the vomer and palatine bones. Two dorsal fins—-the 
first with fourteen or fifteen spines. Body rather elongate, with 
small scales. Preeoperculum not serrated. 

Small freshwater perches abundant in the United States. 
Like the following genus, and some others which need not 
be mentioned here, they can be regarded as small, dwarfed 
representatives of the preceding genera. The species seem 
to be numerous, but have not yet been sufficiently well dis- 
tinguished. The latest and best account of them is by L. 
Vaillant, “Recherches sur les Poissons d’eaux douces de 
VPAmérique septentrionale (Ztheostomatida),” in Nouv. Archiv. 
du Muséum d’Hist. Nat. de Paris, ix., 1873. 


Botnosoma.— Allied to Pileoma, but with only nine or ten 
feeble spines in the first dorsal fin. North America, 


Aspro.—Body elongate, cylindrical ; snout thick, projecting 
beyond the mouth, which is situated at its lower side. All the 
teeth villiform, without canines ; teeth on the vomer and palatine 
bones. Two separate dorsals. Praoperculum serrated ; pre- 
orbital entire. Scales small. 

Two small Perches from the Danube and some other 
rivers of the content of Europe, Aspro vulgaris and A. 
zingel. 


Crntropomus.—Body oblong, compressed, with scales of mode- 
rate size. All the teeth villiform, without canines ; teeth on the 
vomer and palatine bones. Two dorsal fins, the first with eight 
strong spines, the anal with three, the second of which is very 
strong and long. Przoperculum with a double denticulated edge. 


380 FISHES. 


Numerous species are known from the West Indies and 
Central America. These fishes are found in fresh, brackish, 
and salt water, and some of the species indiscriminately enter 
all three kinds of water. They do not grow to any large size, . 
but are esteemed as food. 


Enoriosus.—Body much elevated, the depth being still more 
increased by the high vertical fins. All the teeth are villiform, 
without canines; teeth on the vomer, palatine bones, and the 
tongue. Two dorsal fins, the first with seven spines. Preeoper- 
culum serrated, with spinous teeth at the angle. Scales of mode- 
rate size, 

A small and very common marine species (2. armatus) on 
the coast of Australia, especially New South Wales. It is 
readily recognised by the peculiar shape of its body, and eight 
black transverse bands on a whitish ground. 


This, and the preceding genus, leads to the true “Sea 
perches,’ which never, or but rarely, enter fresh water :— 

CrnTROPRISTIS.— Body oblong, with scales of small or mode- 
rate size. Teeth villiform, with small canines in both jaws ; vome- 
rine teeth placed in an angular band, ora short triangular patch ; 
teeth on the palatine bones, but none onthe tongue. One dorsal, 
with the formula 5.7.3; anal fin 55. Preeoperculum serrated ; 
sometimes with the angle projecting, and armed with long spines. 

About twenty species of small size are known from tem- 
perate and tropical seas. 


Antuias. — Body rather short, compressed, with scales of 
moderate size. Teeth villiform, with small canines in both jaws; 
teeth on the vomer, and palatine teeth. One dorsal, generally 
with ten spines; anal fin with three ; caudal forked. The rays 
of one or more fins may be prolonged. | Przeoperculum serrated. 

About twenty species are known from temperate and 
tropical seas; they are mostly of small size, and agreeably 
coloured, pink and yellow being the predominant colours. 
Anthias sacer is common in the Mediterranean, and was well 


PERCID®. 381 


known to the ancients. Aristotle says that the fishers of 
Sponges call it sacred, because no voracious fishes came to the 
places which it frequented, and the diver might descend with 
safety.—Callanthias is a genus closely allied to Anthias. 


Srerranus. — Body oblong, compressed, with small scales. 
Teeth villiform, with very distinct caniues in both jaws; teeth 
on the vomer and palatine bones, none on the tongue. One 
dorsal, mostly with nine or eleven, rarely with eight, ten or 
twelve spines; anal fin with three: all the spines being stout. 
Preoperculum serrated behind and at the angle, but not below. 


The “Sea perches proper” are found on the shores of all 
temperate and tropical seas, most abundantly in the latter. 
A few species enter brackish and even fresh water, one having 
been found as high up the Ganges as the confines of Nepal. 
However, all spawn in the sea. The variety of species is 
almost infinite, about 150 being tolerably well known, and 
many more having been described. The distinction of the 
species is most difficult, and nearly impossible to those who 
have no opportunity of closely and long observing them in 
nature, as they are not only subject to great variation of 
colour, but also to considerable changes dependent on age. 


Fig. 152.—Serranus altivelis. 


Many are most agreeably coloured, and ornamented with spots, 
or cross bands or longitudinal stripes; colours which become 
more uniform with age in those species which attain to a 


382 FISHES. 


large size. The majority remain of rather small size, growing 
to a length of one or two feet; but not a few reach more 
than twice that length, and may even become dangerous to 
man. Instances of bathers having been attacked by a gigantic 
species not uncommon at the Seychelles and Aden are on 
record, the persons having died from the injuries received. 
Almost all the species are eatable, and many are esteemed as 
food. One species is common on the British coasts (S. cabrilla), 
and probably some of the more southern species (S. seriba 
and S. gigas) occasionally wander as far northwards as the 
British Channel. The species figured, S. altivelis, is locally 
distributed over nearly all the tropical parts of the Indian 
Ocean, and distinguished by particularly high dorsal and anal 
fins. Anyperodon and Prionodes are two genera closely allied 
to Serranus. 

Prectropoma.—Form of the body and dentition (see p. 127, 
Fig. 54) similar to that of Serranus, with a preoperculum serrated 
behind, and armed with spinous teeth below, which are directed 
forwards. Dorsal fin with from seven to thirteen spines. 


About thirty species from tropical seas are known. 
Trachypoma is allied to this genus. 


Potyrrion.—Body oblong, rather compressed, covered with 
small scales. All the teeth. are villiforin ; teeth on the vomer, 
palatine bones, and the tongue. One dorsal with eleven or 
twelve spines ; anal with three. Praeoperculum denticulated ; a 
strong, rough, longitudinal ridge on the operculum. 

Two species are known: one from the European coasts 
(P. cernium), and one from Juan Fernandez (P.kneri). They 
attain to a weight of 80 lbs. and more. The European 
species has the habit of accompanying floating wood, to which 
they are attracted by the small marine species generally 
surrounding such objects, and affording a supply of food. It 
is known by the name of “ Stone-bass,” and excellent eating. 


Grammistes.— Body rather short, compressed, covered with 


PERCIDA. 383 


minute scales imbedded in the thick skin. All the teeth are 
villiform ; teeth on the vomer and palatine bones. Two dorsal 
fins, the first with seven spines. Przoperculum without serra- 
ture, but with three short spines. A short skinny barbel is 
frequently developed at the chin. 

Three species are known from the Indo-Pacific; they are 
of small size. One, G. orientalis, is black, with six or seven 
white longitudinal stripes, and one of the most common 
coast-fishes of that ocean. 


Ruypticus.—Body oblong, compressed, covered with minute 
scales imbedded in the thick skin. All the teeth are villiform ; 
teeth on the vomer and palatine bones. The spines of the ver- 
tical fins are but little developed, always in small number and 
short, and may disappear entirely. Przoperculum not serrated, 
with some obtuse spines. 

Four species are known: three from the West Indies 
and one from the Galapagoes Islands. 

Other genera allied to the two preceding are Aulacoce- 
phalus from Mauritius, Reunion, and Japan; and Myriodon 
from the coasts of Australia. 


DieLoprion.—Body rather elevated, compressed, with small 
scales. All the teeth viliform; teeth on the vomer and pala- 
tine bones. Two dorsal fins, the first with eight spines ; anal 
with two. Przoperculum with a double denticulated limb. 


The single species known (D. bifasciatum), is very com- 


Fig. 153.—Mesoprion monostigma. 


mon in the East Indian Archipelago, and on the coasts of 


384 FISHES. 


Southern China and Japan. It is of small size, and orna- 
mented with two broad black cross-bands. 


Mrsorrion.—Body oblong, compressed, covered with scales of 
moderate size. Teeth 
villiform, with canines in 
both jaws; teeth on the 
vomer and palatine bones. 
One dorsal fin, with ten 
or eleven, rarely with 
more spines ; anal fin with 


three. Preoperculum ser- 
rated ; in some species Fig. 154.—Opercles a, of Mesoprion; 6, of 
(Genyoroge) a more or less “enyoroge; 0, knob received in a notch of 
distinct spinous knob pro- ae aN 

jects from the surface of the interoperculum, and is received in 
a more or less deep notch of the praopercular margin. 

About seventy species are known from tropical seas in 
both hemispheres, but it is noteworthy that the species with 
the peculiar protuberance of the interoperculum are confined 
to the Indo-Pacific. The coloration is much more simple 
than in the small-sealed Serrani, a uniform hue of greenish, 
pink, or red prevailing ; species with longitudinal bands are 
searce, but not rarely dark cross-bands or a large spot on the 
side occur. The majority of the species remain within very 
moderate dimensions, specimens exceeding three feet in 
length being scarce. They are generally eaten, and some of 
the species belong to the commonest fishes of the tropics, as 
M. bengalensis, chrysurus, gembra, griseus, and others. 

Glaucosoma from Japan and Australia is allied to Meso- 
prion. 


Dutrs.—Body oblong, compressed, with scales of moderate 
size, and very indistinctly ctenoid. All the teeth are villiform ; 
teeth on the vomer and palatine bones. One dorsal with ten 
spines ; anal fin with three. Preoperculum serrated. Six 
branchiostegals only. 


» 
} 


PERCID&. 385 


About ten species are known, inhabiting fresh waters of 
the coasts of the Indo-Pacific, and being especially common 
in the islands of this region, and also in Tropical Australia. 
Some live also in brackish water. Though of small size they 
are esteemed as food. 

THERAPON.—Body oblong, compressed, withscales of moderate 
size. All the teeth are villiform, those of the vomer and pala- 
tine bones being rudimentary, and frequently absent. One dorsal, 
with a depression in its upper margin, and twelve or thirteen 
spines ; anal fin with three. Przoperculum serrated.  Air- 
bladder with two divisions, an anterior and posterior. Six 
branchiostegals, 

About twenty species are known, the distribution of which 
nearly coincides with Dules, but as some of the species are 
more or less marine, the genus is spread over the whole area 
of the tropical Indo-Pacific. Other species, especially those 
of Australian rivers, are entirely hmited to fresh water. Zh. 
theraps, Th. servus, and Th. cuviert belong to the most com- 
mon fishes of that area, extending from the east coast of 
Africa to Polynesia. They are readily recognised by the 
blackish longitudinal bands with which the body is orna- 
mented. All the species are of small size. Helotes is closely 
allied to this genus. 

PRISTIPOMA.—Body oblong, compressed, with ctenoid scales of 
moderate size. Cleft of the mouth hori- 
zontal, not very wide, with the jaws nearly 
equal in length anteriorly; a central pit 
below the chin; villiform teeth in the 
jaws without canines; palate toothless. 
One dorsal, with eleven to fourteen spines ; 
anal with three. Vertical fins not scaly, or 
with scales along the base only. Praeoper- FS: 15°.—Lower view of 

mandible of Pristipoma 
culum serrated. Branchiostegals, seven. ee ake 


About forty species are known, all from the sea. They 
are extremely common between the tropics, some of the 
2¢ 


386 FISHES. 


species extending into the neighbouring sub-tropical parts. 
They do not attain a large size, and generally have a plain 
coloration. Conodon is an allied genus. 


HaMULON.—Body oblong, compressed, with ctenoid scales of 
moderate size. Cleft of the mouth horizontal, generally wide, 


Fig. 156.—Hemulon brevirostrum. 


with the jaws equal in length anteriorly ; a central pit below the 
chin ; villiform teeth in the jaws, without canines ; palate tooth- 
less. One dorsal, with twelve or thirteen spines; anal with 
three ; the soft portions of the vertical fins scaly to their margins. 
Preeoperculum serrated. Branchiostegals, seven. 

Marine; sixteen species are known from the coasts of 
Tropical America ; they are of rather small size. The species 
figured occurs on both sides of Central America. Mapalogenys 
is an allied genus. 


DraGRAMMA.—Body oblong, compressed, covered with rather 
small ctenoid scales. Upper profile of the head parabolic ; cleft 
of the mouth small, horizontal ; from four to six pores under the 


PERCIDA. 387 


mandible, but without central pit. Teeth villiform, without 
canines ; palate toothless. One 
dorsal fin, with from nine to 
fourteen spines ; anal with three. 
Vertical fins not scaly. Pre- 
operculum serrated ; infraorbital 
not armed. SBranchiostegals, six 


Fig. 157.—Diagramma orientale, from 
or seven. the Indo-Pacific. 


Forty species are known, which, with very few exceptions, 
belong to the tropical parts of the Indo-Pacific. Some attain 
to a size not very common among Sea-Perches, viz. to a length 
of from three to four feet. Many are agreeably coloured with 
black bands or spots. All appear to be esteemed as food. 
Hyperoglyphe from Australia is allied to this genus. 


Lopotes.—Body rather elevated, compressed, with ctenoid 
scales of moderate size. Eye rather small. Snout obtuse, with 
oblique cleft of the mouth, and with the lower jaw longest. 
Teeth villiform, without canines; palate toothless. One dorsal 
fin with twelve spines; anal with three. Przeoperculum denticu- 
lated. Branchiostegals, six. 

A remarkable fish (Z. auctorwm) on account of its extra- 
ordinary range. Common in many localities, scarcer in 
others, it occurs in the East Indies, and on all the Atlantic 
coasts of tropical and temperate America. Doderlein found 
it on the coast of Sicily in 1875. It lives in salt and brackish 
water, and is known to attain to a length of two feet. 


Hist1oprEeRuS.—Body rather elevated, strongly compressed, 
with very small scales. Snout much produced, the anterior profile 
of the head being concave. Mouth small, at the end of the snout. 
Teeth villiform, without canines ; palate toothless. Some of the 
spines and rays of the vertical and pectoral fins very long. One 
dorsal, with about ten spines; anal with three. Preeopercular 
margin partly serrated. Branchiostegals, six. 

Marine. Four species are known from Japan and South 
Australia. The species figured attains to a length of 20 


388 FISHES. 


inches, and is esteemed as food. It is known at Melbourne 
by the names of “ Boar Fish” or “ Bastard Dorey.” 


Fig. 158.—Histiopterus recurvirostris. 
GERRES.—Body oblong, or rather elevated, covered with scales 
of moderate size, which are either entirely smooth or minutely 
ciliated. Mouth very protractile, and descending when thrust 
out. Eye rather large. No canine teeth ; dentition feeble, and 


Fig. 159.—Gerres altispinis, from the mouth of the Ganges. 


palate toothless. The two divisions of the dorsal fin are nearly 
separated by a deep incision. Formula of the vertical fins— 
D. 7% A. #3. Caudal fin forked. Praoperculum generally 
without denticulation. Lower pharyngeal bones coalescent. 


PERCID A. 389 


More than thirty species are known of this genus, which 
bear so close a resemblance to one another that their distinc- 
tion is rather difficult. They live in the seas between the 
Tropics, and some, perhaps all, of the species enter fresh 
water. Very rarely they exceed a length of ten inches; 
nearly all have a plain silvery coloration. The coalescence 
of their lower pharyngeals renders their systematic position 
rather uncertain, and, indeed, some Ichthyologists have referred 
them to the Pharyngognaths. 


ScoLopsis.—Body oblong, covered with scales finely serrated 
and of moderate size. Jaws nearly ~~ 
equal in length anteriorly ; cleft of the 


mouth horizontal. Teeth villiform, Oe 
without canines ; palate toothless. One Oz, oS 
dorsal fin. Formula of the vertical \ 5 


\ to | 
=> Voy 
~—S é 


fins: D. 419 A. 2. Caudal fin forked. i) 
Preoperculum distinctly denticulated ; “1. 
infraorbital ring with a spine directed 
backwards. Branchiostegals, five. 


Fig. 160.—Infraorbital spine 
of Scolopsis monogramma. 


Marine, and of small size. Twenty-five species are known 
from the tropical parts of the Indo-Pacific. Heterognathodon 
is an allied genus, but without the infraorbital spine. 


DENTEX.— Body oblong, covered with ctenoid scales of moderate 
size. Cleft of the mouth nearly horizontal, with the jaws equal 
in length anteriorly. Canine teeth in both jaws; palate tooth- 
less. One dorsal fin. Formula of the vertical fins: D. 1943 
A. <85. Caudal fin forked. Preoperculum without serrature ; 
preorbital unarmed and broad, there being a wide space between 
the eye and the cleft of the mouth. Cheek covered by more 
than three series of scales. Branchiostegals, six. 


Marine Fishes, rather locally distributed in the Mediter- 
ranean, on the south coast of Africa, in the Red Sea, East 
Indian Archipelago, and on the coasts of China and Japan. 
About fourteen species are known, some of which attain a 


390 FISHES. 


weight of 30 Ibs. and more. They form a not unimportant 
article of food where they are found in any number, as on 
the Cape of Good Hope. The species found in the Mediter- 
ranean (2. vulgaris) wanders sometimes to the south coast of 
England, and is one of the larger species. The coloration of 
these fishes is rather uniform, silvery, or pink, or greenish. 
Symphorus is an allied genus from the Indo-Pacific. 


SYNAGRIS.—Body rather elongate, covered with ciliated scales 
of moderate size. Cleft of the mouth horizontal, with the jaws 
equal in length anteriorly. One continuous dorsal, with feeble 
spines ; dorsal 1,9, anal 2. Caudal deeply forked. Teeth villi- 
form, with canines at least in the upper jaw. Infraorbital not 
armed ; preeoperculum without, or with a very indistinct ser- 
rature. Cheek with three series of scales, Branchiostegals six. 


Marine fishes of small size; about twenty species are 
known from the tropical parts of the Indo-Pacific. Pentapus, 
Chetopterus, and Aphareus are allied genera from the same 


area. 


MaArENA.—Body oblong, compressed, covered with ciliated scales 
of moderate size. Mouth very protractile, the intermaxillary 
pedicles extending backwards to the occiput. Teeth villiform ; 
minute teeth on the vomer. One dorsal, scaleless, with feeble 
spines. D. 74, A. 8. Caudal fin forked. Przeoperculum without 
serrature. Branchiostegals six. 

Small fishes from the Mediterranean, known to the 


ancients; valueless as food. Three species. 


SMARIS.—Body oblong or cylindrical, covered with rather 
small ciliated scales. Mouth very protractile, the intermaxillary 
pedicles extending backwards to the occiput. Teeth villiform. 
Palate toothless. One dorsal, scaleless, with eleven or more very 
feeble spines; anal with three. Caudal fin forked. Preeoper- 
culum without serrature. Branchiostegals six. 


Small fishes from the Mediterranean. Six species. 


C.s10.—Body oblong, covered with ciliated scales of moderate 
size. Cleft of the mouth more or less oblique, with the jaws 


PERCID A. 391 


equal in length anteriorly, or with the lower somewhat projecting. 
Teeth villiform ; palate generally toothless. One dorsal, with 
from nine to thirteen very feeble spines, with the anterior part 
highest, and the posterior covered with minute scales. Caudal 


fin deeply forked. Preoperculum without, or with minute, 
serrature. 


Small fishes from the Indo-Pacific. Twelve species. 


ERYTHRICHTHYS.— Body elongate, covered with small ciliated 
scales. Mouth very protractile, the pedicles of the intermaxillary 
extending to the occiput. Dentition quite rudimentary or entirely 
rbsent. Two dorsal fins connected by a series of very feeble 


spines ; also the anterior spines are feeble. Preeoperculum not 
serrated. 


Fig. 162.—Enlarged scale. Fig. 163.—Protractile mouth. 


Small fishes from various tropical and temperate seas. 
Four species: the species figured occurs, but is not common, 


392 FISHES. 


on the coasts of Western Australia, Tasmania, and New 
Zealand. 


OLicoRUs.—Body oblong, covered with small scales. Cleft of 
the mouth rather oblique, the lower jaw being the longer. Teeth 
villiform, without canines; teeth on the vomer and palatine 
bones. One dorsal, with eleven spines ; anal with three ; caudal 
fin rounded. Prxoperculum with a single smooth or obtusely 
denticulated margin. 

To this genus belong two fishes well known on account of 
the excellent flavour of their flesh. The first (0. macguariensis) 
is called by the colonists “ Murray-Cod,” being plentiful in the 


\ MAA\ x 


Fig. 164.—The Murray-Cod, Oligorus macquariensis. 


Murray River and other rivers of South Australia. It attains 
to a length of more than three feet, and to a weight of nearly 
100 Ibs. The second (0. gigas) is found in the sea, on the 
coast of New Zealand, and called by the Maoris and colonists 
“Hapuku.” Its average weight is about 45 lbs., but occasion- 
ally large specimens of more than a hundredweight are caught. 
At certain localities it is so plentiful that it may form an 
important article of trade. Dr. Hector, who has had oppor- 
tunity of examining it in a fresh state, has pointed out 
anatomical differences from the Murray-Cod, from which it 
appears that it would be better placed in a distinct genus. 
GRYSTES.—Body oblong, covered with scales of moderate size. 
All the teeth villiform, without canines ; teeth on the vomer and 


palatine bones. One dorsal fin with ten spines ; anal with three ; 
caudal fin rounded. Preoperculum with a single smooth margin. 


PERCIDA. 393 


One species, from the fresh waters of the United States 
(G. salmonoides), attains to a length of more than two feet. 
It is known by the name of “Growler,” and eaten. 


ARRIPIS.—Body oblong, covered with scales of moderate size. 
All the teeth villiform, without canines ; teeth on the vomer and 
palatine bones. One dorsal fin, with nine slender spines ; anal 
with three. Praeoperculum denticulated. 


Fig. 165.—Arripis salar, South Australia. 


Three species are known, from the coasts of Southern 
Australia and New Zealand. They are named by the colon- 
ists Salmon or Trout, from their elegant form and lively 
habits, and from the sport they afford to the angler. Their 
usual size is from 1 to 3 lbs., but specimens of double that 
weight are taken. The smaller specimens are the more deli- 
cate and better flavoured. When not fresh, they are lable 
to assume poisonous properties; and cases of poisoning are 
not unfrequently caused by them. 


Huro.— Body oblong, compressed, covered with scales of 
moderate size. All the teeth villiform ; bones of the head 
without serrature. Mouth rather oblique, with the lower jaw 
projecting. Two dorsal fins, the first with six spines, 


The “ Black Bass” of Lake Huron (Huro nigricans). 


Ampassts.—Body short, strongly compressed, covered with 
large thin deciduous scales. Mouth oblique, with the lower jaw 
longest ; teeth villiform, without conspicuously larger canines ; 
teeth on the vomer and palatine bones. Two dorsal fins, the 
first with seven, the anal with three spines ; a horizontal spine 


394 FISHES. 


pointing forwards in front of the dorsal fin. The lower limb 
of the preeoperculum with a double serrated margin. 

This genus comprises the smallest of all Percoids, some 
of the species not much exceeding one inch in length. They 
are most abundant on the coasts of the tropical Indo- 
Pacific, and in the fresh waters belonging to that area. The 
species are numerous (some thirty having been described), 
and very difficult to distinguish. Their coloration is very 
plain, a silvery hue prevailing over the whole fish. 


APpoGoNn.—Body rather short, covered with large deciduous 
scales. Mouth oblique, with the lower jaw longest ; teeth villi- 
form, without canines ; teeth on the vomer and palatine bones. 
Two dorsal fins, the first with six or seven, the anal with two 
spines. Przeoperculum witha double edge on the margin, one 
or both edges being serrated. Seven branchiostegals, 


Although of similarly small size, the fishes of this genus 
represent a more highly developed form of the Percoid type 
than Ambassis. Their distribution coincides very much with 


Fig. 166.—Apogon frenatus. 


that of Ambassis, but they are chiefly marine, comparatively 
few of the species entering fresh water. They belong to the 
kind of fishes which, from their habit, are termed “ Coral 
Fishes,” bemg found in greatest abundance on, or in the 


PERCID A. 395 


neighbourhood of, coral reefs, in company with Cheetodonts, 
Pomacentride, and others. Their colours also are orna- 
mental and highly diversified, as is generally the case in 
coral fishes, the majority of the species showing transverse 
or longitudinal bands or large spots, and numerous other 
smaller markings which, in the dead fish, soon disappear. 
Nearly one hundred species have been described, of which 
a few only occur in the Atlantic, one extending northwards 
into the Mediterranean. 

Chilodipterus, Acropoma, and Scombrops are allied genera, 
but with canine teeth in one or both jaws. 


PomMatTomus.—Body oblong, covered with scales of moderate 
size, Eye very large. All the teeth villiform, without canines ; 
teeth on the vomer and palatine bones. Two dorsal fins, the 
first with seven, the anal with two spines. No serration on 
any of the bones of the head. Branchiostegals seven. 

One species only is known, P. ¢elescopiwm, which grows 
to a length of nearly two feet. It is not uncommon in the 
Mediterranean and neighbouring parts of the Atlantic, but 
only occasionally caught, as it lives habitually at a greater 
depth than any other Percoid as far as is known at present, 
probably at depths from 80 to 200 fathoms; a habit suffi- 
ciently indicated by its exceedingly large eye. 


PRIACANTHUS.—Body short, compressed, covered with small 
rough scales, which extend also over the short snout. Lower 
jaw and chin prominent. Eye large. All the teeth villiform, 
without canines ; teeth on the vomer and palatine bones, One 
dorsal fin with ten spines, anal with three. Prseoperculum ser- 
rated, with a more or less prominent, flat, triangular spine at 
the angle. 


A very natural genus, easily recognised, and without 
direct relation to the other Percoid genera. The species, of 
which seventeen are known, are spread over nearly all the 
tropical seas, and belong to the more common fishes. They 


396 FISHES. 


scarcely exceed a length of twelve inches, and are very uni- 
formly coloured, red, pink, and silvery prevailing. 


TuE following three genera form a group by themselves, which, 
however, is defined rather by its geographical limits and 
similarity of general appearance than by distinctive anatomical 
characters. The species are abundant in the fresh waters 
of the United States, and well known by the name of “Sun 
Fishes.” They rarely exceed a length of six inches, and are 
not used as food. The number of species is uncertain. 


CENTRARCHUS.—Body short, compressed, with scales of mode- 
rate size. All the teeth villiform, without canines; teeth on 
the vomer, palatines, and on the tongue. One dorsal fin ; anal 
generally with more than three spines. Praoperculum without 
serrature ; operculum not lobed. 

Bryttus.—Body short, compressed, with scales of moderate 
size. All the teeth villiform, without canines; teeth on the 
vomer and palatine bones. One dorsal fin with nine or ten, 
anal with three spines. Preeoperculum not serrated ; operculum 
with a rounded membranaceous coloured lobe behind. 

Pomotis.—Body short, compressed, with scales of moderate 
length. All the teeth villiform, without canines ; teeth on the 
vomer, but none on the palatine bones. One dorsal, with from 
nine to eleven spines, anal with three. Przeoperculum entire or 
minutely serrated ; operculum with a rounded membranaceous 
coloured lobe behind. 


A Nortu AMERICAN Freshwater genus, Aphredoderus, occu- 
pies a perfectly isolated position in the system, and is evidently 
the type of a distinct family. It resembles the “Sun-fishes ” 
of the same country with regard to the structure of the verti- 
eal fins, but has the vent situated in front of the ventrals, 
which are composed of more than five soft rays. The body is 
oblong, compressed, covered with ctenoid scales. The dorsal 
fin is single, and has three spines in front. Infraorbital and 
preoperculum with spinous teeth. Villiform teeth in the 


SQUAMIPINNES. 397 
jaws, on the vomer and palatine bones. 4. sayanus from the 
southern streams and fresh waters of the Atlantic States. 


To complete the list of Percoid genera, we have to mention 
the following :—Siniperca, Etelis, Niphon, Aprion, Apsilus, 
Pentaceros, Velifer, Datnioides, Percilia, Lanioperca. 


SECOND FAMILY—SQUAMIPINNES. 


Body compressed and elevated, covered with scales, either 
finely ctenoid or smooth. Lateral line continuous, not continued 
over the caudal fin. Mouth in front of the snout, generally 
small, with lateral cleft. Eye lateral, of moderate size. Six or 
seven branchiostegals. Teeth villiform or setiform, in bands, 
without canines or incisors. Dorsal fin consisting of a spinous 
and soft portion of nearly equal development ; anal with three 
or four spines, similarly developed as the soft dorsal, both being 
many-rayed. The vertical fins more or less densely covered with 
small scales. The lower rays of the pectoral fin branched, not 
enlarged ; ventrals thoracic, with one spine and five soft rays. 
Stomach coecal. 

The typical forms of this family are readily recognised by 
the form of their body, and by a peculiarity from which they 
derive their name Sguamipinnes ; the soft, and frequently 
also the spinous part of their dorsal and anal fins are so 
thickly covered with scales that the boundary between fins 
and body is entirely obliterated. The majority are inhabit- 
ants of the tropical seas, and abound chiefly in the neigh- 
bourhood of coral-reefs. The beauty and singularity of distri- 
bution of the colours of some of the genera, as Chetodon, 
Heniochus, Holacanthus, is scarcely surpassed by any other 
group of fishes. They remain within small dimensions, and 
comparatively few are used as food. They are carnivorous, 
feeding on small invertebrates. Only a few species enter 
brackish water. 


398 FISHES. 


Extinct representatives of this family are not scarce at 
Monte Bolca and in other tertiary formations. All, at least 
those admitting of definite determination, belong to existing 
genera, viz. Holacanthus, Pomacanthus, Ephippium, Scato- 
phagus. Very singular is the occurrence of Yoxotes in the 
Monte Bolea strata. 

The following genera have no teeth on the palate :— 


Oc 
CH#&TopON.—One dorsal fin, without any notch in its upper 
margin, and with the soft and spinous portions similarly developed ; 
none of the spines elongate. Snout short or of moderate length. 
Preeoperculum without, or with a fine, serration, and without spine 
at the angle. Scales generally large or of moderate size. 


Seventy species are known from the tropical parts of the 
Atlantic and Indo-Pacific, nearly all being beautifully orna- 
mented with bands or spots. Of the ornamental markings a 
dark or bicoloured band, passing through the eye and ascend- 
ing towards the back, is very generally found in these fishes ; 
it frequently occurs again in other marime Acanthoptery- 
gians, in which it is not rarely a sign of the immature 
condition of the individual. The Chetodonts are most 


Fig. 167.—Chetodon ephippium. 


numerous in the neighbourhood of the coral-reefs of the Indo- 
Pacific, the species figured (C. ephippivm) being as common 


SQUAMIPINNES. 399 


in the East Indian Archipelago as in Polynesia, like many 
others of its congeners. 


CHELMO differs from Chetodon only in having the snout 
produced into a more or less long tube. 


Only four species are known, locally distributed in the 
tropical seas. Ch. rvostratus, the oldest species known, is 


Fig. 168.—Chelmo marginalis, from the coast of Australia. 


said to have the instinct of throwing a drop of water from 
its bill so as to light upon any insect resting on a leaf, 
and thus make it fall, that it may instantly dart upon it. 
This statement is erroneous, and probably rests upon the 
mistaken notion that the long bill is especially adapted for 
this manceuvre, which, indeed, is practised by another fish 
of this family (Zoxotes). The long slender bill of Chelmo 
(which is a true saltwater fish) rather enables it to draw from 
holes and crevices animals which otherwise could not be 
reached by it. 


HeEnrocHus.—One dorsal, with from eleven to thirteen spines, 
the fourth of which is more or less elongate and filiform. Snout 


400 FISHES. 


rather short or of moderate length. Praeoperculum without spine. 
Scales of moderate size. 

Four species are known from the tropical Indo-Pacific. 
FH. macrolepidotus is one of the most common fishes of that 
area; the species figured (HZ. varius) retains in a conspicuous 


Fig. 169.—Heniochus varius. 


manner horn-like protuberances on bones of the head, with 
which the young of all the species of this genus seem to be 
armed. 


HoLacANTHus.—Properculum with a strong spine at the 
angle. One dorsal, with from twelve to fifteen spines. Scales of 
moderate or small size. 

Forty species are known, which, in their geographical 
distribution accompany, and are quite analogous to, the 
Cheetodonts. One of the most common and most beautiful 
is called “Emperor of Japan” by the Dutch, which name 
has been adopted by Bloch for its specific designation, 
Holacantiius tmperator. Its body is blue, longitudinally tra- 


SQUAMIPINNES. 401 


versed by about thirty yellow bands; the ocular band, and 
the side behind the head, are black, edged with yellow; the 
caudal fin is yellow. It is a large species of this genus, some- 
times attaining a length of 15 inches, and as an article of 
food is one of the most esteemed of all the Indian species. 
With regard to beauty of colours it is surpassed by another 
allied species, H. diacanthus, which likewise ranges from the 
east coast of Africa to Polynesia. 


Pomacantuus differs from Holacanthus in having from eight 
to ten spines only in the dorsal fin. 


The single species (P. parwv) on which this genus is founded 
is one of the most common fishes of the West Indies, and 
offers one of the most remarkable instances of variation of 
colour within the limits of the same species: some specimens 
being ornamented with more or less distinct yellowish cross- 
bands, others with yellow crescent-shaped spots; in others 
black spots predominate. 


Scaropuacus.—Two dorsal fins, united at the base, the first 
with ten or eleven spines; only the second is scaly. A recum- 


Fig. 170.—Scatophagus multifasciatus. 


bent spine before the dorsal, pointing forwards. Anal with four 
2D 


402 eRISEHSE 


spines. Snout rather short. Przoperculum without spine. 
Scales very small. 

Four species are known, from the Indian Ocean, of which 
S. argus is the most generally known, in fact, one of the most 
common Indian shore-fishes. It freely enters large rivers, 
and is said not to be particular in the selection of its food. 
The species figured (S. multifasciatus) represents S. argus on 
the coasts of Australia. 

Epuiprus.—Snout short, with the upper profile parabolic. 
Dorsal fin deeply emarginate between the spinous and soft portions, 
the former with nine spines, the third 
of which is rather elongate, and flexible ; 
spinous portion not scaly ; anal spines 
three. Pectoral fin. short. Przeoper- 
culum without spine. Scales of moderate 
size, or rather small. 

Two or three species are known 
from the warmer parts of the Atlantic 
and Indian Oceans. The Atlantic 
species (#. faber) shows the remark- 
able peculiarity that im old specimens 
(12 and more inches long) the occi- 
pital crest, and sometimes some of the 


anterior neural and hzemal spines are 
Fig. 171.—Bony enlargement of 
cranial bones of Ephippus. 
a, Enlargement of the frontal, bony mass. This can hardly be 
and 6, of the supraoccipital 
bones; ¢, interorbital sep- F 
tum; d, basis cranii, } nat, the bone, as it has been found in all 


ae old specimens, without exception. 
Drepane is allied to Ephippus, but has very long falciform 
pectoral fins. The single species D. punctata is common in 
the Indian Ocean and on the coasts of Australia. Hypsinotus, 
from Japan, appears to inhabit a greater depth than the 


enormously enlarged into a globular 


regarded as a pathological change of 


other Squamipinnes. 


Scorpis and Atypichthys are genera distinguished from the 


RED MULLETS. 403 


preceding by the presence of vomerine teeth. They belong 
to the coast-fauna of Australia, New Zealand, and Chili. 


Toxotrs.—Body short, compressed, covered with scales of 
moderate size. Snout pointed, with a wide lateral mouth and 
projecting lower jaw. One dorsal, with five strong spines 
situated on the posterior part of the back ; the soft portion and 
the anal fin scaly, the latter with three spines. Villiform teeth 
in the jaws, on the yomer and palatine bones. Scales of moder- 
ate size, cycloid. 

Two species are known from the East Indies, one (7. 
jaculator), which is the more common, ranging to the north 
coast of Australia. It has received its name from its habit of 
throwing a drop of water at an insect which it perceives close 


Fig, 172.—Toxotes jaculator. 


to the surface, in order to make it fall into it. The Malays, 
who call it “Ikan sumpit,’ keep it in a bowl, in order to 
witness this singular habit, which it continues even in 
captivity. 

THIRD FaMILY—MULLID#. 


Body rather low and slightly compressed, covered with large 
thin scales, without or with an extremely fine serrature. Two 
long erectile barbels are suspended from the hyoid, and are re- 
ceived between the rami of the lower aw and opercles. Lateral 
line continuous. Mouth in front of the snout, with the cleft 


404 FISHES. 


lateral and rather short; teeth very feeble. Eye lateral, of 
moderate size. Two short dorsal fins remote from each other, 
the first with feeble spines; anal similar to the second dorsal. 
Ventrals with one spine and five rays. Pectorals short. Bran- 
chiostegals four ; stomach siphonal. 

The “Red Mullets” form a very natural family, which, on 


account of slight modifications of the dentition, has been 
Upeneoides, Upeneichthys, 


divided into several sub-genera 
Mullus, Mulloides, and Upeneus. They are marine fishes, but 
many species enter brackish water to feed on the animalcules 
abounding in the flora of brackwater. About forty different 
species are known chiefly from tropical seas, the European 
species (IL. barbatus, see p. 48, Fig. 7), extending far north- 
wards into the temperate zone. None attain to a large size, 
specimens of from two to three lbs. being not common, but 
all are highly esteemed as food. 

The most celebrated is the European species (of which 
there is one only, JZ swrmuletus being probably the female). 
The ancient Romans called it Mullus, the Greeks tTpiydn. 
The Romans priced it above any other fish; they sought for 
large specimens far and wide, and paid ruinous prices for 
them. 

“Mullus tibi quatuor emptus 
Librarum, coens pompa caputque fuit, 
Exclamare libet, non est hic improbe, non est 
Piscis: homo est ; hominem, Calliodore, voras.” 
MARTIAL, x. 31. 

Then, as nowadays, it was considered essential for the 
enjoyment of this delicacy that the fish should exhibit the 
red colour of its integuments. The Romans brought it, for 
that purpose, living into the banqueting room, and allowed it 
to die in the hands of the guests, the red colour appearing in 
all its brilliancy during the death struggle of the fish. The 
fishermen of our times attain the same object by scaling the 


SEA-BREAMS. 405 


fish immediately after its capture, thus causing a permanent 
contraction of the chromatophors containing the red pigment 
(see p. 183). 


FourTH FAMILY—SPARIDA. 


Body compressed, oblong, covered with scales, the serrature of 
which is very minute, and sometimes altogether absent. Mouth 
in front of the snout, with the cleft lateral. Eye lateral, of 
moderate size. Hither cutting teeth in front of the jaws, or 
molar teeth on the side ; palate generally toothless. One dorsal 
jin, formed by a spinous and soft portion of nearly equal 
development. Anal fin with three spines. The lower rays of 
the pectoral fin are generally branched, but in one genus sinrple. 
Ventrals thoracic, with one spine and five rays. 


The “Sea-breams” are recognised chiefly by their denti- 
tion, which is more specialised than in the preceding families, 
and by which the groups, into which this family has been 
divided, are characterised. They are inhabitants of the shores 
of all the tropical and temperate seas. Their coloration is 
very plain. They do not attain to a large size, but the 
majority are used as food. 

The extinct forms found hitherto are rather numerous ; 
the oldest come from the cretaceous formation of Mount 
Lebanon ; some belong to living genera, as Sargus, Pagellus ; 
of others from Eocene and Miocene formations no living 
representative is known—Sparnodus, Sargodon, Capitodus, 
Soricidens, Asima. 

First Group—Cantharina.—More or less broad cutting, 
sometimes lobate, teeth in front of the jaws; no molars or 
vomerine teeth; the lower pectoral rays are branched. Partly 
herbivorous, partly carnivorous. The genera belonging to 
this group are:—Cantharus from the European and South 
African coasts, of which one ‘species (C. lineatus), is common 
on the coasts of Great Britain, and locally known by the 


406 FISHES. 


names “Old Wife,” “ Black Sea-bream ;” Box, Scatharus, and 
Oblata from the Mediterranean and neighbouring parts of the 
Atlantic ; Crenidens and Tripterodon from the Indian Ocean ; 
Pachymetopon, Dipterodon, and Gymnocrotaphus from the Cape 


Fig. 173.—Tephreops richardsonii, from King George’s Sound. 


of Good Hope; Givella and Tephrwops from Chinese, Japanese, 
and Australian Seas ; Doydixodon from the Galapagos Islands 
and the coasts of Peru. 

Second Group—Haplodactylina—In both jaws flat and 
generally tricuspid teeth; no molars; vomerine teeth. The 
lower pectoral rays simple, not branched. Vegetable feeders. 
Only one genus is known, Haplodactylus, from the temperate 
zone of the Southern Pacific. 


Third Group—Sargina.—Jaws with a single series of 
incisors in front, and with several series of rounded molars on 
the side. One genus is known, Sargus, which comprises 
twenty species; several of them occur in the Mediterranean 
and the neighbouring parts of the Atlantic, and are popularly 
called “Sargo,” “Sar,” “Saragu:” names derived from the 
word Sargus, by which name these fishes were well known 
to the ancient Greeks and Romans. One of the largest species 
is the “Sheep’s-head” (Sargus ovis), from the coasts of the 
United States, which attaims to a weight of 15 lbs., and is 
highly esteemed on account of the excellency of its flesh. 
Singularly enough, this genus occurs also on the east coast of 
Africa, one of these East-African species being identical with 


SEA-BREAMS. 407 


S. noct from the Mediterranean. These fishes evidently feed 


Fig. 174.—The Sheep’s-head, Sargus ovis, of North America, 


on hard-shelled animals, which they crush with their molar 
teeth. 

Fourth Group—Pagrina.—Jaws with conical teeth in 
front and molar teeth on the sides. Feeding, as the preced- 
ing, on hard-shelled animals, hke Mollusks and Crustaceans. 
This group is composed of several genera :— 

Lernrinus.—Cheeks scaleless. Body oblong, covered with 
scales of moderate size (L. lat. 45-50). 
Canine teeth in front; lateral teeth 
in a single series, broadly conical or 
molar-like. Formula of the fins: 
D. 49, A. 2. 

More than twenty species are 


Fal wit 

PN 

WY 

Wn! 
WANA 

Vy 

vyy' vay 
te mat 


known, all of which, with one excep- 
tion, occur in the tropical Indo- 
Pacific. The species, forming this 
exception, occurs, singularly enough, 
on the west coast of Africa, where more than one Indian genus 


408 FISHES. 


reappears in isolated representative species. Some Lethrini 
attain to a leneth of three feet. . 

Spherodon is closely allied to Lethrinus, but has scales on 
the cheek. One species from the Indo-Pacific. 


Pacrus.—Body oblong, compressed, with scales of moderate 
size. Several pairs of strong canine-like teeth in both jaws ; 
molars arranged in two series. Cheeks scaly. The spines of the 
dorsal fin, eleven or twelve in number, are sometimes elongate, 
and can be received in a groove; anal spines three. 


Thirteen species are known, chiefly distributed in the 
warmer parts of the temperate zones, and more scantily repre- 
sented between the tropics. Several species (P. vulgaris, 
P. auriga, P. bocagii) occur in the Mediterranean and the 
neighbouring parts of the Atlantic; one (P. argyrops) is well 
known on the coasts of the United States under the names of 
“Scup,” “ Porgy,” or “Mishcup,” and one of the most important 
food fishes, growing to a length of 18 inches and a weight of 4 
lbs.; another (P. wnicolov) is one of the best-known sea-fishes 
of Southern Australia and New Zealand, where it is called 
“Snapper;” it is considered very good eating, like all the 
other Species of this genus, and attains, hke some of them, a 
length of more than 3 feet and a weight exceeding 20 Ibs. 


PacEtLus.—Body oblong, compressed, with scales of moderate 
size. Jaws without canines; molars on the sides arranged in 
several series. Cheeks scaly. The spines of the dorsal fin, 
from eleven to thirteen in number, can be received in a groove ; 
anal spines three, 


Seven species are known, the majority of which are Euro- 
pean, as P. erythrinus, common in the Mediterranean, and not 
rare on the south coast of England, where it is generally 
termed “ Becker ;” P. centrodontus, the common “Sea-bream” 
of the English coasts, distinguished by a black spot on the 
origin of the lateral line; in the young, which are called 
“Chad” by Cornish and Devon fishermen, this spot is absent ; 


SEA-BREAMS. 409 


P. owenw, the “ Axillary or Spanish Sea-Bream,” likewise 
from the British coasts. Pagellus lithognathus, from the coasts 
of the Cape of Good Hope, attams to a length of four feet, 
and is one of the fishes which are dried for export and sale 
to whalers. 


Curysopurys.—Body oblong, compressed, with scales of 
moderate size. Jaws with four or six canine teeth in front, and 
with three or more series of rounded molars on each side. Cheeks 
scaly. The spines of the dorsal fin, eleven or twelve in number, 
can be received in a groove ; anal spines three. 


Some twenty species are known from tropical seas and 
the warmer parts of the temperate zones. Generally known 
is Ch. awrata, from the Mediterranean, occasionally found on 
the south coast of England, where it is named “ Gilthead.” 
The French eall it “ Daurade,”’ no doubt from the Latin Awrata, 
a term applied to it by ancient authors. The Greeks named 
it Chrysophrys (7.e. golden eyebrow), in allusion to the bril- 
lant spot of gold which it bears between its eyes. According 
to Columella, the Aurata was among the number of the fishes 
brought up by the Romans in their vivaria; and the inventor 
of those vivaria, one Sergius Orata, is supposed to have derived 
his surname from this fish. It is said to grow extremely fat 
in artificial ponds. Duhamel states that it stirs up the sand 
with the tail, so as to discover the shell-fish concealed in it. 
It is extremely fond of mussels, and its near presence is 
sometimes ascertained by the noise which it makes while 
breaking their shells with its teeth. Several species found on 
the Cape of Good Hope attain to as large a size as Pagellus 
lithagnathus, and are preserved for sale like that species. 
Chrysophrys hasta is one of the most common species of the 
East Indian and Chinese coasts, and enters large rivers. 

Lifth Group—Pimelepterina.—In both jaws a single 
anterior series of cutting teeth, implanted by a horizontal 
posterior process, behind which is a band of villiform teeth. 


410 FISHES. 


Villiform teeth on the vomer, palatines and the tongue. 

Vertical fins densely covered with minute scales. Only one 

genus is known, Pimelepterus, with six species from tropical 

seas. These fishes are sometimes 

found at a great distance from 
the land. 


FirtH FAMILY—HOPLOGNATHIDA, 


Body compressed and elevated, 
covered with very small ctenoid 
scales. Lateral line continuous. 
The bones of the jaws have a sharp 


dentigerous edge, as im Scarus, 
Fig. 176.—Teeth of Hoplognathus. The teeth, if at all conspicuous, 
being continuous with the bone, forming a more or less 
indistinct serrature; no teeth on the palate. The spinous 
portion of the dorsal fin is rather more developed than the soft ; 
the spines strong; anal with three spines, similar to the soft 
dorsal. Ventrals thoracic, with one spine and five soft rays. 

One genus only is known, Hoplognathus, with four species 
from Australian, Japanese, and Peruvian coasts. 


SrxtH FAMILY—CIRRHITIDA. 


Body oblong, compressed, covered with cycloid scales ; lateral 
line continuous. Mouth in front of the snout, with lateral 
cleft. Eye lateral, of moderate size. Cheeks without a bony stay 
for the preoperculum. Generally six, sometimes five or three 
branchiostegals. Dentition more or less complete, convposed of 
small pointed teeth, sometimes with the addition of canines, 
One dorsal fin, formed by a spinous and soft portion, of nearly 
equal development. Anal with three spines, generally less 
developed than the soft dorsal. The lower rays of the pectoral 
fins simple and generally enlarged ; ventrals thoracic, but remote 
from the root of the pectorals, with one spine and five rays. 


CIRRHITIDA. ZEL 


The fishes of this family may be readily recognised by 
their thickened, undivided lower pectoral rays, which in some 
are evidently auxiliary organs of locomotion, in others, 
probably, organs of touch. They differ from the following 
family, the Scorpeenide, in lacking the bony connection 
between the infraorbital ring and the przoperculum. Two 
groups may be distinguished in this family, which, however, 
are connected by an intermediate genus (Chironemus). The 
first, distinguished by the presence of vomerine teeth, consists 
of Cirrhites and Chorinemus, small prettily coloured fishes. 
The former genus is peculiar to the Indo-Pacific, and con- 
sists of sixteen species; the second, with three species, 
seems to be confined to the coasts of Australia and New 
Zealand. The second group lacks the vomerine teeth, and 
comprises the following genera :— 

CuttopactyLus.—One dorsal fin, with from sixteen to nineteen 
spines ; anal fin of moderate length ; caudal forked. One of the 
simple pectoral rays more or less prolonged, and projecting be- 
yond the margin of the fin. Teeth in villiform bands ; no canines. 


Preeoperculum not serrated. Scales of moderate size.  Air- 
bladder with many lobes. 
i 


mW Ny, 


macnn 


2 
cee Me es HR 


Fig. 177.—Chilodactylus macropterus, from Australia. 


Seventeen species are known, chiefly from the temperate 
parts of the Southern Pacific, and also from the coasts of 
Japan and China. They belong to the most valuable food- 
fishes, as they grow to a considerable size (from five to 


412 FISHES. 


twenty-five lbs.), and are easily caught in numbers. At 
the Cape of Good Hope they are very abundant, and pre- 
served in large quantities for export. 

Mendosoma from the coast of Chil, and Nemadactylus 
from Tasmania, are allied genera. 

Larris.—Dorsal fin deeply notched ; the spinous portion with 
seventeen spines; anal fin many-rayed. None of the simple 


pectoral rays passes the margin of the fin. Teeth villiform ; no 
canines. Praoperculum minutely serrated. Scales small. 


Two species only are known from Tasmania and New 
Zealand, which belong to the most important food-fishes of 
the Southern Hemisphere. Latris hecateia or the “Trumpeter,” 
ranges from sixty to thirty Ibs. in weight, and is con- 
sidered by the colonists the best flavoured of any of the fishes 
of South Australia, Tasmania, and New Zealand, and con- 
sumed smoked as well as fresh. The second species, Latvis 
ciliaris, is smaller, scarcely attainmg a weight of twenty 
lbs., but. more abundant; it is confined to the coast of 
New Zealand. 

SEVENTH FAMILY—SCORPANID. 

Body oblong, more or less compressed, covered with ordinary 
scales, or naked. Cleft of the mouth lateral or subvertical. 
Dentition feeble, con- 
sisting of  villiform 
teeth; and generally 
without canines. Some 
bones of the head 
armed, especially the 
angle of the preoper- 
culum, its armature 


Fig. 178.—Skull of Scorpena percoides ; so, Sub- TCCCWING additional 
orbital ring ; pr, Preoperculum ; st, Bony stay, support by a bony stay, 


connecting the suborbital with the przeoperculum. : c 0 
connecting it urth the 


infraorbital ring. The spinous portion of the dorsal fin equally 


SCORPENID A. 413 


or more developed than the soft and than the anal. Ventrals 
thoracic, generally with one spine and five soft rays, sometimes 
rudimentary. 


This family consists of carnivorous marine fishes only ; 
some resemble the Sea-Perches in form and habits, as 
Sebastes, Scorpena, ete., whilst others live at the bottom 
of the sea, and possess in various degrees of development 
those skinny appendages resembling the fronds of seaweeds, 
by which they either attract other fishes, or by which they 
are enabled more effectually to hide themselves. Species 
provided with those appendages have generally a coloration 
resembling that of their surroundings, and varying with the 
change of locality. The habit of living on the bottom has 
also developed in many Scorpenoids separate pectoral rays, by 
means of which they move or feel. Some of the genera live 
at a considerable depth, but apparently not beyond 3800 
fathoms. Nearly all are distinguished by a powerful armature 
either of the head, or fin spines, or both; and in some the 
spines have been developed into poison organs. 

The only fossil representative known at present is a 
species of Scorpena from the Eocene of Oran. 


Srepastes.—Head and body compressed ; crown of the head 
scaly to, or even beyond, the orbits ; no transverse groove on 
the occiput. Body covered with scales of moderate or small size, 
and without skinny tentacles. Fin-rays not elongate ; one dorsal, 
divided by a notch into a spinous and soft portion, with twelve 
or thirteen spines ; the anal with three. No pectoral appendages. 
Villiform teeth in the jaws, on the vomer, and generally on the 
palatine bones. Vertebra more than twenty-four. 

About twenty species are known, principally from seas of 
the temperate zones, as from the coasts of Northern Europe 
(S. norvegicus, S. viviparus), of Japan, California, New Zealand, 
and Van Diemen’s Land. All seem to prefer deep water to 
the surface, and Sebastes macrochir has been obtained at a 


re 


414 FISHES. 


depth of 545 fathoms. In their general form they resemble 
the Sea-Perches, attain to a weight of from one to four lbs., 
and are generally esteemed as food. 


Scorpana.—Head large, slightly compressed, generally with a 
transverse naked depression on the occiput; bones of the head 
armed with spines, and generally with skinny tentacles. Scales 
of moderate size. Mouth large, oblique. Villiform teeth in the 
jaws, and at least on the vomer. One dorsal, 1°-4%, A, % iis 
Pectoral fins without detached rays, large, rounded, with the 
lower rays simple and thickened. Air-bladder none. Vertebre 


twenty-four. 


Fig. 179.—Head of Scorpeena percoides, from New Zealand. 


About forty species are known from tropical and sub- 
tropical seas. They lead a sedentary life, lying hidden in the 
sand, or between rocks covered with seaweed, watching for 
their prey, which chiefly consists of small fishes. Their 


Fig. 180.—Scorpena bynoensis, from the coasts of Australia, 


strong undivided pectoral rays aid them in burrowing in the 


SCORPANIDA. 415 


sand, and in moving alone the bottom. The type of their 
coloration 1s very much the same in all the species, viz. an 
irregular mottling of red, yellow, brown, and black colours, 
but the distribution of these colours varies exceedingly, not 
only in the same species but also in the same individuals. 
They do not attain to any considerable size, probably never 
exceeding a length of 18 inches. Their flesh is well flavoured. 
Wounds inflicted by their fin-spines are exceedingly painful, 
but not followed by serious consequences. 

Glyptauchen and Lioscorpius are genera closely allied to 
Scorpena, from Australian seas. 

Setarches is also allied to the preceding genera, and pro- 
vided with very large eyes, in accordance with the depth 
(215 fathoms) which the two species known at present 
inhabit; one has been found near Madeira, the other near 
the Fidji Islands. 

Prrerois.—Head and body compressed ; scales of small or 
moderate size. Bones of the head armed with numerous spinous 
projections, between which often skinny tentacles are developed. 
The dorsal spines and pectoral rays are more or less prolonged, 
passing beyond the margin of the connecting membrane. Twelve 


or thirteen dorsal spines. Villiform teeth in the jaws and on 
the vomer. 


Nine species are known from the tropical Indo-Pacific. 
They belong to the most singularly formed and most beauti- 
fully coloured fishes of the Tropics, and formerly were 
believed to be able to fly, like Dactylopterus. But the 
membrane connecting their pectoral rays is much too short 
and feeble to enable them to raise themselves from the 
surface of the water. 

Apistus.—Head and body compressed, covered with ctenoid 
scales of rather small size. Some bones of the head, and 
especially the preorbital, are armed with spines. One dorsal 
with fifteen spines; the anal with three. The pectoral fin is 
elongate, and one ray is completely detached from the fin. 


416 FISHES. 


Villiform teeth in the jaws, on the vomer, and palatine bones. 
Air-bladder present. A cleft behind the fourth gill. 

Two species from the Indian Ocean. These fishes are 
very small, but of interest on account of the prolongation of 
their pectoral fins, which indicates that they can take long 
flying leaps out of the water. However, this requires confir- 
mation by actual observation. 

Acriopus.—Head and body compressed, scaleless ; head with- 
out any, or with very feeble, armature. Cleft of the mouth 
small, at the end of the produced snout. One dorsal fin, which 
commences from the head, the spinous portion being formed 
by from seventeen to twenty-one strong spines; anal short. 
Villiform teeth in the jaws, generally none on the vomer. 

Seven species. This singular genus is peculiar to the 
temperate parts of the South Pacific, occurring at the Cape, 
on the coast of South Australia, and Chili, The largest 
species (4. torvus) attains a length of two and a half feet. 
Nothing is known of its mode of life. 

SynancerA.—General appearance of the fish, especially of the 
head, monstrous. Scales none; skin with numerous soft warty 
protuberances or filaments. Mouth directed upwards, wide. 
Eyes small. From thirteen to sixteen dorsal spines ; pectoral 
fins very large. Villiform teeth in the jaws, and sometimes on 
the vomer. 


Four species are known from the Indo-Pacific, of which 
S. horrida and S. verrucosa are the most generally distributed, 
and, unfortunately, the most common. They are justly feared 
on account of the great danger accompanying wounds which 
they inflict with their poisoned dorsal spines, as has been 
already noticed above, p. 191. The greatest length to which 
they attain does not seem to exceed eighteen inches. They 
are very voracious fishes, and their stomach is of so great a 
capacity that they are able to swallow fishes one-third of 
their own bulk. 


Micropus.—Head and body strongly compressed, short, and 


SCORPANID A. 417 


deep ; no scales, but the skin is covered with minute tubercles. 
Snout very short, with nearly vertical anterior profile. Pre- 
orbital, pre- and inter-operculum with spines on the edge. 
Dorsal fin with seven or eight, anal with two spines. Pectorals 
short, ventrals rudimentary. Jaws with villiform teeth. 

These fishes belong to the smallest of Acanthopterygians, 
scarcely exceeding 14 inches in length. Two species are 
known, which are rather common on the coral reefs of the 
Pacific. 

CuorismopactyLus.—Head and body rather compressed, scale- 
less, with skinny flaps. Bones of the head with prominent 
ridges; the preeorbital, preoperculum, and operculum armed ; 


Fig. 181.—Chorismodactylus multibarbis. 


a depression on the occiput. One dorsal fin, with thirteen 
spines ; the anal with two. Three free pectoral appendages. 
Ventral fins with one spine and five rays. Villiform teeth in 
the jaws only. 

Only one small species, Ch. multibarbis, is known, from 
the coasts of India and China. 

To complete the list of Scorpzenoid genera, we have to 
mention Twnianotus, Centropogon, Pentaroge, Tetraroge, Pro- 
sopodasys, Aploactis, Trichopleura, Hemitripterus, Minous 
and Pelor. 


418 FISHES. 


EIGHTH FAMILY—NANDIDA. 


Body oblong, convpressed, covered with scales. Lateral line 
interrupted. Dorsal fin formed by a spinous and soft portion, 
the number of spines and rays being nearly equal ; anal fin with 
three spines, and with the soft portion similar to the soft dorsal. 
Ventral fins thoracic, with one spine, and five or four rays. 
Dentition more or less convplete, but feeble. 


This small family consists of two very distinct groups. 

A. Plesiopina. Marine fishes of small size, with pseudo- 
branchize and only four ventral rays. Plesiops from the coral- 
reefs of the Indo-Pacific, and Zrachinops from the coast of 
New South Wales, belong to this group. 

B. Nandina. Freshwater fishes of small size from the 
East Indies, without pseudobranchi, and five ventral rays. 
The genera are Badis, Nandus, and Catopra. 


NINTH FAMILY—POLYCENTRID#. 


Body compressed, deep, scaly. Lateral line none. Dorsal 
and anal fins long, both with numerous spines, the spinous 
portion being the more developed. Ventrals thoracic, with one 
spine and five soft rays. Teeth feeble.  Pseudobranchie 
hidden. 

Only two genera, each represented by one or two species 
in the Atlantic rivers of Tropical America, Polycentrus and 
Monocirrhus, belong to this family. They are small insecti- 
vorous fishes. 


TENTH FAMILY—TEUTHIDIDA. 


Body oblong, strongly compressed, covered with very small 
scales. Lateral line continuous. Eye lateral, of moderate size. 
A single series of cutting incisors in each jaw; palate tooth- 


less. One dorsal fin, the spinous portion being the more deve- 


TEUTHIDIDA. 419 


loped ; anal with seven spines. Ventral fins thoracic, with an 
outer and an inner spine, and with three soft rays between. 


This family consists of one very natural genus, Teuthis, 
readily recognised by the singular structure of the fins. In 
all the species the fin-formula is D. +§. A. 7. The inci- 
sors are small, narrow, and provided with a serrated edge. 
The air-bladder is large, and forked anteriorly as well as 
posteriorly. Their skeleton shows several peculiarities: the 
number of vertebrae is twenty-three, ten of which belong to 


Fig. 182.—Teuthis nebulosa, Indian Ocean. 


the abdominal portion. The abdominal cavity is surrounded 
by a complete ring of bones, the second piece of the coracoid 
being exceedingly long, and extending along the whole length 
of the abdomen, where it is joined to a spinous process of the 
first interheemal. The pubic bones are slender, long, firmly 
attached to each other, without leaving a free space between 
them. They are fastened by a long process which passes the 
symphysis of the radu, and extends on to that of the humeri. 

Thirty species are known, all from the Indo-Pacific; but 
they do not extend eastwards beyond 140° long., or to the 
Sandwich Islands. They are herbivorous, and do not exceed 
a length of fifteen inches. 


SECOND DIVISION—ACANTHOPTERYGII BERYCIFORMES. 


Body compressed, oblong, or elevated ; head with large 


420 FISHES. 


muciferous cavities which are covered with a thin skin. Ven- 
tral fins thoracic, with one spine and more than five soft rays 
(in Monocentris with two only). 

One family only belongs to this division. 


FAMILY—BERYCIDA. 

Body short, with ctenoid scales, which are rarely absent. 
Eyes lateral, large (except Melamphaés). Cleft of the mouth 
lateral, oblique ; jaws with villiform teeth ; palate generally 
toothed. Opercular bones more or less armed. Eight (four) 
branchiostegals. 

This family offers several points of biological interest. 
All its members are strictly marine; but only two of the 
genera are surface-forms (Holocentrum and Myripristis). All 
the others descend considerably below the surface, and even 
some of the species of Myripristis habitually inhabit depths 
of from 50 to 100 fathoms. Polymiaia and Beryx have been 
found in 545 fathoms. MZelamphaés must live at a still greater 
depth, as we may infer from the small size of its eye; this 
fish is not likely to come nearer to the surface than to about 
200 fathoms. The other genera named have extremely large 
eyes, and, therefore, may be assumed to ascend into such 
superficial strata as are still ht up by a certain proportion 
of sun-rays. The highly-developed apparatus for the secre- 
tion of superficial mucus, with which these fishes are provided, 
is another sign of their living at a greater depth than any of 
the preceding families of Acanthopterygians. In accordance 
with this vertical distribution, Berycoid fishes have a wide 
horizontal range, and several species occur at Madeira as well 
as in Japan. 

Fossil Berycoids show a still greater diversity of form 
than living; they belong to the oldest Teleosteous fishes, the 
majority of the Acanthopterygians found in the chalk being 
representatives of this family. Seryx has been found in 


BERYCIDA. Amt 


several species, with other genera now extinct : Psewdoberyz, 
with abdominal ventrals, from Mount Lebanon ; Berycopsis, 
with cycloid scales; Homonotus, Stenostoma, Sphenocephalus, 
Acanus, Hoplopteryx, Platycornus, with granular scales ; 
Podocys, with a dorsal fin extending to the neck; Acrogaster, 
Macrolepis, and Rhacolepis, from the chalk of Brazil. Species 
of Holocentrum and Myripristis occur in the Monte Bolca 
formation. 

Monocenrris.—Snout obtuse, convex, short ; eye of moderate 
size. Villiform teeth on the palatine bones, but none on the 
vomer. Opercular bones without armature. Scales very large, 


bony, forming a rigid carapace. Ventrals reduced to a single 
strong spine and a few rudimentary rays. 


Fig. 183.—Monocentris japonicus. 


One species only is known (JZ. japonicus) from the seas off 
Japan and Mauritius. It does not attain to any size, and is 
not common. 


Hopiostetuus.—Snout very short and obtuse ; eye large. 
Villiform teeth on the palatine bones, but none on the vomer. 
Operculum unarmed, a strong spine at the scapulary and the 
angle of the przoperculum. Scales ctenoid, of moderate size ; 
abdominal edge serrated. One dorsal, with six spines; ventrals 
with six soft rays ; caudal deeply forked. 


One species only is known (H. mediterraneus), which 


4922 FISHES. 


occurs in the Mediterranean, the neighbouring parts of the 
Atlantic, and in the sea off Japan. 


TRACHICHTHYs.—Snout very short and obtuse, with prominent 
chin; eye large. Villiform teeth on the palatine bones and on 
the vomer. <A strong spine at the scapulary and at the angle of 
the przoperculum. Scales rather small; abdomen serrated. 
One dorsal, with from three to six spines; ventral with six soft 
rays. Caudal forked. 

Four species are known from New Zealand and Madeira. 

Anoplogaster is an allied genus from tropical parts of the 
Atlantic ; it is scaleless. 


Breryx.—Snout short, with oblique cleft of the mouth and 
prominent chin; eye large.  Villiform teeth on the palatine 
bones and vomer. Opercular bones serrated ; no spine at the 
angle of the properculum. Scales ctenoid, of moderate or large 
size. One dorsal, with several spines; ventrals with seven or 
more soft rays. Anal with four spines ; caudal forked. 

Five species are known from Madeira, the tropical 
Atlantic, and the seas of Japan and Australia. The species 


Fig. 184.—Beryx decadactylus. 


figured is B. decadactylus, common at Madeira, and occurring 


BERYCIDA. 423 


near Japan at a depth of 345 fathoms; it attains a length 
of 14 feet. 

Merameuars.—Head large and thick, with very thin bones, 
nearly all the superficial bones being transformed into wide 
muciferous channels. Eye small. Palate toothless ; no barbels ; 
opercles not armed. Scales large, cycloid. One dorsal, with six 
spines ; anal spines very feeble ; caudal forked. Ventrals with 
seven rays. 

Two species, deep-sea fishes of the Atlantic; they are 
very scarce, as only three or four specimens have been found 
hitherto. 


Potymrx1a.—Snout short, with the cleft of the mouth nearly 
horizontal; eye large. Two barbels at the throat. Opercles 
without armature. Scales of moderate size. One dorsal. Anal 
with three or four spines; caudal forked ; ventrals with six or 
seven soft rays. 

Three species are known: P. nobilis from Madeira and 
St. Helena, P. Jowei from Cuba, and P. japonica from Japan ; 
the latter species from a depth of 545 fathoms. Average size 
eighteen inches. 


Myripristis.—Snout short, with oblique cleft of the mouth 
and prominent chin; eye large or very large. Villiform teeth 
on the vomer and palatine bones. Opercular bones serrated ; 
preoperculum without spine. Scales large, ctenoid. Two dor- 
sals, the first with ten or eleven spines ; anal with four spines ; 
caudal forked; ventrals with seven soft rays. Air-bladder 
divided by a contraction in two parts, the anterior of which is 
connected with the organ of hearing. 

Eighteen species from the tropical seas of both hemi- 
spheres, the majority living near the coast at the surface. 
The coloration is (principally) red or pink tn the back and 
silvery on the sides. They attain a length of about 15 inches, 
and are esteemed as food. 


HoLocentruM.—Snout somewhat projecting, with the cleft of 
the mouth nearly horizontal; eye large. Villiform teeth on the 


4.34 FISHES. 


vomer and palatine bones. Opercular bones and_ przorbital 
serrated ; operculum with two spines behind; a large spine at 
the angle of the preoperculum. Scales ctenoid, of moderate 
size. ‘Two dorsals, the first with twelve spies; anal with four 
spines, the third being very long and strong; caudal forked. 
Ventrals with seven soft rays. 

About thirty species are known from the tropical seas of 
both hemispheres; all are surface fishes, and very common. 


The young have the upper part of the snout pointed and 


AAA 
aN NCGGORNS 


Fig. 185.—Holocentrwm unipunctatum, from the South Sea. 


elongate, and were described as a distinct genus (Rhynchich- 
thys). The coloration of the adult is uniform; red, pink, and 
silvery prevailing. They attain to a length of about 15 inches, 
and are esteemed as food. 


TutrD DIVISION—ACANTHOPTERYGIIL KURTIFORMES. 


One dorsal fin only, much shorter than the anal, which is 
long and many-rayed. No superbranchial organ. 


One family only belongs to this division. 


FAMILY—K URTID. 


Body compressed, oblong, deep in front, attenuated behind. 
Snrout short. The spines of the short dorsal are few in number, 


POLYNEMID. 425 


if developed. Scales small or of moderate size. Villiform teeth 
in the jaws, on the vomer, and palatine bones. 


This family consists of a small number of species only, 
which form two distinct genera, Pempheris and Kurtus. They 
are shore fishes of tropical seas. In both the air-bladder 
shows some peculiarity : in Pempheris it is divided into an 
anterior and posterior portion; in Aurtus it is lodged within 
the ribs, which are dilated, convex, forming rings. The 
number of vertebre is respectively twenty-four and twenty- 
three. 


FourtH DIVISION—ACANTHOPTERYGII POLYNEMIFORMES. 


Two rather short dorsal fins, somewhat remote from each 
other ; free filaments at the humeral arch, below the pectoral 
fins; muciferous canals of the head well developed. 


One family only belongs to this division. 


FAMILY—POLYNEMIDA. 


Body oblong, rather compressed, covered with smooth or very 
feebly ciliated scales. Lateral line continuous. Snout project- 
ing beyond the mouth, which is inferior, with lateral cleft. Hye 
lateral, large. Villiform teeth in the jaws and on the palate. 
Ventrals thoracic, with one spine and five rays. 

The fishes of this natural family have been divided, on 
slight differences, into three genera—Polynemus, Pentanemus, 
and Galeoides. They are found in rather numerous species 
on the coasts between the tropics, and the majority enter 
brackish or even fresh water. Very characteristic are the free 
filaments which in this family are organs of touch; they are 
inserted on the humeral arch at some distance from the pec- 
toral fin ; but, nevertheless, can be regarded only as a detached 
portion of that fin; they can be moved quite independently 
of the fin; their number varies from three to fourteen, accord- 


426 FISHES. 


ing to the species; in some they are exceedingly elongate, 
twice as long as the fish, in others they are not longer or even 


a , 

C CARO AAAS 

ua OAs ction 
AK , i 

SS EO Naa 

ie: y 


Y 


iii 


Uy, 


Fig. 186.—Pentanemus quinguarius, from the West Coast of Africa and 
the West Indies. 


shorter than the pectoral. It is evident from the whole 
organisation of these fishes that they live on muddy bottom 
or in thick water, such as is found near the mouths of great 
rivers. Their eyes are large, but generally obscured by a 
filmy skin, so that those feelers must be of great use to them 
in finding their way and their food. The Polynemoids are 
very useful to man: their flesh is esteemed, and some of 
the species are provided with an air-bladder which yields a 
good sort of isinglass, and forms an article of trade im the 
East Indies. Some of these fishes attain to a length of four 
feet. 


FirrH DIVISION—ACANTHOPTERYGIL SCLANIFORMES. 


The soft dorsal is more, generally much more, developed than 
the spinous, and than the anal. No pectoral filaments ; head 
with the muciferous cunals well developed. 

Also this division is composed of one family only. 


FAMILY—SCLAENID &, 


Body rather elongate, compressed, covered with ctenoid scales. 
Lateral line continuous, and frequently extending over the caudal 


SCLENID A. 427 


jin. Mouth in front of the snout. Eye lateral, of moderate size. 
Teeth in villiform bands, sometimes with the addition of canines ; 
no molars or tneisor-like teeth im the jaws ; palate toothless. 
Preoperculum unarmed, and without bony stay. Ventrals 
thoracic, with one spine and five soft rays. Bones of the head 
with wide muciferous channels. Stomach coecal. Air-bladder 
Jrequently with numerous appendages (see pp. 144 and seq.) 

The fishes of the “ Meagre” family are chiefly coast-fishes 
of the tropical and sub-tropical Atlantic and Indian Oceans, 
preferrmg the neighbourhood of the mouths of large rivers, 
into which they freely enter, some of the species having 
become so completely naturalised in fresh water that they 
are never found now-a-days in the sea. Some of the larger 
species wander far from their original home, and are not 
rarely found at distant localities as occasional visitors. In 
the Pacific and on the coast of Australia, where but a few 
large rivers enter the ocean, they are extremely rare and, in 
the Red Sea, they are absent. Many attain a large size, and 
almost all are eaten. 

No fossil species have been as yet discovered. 


Poconras.—Snout convex, with the upper jaw overlapping 
the lower. Mandible with numerous small barbels. No canines. 
The first dorsal with ten stout spines. Two anal spines, the 
second very strong. Scales of moderate size. 

To this fish (P. chromis) more especially is given the 
name of “ Drum,” from the extraordinary sounds which are 
produced by it and other allied Scizenoids. These sounds are 
better expressed by the word drumming than by any other, 
and are frequently noticed by persons in vessels lying at 
anchor on the coasts of the United States, where those fishes 
abound. It is still a matter of uncertainty by what means 
the “ Drum ” produces the sounds. Some naturalists believe 
that it is caused by the clapping together of the pharyngeal 
teeth, which are very large molar teeth. However, if it be 


428 FISHES. 


true that the sounds are accompanied by a tremulous motion 


A 


Fig. 187.—Pharyngeal bones and 
teeth of Pogonias chronvis. 
A, Upper; B, Lower pharyngeals. 


of the vessel, it seems more pro- 
bable that they are produced by 
the fishes beating their tails 
against the bottom of the vessel 
in order to get rid of the para- 
sites with which that part of 
their body is infested. The 
“Drum ” attains to a length of 
more than four feet, and to a 
weight exceeding a hundred Ibs. 
Its air-bladder has been figured 
on p. 146. 

Micropogon is closely allied to 
Pogonias, but has conical pharyn- 
eeal teeth. Two species from the 


western parts of the Atlantic. 


Umprina.—Snout convex, with the upper jaw overlapping 
the lower ; a short barbel under the symphysis of the mandible. 
The first dorsal with nine or ten flexible spines, the anal with 
one or two. Scales of moderate size. 


Fig. 188.—Uimbrina nasus, from Panama. 


Twenty species are known from the Mediterranean, 


, 
‘ 
‘ 
- 
: 
i 
. 


SCLENIDA. 429 


Atlantic, and Indian Ocean. One well known to the ancients, 


Fig. 189.—Umbrina nasus, from Panama. 


under the name of Umbra, is the Umbrina cirrhosa of the 
Mediterranean, the “ Umbrine” or “Ombre” of the French, 
and the “Corvo” of the Italians. It ranges to the Cape of 
Good Hope, and attains a length of three feet. Also on the 
coasts of the United States several species occur, as U. alburna, 
U. nebulosa, ete. 

Scrana (including Corvina).—The upper jaw overlapping the 
lower, or both jaws equal in front. Interorbital space moderately 
broad and slightly convex. Cleft of the mouth horizontal or 
slightly oblique. The outer series of teeth is generally composed 


of teeth larger than the rest, but there are no canines. Eye of 
moderate size, barbel none. 


Some fifty species are known, but their distinctive char- 


Fig. 190.—Scizena richardsonii. 


acters have been but imperfectly pointed out. They are found 


43 FISHES. 


in all the seas and rivers in which Scienoids generally occur, 
and many are entirely confined to fresh water, for instance the 
species figured, Sctwna richardson, from Lake Huron; Se. 
amazonica ; Se. obliqua, ocellata, oscula, ete., from fresh waters 
of the United States. Sciwna diacanthus and Se. coitor belong 
to the most common fishes of the coasts of the East Indies, 
ascending the great rivers for a long distance from the sea. 
One of the European species, Sctwna aquila, has an extremely 
wide range; it not rarely reaches the British coasts, where it 
is known as “ Meagre,” and has been found at the Cape of 
Good Hope and on the coast of southern Australia. Like some 
of the other species it attains to a length of six feet, but the 
majority of the species of this genus remain within smaller 
dimensions. <A part of the species have the second anal ray 
very strong, and have been placed into a distinct genus, 
Corvina,—thus, among others, Sc. nigra from the Mediter- 
ranean, and Sc. vichardsonit. 

Pachyurus is closely allied to Sciena, but has the vertical 
fins densely covered with small scales. 


OrotitHus.—Snout obtuse or somewhat pointed, with the 
lower jaw longer. The first dorsal with nine or ten feeble spines. 
Canine teeth more or less distinct. Preeeperculum denticulated. 
Scales of moderate or small size. 

About twenty species are known from the tropical and 
sub-tropical parts of the Atlantic and Indian Oceans. The 
air-bladder is figured on p. 144. 


AncyLopon differs from O¢olithus in having very long arrow- 
shaped or lanceolate canine teeth. Coasts of tropical America. 

CoLiticutHys.—Body elongate ; head very broad, with the 
upper surface very convex ; cleft of the mouth wide and oblique ; 
no large canines. Eye small. No barbel. Scales small, or of 
moderate size. The second dorsal very long, caudal pointed. 

Three species from the East Indian and Chinese coasts. 
The great development of the muciferous system on the head 


SWORD-FISHES. A431 


and the small eye leads one to suppose that these fishes live 
in muddy water near the mouths of large rivers. The air- 
bladder has been described on p. 144. 

Other genera belonging to this family are Larimus, Hques, 
Nebris, and Lonchurus. 


SrxtH DIVISION—ACANTHOPTERYGIL XIPHIIFORMES. 


The upper jaw is produced into a long cuneiform weapon. 


These fishes form one small family only, Xiphiide. 

The “Sword-fishes” are pelagic fishes, occurring in all 
tropical and sub-tropical seas. Generally found in the open 
ocean, always vigilant, and endowed with extraordinary 
strength and velocity, they are but rarely captured, and still 
more rarely preserved. The species found in the Indian and 
Pacific Oceans belong to the genus Histiophorus, distinguished 
from the common Mediterranean Sword-fish, or Xiphias, by 


Fig. 191.—Histiophorus pulchellus. 


the presence of ventral fins, which, however, are reduced to 
two long styliform appendages. The distinction of the 
species is beset with great difficulties, owing to the circum- 
stance that but few examples exist in museums, and further, 
because the form of the dorsal fin, the length of the ventrals, 
the shape and length of the sword, appear to change accord- 
ing to the age of the individuals. Some specimens or species 
have only the anterior dorsal rays elevated, the remainder of 


432 FISHES. 


the fin being very low, whilst in others all the rays are 
exceedingly elongate, so that the fin, when erected, projects 
beyond the surface of the water. It is stated that Sword- 
fishes, when quietly floating with the dorsal fin erect, can 
sail before the wind, like a boat. 

Sword-fishes are the largest of Acanthopterygians, and 
not exceeded in size by any other Teleostean; they attain to 
a leneth of from 12 to 15 feet, and swords have been obtained 
more than three feet long, and with a diameter of at least 
three inches at the base. The sword is formed by the pro- 
longation and coalescence of the maxillary and intermaxillary 
bones; it is rough at its lower surface, owing to the develop- 
ment of rudimentary villiform teeth, very hard and strong, 
and forms a most formidable weapon. Sword-fishes never 
hesitate to attack whales and other large Cetaceans, and by 
repeatedly stabbing these animals generally retire from the 
combat victorious. The cause which excites them to those 
attacks is unknown; but they follow this instinct so blindly 
that they not rarely attack boats or large vessels in a similar 
manner, evidently mistaking them for Cetaceans. Sometimes 
they actually succeed in piercing the bottom of a ship, 
endangering its safety; but as they are unable to execute 
powerful backward movements they cannot always retract 
their sword, which is broken off by the exertions of the fish 
to free itself. A piece of a two-inch plank of a whale-boat, 
thus pierced by a sword-fish, in which the broken sword still 
remains, 1s preserved in the British Museum. 

The Rev. Wyatt Gill, who has worked as a missionary 
for many years in the South Sea Islands, communicates that 
young Sword-fishes are easily caught in strong nets, but no net 
is strong enough to hold a fish of six feet in length. Speci- 
mens of that size are now and then captured by hook and 
line, a small fish being used as bait. Individuals with the 
sword broken off are not rarely observed. Larger specimens 


TRICHIURIDZ. Aso 


cannot be captured by the natives, who are in great fear of 
them. They easily pierce their canoes, and only too often 
dangerously wound persons sitting in them. 

The Mediterranean Sword-fish is constantly caught in the 
nets of the Tunny-fishers off the coast of Sicily, and brought 
to market, where its flesh sells as well as that of the Tunny. 

The remarkable changes which Sword-fishes undergo at 
an early stage of their growth have been noticed above, p. 
173 and seq. 

Sword-fishes are as old a type as the Berycoids. Their 
remains have been found in the chalk of Lewes, and more 
frequently in the London clay of Sheppy, where an extinct 
genus, Coelorhynchus, has been recognised. 


SEVENTH DIVISION—ACANTHOPTERYGII TRICHIURIFORMES. 


Body elongate, compressed or band-like ; cleft of the mouth 
wide, with several strong teeth in the jaws or on the palate. The 
spinous and soft portions of the dorsal fin and the anal are of 
nearly equal extent, long, many-rayed, sometimes terminating vir 
finlets ; caudal fin forked, if present. 


FAMILY—TRICHIURIDA. 


Marine fishes inhabiting the tropical and sub-tropical seas ; 
some of them are surface-fishes, living in the vicinity of the 
coast, whilst others descend to moderate depths, as the Bery- 
coids. All are powerful rapacious fishes, as is indicated by 
their dentition. 

The oldest of the extinct genera are Hnchodus and Anen- 
chelum ; they were formerly referred to the Scombroids, but 
belong to this family. The former has been found in the 
chalk of Lewes and Messtricht; the latter is abundant in the 
Eocene schists of Glaris. Anenchelum is much elongate, and 
exhibits in the slender structure of its bones the character- 

2F 


434 FISHES. 


istics of a deep-sea fish; it resembles much Lepidopus, but 
has some long rays in the ventrals. Other Eocene genera 
are Nemopteryx and Xiphopterus. In the Miocene of Licata 
in Sicily Trichiuridw are well represented, viz. by a species 
of Lepidopus, and by two genera, Hemithyrsites and Trichiu- 
richthys, which are allied to Thyrsites and Trichiurus, but 
covered with scales. 

The following is a complete list of the genera referred to 
this family :— 

Neatotus.—Body incompletely clothed with delicate scales. 
Small teeth in the jaws and on the palatine bones ; none on the 
vomer. Two dorsal fins, the first continuous and extending to 
the second; finlets behind the second and anal fins. Each 
ventral fin represented by a single small spine. A dagger-shaped 
spine behind the vent. Caudal fin well developed. 

One specimen only of this fish (V. ¢ripes), 10 inches long, 
has been obtained off Madeira; it evidently lives at a con- 
siderable depth, and comes to the surface only by accident. 

NestarcHus.—Body covered with small scales. Several strong 
fangs in the jaws; no teeth on the palate. First dorsal not ex- 
tending to the second. No detached finlets, Ventrals small, 
but perfectly developed, thoracic. Caudal fin present. <A 
dagger-shaped spine behind the vent. 

A rather large fish (V. naswtus), very rarely found in the 
sea off Madeira. The two or three specimens found hitherto 
measure from three to four feet in length. Probably living 
at the same depth as the preceding genus. 

Apuanopus.—Scales none. Two very long dorsal fins ; 
caudal well developed ; ventrals none. A strong dagger-shaped 
spine behind the vent, Strong teeth in the jaws; none on the 
palate. 


One species only is known, named A. carbo from its coal- 
black colour; it is evidently a deep-sea fish, very rarely ob- 
tained in the sea off Madeira. Upwards of four feet long. 


Evoxymetoron. — Body naked, very long and thin. Profile 


TRICHIURIDA. 435 


of the head regularly decurved from the nape to the snout, the 
occiput and forehead being elevated and trenchant. Jaws with 
fangs ; palatine teeth present. One dorsal only, continued from 
the head to the caudal fin, which is distinct. A dagger-shaped 
spine behind the vent. Pectoral fins inserted almost horizontally, 
with the lowest rays longest, and with the posterior border 
emarginate, Ventral fins rudimentary, scale-like. 


This is another deep-sea form of this family, but, at pre- 
sent, no observations have been made as regards the exact 
depth at which it occurs. A specimen has been known since 
the year 1812; it was found on the coast of Scotland, and 
described as Trichiurus lepturus. The same species has been 
re-discovered in the West Indies, where, however, it is also 
extremely scarce. 


Lupipopus.—Body band-like ; one single dorsal extends along 
the whole length of the back ; caudal well developed. Ventrals 
reduced to a pair of scales. Scales none. Several fangs in the 
jaws ; teeth on the palatine bones. 

The Scabbard-fish (Z. caudatus) is rather common in the 


Mediterranean and warmer parts of the Atlantic, extending 


PR puns Su SSNS SESNES : 


Fig. 192.—Lepidopus caudatus. 


northwards to the south coast of England, where it is an 
occasional visitor, and southwards to the Cape of Good Hope. 
More recently it has been observed on the coasts of Tasmania 
and New Zealand. We may, therefore, justly consider it to 
be a deep-sea fish, which probably descends to the same depth 


436 FISHES. 


as the preceding allied forms. It grows to a length of five or 
six feet, but its body is so much compressed that it does not 
weigh more than as many pounds. It is well known in 
New Zealand, where it is called “ Frost-fish,” and esteemed 
as the most delicious fish of the colony. A still more 
attenuated species (Z. ¢enwis) occurs in the sea off Japan, at a 
depth of some 540 fathoms. 

Tricuiurus.—Body band-lke, tapering into a fine point, with- 
out caudal fin. One single dorsal extending the whole length of 
the back. Ventrals reduced to a pair of scales, or entirely 
absent. Anal fin rudimentary, with numerous extremely short 
spines, scarcely projecting beyond the skin. Long fangs in the 
jaws ; teeth on the palatine bones, none on the vomer. 

The “Hairtails” belong to the tropical marine fauna, 
and although generally found in the vicinity of land, they 
wander frequently out to sea, perhaps merely because they 
follow some ocean-currents. Therefore they are not rarely 
found in the temperate zone, the common West Indian species 
(T. lepturus), for instance, on the coast of England. They 
attain to a leneth of about four feet. The number of their 
vertebre is very large, as many as 160, and more. Six 
species are known. 

EPINNULA—Body rather elongate, covered with minute scales, 
The first dorsal fin continuous, with spines of moderate strength, 
and extending on to the second; finlets none; ventrals well 
developed. Lateral lines two. Teeth of the jaws strong ; 
palatine teeth, none. 

The “Domine” of the Havannah, /. magistralis. 

THYRSITES.— Body rather elongate, for the greater part naked. 
The first dorsal continuous, with the spines of moderate strength, 
and extending on to the second. From two to six finlets behind 
the dorsal and anal. Several strong teeth in the jaws; teeth 
on the palatine bones. 

The species of this genus attain to a considerable size’ 
(from four to five feet), and are valuable food fishes; Zh. atun 


PALHORHYNCHIDA. A3i7 


from the Cape of Good Hope, South Australia, New Zealand, 
and Chili, is preserved, pickled or smoked. In New Zea- 
land it is called “Barracuda” or “Snoek,’ and exported 
from the colony into Mauritius and Batavia as a regular 
article of commerce, being worth over £17 a ton; Zh. pretiosus, 
the “Escholar” of the Havannah, from the Mediterranean, 
the neighbouring parts of the Atlantic, and the West Indies ; 
Th. prometheus from Madeira, Bermuda, St. Helena, and 
Polynesia; Zh. solandri from Amboyna and Tasmania is 
probably the same as Zh. prometheus. 

Young specimens of this (or, perhaps, the following) genus 
have been described as Dicrotus. In them the finlets are not 
yet detached from the rest of the fin; and the ventral fins, 
which are entirely obsolete in the adult fish, are represented 
by a long crenulated spine. 


GEMPYLUS.—Body very elongate, scaleless. The first dorsal 
fin continuous, with thirty and more spines, and extending on 
to the second. Six finlets behind the dorsal and anal. Several 
strong teeth in the jaws, none on the palate. 

One species (G. serpens), inhabiting considerable depths of 


the Atlantic and Pacific Oceans. 


FAMILY—PALAORHYNCHIDA. 


This family has been formed for two extinct genera: 
Paleorhyinchus from the schists of Glaris, and Hemirhynchus 
from tertiary formations near Paris. These genera resemble 
much the Zrichiuride in their long, compressed body, and 
long vertical fins, but their jaws, which are produced into a 
long beak, are toothless, or provided with very small teeth. 
The dorsal fin extends the whole length of the back, and the 
anal reaches from the vent nearly to the caudal, which is 
forked. The ventrals are composed of several rays and 
thoracic. The vertebre long, slender, and numerous, and, like 
all the bones of the skeleton, thin, indicating that these fishes 


438 FISHES. 


were inhabitants of considerable depths of the ocean. Both 
the jaws of Palworhynchus are prolonged into a beak, whilst 
in Hemirhynchus the upper exceeds the lower in length. 


EIGHTH DIVISION—ACANTHOPTERYGIL COTTO-SCOMBRIFORMES. 


Spines developed in one of the fins at least. Dorsal fins 
either continuous or close together ; the spinous dorsal, if pre- 
sent, always short ; sometimes modified into tentacles, or into 
a suctorial disk ; soft dorsal always long, uf the spinous is 
absent ; anal similarly developed as the soft dorsal, and both 
generally much longer than the spinous, sometimes terminating 
in finlets.  Ventrals, thoracic or jugular, uf present, never 
modified into an adhesive apparatus. No prominent anal 
papula. 

Marine fishes, with few exceptions. 


First FAMILY—ACRONURID. 


Body compressed, oblong or elevated, covered with minute 
scales. Tail generally armed with one or more bony plates or 
spines, which are developed with age, but absent in very young 
individuals. Eye lateral, of moderate size. Mouth small; a 
single series of more or less compressed, sometimes denticulated, 
sometimes pointed incisors in each jaw ; palate toothless. One 
dorsal fin, the spinous portion being less developed than the soft ; 
anal with two or three spines; ventral fins thoracic, <Avr- 
bladder forked posteriorly. Intestines with more or less 
numerous circumvolutions. Nine abdominal, and thirteen 
caudal vertebra. 

Inhabitants of the tropical seas, and most abundant on 
coral-reefs. They feed either on vegetable substances or on 
the superficial animal matter of corals. 

Extinct species of Acanthurus and Naseus have been dis- 
covered in the Monte Bolca formation. 


ACRONURID. 439 


ACANTHURUS.—Jaws with a single series of lobate incisors, 
which are sometimes movable. An erectile spine hidden in a 
groove on each side of the tail, Ventral fins with one spine 
and generally five rays. Scales ctenoid, sometimes with minute 
spines. Branchiostegals five. 


The fishes of this genus, which sometimes are termed 
“ Surgeons,” are readily recognised by the sharp lancet-shaped 
spine with which each side of the tail is armed. When at 
rest the spine is hidden in a sheath; but it can be erected 
and used by the fish as a very dangerous weapon, by striking 
with the tail towards the right and left. “Surgeons” occur 
in all tropical seas, with the exception of the eastern part of 
the Pacific, where they disappear with the corals. They do 


Fig. 193.—Acanthurus leucosternum, Indian Ocean. 


not attain to any size, the largest species scarcely exceeding 
a length of eighteen inches. Many are agreeably or showily 
coloured, the ornamental colours being distributed in very 
extraordinary patterns. The larger species are eatable, and 
some even esteemed as food. It is stated that the fry of 
some species periodically approaches, in immense numbers, 
the coasts of some of the South Sea Islands (Caroline Archi- 
pelago), and serves as an important article of food to the 
natives. Nearly fifty species are known. 

At an early period of their growth these fishes present so 
different an aspect that they were considered a distinct genus, 
Acronurus. The form of the body is more circular and ex- 


440 FISHES. 


ceedingly compressed. No scales are developed, but the 
skin forms numerous oblique parallel folds. The gill-cover 
and the breast are shining silvery. 


NaseEvus.—Tail with two (rarely one or three) bony keeled 
plates on each side (in the adult). Head sometimes with a bony 
horn or crest-like prominence directed forwards. Ventral fins 
composed of one spine and three rays. From four to six spines 
in the dorsal ; two anal spines. Scales minute, rough, forming a 
sort of fine shagreen. Air-bladder forked behind. Intestinal 
tract with many circumvolutions. 

Twelve species are known from the tropical Indo-Pacific, 
but none of them extend eastwards beyond the Sandwich 
Islands. In their mode of life these fishes resemble the 
Acanthuri. Likewise, the young have a very different appear- 
ance, and are unarmed, and were described as a distinct 


Fig. 194.—Naseus unicornis. 


genus, Kerts. One of the most common species is WV. wnicor- 
nis, Which, when adult (22 inches long), has a horn about 
2 inches long, whilst it is merely a projection in front of the 
eye in individuals of 7 inches in length. 


Prionurus is an allied genus with a series of several keeled 
bony laminze on each side of the tail. 


SECOND FAMILY. 


CARANGIDA. 

Body more or less compressed, oblong or elevated, covered with 
small scales or naked ; eye lateral. Teeth, uf present, conical. 
No bony stay for the preoperculum. The spinous dorsal is less 
developed than the soft or than the anal, either continuous with, 


or separated from, the soft portion ; sometimes rudimentary. 


HORSE-MACKERELS. 441 


Ventrals thoracte, sometimes rudimentary or entirely absent. 
No prominent papilla near the vent. Gill-opening wide. Ten 
abdominal and fourteen caudal vertebre. 

Inhabitants of tropical and temperate seas. Carnivorous. 
They appear first in cretaceous formations, where they are 
represented by Plataz and some Caranx-like genera (Vomer 
and Atpichthys from the chalk of Comen in Istria). They are 


Fig. 195.—Semiophorus velitans. 


more numerous in various Tertiary formations, especially in 
the strata of Monte Bolca, where sonte still existing genera 


4492 FISHES. 


occur, as Zanclus, Platax, Caranz (Carangopsis), Argyriosus 
(Vomer), Lichia, Trachynotus. Of the extinct genera the fol- 


lowing belong to this family :—Psewdovomer (Licata), Amphis- 


tium, Archeus, Ductor, Plionemus (2), and Semiophorus. Equula 
has been recently discovered in the Miocene marls of Licata 
in Sicily. 

Caranx (including Zrachurus).—Body more or less compressed, 
sometimes sub-cylindrical. Cleft of the mouth of moderate width. 
The first dorsal fin continuous, with about eight feeble spines, 


sometimes rudimentary ; the soft dorsal and anal are succeeded 
by finlets in a few species. Two anal spines, somewhat remote 


Fig. 196.—Plates of the lateral line of Caranx hippos. 


from the fin. Scales very small. Lateral line with an anterior 
curved, and a posterior straight, portion, either entirely or pos- 
teriorly only covered by large plate-like scales, several of which 
are generally keeled, the keel ending in a spine. Dentition feeble, 
Air-bladder forked posteriorly. 

The “ Horse-mackerels” are found in abundance in almost 
all temperate and, especially, tropical seas. Many species 
wander to other parts of the coast, or to some distance from 
land, and have thus gradually extended their range over two 
or more oceanic areas; some are found in all tropical seas. 
The species described are very numerous, about ninety 
having been properly characterised and distinguished. Some 
attain to a leneth of three feet and more, and all are eatable. 
They feed on other fish and various marine animals. 

Of the most noteworthy species the following may be 
mentioned :—C. trachurus, the common British Horse-mackerel, 
distinguished by having the lateral line in its whole length 
armed with large vertical plates; it is almost cosmopolitan 
within the temperate and tropical zones of the northern and 


HORSE-MACKERELS. 443 


southern hemispheres. C. crumenophthalmus, C. carangus, and 
C. hippos, three of the most common sea-fishes, equally abun- 


Fig. 197.—Caranx ferdau. 


dant in the Atlantic and Indo-Pacific oceans; C. ferdau, 
from the Indo-Pacific, upwards of three feet in leneth. C. 
armatus, ciliaris, gallus, ete., which have an exceedinely short 
and compressed body, with rudimentary spinous dorsal fin, 
and with some of the rays of the dorsal and anal prolonged 
into filaments. 


Areyriosus is closely allied to Caranz, especially to the last- 
named species, but the lateral line has no plates whatever ; and 
the body is scaleless, chiefly of a bright silvery colour. 


Two species from the tropical Atlantic. 


Micropreryx.—Body much compressed, with prominent tren- 
chant abdomen, covered with small scales; lateral line not 
shielded ; preeopercular margin entire. Cleft of the mouth rather 
small ; preeorbital of moderate width. The first dorsal continu- 
ous, with seven feeble spines. No detached finlets. Small teeth 
on the vomer and palatine bones. 


444 FISHES. 


Micropteryx chrysurus is a semi-pelagic fish, and very 
common in the tropical Atlantic, less so in the Indian 
Ocean. 


Seriota.— Body oblong, slightly compressed, with rounded 
abdomen, covered with very small scales; lateral line not shielded ; 
preopercular margin entire. Cleft of the mouth of moderate 
width, or rather wide. The first dorsal continuous, with feeble 
spines. No detached finlets. Villiform teeth in the jaws, on 
the vomer and palatine bones. 


These fishes are often called “ Yellow-tails,” and oceur in 
nearly all the temperate and tropical seas, sometimes at a 
ereat distance from land. Twelve species are known, and the 
majority have a wide geographical range. The larger grow 
to a length of from four to five feet, and are esteemed as food, 
especially at St. Helena, the Cape of Good Hope, in Japan, 
Australia, and New Zealand. 

Seriolella and Serivlichthys, the latter from the Indo-Pacific, 
and distinguished by a finlet behind the dorsal and anal, are 
allied genera. 


Navucrates.—Body oblong, sub-cylindrical, covered with small 
scales ; a keel on each side of the tail. The spinous dorsal con- 
sists of a few short free spines; finlets none. Villiform teeth in 
the jaws, on the vomer and palatine bones. 


The “ Pilot-fish” (V. ductor) is a truly pelagic fish, known 
in all tropical and temperate seas. Its name is derived from 
its habit of keeping company with ships and large fish, espe- 
cially Sharks. Itis the Poimpilus of the ancients, who describe 
it as pointing out the way to dubious or embarrassed sailors, 
and as announcing the vicinity of land by its sudden disap- 
pearance. It was therefore regarded as a sacred fish. The 
connection between the Shark and the Pilot-fish has received 
various interpretations, some observers having perhaps added 
more sentiment than is warranted by the actual facts. It was 
stated that the Shark never seized the Pilot-fish, that the 


PILOT-FISH. 445 


latter was of great use to its big companion in conducting it 
and showing it the way to its food. Dr. Meyen in his “ Reise 
um die Erde” states: “The pilot swims constantly in front 
of the Shark; we ourselves have seen three instances in 
which the Shark was led by the Pilot. When the Shark 
neared the ship the Pilot swam close tothe snout, or near 
one of the pectoral fins of the animal. Sometimes he darted 
rapidly forwards or sidewards as if looking for something, and 
constantly went back again to the Shark. When we threw 
overboard a piece of bacon fastened on a great hook, the 
Shark was about twenty paces from the ship. With the 
quickness of lightning the Pilot came up, smelt at the dainty, 
and instantly swam back again to the Shark, swimming many 
times round his snout and splashing, as if to give him exact 
information as to the bacon. The Shark now began to put 
himself in motion, the Pilot showing him the way, and in a 
moment he was fast upon the hook." Upon a later occasion 
we observed two Pilots in sedulous attendance on a Blue 
Shark, which we caught in the Chinese Sea. It seems probable 
that the Pilot feeds on the Sharks’ excrements, keeps his com- 
pany for that purpose, and directs his operations solely from 
this selfish view.” We believe that Dr. Meyen’s opinion, as 
expressed in his last words, is perfectly correct. The Pilot 
obtains a great part of his food directly from the Shark, in 
feeding on the parasitic crustaceans with which Sharks and 
other large fish are infested, and on the smaller pieces of flesh 
which are left unnoticed by the Shark when it tears its prey. 
The Pilot also, being a small fish, obtains greater security when 
in company of a Shark, which would keep at a distance all 
other fishes of prey that would be likely to prove dangerous 
to the Pilot. Therefore, in accompanying the Shark, the 
Pilot is led by the same instinct which makes it followa ship. 


1 Tn this instance, one may entertain reasonable doubts as to the usefulness 
of the Pilot to the Shark. 


446 FISHES, 


With regard to the statement that the Pilot itself is never 
attacked by the Shark all observers agree as to its truth; but 
this may be accounted for in the same way as the impunity 
of the swallow from the hawk, the Pilot-fish being too nimble 
for the unwieldy Shark. 

The Pulot-fish does not always leave the vessels on their 
approach to land. In summer, when the temperature of the 
sea-water is several degrees above the average, Pilots will 
follow ships to the south coast of England into the har- 
bour, where they are generally speedily caught. Puilot-fish 
attain a length of 12 inches only. When very young 
their appearance differs so much from the mature fish that 
they have been described as a distinct genus, Nauclerus. 
This fry is exceedingly common in the open ocean, and con- 
stantly obtained in the tow-net; therefore the Puilot-fish 
retains its pelagic habits also during the spawning season, 
and some of the spawn found by voyagers floating on the 
surface is, without doubt, derived from this species. 


CuHorinemMus.—Body compressed, oblong ; covered with small 
scales, singularly shaped, lanceolate, and hidden in the skin. The 
first dorsal is formed by free spines in small numbers; the 
posterior rays of the second dorsal and anal are detached finlets. 
Small teeth in the jaws, on the vomer and palatine bones. 


Twelve species are known from the Atlantic and Indo- 
Pacific; some enter brackish water, whilst others are more 
numerous at some distance from the shore. They attain to a 
leneth of from 2 to 4 feet. In the young, which have been 
described as Porthmeus, the spines and finlets are connected 
by membrane with the rest of the fin. 

Lichia is an allied genus from the Mediterranean, tropical 
Atlantic, and the coast of Chili; five species. 

Temnopon.—Body oblong, compressed, covered with cycloid 


scales of moderate size. Cleft of the mouth rather wide. Jaws 
with a series of strong teeth; smaller ones on the vomer and 


HORSE-MACKERELS, 447 


the palatine bones. The first dorsal with eight feeble spines 
connected by membrane ; finlets none, Lateral line not shielded. 
The second dorsal and anal covered with very small scales, 


Temnodon saltator, sometimes called “ Skip-jack,” is spread 
over nearly all the tropical and sub-tropical seas ; it frequents 
principally the coasts, but is also met with in the open sea. 
On the coasts of the United States it 1s well known by the 
name of “ Blue-fish,” being highly esteemed as food, and fur- 
nishing excellent sport. It is one of the most rapacious 
fishes, destroying an immense number of other shore-fishes, 
and killing many more than they can devour. It grows to a 
length of 5 feet, but the majority of those brought to market 
are not half that length. 


TracHynotus.—Body more or less elevated, compressed, covered 
with very small scales. Cleft of the mouth rather small, with 
short convex snout. Opercles entire. The first dorsal composed 
of free spines in small number. No finlets. Teeth always 
small, and generally lost with age. 

Ten species are known from the tropical Atlantic and 
Indo-Pacific ; they rarely exceed a length of 20 inches. Some 
of the most common marine fishes belong to this genus, for 
instance 7’ ovatus, which ranges over the entire tropical zone. 

PAMMELAS (perciformis) is allied to the preceding genus ; 
from the coast of New York. 


Psertus.—Body much com- 
pressed and elevated; snout , 
rather short. One dorsal, entirely / 
covered with scales, with seven 
or eight spines; anal fin with 
three. Ventrals very small, rudi- \\\ 
mentary. Teeth villiform; no 
teeth on the palate. Scales small, 
cetenoid. 

Only three species are PU SSIMONS: 


known; one, P. sche, from the west coast of Africa, the two 


448 FISHES. 


others from the Indo-Pacific. P. argenteus is a very com- 
mon fish, attaining to a leneth of about 10 inches. 


Fig. 199. 


Psettus argenteus. 


Puatax.—Body much compressed and elevated ; snout very 
short. One dorsal, with the spinous portion nearly entirely 
hidden, and formed by from three to seven spines; anal with 
three. Ventrals well developed, with one spine and five rays. 
Teeth setiform, with an outer series of rather larger teeth, 
notched at the top; palate toothless. Scales of moderate size or 
rather small. 

These fishes are called “ Sea-bats,” from the extraordinary 
length of some portion of their dorsal and anal fins and of 
their ventrals. These long lobes are generally of a deep 
black colour. In mature and old individuals the fin-rays 
are much shorter than in the young, which have been de- 
scribed as distinct species. There are probably not more 
than seven species of “Sea-bats,’ if so many, and they all 
belong to the Indian Ocean and Western Pacific, where they 
are very common. 


HORSE-MACKERELS, 449 


ZancLus.— Body much compressed and elevated. One dorsal, 
with seven spines, the third of which is very elongate. No teeth 
on the palate. Scales minute, velvety. 


One species (Z. cornutus), which is extremely common in 
the Indo-Pacific. It is easily recognised by its snout, which 
is produced like that of Chelmon, and by the broad black 
bands crossing the yellow ground-colour. It attains to a 
length of eight inches, and undergoes during growth similar 
changes as Acanthurus. 


AwnomaLors.—Body oblong, covered with small, rough scales. 
Snout very short, convex, with wide cleft of the mouth. Eyes 
very large ; below the eye, in a cavity of the infraorbital ring, 
there is a glandular phosphorescent organ. Villiform teeth in 
the jaws and on the palatine bones, none on the vomer. First 
dorsal fin short, with a few feeble spines connected by membrane. 


This genus, of which one species only is known (A. palpe- 
bratus), represents the family of Horse-Mackerels in the 
depths of the sea; but we do not know, at present, at what 
depth it lives. Only six specimens have been obtained 
hitherto from the vicinity of Amboyna, the Fidji, and Paumotu 
Islands ; the largest was twelve inches long. 

Capros.—Body compressed and elevated. Mouth very pro- 
tractile. Scales rather small, spiny. First dorsal with nine spines, 


anal with three. Ventral fins well developed. Minute teeth 
in the jaws and on the vomer ; none on the palatine bones. 


The “ Boar-fish ” (C. aper) is common in the Mediterranean, 
and not rarely found on the south coast of England. 

Allied are Antigonia and Diretmus, known from a few 
individuals obtained at Madeira and Barbadoes; they are 
probably fishes which but rarely come to the surface. 


Equuta.—Body more or less compressed, elevated or oblong, 
covered with small, deciduous, cycloid scales. Mouth very pro- 
tractile. Minute teeth in the jaws; none on the palate. One 
dorsal. Formula of the fins: D. ~8;5, A. 3%, V.1/5. The 
lower preopercular margin serrated. 

2G 


450 FISHES. 


Small species, abundant in the Indo-Pacific, disappearing 


Fig. 200.—Equula edentula. 


on the coasts of Japan and Australia. Some eighteen species 
have been described. 

Gazza is very similar to Lquwula, but armed with canine 
teeth in the jaws. 

Other genera referred to this family are Lactarius (L. deli- 
catulus, common, and eaten on the East Indian coasts), Sezio- 
lella, Paropsis, and Platystethus. 


THIRD FAMILY—CYTTID&. 


Body elevated, compressed, covered with small scales, or with 
bucklers, or naked ; eye lateral. Teeth conical, small. No 
bony stay for the preoperculum. Dorsal fin composed of two 
distinct portions. Ventrals thoracic. No prominent papilla 
near the vent. Gill-opening wide. More than ten abdominal 
and more than fourteen caudal vertebre. 

The fishes of the “Dory” family are truly marine, and 
inhabit the temperate zone of the Northern and Southern 
Hemispheres. Some fossils from tertiary formations (one from 
Licata) belong to the genus Zeus. 


CYTTIDA. 451 


Zuus.—A. series of bony plates runs along the base of the 
dorsal and anal fins ; another series on the abdomen. Three or 
four anal spines. 


“John Dorys” are found in the Mediterranean, on the 
eastern temperate shores of the Atlantic, on the coasts of 
Japan and Australia. Six species are known, all of which 
are highly esteemed for the table. The English name given 
to one of the European species (Zeus Jaber) seems to be partly 
a corruption of the Gascon “Jau,” which signifies cock, 
“Dory” being derived*from the French Dorée, so that the 
entire name means Gilt-Cock. Indeed, in some other locali- 
ties of Southern Europe it bears the name of Gallo. The 
same species occurs also on the coasts of South Australia and 
New Zealand. The fishermen of Roman Catholic countries 
hold this fish in special respect, as they recognise in a black 
round spot on its side the mark left by the thumb of St. 
Peter when he took the piece of money from its mouth. 


Cyttus.—Body covered with very small scales; no osseous 


Fig. 201.—Cyttus australis. 


452 FISHES. 


bucklers on any part of the body. Two anal spines; ventral 
fins composed of one spine and six or eight rays. 
Three species are known from Madeira, South Australia, 


and New Zealand. 


FourtTH FAMILY—STROMATEID. 


Body more or less oblong and compressed, covered with very 
small scales; eye lateral. Dentition very feeble ; wsophagus 
armed with numerous horny, barbed processes. No bony stay 
Jor the preoperculum. Dorsal fin single, long, without distinct 
spinous division. More than ten abdominal and more than 
Sourteen caudal vertebre. 

This small family consists of strictly marine and partly 
pelagic species referred to two genera, Stromateus and Centro- 
lophus. The former lacks ventral fins, at least in the adult 
stage, and is represented by about ten species in almost all 
the tropical and warmer seas. Centrolophus, hitherto known 

- from two or three European species only (of which one occa- 
sionally reaches the south coast of England, where it is named 
“ Black-fish”), has recently been discovered on the coast of 
Peru, and has probably a much wider range. 


FirtH FAMILY—CoRYPHANID. 


Body compressed ; eye lateral. Teeth small, conical, if 
present ; wsophagus smooth. No bony stay for the preeoper- 
culum. Dorsal fin single, long, without distinct spinous divi- 
sion. More than ten abdominal and more than fourteen 
caudal vertebra. 

All the members of this family have pelagic habits. Re- 
presentatives of it have been recognized in some fossil 
remains : thus Goniognathus from the Isle of Sheppey, and the 
living genus Mene (Gastrocnemus) at Monte Bolea. 


CorypH£NA.—Body compressed, rather elongate ; adult speci- 
mens with a high crest on the top of the head ; cleft of the mouth 


ee 


DOLPHINS. ADS 


wide. A single dorsal extending from the occiput almost to the 
caudal, which is deeply forked; no distinct dorsal and anal 
spines. The ventrals are well developed, and can be received in 
a groove on the abdomen. Scales very small. Rasp-like teeth 
in the jaws, on the vomer and the palatine bones. Air-bladder 
absent. 

Generally, though by misapplication of the name, called 


“Dolphins.” About six species are known, each of which is 


Fig. 202.—Dolphin from the Atlantic. 


probably distributed over all the tropical and sub-tropical 
seas. Strictly pelagic in their habits, they are most powerful 
swimmers ; they congregate in shoals, and pursue unceasingly 
the Flying-Fish, which try to escape their enemies by long 
flying leaps. They attain to a length of six feet, and are eagerly 
caught by sailors on account of their well-flavoured flesh. 
The beauty of their, unfortunately fugitive, colours has ever 
been a subject of admiration. As far as the colours are 
capable of description, those of the common species (C. hip- 
purus), which is often seen in the Mediterranean, are silvery 
blue above, with markings of a deeper azure, and reflections 
of pure gold, the lower parts being lemon-yellow, marked with 
pale blue. The pectoral fins are partly lead colour, partly 
yellow ; the anal is yellow, the iris of the eye golden. These 
iridescent colours change rapidly whilst the fish is dying, as 
in the Mackerel. The form of the body, and especially of the 
head, changes considerably with age. Very young specimens, 
from one to six inches in length, are abundant in the open 
sea, and frequently obtained in the tow-net. Their body is 
cylindrical, their head as broad as high, and the eye relatively 


454. FISHES. 


very large, much longer than the snout. As the fish grows 
the body is more compressed, and finally a high crest is 
developed on the head, and the anterior part of the dorsal fin 
attains a height equal to that of the body. 


Brama.—Body compressed, and more or less elevated, covered 
with rather small scales ; cleft of the mouth very oblique, with 
the lower jaw longest. Dorsal and anal fins many-rayed, the 
former with three or four, the latter with two or three, spines ; 
caudal deeply forked. Ventrals thoracic, with one spine and 
five rays. The jaws with an outer series of stronger teeth. 

Pelagic fishes which, lke the allied genus Taractes, range 
over almost all the tropical and temperate seas. 


Lampris.—Body compressed and elevated, covered with very 
small deciduous scales; cleft of the mouth narrow. A single 
dorsal, without a spinous portion. Ventrals composed of numer- 
ous rays. ‘Teeth none. 


The “Sun-fish” (Z. luna) is one of the most beautiful 


Fig. 203.—Lampris luna, 


fishes of the Atlantic. It attains to the large size of four feet 
in length, is bluish on the back, with round silvery spots, 
which colour prevails on the lower parts; the fins are of a 


NOMEID”. 455 


deep scarlet. It is said to be excellent eating. It is a pelagic 
fish, not rare about Madeira, but extending far northwards in 
the Atlantic ; it seems to be rarer in the Mediterranean. All 
the specimens hitherto obtained were full-grown or nearly so. 
The skeleton exhibits several peculiarities, viz. an extra- 
ordinary development and dilatation of the humeral arch, and 
great strength of the numerous and closely-set ribs. 


Other Coryphenoid genera are Pteraclis, Schedophilus, 
Nana, Ausonia, and Mene ; all pelagic forms. 


SIXTH FAMILY—NOMEIDA, 


Body oblong, more or less convpressed, covered with cycloid 
scales of moderate size ; eye lateral. No bony stay for the pre- 
operculum. Dorsal fin with a distinct spinous portion separated 
Jrom the soft; sometimes finlets ; caudal forked. More than 
ten abdominal, and more than fourteen caudal vertebra. 

Marine fishes ; pelagic, at least when young. 


GastTrocuisma.—Cleft of the mouth wide. Finlets behind the 


Fig. 204.—Gastrochisma melampus. 


dorsal and anal fins. The ventral fins are exceedingly broad 


456 FISHES. 


and long, and can be completely concealed in a fold of the 
abdomen. 
G. melanypus, from the coast of New Zealand ; scarce. 
Nomevs.—Cleft of the mouth narrow. No finlets. The 


ventral fin is long and broad, attached to the abdomen by a 
membrane, and can be received in a fissure of the abdomen. 


NV. gronovii is a common pelagic fish in the Atlantic and 
Indian Oceans; of small size. 
Other genera belonging to this family are Psenes and 
Cubiceps. 
SEVENTH FAMILY—ScoMBRID&. 


Body oblong, scarcely compressed, naked or covered with small 
scales ; eye lateral. Dentition well developed. No bony stay 
Jor the preoperculum. Two dorsal fins ; generally finlets. 
Ventrals thoracic, with one spine and five rays. More than ten 
abdominal, and more than fourteen caudal vertebra. 

The fishes of the “Mackerel” family are pelagic forms, 
abundant in all the seas of the tropical and temperate zones. 
They are one of the four families of fishes which are the most 
useful to man, the others being the Gadoids, Clupeoids, and 
Salmonoids. They are fishes of prey, and unceasingly active, 
their power of endurance in swimming being equal to the 
rapidity of their motions. Their muscles receive a greater 
supply of blood-vessels and nerves than in other fishes, and 
are of a red colour, and more like those of birds or mammals. 
This energy of muscular action causes the temperature of 
their blood to be several degrees higher than in other fishes. 
They wander about in shoals, spawn in the open sea, but 
periodically approach the shore, probably in the pursuit of 
other fishes on which they feed.’ 

' Mackerel, like other marine fishes, birds, and mammals of prey, follow 
the shoals of young and adult Clupeoids in their periodical migrations ; on 
the British coasts it is principally the fry of the Pilchard and Sprat which 
wanders from the open sea towards the coast, and guides the movements of 
the Mackerel. 


MACKERELS. 457 

Scombride are well represented in tertiary formations: in 
the Eocene schists of Glaris two extinct genera, Palimphyes 
and Jsurus, have been discovered. In Eocene and Miocene 
formations Scomber, Thynnus, and Cybiwm are not wicommon. 


Scomper.—The first dorsal continuous, with feeble spines ; 
five or six finlets behind the dorsal and anal. Scales very small, 
and equally covering the whole body. Teeth small. Two short 
ridges on each side of the caudal fin. 

Mackerels proper are found in almost all temperate and 
tropical seas, with the exception of the Atlantic shores of tem- 
perate South America, where they have not been found hitherto. 
In Europe, and probably also on the coast of England, three 
species occur: S. scomber, the common Mackerel, which lacks: 
an air-bladder; S. pnrewmatophorus, a more southern species, 
with an air-bladder; and S. colias, like the former, but with 
a somewhat different coloration, and often called “Spanish” 
Mackerel. On the Cape of Good Hope, in Japan, on the 
eoast of California, in South Australia, and New Zealand, 
Mackerels are abundant, which are either identical with, or 
very closely allied to, the European species. On the coasts 
of the United States the same species occur which tenant the 
western parts of the Atlantic. Altogether seven species are 


known. 


Tuaynnus.—The first dorsal continuous, with the spines rather 


Fig, 205.—Thynnus thynuus. 


feeble ; from six to nine finlets behind the dorsal and anal. 


458 FISHES. 


Scales of the pectoral region crowded, forming a corslet. Teeth 
rather small. A longitudinal keel on each side of the tail. 


The best-known species of this genus is the “Tunny” 
(Thynnus thynnus), abundant in the Mediterranean, and rang- 
ing to the south coast of England and to Tasmania. It is 
one of the largest fishes of the ocean, attaining to a length of 
10 feet, and to a weight of more than 1000 lbs. The fishery 
of the Tunny is systematically carried on in the Mediter- 
ranean, and dates from the most remote antiquity. Its salted 
preparation was esteemed by the Romans under the name of 
Saltamentum sardicum. Its flesh is extensively eaten now, 
fresh as well as preserved. 

Thynnus pelamys, or the “ Bonito,” is equally well known, 
and ranges over all the tropical and temperate seas ; it eagerly 
pursues the Flying-fish, and affords welcome sport and food 
to the sailor. In its form it resembles the Tunny, but is 
more slender and rarely above three feet long. 

Some of the other species are provided with very long 
pectoral fins, and generally called by sailors “ Albacore.” 
They are said to grow to a length of six feet; Bennett in his 
“Whaling Voyage,” vol. ii. p. 278, makes the following obser- 
vations on 7. germo, from the Pacific: “ Ships when cruising 
slowly in the Pacific Ocean, are usually, attended by myriads 
of this fish for many successive months. A few days’ rapid 
sailing is, nevertheless, sufficient to get rid of them, however 
numerous they may be, for they seldom pay more than very 
transient visits to vessels making a quick passage. When 
the ship is sailing with a fresh breeze they swim pertinaciously 
by her side and take the hook greedily, but should she be 
lying motionless or becalmed they go off to some distance in 
search of prey, and cannot be prevailed upon to take the 
most tempting bait the sailor can devise. It is probably as 
a protection from their chief enemy, the Sword-fish, that they 
seek the society of a ship. I am not aware that the Shark is 


MACKERELS. 459 


also their enemy; but they seemed to have an instinctive 
dread of this large fish, and when it approached the ship, 
would follow it in shoals, and annoy it in the same manner 
as the smaller birds may be seen to annoy those of a larger 
and predaceous kind, as the hawk or owl. They are very 
voracious and miscellaneous feeders. Flying-fish, Calmars, 
and small shoal-fish are their most natural food; though 
they do not refuse the animal offal from a ship. Amongst 
the other food contained in their maw, we have found small 
Ostracions, File-fish, Sucking-fish, Janthina shells, and pelagic 
crabs; in one instance a small Bonita, and in a second a 
Dolphin eight inches long, and a Paper-nautilus shell con- 
taining its sepia-tenant. It was often amusing to watch an 
Albacore pursuing a Flyine-fish, and to mark the precision 
with which it swam beneath the feeble eronaut, keeping 
him steadily in view, and preparing to seize him at the 
moment of his descent. But this the Flying-fish would often 
elude by instantaneously renewing his leap, and not un- 
frequently. escape by extreme agility.” 


Prtamys.—tThe first dorsal continuous, with the spines rather 
feeble ; from seven to nine finlets behind the dorsal and anal. 
Scales of the pectoral region forming a corslet. Teeth moderately 
strong. <A longitudinal keel on each side of the tail. 

Five species are known, of which P. sarda is common in 
the Atlantic and Mediterranean. 


Avxis.—Differing from the preceding two genera in having 
very small teeth in the jaws only, none on the palate. 


Auzis roches common in the Atlantic, Mediterranean, and 
Indian Ocean. 


Cypium.—The first dorsal continuous, with the spines rather 
feeble ; generally more than seven finlets behind the dorsal and 
anal. Scales rudimentary or absent. Teeth strong; a longi- 
tudinal keel on each side of the tail. . 


Twelve species from the tropical Atlantic and Indian 


460 FISHES. 


Ocean ; frequenting more the coast-region than the open sea ; 
attaining to a length of four or five feet. 


ELACATE.—Body covered with very small scales; head de- 
pressed ; cleft of the mouth moderately wide; no keel on the 
tail. The spinous dorsal is formed by eight small free spines ; 
finlets none. Villiform teeth in the jaws, on the vomer and the 
palatine bones. 


Hlacate nigra, a coast fish common in the warmer parts of 
the Atlantic and the Indian Ocean. 


EcHENEIS.—The spinous dorsal fin is modified into an adhesive 
disk, occupying the upper side of the head and neck, 


This genus is closely allied to the preceding, from which 
it differs only by the transformation of the spinous dorsal 
fin into a sucking organ. The spines being composed of two 
halves, each half is bent down towards the right and the left, 
forming a support to a double series of transverse lamelle, 
rough on their edges, the whole disk bemg of an oval shape 
and surrounded by amembranous fringe. Each pair of lamelle 
is formed out of one spine, which, as usual, is supported at 
the base by an interneural spine. By means of this disk the 
“Sucking-fishes ” or “Suckers” are enabled to attach them- 
selves to any flat surface, a series of vacuums being created 
by the erection of the usually recumbent lamelle. The ad- 
hesion is so strong that the fish can only be dislodged with dift- 
culty, unless it is pushed forward by a sliding motion. The 
Suckers attach themselves to sharks, turtles, ships, or any 
other object which serves their purpose. They cannot be 
regarded as parasites, inasmuch as they obtain their food 
independently of their host. Being bad swimmers they 
allow themselves to be carried about by other animals 
or vessels endowed with a greater power of locomotion. 
They were as well known to the ancients as they are to 
the modern navigators. Aristotle and Aelian mention the 
Sucker under the name of @@eip, or the Louse ; “In the sea 


SUCKING-FISH. A461 


between Cyrene and Egypt there is a fish about the Dolphin 
(Delphinus), which they call the Louse; this becomes the 
fattest of all fishes, because it partakes of the plentiful supply 
of food captured by the Dolphin.” Later writers, then, repeat 
a story, the source of which is unknown, viz. that the 
“Remora” is able to arrest vessels in their course, a story 
which has been handed down to our own time. It need not 
be stated that this is an invention, though it cannot be denied 
that the attachment of one of the larger species may retard 
the progress of a sailing vessel, especially when, as is some- 
times the case, several individuals accompany the same ship. 
An account of a somewhat ingenuous way of catching 
sleeping turtles by means of a Sucking-fish held by a ring 
fastened round its tail, appears to have originated rather from 
an experiment than from regular practice. 

Ten different species are known, of which Eeheneis remora 
and Heheneis naucrates are the most common. The former is 
short and grows to a length of eight inches only, the latter is 
a slender fish, not rarely found three feet long. The bulkiest 
is Hehencis scutata, which attains to a leneth of two feet; 
individuals of that size weighing about eight lbs. 

The number of pairs of Jamelle varies in the various 
species, from 12 to 27. The caudal fin of some of the species 
undergoes great changes with age. In young specimens 
the middle portion of the fin is produced into a long 
filiform lobe. This lobe becomes gradually shorter, and the 
fin shows a rounded margin in individuals of middle age. 
When the fish approaches the mature state, the upper and 
lower lobes are produced, and the fin becomes subcrescentic 
or forked. 


{See Giinther, ‘‘On the History of Echeneis.” Ann. and Mag. Nat. 
Hist., 1860. ] 


462 FISHES. 


EIGHTH FAMILY.—TRACHINID&. 


Body elongate, low, naked or covered with scales. Teeth 
small, conical. No bony stay for the preoperculum. One or 
two dorsal fins, the spinous portion being always shorter and 
much less developed than the soft; the anal similarly developed 
as the soft dorsal ; no finlets. Ventrals with one spine and five 
rays.  Gill-opening more or less wide. Ten or more than ten 
abdominal, and more than fourteen caudal vertebre. 

Carnivorous coast-fishes of small size, found in every 
quarter of the globe, but scarcely represented in the Arctic 
zone (Z'richodon); on the other hand, they are rather numer- 
ous towards the Antarctic circle. All are bad swimmers, 
generally moving along the bottom in small depths. Only 
one genus (Bathydraco) is known from the deep-sea. 

A genus which shows the principal characters of this 
family (Callipteryx), has been found in the tertiary deposits 
of Monte Bolea; it is scaleless, A second genus, Z'rachinopsis, 
has been recently described by Sauvage from the Upper 
Tertiary of Lorca in Spain; and a third (Pseudoeleginus) from 
the Miocene of Licata. 

This family may be subdivided into five groups :— 


1. In the Uranoscorina the eyes are on the upper surface of 
the head, directed upwards ; the lateral line is continuous. 

Uranoscopus. — Head large, broad, thick, partly covered 
with bony plates ; cleft of the mouth vertical. Scales very small. 
Two dorsal fins, the first with from three to five spines ; ventrals 
jugular ; pectoral rays branched. Villiform teeth in the jaws, 
on the vomer and palatine bones; no canines. Generally a 
long filament below and before the tongue. Gill-cover armed. 

The position of the eyes on the upper surface of the head, 
which these fishes have in common with many others, is well 
expressed by the name Uranoscopus (Stare-gazer). Their eyes 
are very small, and can be raised or depressed at the will of 


TRACHINID AL. 463 


the fish. They are inactive fishes, generally lying hidden at 
the bottom between stones, watching for their prey. The 
delicate filament attached to the bottom of their mouth, and 
playing in front of it in the current of water which passes 
through the mouth, serves to lure small animals within reach 
of the fish, Eleven species are known from the Indo-Pacific 
and Atlantic, and one (U. scaber) from the Mediterranean ; 
they attain rarely a length of twelve inches. 
Leproscopus.—Form of thehead as in Uranoscopus, but entirely 
covered with a thin skin. Scales small, cycloid. One continuous 
dorsal; ventrals jugular; pectoral rays branched. Villiform 


teeth in both jaws, on the vomer and palatine bones; canines 
none. No oral filament. Gill-cover unarmed. 


Fig. 206.—Leptoscopus macropygus. 


Leptoscopus macropygus, not rare on the coast of New 
Zealand. 

Other genera of Stare-gazers are Agnus from the Atlantic 
coasts of North America; Anema from the Indian Ocean and 
New Zealand; and Kathetostoma from Australia and New 
Zealand. 

2. In the Tracuinina the eyes are more or less lateral; the 
lateral line is continuous; and the intermaxillary without a 
larger tooth on its posterior portion. 

TRACHINUS.—Cleft of the mouth very oblique ; eye lateral, 
but directed upwards. Scales very small, cycloid. Two dorsal 
fins, the first short, with six or seven spines; ventrals jugular ; 
the lower pectoral rays simple. Villiform teeth in the jaws, on 
the vomer and palatine bones. Preorbital and preoperculum 


armed. 


464 FISHES. 


The “ Weevers” are common fishes on the European 
coasts, and but too well known to all fishermen ; singularly 
enough they do not extend across the Atlantic to the 
American coast, but reappear on the coast of Chi! Wounds 
by their dorsal and opercular spines are much dreaded, being 
extremely painful, and sometimes causing violent inflamma- 
tion of the wounded part. No special poison-organ has been 
found in these fishes, but there is no doubt that the mucous 
secretion in the vicinity of the spines has poisonous properties. 
The dorsal spines as well as the opercular spine have a deep 
double groove in which the poisonous fluid is lodged, and by 
which it is inoculated in the punctured wound. On the 
British coasts two species occur, 7. draco, the Greater Weever, 
attaining to a leneth of twelve inches, and 7. vipera, the 
Lesser Weever, which grows only to half that size. 

CHamPsopon.—Body covered with minute granular scales ; 
lateral lines two, with numerous vertical branches. Cleft of the 
mouth wide, oblique. Eye lateral, but directed upwards. Two 
dorsal fins ; ventral fins jugular ; pectoral rays branched. Teeth 
in the jaws in a single series, thin, long, of unequal size. Teeth 
on the vomer, none on the palate. Gill-openings exceedingly — 
wide. Preoperculum with a spine at the angle and a fine serra- 
ture on the posterior margin. 

Champsodon voraxz is not uncommon at small depths off 
the Philippine Islands, Admiralty Islands, and in the Arafura 
Sea. 

Percis.—Body cylindrical, with small ctenoid scales ; cleft 
of the mouth slightly oblique ; eye lateral, but directed upwards. 
Dorsal fins more or less continuous, the spinous with four or five 
short stiff spines ; ventrals a little before the pectorals. Villi- 
form teeth in the jaws, with the addition of canines ; teeth on 
the vomer, none on the palatines. Opercles feebly armed. 


Fifteen species; small, but prettily coloured shore-fishes 
of the Indo-Pacific. 


SILLAGO.—Body covered with rather small, ctenoid scales. 


TRACHINID A, 465 


Cleft of the mouth small, with the upper jaw rather longer; eye 
lateral, large. Two dorsals, the first with from nine to twelve 
spines; ventrals thoracic. Villiform teeth in the jaws, and on 
the vomer, none on the palatine bones. Operculum unarmed ; 
preoperculum serrated. The bones of the head with wide 
muciferous channels. 

Eight species; small, plain-coloured shore-fishes, common 


in the Indian Ocean to the coasts of Australia. 


BovicutHys.—Head broad and thick ; cleft of the mouth 
horizontal, with the upper jaw rather longer; eye lateral, more 
or less directed upwards. Scales none. ‘Two separate dorsal 
fins, the first with eight spines; ventrals jugular; the lower 
pectoral rays simple. Villiform teeth in the jaws, on the vomer 
and the palatine bones ; no canines. Operculum with a strong 
spine ; prorbital and preoperculum not armed. 

Three species are known from the South Pacific. 


Fig. 207.—Head of Bovichthys variegatus, from New Zealand. 


BaTHyDRACO.— Body elongate, sub-cylindrical; head depressed, 
with the snout much elongate, spatulate ; mouth wide, horizon- 
tal, with the lower jaw prominent; eyes very large, lateral, 
close together. Scales very small, imbedded in the skin. Lateral 
line wide, continuous. One dorsal fin; ventrals jugular; the 

2H 


466 FISHES. 


lower pectoral rays branched. Teeth in the jaws in villiform 
bands ; none on the vomer or the palatine bones. Opercles 
unarmed ; ten branchiostegals ; the gill-membranes free from the 
isthmus, and but slightly united in front. Air-bladder none. 


A deep-sea fish, found at a depth of 1260 fathoms in the 
Antarctic Ocean (south of Heard Island). 


CHANICHTHYS.—Head very large, with the snout spatulate,and 
with the cleft of the mouth very wide. Eye lateral. Scales 
none; lateral line sometimes with granulated scutes. Two 
dorsals, the first with seven spines ; ventrals jugular. Jaws with 
rasp-like teeth ; palate toothless. 


Chenichthys rhinoceratus from Kerguelen’s Land (see Fig. 
108, p. 291); and Ch. esow from the Straits of Magelhaen. 

Other genera belonging to this group are Aphritis, Acan- 
thaphritis, Eleginus, Chenichthys, and Chimarrhichthys from 
the South Pacific and Antarctic zone; Cottoperca from the 
west coast of Patagonia; Percophis from the coast of Southern 
Brazil; and Zrichodon from the coast of Kamtschatka. 


3. Inthe Pincurreprna the body is covered with small scales ; 
the eye lateral; the lateral line continuous; and the inter- 
maxillary is armed with a larger tooth on its posterior portion, 
as in many Labroids. 

Two genera, Pinguipes and Latilus, from various parts of 
tropical and sub-tropical seas, belong to this group. 


4, In the Psrupocuromipgs, the lateral line is interrupted or 
not continued to the caudal fin; they have one continuous 
dorsal only. 


These fishes are inhabitants of coral reefs or coasts: 
Opisthognathus, Pseudochromis, Cichlops, and Pseudoplesvops. 

5. In the Nororaenmna the lateral line is interrupted ; and 
the dorsal fin consists of two separate portions. 

They (with others) represent in the Antarctic zone the 
Cottoids of the Northern Hemisphere: they have the same 
habits as their northern analogues. In Notothenia, which on 


BATRACHID.®, 467 


the southern extremity of South America, in New Zealand, 
Kerguelen’s Land, etc., is represented by about twenty species, 
the body is covered with ctenoid scales, and the bones of the 
head are unarmed; whilst Harpagifer, a small species with 
a similar range as Notothenia, has the body naked, and the 
operculum and sub-operculum armed with long and strong 
spines. 


NINTH FAMILY—MALACANTHIDA, 


Body elongate, with very small scales; mouth with thick 
lips ; a strong tooth posteriorly on the intermaxillary. Dorsal 
and anal fins very long, the former with a few simple rays 
anteriorly ; ventrals thoracic, with one spine and five rays. 
tull-opening wide, with the gill-membranes united below the 
throat. Ten abdominal and fourteen caudal vertebre. 

One genus only, Malacanthus, with three species from 
tropical seas. 


TENTH FAMILY—BATRACHIDA, 


Head broad and thick; body elongate, compressed behind ; 
skin naked or with small scales. No bony stay for the pre- 
operculum. Teeth conical, small or of moderate size. The 
spinous dorsal consists of two or three spines only ; the soft and 
the anal long. Ventrals jugular, with two soft rays ; pectorals 
not pediculated. ull-opening a more or less vertical slit before 
the pectoral, rather narrow. 

Carnivorous fishes, of small size, living on the bottom of 
the sea near the coast in the tropical zone, some species 
advancing into the warmer parts of the temperate zones. 


Barracuus.—The spinous dorsal is formed by three stout 
spines. Gill-covers armed with spines. Circumference of the 
mouth and other parts of the head frequently provided with 
small skinny tentacles. 


Some of the fishes of this genus possess a subcutaneous 


468 FISHES. 


spacious cavity behind the base of the pectoral fin, the inside 
of which is coated with a reticulated mucous membrane. It 
opens by a foramen in the upper part of the axil.— This 
apparatus is the same which is found in many Siluroid fishes, 
and which has been noticed above, p. 192. There cannot be 
any doubt that it is a secretory organ, but whether the 
secretion has any poisonous properties, as in the Siluroids, or 
as in Thalassophryne, has not been determined. No instance 
of poisonous wounds having been inflicted by these fishes is 
on record. Twelve species are known, the distribution of 
which coincides with that of the family ; one very fine species, 
BL. didactylus, occurs in the Mediterranean. 


THALASSOPHRYNE.—The spinous dorsal is formed by two 
spines only, each of which is hollow, like the opercular spine, and 
conveys the contents of a poison-bag situated at its base. Canine 
teeth none. 

Two species are known from the Atlantic and Pacific 
coasts of Central America. The poison-apparatus is more 
perfectly developed than any other known at present in the 
class of fishes; it has been described above, p. 192. The 


Fig. 208.—Thalassophryne reticulata. 


of 


species figured, Zh. reticulata, is not uncommon at Panama, 
and attains to a length of fifteen inches. 


PoricHTHys.—Two small dorsal spines; a canine tooth on 
each side of the vomer. 
Two species, from the Atlantic and Pacific sides of Central 


and South America. 


PEDICULATI. 469 


ELEVENTH FAMILY—PSYCHROLUTID&. 


Body rather elongate, naked ; head broad. Spinous dorsal 
separate or absent. Ventral fins close together, thoracic, com- 
posed of a few rays. Teeth small. Three gills and a half; 
pseudobranchice well developed ; gill-openings of moderate width, 
the gill-membranes being attached to the isthmus. 

Of this family only two representatives are known, viz. 
Psychrolutes paradoxus, from Vancouver's Islands, without 
first dorsal fin; and Neophrynichthys latus, from New Zealand, 
with two dorsal fins. Both are very scarce marine fishes. 


TWELFTH FAMILY—PEDICULATI. 


Head and anterior part of the body very large, without 
scales. No bony stay for the preoperculum. Teeth villiform 
or rasp-like. The spinous dorsal is advanced forwards, com- 
posed of a few more or less isolated spines, often transformed 
into tentacles ; or entirely absent. Ventral fins jugular, with 
four or five soft rays, sometimes absent. The carpal bones are 
prolonged, forming a sort of arm, terminating in the pectoral. 
Gill-opening reduced to a small foramen, situated im or near 
the avil. Gills two and a half, or three, or three and a half ; 
pseudobranchie generally absent. 

This family contains a larger number of bizarre forms 
than any other; and there is, perhaps, none in which the 
singular organisation of the fish is more distinctly seen to be in 
consonance with its habits. Pediculates are found in all seas. 
The habits of all are equally sluggish and inactive ; they are 
very bad swimmers; those found near the coasts lie on the 
bottom of the sea, holding on with their arm-like pectoral 
fins by sea-weed or stones, between which they are hidden ; 
those of pelagic habits attach themselves to floating sea-weed 
or other objects, and are at the mercy of wind and current. A 


470 FISHES. 


large proportion of the genera, therefore, have gradually found 
their way to the greatest depths of the ocean; retaining all 
the characteristics of their surface-ancestors, but assuming the 
modifications by which they are enabled to live in abyssal 
depths. 

Lopuius.—Head exceedingly large, broad, depressed, with the 
eyes on its upper surface ; cleft of the mouth very wide. Jaws 
and palate armed with rasp-lke depressible teeth of unequal 
size. Body naked; bones of the head armed with numerous 
spines. The three anterior dorsal spines are isolated, situated 
on the head, and modified into long tentacles ; the three follow- 
ing spines form a continuous fin; the soft dorsal and anal 
short. Gills three. Young individuals have the tentacles beset 
with lappets, and most of the fin-rays prolonged into filaments. 


These fishes are well known under the names “ Fishing- 
Frog,” “ Frog-fishes,’ “ Anglers,” or “Sea-devils.” They are 
coast-fishes, living at very small depths. Four species are 
known: the British species (LZ. piscatorius) found all round 
the coasts of Europe and Western North America, and on the 
Cape of Good Hope; a second (Mediterranean) species, ZL. 


Fig. 209.—Lophius piscatorius. 


budegassa ; L. setigerus from China and Japan; and JL. 
naresit from the Admiralty Islands. 
The habits of all these species are identical. The wide 


FISHING-FROG. 471 


mouth extends all round the anterior circumference of the 
head, and both jaws are armed with bands of long pointed 


Fig. 210.—A young Fishing-Frog. 


teeth, which are inclined inwards, and can be depressed so 
as to offer no impediment to an object ghding towards the 
stomach, but prevent its escape from the mouth. The pec- 
toral and ventral fins are so articulated as to perform the 
functions of teeth, the fish being enabled to move, or rather 
to walk, on the bottom of the sea, where it generally hides 
itself in the sand, or amongst sea-weed. All round its head, 
and also along the body, the skin bears fringed appendages, 
resembling short fronds of sea-weed; a structure which, 
combined with the extraordinary faculty of assimilating the 
colours of the body to its surroundings, assists this fish 
ereatly in concealing itself. in places which it selects on 
account of the abundance of prey. To render the organisa- 
tion of these creatures perfect in relation to their wants, they 


472 FISHES. 


are provided with three long filaments inserted along the 
middle of the head, which are, in fact, the detached and 
modified three first spines of the anterior dorsal fin. The 
filaments most important in the economy of the fishing-frogs 
is the first, which is the longest, terminates in a lappet, and 
is movable in every direction. There is no doubt that the 
Fishing-frog, like many other fish provided with similar 
appendages, plays with this filament as with a bait, attract- 
ing fishes, which, when sufficiently near, are ingulfed by the 
simple act of the Fishing-frog opening its gape. Its stomach 
is distensible in an extraordinary degree, and not rarely fishes 
have been taken out of it quite as large and heavy as their 
destroyer. The British species grows to a length of more 
than five feet; specimens of three feet are common. Baird 
records that the spawn of the same species has been observed 
as a floating sheet of mucus, of from some 60 to 100 square feet. 


CERATIAS.—Head and body much compressed and elevated ; 
cleft of the mouth wide, subvertical. Eyes very small. Teeth 
in the jaws rasp-like, depressible ; palate toothless. Skin covered 
with numerous prickles. The spinous dorsal is reduced to two 
long isolated spines, the first on the middle of the head, the 
second on the back. The soft dorsal and anal short ; caudal 
very long. Ventrals none ; pectorals very short. Two and a 
half gills. Skeleton soft and fibrous. 

Ceratias holbolli, a deep-sea fish; only a few examples 
have been found near the coast of Greenland, and from the 
mid-Atlantic ; the latter at a depth of 2400 fathoms. Deep 
black. 


HmranroLopHus.—Head and body compressed and elevated ; 
cleft of the mouth wide, oblique. Eyes very small. Teeth of 
the jaws rasp-like, depressible ; palate toothless. Skin with 
scattered conical tubercles. The spinous dorsal is reduced to a 
single tentacle on the head. The soft dorsal, anal, caudal, and 
pectoral short. Ventrals none. Three and a half gills, Skele- 
ton soft and fibrous. 


—. “os 


” 


PEDICULATI. 473 

This is another deep-sea form, hitherto found in very few 

examples in the Arctic and Mid-Atlantic Oceans. The 

single tentacle is beset with many long filaments at its 

extremity, thus answering the same purpose which is attained 
by a greater number of tentacles. Deep black. 


MELANOCETUS.—Head and body compressed ; head very large ; 
cleft of the mouth exceedingly wide, vertical. Eyes very small. 


Fig. 211.—Melanocetus johnsonii. 


Teeth of the jaws and vomer rasp-like, depressible. Skin smooth. 
The spinous dorsal is reduced to a single filament placed on the 
head. The soft dorsal and anal short. Ventrals none. 


Two species are known from the Atlantic : JZ. bispinossus 
and M. johnsonii, obtained at depths of from 560 to 1800 
fathoms. The specimen figured was not quite four inches 
long, and contained in its stomach, rolled up spirally into a 
ball, a Scopeline fish which measured 7} inches in length 
and one inch in depth. 


Onetropes.—A deep-sea fish from the Arctic Ocean, differing 
from the preceding in possessing a second isolated dorsal ray 
on the back. 

AnTENNARIUS.—Head very large, high, compressed ; cleft of 
the mouth vertical or sub-vertical, of moderate width. Jaws 
and palate armed with rasp-like teeth. Eye small. Body naked 


474 FISHES. 


or covered with minute spines; generally with tentacles. The 
spinous dorsal is reduced to three isolated spines, the anterior 
of which is modified into a tentacle, situated above the snout. 
The soft dorsal of moderate length; anal short. Ventrals 
present. 


The fishes of this genus are pelagic, frequently met with in 
mid-ocean between the tropics, especially in parts of the sea 
with floating vegetation ; not rarely individuals are found far 
from their native latitudes, carried by currents to the coasts 
of Norway and New Zealand. Their power of swimming is 
most imperfect. When near the coast they conceal them- 
selves between corals, stones, or fucus, holding on to the 
eround by means of their arm-like pectoral fins. Their 
coloration is so similar to their surroundings that it is hardly 
possible to distinguish the fish from a stone or coral over- 
erown with vegetation. Their way of attracting and seizing 
their prey is evidently the same as in the other fishes of this 
family. The extraordinary range of some of the species which 
inhabit the Atlantic as well as the Indo-Pacific Oceans, is the 
consequence of their habit of attaching themselves to floating 
objects. Almost all the species are highly coloured, but the 
pattern of the various colours varies exceedingly. These 
fishes do not attain to any considerable size, and probably 
never exceed a length of ten inches. A great number of 
species have been distinguished by ichthyologists, but pro- 
bably not more than twenty are known at present. The 
species figured on p. 295 (A. caudomaculatus) is common 
in the Red Sea, and probably occurs in other parts of the 
Indian Ocean. 


Brachionichthys and Saecarius are allied genera from South 
Australia, Tasmania, and New Zealand. 
? } 


CHAUNAX.—Head very large, depressed ; cleft of the mouth 
wide, sub-vertical ; eye small; rasp-like teeth in the jaws and 
palate. Skin covered with minute spines. The spinous dorsal 


PEDICULATI. 475 


is reduced to a small tentacle above the snout; the soft dorsal 
of moderate length ; anal short ; ventrals present. 


A deep-sea fish (Ch. pictus), of uniform pink colour ; 
hitherto found near Madeira and the Fidji Islands, at a depth 
of 215 fathoms. 


MaurHe.— Anterior portion of the body very broad and 
depressed. The anterior part of the snout is produced into a 
more or less prominent process, beneath which there is a tentacle 
retractile into a cavity. Jaws and palate with villiform teeth. 
Skin with numerous conical protuberances. Soft dorsal fin and 
anal very short. Gull-opening superiorly in the axil; gills two 
and a half. 

Although the rostral tentacle is situated at the lower side 
of the projection of the snout, it must be regarded as the 
homologue of a dorsal spine. In some of the preceding 
genera, Onetrodes and Chaunaz, the first dorsal spine is so far 
advanced on the snout as to come into connection with the 
intermaxillary processes; and the position of the rostral 
tentacle in A/althe is only a still more advanced step towards 
the same special purpose for which the first dorsal spine is used 
in this family, viz. for the purpose of obtaining food. In 
Malthe it is obviously an organ of touch. This genus belongs 
to the American shores of the Atlantic; JL vespertilio being 
a tropical, M/Z. cubifrons a northern species. 


HALIEUTzZA.— Head exceedingly large, depressed, nearly circular 
in its circumference. Cleft of the mouth wide, horizontal. Jaws 
with small rasp-like teeth; palate smooth. Forehead with a 
transverse bony bridge, beneath which is a tentacle (rostral spine) 
retractile into a cavity. Body and head covered with small 
stellate spines. Soft dorsal and anal very short. Gill-opening 
superiorly in the axil; gills two and a half. 

A coast-fish (ZZ. stellata) from China and Japan. Frequently 
found dry in Chinese insect-boxes. 

This genus appears to be represented in the Atlantic 
Ocean by Halieutichthys from Cuba, and by Dibranchus, 


476 FISHES. 


dredged at a depth of 360 fathoms off the coast of West 
Africa; the latter genus possesses two gills only. Another 
genus, covered with large scattered tubercles, Aegwonichthys, 
has recently been described from New Zealand. 


THIRTEENTH FAMILY—COTTIDA, 


Form of the body oblong, sub-cylindrical. Cleft of the 
mouth lateral. Dentition feeble, generally in villiform bands. 
Some bones of the head are armed; and a bony stay connects 
the preopercular spine with the infraorbital ring. Two dorsal 
jins (rarely one), the spinous being less developed than the soft 
and than the anal. Ventrals thoracic, with five or less soft 
TUYS. 

The fishes of this family are of small size, bad swimmers, 
and generally living on the bottom, near the coasts, of almost 
all the arctic, temperate, and tropical seas. Only a few live 
in fresh water. They prefer shallow to deep water; and there 
is only one instance known of a member of this family living 
at a great depth, viz. Cottus bathybius from the Japanese sea, 
which is stated to have been dredged in a depth of 565 
fathoms. Fossil representatives are few in number: two or 
three species of Zrigla; others, although having a general 
resemblance to the genus Cottus, were covered with ctenoid 
scales, and therefore are referred to a distinct genus, Lepido- 
cottus ; they are from tertiary formations. 


Cotrus.—Head broad, depressed, rounded in front ; body sub- 
cylindrical, compressed posteriorly. Scaleless ; lateral line pre- 
sent. Pectoral rounded, with some or all the rays simple. Jaws 
and vomer with villiform teeth ; palatine teeth none. 

The “ Bull-heads” or “ Miller’s Thumbs” are small fishes 
from the shores and fresh waters of the northern temperate 
zone. Some forty species are known; the greater number 


COTTIDA. ATT 


live in the northern half of the temperate zone. On the 
shore, as well as in rivers, they prefer rocky or stony to 
muddy ground, lying concealed between the stones, and 
watching for their prey, which consists of small crustaceans 
and other aquatic animals. The common British Miller’s 
Thumb (C. gobio) is found in almost all suitable fresh waters 
of Northern and Central Europe, especially in small streams, 
and extends into Northern Asia. Other freshwater species 
abound in North America and Northern Asia.  Cottus 
scorpius and C. bubalis, the common European marine species, 
range across the Atlantic to the American coasts. The male 
is said to construct a nest, for the reception of the spawn, of 
sea-weeds and stones, and to anxiously watch and defend 
his offspring. The spine at the angle of the preeoperculum, 
which is simple in the majority of the freshwater species, is 
frequently armed with accessory processes, and antler-like, 
in marine. 


CANTRIDERMICHTHYS differs from Cottus in having teeth on the 
palatine bones. 

Eleven species are known, distributed like Cottus, but 
absent in Europe and North-western Asia. 


IcELus.—Head large, armed at the gill-covers and on the 
neck ; body with a dorsal series of bony plates from the neck to 
the base of the caudal; lateral line with osseous tubercles ; 
scattered scales on the sides and abdomen. Ventrals thoracic, 
with less than five rays. No pectoral filaments. Villiform teeth 
in the jaws, on the vomer and palatine bones. 

Represents Cottus in the far north; LZ. hamatus is common 
in Spitzbergen and Greenland, and has been found in abun- 
dance in lat. 81° 44’, 


PLATYCEPHALUS.—Head broad, much depressed, more or less 
armed with spines; body depressed behind the head, sub- 
cylindrical towards the tail, covered with ctenoid scales. Two 
dorsal fins ; the first spine isolated from the others. Ventrals 


478 FISHES. 


thoracic, but rather remote from the base of the pectorals. 
Villiform teeth in the jaws, on the vomer and palatine bones. 


‘ hes 
ay. 


i 
RF 


Fig. 212.—Platycephalus cirrhonasus, from Port Jackson. 
About forty species are known, of which some attain a 
leneth of two feet. This genus 
represents in the tropical Indian 
Ocean the Cotti of the Arctic, and 
the Notothene of the Antarctic 
zone. Like these, they live on the 
bottom in shallow water, hidden 
Fig. 213.—Scale from the lateral in the sand, the colours of which are 

line of the same fish. assimilated by those of their body. 
Therefore, they are very scarce near coral islands which are 
surrounded by great depths; whilst the number of species 
is rather considerable on many points of the shelving Aus- 
tralian coasts. Their long and strong ventral fins are of great 
use to them in locomotion. JP. insidiator is one of the most 
common Indian and Australian fishes, and readily recog- 
nised by two oblique black bands on the upper and lower 
caudal lobes. 

HopLicHTHys, similar to Platycephalus, but with the back and 
sides of the body covered with bony spiny plates. No separate 
dorsal spine. 

One species, HZ. langsdor fii, is common on the coast of 
Japan, and frequently placed dry by the Chinese into their 
insect-boxes. 

TrIcLA.—Head parallelopiped, with the upper surface and the 
sides entirely bony, the enlarged infraorbital covering the cheek. 


GURNARDS. 


Two dorsal fins. Three free pectoral 


479 


rays. Villiform teeth. 


Air-bladder generally with lateral muscles, often divided into two 

lateral halves. The species may be referred to three groups :— 

1. Palatine teeth none; scales exceedingly small, except 
those of the lateral line: Tvrigla. 

2. Palatine teeth none; scales of moderate size: Lepido- 


trigla. 


3. Palatine teeth present : Prionotus. 


About forty species of “Gurnards” are known from tropical 


and temperate zones. They are too 


well known to need 


detailed description ; one of their principal characteristics is 


the three free finger-like pectoral appendages, which serve as 


Fig. 214,.—Trigla pleuracanthica. 


organs of locomotion as well as touch, and which are supplied 


with strong nerves, as noticed above 
(pp. 108 and 120). The fins are fre- 
quently beautifully ornamented, espe- 
cially the inner side of the long and 
broad pectorals, which is most exposed 
to the light when the fish is floating 
on the surface of the water, with pec- 
torals spread out like wings. The 
erunting noise made by Gurnards when 
taken out of the water is caused by 
the escape of gas from the air- 
bladder through the open pneumatic 


Fig. 215. —Scute of the 
lateral line of the same fish. 


duct. Gurnards are 


480 FISHES. 


generally used as food; seven species occur on the British 
coast: the Red Gurnard (7. pind), the Streaked Gurnard 
(7. lineata), the Sapphirine Gurnard (7. hirundo), the Grey 
Gurnard (7. gurnardus), Bloch’s Gurnard (7. ceuculus), the 
Piper (7. lyra), and the Long-finned Gurnard (7. obscura or 7. 
lucerna). Singularly, the European species cross the Atlantic 
but rarely, the American species belonging chiefly to the 
division Prionotus. 

Several other genera belong to this family; for com- 
pleteness’ sake they are mentioned here, viz. Bunocottus from 
Cape Horn; Rhamphocottus, Triglops from Arctic North 
America ; Podabrus, Blepsias, Nautichthys, Scorpenichthys, 
Hemilepidotus, Artedius, from the North Pacific ; Ptyonotus, 
from Lake Ontario; Polycaulus from Indian Seas; Bembras 
from the Japanese Sea. 


FOURTEENTH FAMILY—CATAPHRACTI. 


Form of the body elongate, sub-cylindrical. Dentition feeble. 
Body completely cwirassed with osseous keeled scales or plates. 
A bony stay connects the angle of the preoperculum with the 
infraorbital ring. Ventrals thoracie. 

Marine fishes, and partly pelagic. Petalopteryx, from the 
chalk of Mount Lebanon, is supposed to have a resemblance 
to Dactylopterus. 

AGonus.—Head and body angular, covered with bony plates. 
Two dorsal fins ; no pectoral appendages. Small teeth in the 
jaws. 

Small fishes, from the northern parts of the temperate 
zone and extending into the Arctic Ocean ; the genus re- 
appears in the Southern Hemisphere on the coast of Chile. 
Of the eleven species known, one (A. cataphractus) 1s not 
uncommon on the coast of Great Britain. 


ASPIDOPHOROIDES, from Greenland, has a very similar form 
of the body, but possesses one short dorsal fin only. 


CATAPHRACTI. 481 


SIpHAGONUS.—With the snout produced into a long tube 
like a Syngnathus ; chin prominent, with a barbel. 

From Behring’s Strait and Japan. 

PERISTETHUS.—Head parallelopiped, with the upper surface 
and the sides entirely bony ; each preeorbital prolonged into a long 
flat process, projecting beyond the snout. Body cuirassed with 
large bony plates. One continuous dorsal, or two dorsals, of which 
the second is the more developed. Two free pectoral appendages. 
Teeth none ; lower jaw with barbels. 


Singularly shaped fishes, of rather small size, from the 
Mediterranean, the warmer parts of the Atlantic, and the 
Indian Ocean ; of the ten species known one species only has 
been found in the Pacific, near the Sandwich Islands. The 
European species is P. cataphractum. They are not common, 
and probably inhabit greater depths than the Gurnards, with 
which they have much in common as regards their habits, 


DACTYLOPTERUS.—Head parallelopiped, with the upper surface 
and the sides entirely bony ; scapula and angle of the przoper- 
culum produced into long spines. Body with strongly keeled 
scales of moderate size; lateral lime none. Two dorsal fins, 


\ 


Zi 


Fig. 216. 


Dactylopterus volitans. 


the second not much longer than the first ; pectoral very long, 
an organ of flying, with the upper portion detached and shorter. 
Granular teeth in the jaws ; none on the palate. Air-bladder 
divided into two lateral halves, each with a larger muscle. 

21 


482 FISHES. 


Of “Flymg Gurnards” three species only are known, 
which are very abundant in the Mediterranean, the tropical 
Atlantic, and Indo-Pacific. They, and the Flying Herrings 
(Exocoetus), are the only fishes which are enabled by their 
long pectoral fins to take flymg leaps out of the water, and 
deserve the name of “ Flying-Fishes.” They are much heavier, 
and attain to a larger size, than the Exocoeti, specimens of 
eighteen inches in length not being scarce. When young, 
their pectorals are much shorter, and, consequently, they are 
unable to raise themselves out of the water (Cephalacanthus). 

The vertebral column shows a singular coalescence of the 
anterior vertebree, which form a simple tube, as in /istularia. 


WE insert here as an appendix to this division the small 
family of Pegasida, the natural affinities of which are not yet 
clearly understood, but which resembles in some of its char- 
acters the Cataphracti. 


FIFTEENTH FAMILY—PEGASID. 


Body entirely covered with bony plates, anchylosed on the 
trunk and movable on the tail. Barbels none. The margin of 
the upper jaw is formed by the intermaxillaries and their cuta- 
neous prolongation, which extends downwards to the extremity 
of the maxillaries, Crill-cover formed by a large plate, homolo- 
gous to the operculum, preoperculum, and suboperculum ; in- 
teroperculum a long fine bone, hidden below the gill-plate. One 
rudimentary branchiostegal. The gill-plate is united with the 
isthinus by a narrow membrane ; gill-openings narrow, in front 
of the base of the pectoral fin. Gulls four, lamellated. Pseudo- 
branchie and air-bladder absent. One short dorsal and anal 
Jin, opposite to each other. Ventral fin present. Ovarian sacs 
closed. 

One genus only is known, Pegasus. Its pectoral fins are 
broad, horizontal, long, composed of simple rays, some of which 


PEGASUS. 483 


are sometimes spinous. Ventral fins one- or two- rayed. 
Upper part of the snout produced into a shorter or longer 
process. Mouth inferior, toothless. Suborbital ring well 
developed, forming a suture with the gill-cover. Vertebre 
in small number, thin; no ribs. Four species are known, 
two of which are of a shorter, and the two others of a longer 
form. The former are P. draconis, common in the Indian 
Ocean, and P. volans, which is frequently stuck by the Chinese 
into the insect-boxes which they manufacture for sale. The 


Fig. 217.—Pegasus natans. 


two elongate species, P. natans and P. lancifer, are from the 
Chinese and Australian coasts. They are all very small fishes, 
probably living on sandy shoal places near the coast. 


q 


NintH DIvIsSION—ACANTHOPTERYGIL GOBIIFORMES, 


The spinous dorsal, or spinous portion of the dorsal is 
always present, short, either composed of flexible spines, or much 
less developed than the soft ; the soft dorsal and anal of equal 
extent. No bony stay for the angle of the preoperculum.  Ven- 
trals thoracic or jugular, of present, composed of one spine and 
jive, rarely four, soft rays. A prominent anal papilla. 

Shore-fishes, mostly exclusively marine, but some entering 
and living in fresh waters. 


First FAMILY—DISCOBOLI. 


Body thick or oblong, naked or tubercular. Teeth small. 


484. FISHES. 


Ventral fins with one spine and five rays, all being rudimentary 
and forming the osseous support of a round disk, which is sur- 
rounded by a cutaneous fringe. Gull-openings narrow, the qill- 
membranes being attached to the isthmus. 

Carnivorous fishes, living at the bottom of the shores of 
northern seas. By their ventral disk they are enabled to 
attach themselves very firmly to rocks. 


CycLopTEerus.— Body thick, short, covered with a viscous, 
tubercular skin. Head large, snout short. Villiform teeth in 
the jaws, none onthe palate. Skeleton soft, with but little earthy 
matter. 

Three species of “ Lump-suckers” are known from the 
northern temperate and the arctic zones. The common 
North European and North American species, C. lwmpus, is 


Fig, 218.—Cyclopterus lumpus. a, Ventral disk. 


known also by the names of “Cock- and Hen- Paddle.” It 
attains to a length of twenty-four inches, but generally is 
much smaller. It is difficult to remove it from any object to ~ 
which it once has attached itself by means of its sucking-disk. 
Its skin is so thick as to more or less entirely conceal the first 
dorsal fin; it is covered with rough tubercles, the larger ones 
being arranged in four series along each side of the body. 
In young specimens these tubercles are absent. The arctic 
species, C. spinosus, has large conical plates on the head and 


. GOBIES. 485 


body, each plate with a spine in the centre. Also of this 
‘species the young are naked, the plates making only gradu- 


Fig. 219.—Young of Cyclopterus spinosus, from the Arctic Ocean, natural size. 


ally their appearance, in the form of groups of tubercles. 
Their development is irregular, as young specimens of the 
same size may be entirely naked or tubercular. This species 
ranges beyond the 81° lat. N. 


Liparts.—Body sub-cylindrical, enveloped in a more or less 
loose naked skin ; head broad, obtuse. The infraorbital bone is 
styliform posteriorly, extending backwards to the margin of the 
preoperculum. One dorsal fin, with feeble flexible rays.  Villi- 
form teeth in the jaws, none on the palate. 


Small fishes from the northern coasts of the temperate 
zone, ranging beyond the arctic circle. Eight species are 
known, of which two (LZ. lineatus and L. montagui) occur on 
the British coasts. : 


SECOND FAMILY—GOBIIDA. 


Body elongate, naked or scaly. Teeth generally small, 
sometimes with canines. The spinous dorsal fin, or portion of 
the dorsal fin, is the less developed, and composed of flexrble 
spines ; anal similarly developed as the soft dorsal. Sometimes 
the ventrals are wnited into a disk. Cill-opening more or less 
narrow, the gill-membranes being attached to the isthmus. 

Small carnivorous littoral fishes, many of which have 
become acclimatised in fresh water. They are very abundant 
with regard to species as well as individuals, and found on or 


486 FISHES. ° 


near the coasts of all temperate and tropical regions. Geo- 
logically they appear first in the chalk. 

Gopius.—Body scaly. Two dorsal fins, the anterior generally 
with six flexible spines. Ventral fins united, forming a disk 
which is not attached to the abdomen. Gill-opening vertical, 
moderately wide, 

The “Gobies” are distributed over all temperate and 
tropical coasts, and abundant, especially on the latter. Nearly 
three hundred species have been described. They live espe- 
cially on rocky coasts, attaching themselves firmly with their 
ventrals to a rock in almost any position, and thus withstand- 
ing the force of the waves. Many of the species seem to 
delight in darting from place to place in the rush of water 
which breaks upon the shore. Others live in quiet brackish 
water, and not a few 
have become entirely 
acchmatised in fresh 


water, especially lakes. 


The males of some species 


Fig. 220.—Gobius lentiginosus, from construct nests for the 
New Zealand. egos, which they jeal- 


ously watch, and defend even for some time after the young 
are hatched. Several species are found on the British coast : 
Gt. niger, paganellus, auratus, minutus, ruthensparre. Fossil 
species of this genus have been found at Monte Bolea. 

A very small Goby, Zatrunculus pellucidus, common in 
some localities of the British Islands and other parts of 
Europe, is distinguished by its transparent body, wide mouth, 
and uniserial dentition. According to R. Collett it offers 
some very remarkable peculiarities. It lives one year only, 
being the first instance of an annual vertebrate. It spawns 
in June and July, the eges are hatched in August, and the 
fishes attain their full growth in the months from October to 
December. In this stage the sexes are quite alike, both 


¥ 


GOBIES. 487 


having very small teeth and feeble jaws. In April the males 
lose the small teeth, which are replaced by very long and 
strong teeth, the jaws themselves becoming stronger. The 
teeth of the females remain unchanged. In July and August 
all the adults die off, and in September only the fry are to 
be found. 

There are several other genera, closely allied to Gobius, 
as Huctenogobius, Lophiogobius, Doliichthys, Apocryptes, Hvor- 
thodus, Gobiosoma and CGobiodon (with scaleless body) 7riceno- 
phorichthys. 


StcypruM.—Body covered with ctenoid scales of rather small 
size. Cleft of the mouth nearly horizontal, with the upper jaw 
prominent ; lips very thick ; the lower lip generally with a series 
of minute horny teeth. A series of numerous small teeth in 
upper jaw, implanted in the gum, and generally movable ; the 
lower jaw with a series of conical widely-set teeth. Two dorsal 
fins, the anterior with six flexible spines. Ventral fins united, 
and forming a short disk, more or less adherent to the abdomen. 

Small freshwater fishes inhabiting the rivers and rivulets 
of the islands of the tropical Indo-Pacific. About twelve 
species are known; one occurs in the West Indies. Lentipes 
from the Sandwich Islands is allied to Steydium. 


PrriopuTtHaLmus.—Body covered with ctenoid scales of small 
or moderate size. Cleft of the mouth nearly horizontal, with the 
_ upper jaw somewhat longer. Eyes very close together, imme- 
diately below the upper profile, prominent, but retractile, with a 
well-developed outer eyelid. Teeth conical, vertical in both 
jaws. Two dorsal fins, the anterior with flexible spines ; caudal 
fin with the lower margin oblique ; base of the pectoral fin free, 
with strong muscles. Ventral fins more or less coalesced. Gull- 
openings narrow. 

The fishes of this genus, and the closely-allied Boleophthal- 
mus, are exceedingly common on the coasts of the tropical 
Indo-Pacific, especially on parts covered with mud or fucus. 


During ebb they leave the water and hunt for small crusta- 


488 FISHES. 


ceans, and other small animals disporting themselves on the 
eround which is left uncovered by the receding water. With 
the aid of their strong pectoral and ventral fins and their 
tail, they hop freely over the ground, and escape danger by 
rapid leaps. The peculiar construction of their eyes, which 


Fig. 221.—Periophthalmus koelreuteri. 


are very movable, and can be thrust far out of their sockets, 
enables them to see in the air as well as in the water ; when 
the eyes are retracted they are protected by a membranous 
eyelid. These fishes are absent in the eastern parts of the 
Pacific and on the American side of the Atlantic; but singu- 
larly enough one species reappears on the West African 
coast. About seven species are known (including Boleoph- 
thalmus), P. koelreutert being one of the most common fishes 


of the Indian Ocean. 


Exrorris.—Body scaly ; eyes of moderate size, lateral, not 
prominent. Teeth small. Two dorsal fins, the anterior generally 
with six spines. Ventrals not united, though close together, with 
one spine and five rays. 


About sixty species are known from the tropics, only a 
few extending into the temperate zone. As regards form, 
they repeat almost all the modifications observed among the 
Gobies, from which they differ only in having the ventral 
fins non-coalescent. On the whole they are somewhat larger 
than the Gobies, and rather freshwater than marine species, 
some of them being abundant in the rivulets of the islands of 


ol 
es | 


GOBIES. 489 


the Indo-Pacific and Atlantic. Others have even penetrated 
into the inland-waters of the African continent. 


TrypavucHen.—Body elongate, covered with minute scales ; 
head compressed, with a deep cavity on each side, above the 
operculum. Teeth small, in a band. One dorsal, the spinous 
portion composed of six spines ; dorsal and anal fins continuous 
with the caudal, ventral fins united. 

Small fishes of singular aspect, from the East Indian 


coasts. Three species, of which 7. vagina is common. 


CALLIONYMusS.—Head and anterior part of the body depressed, 
the rest cylindrical, naked. Snout pointed, with the cleft of the 
mouth narrow, horizontal, and with the upper jaw very pro- 
tractile. Eyes rather large, more or less directed upwards. 
Teeth very small, palate smooth. A strong spine at the angle 
of the preoperculum. Two dorsal fins, the anterior with three 
or four flexible spines ; ventrals five-rayed, widely apart from 
each other. Gill-openings very narrow, generally reduced to a 
foramen on the upper side of the operculum. 

The “Dragonets” are small, and generally beautifully 
coloured marine fishes, inhabitants of the coasts of the 
temperate zone of the Old World; the minority of species 
live in tropical parts of the Indo-Pacific; and these seem to 
descend to somewhat greater depths than the littoral species 
of the northern hemisphere. Secondary sexual characters 
are developed in almost all the species, the mature males 
having the fin-rays prolonged into filaments, and the fin- 
membranes brightly ornamented. On the British coast one 
species ((. draco) is very common, and locally called 
“Skulpin.” About thirty species are known, many of which 
have the preeopercular spine armed with processes or barbs. 
Vulsus is allied to Callionymus. 

Other genera belonging to this family are—Benthophilus 
from the Caspian Sea; Amblyopus, Orthostomus, Platyptera, 
Luciogobius, Oxymetopon, and, perhaps, Oxuderces. 


49() FISHES. 


TENTH DIVISION—ACANTHOPTERYGII BLENNIIFORMES. 


Body low, sub-cylindrical or compressed, elongate. Dorsal 
jin very long; the spinous portion of the dorsal, if distinct, is 
very long, as well developed as the soft, or much more ; sometimes 
the entire fin is composed of spines only; anal more or less 
long; caudal fin subtruncated or rounded, if present. Ventral 
jins thoracic or jugular, if present. 


First FAMILY—CEPOLID&. 


Body very elongute, compressed, covered with very small 
eycloid scales; eyes rather large, lateral. Teeth of moderate 
size. No bony stay for the angle of the preoperculum. One 
very long dorsal fin, which, like the anal, is composed of soft 
rays. Ventrals thoracic, composed of one spine and five rays. 


Gill-opening wide. Caudal vertebra: exceedingly numerous. 


The “ Band-fishes” (Cepola) are small marine fishes, belong- 
ing principally to the fauna of the northern temperate zone; in 
the Indian Ocean the genus extends southwards to Pinang. 
The European species (C. rubescens) is found in isolated ex- 
amples on the British coast, but is less scarce in some years 
than in others. These fishes are of a nearly uniform red 
colour. 


SECOND FAMILY—TRICHONOTIDA. 


Body elongate, sub-cylindrical, covered with cycloid scales of 
moderate size. Eyes directed upwards. Teeth in villiform 
bands. No bony stay for the angle of the preoperculum. One 
long dorsal fin, with simple articulated rays, and without a 
spinous portion ; anal long. Ventrals jugular, with one spine 
and five rays. Gill-opening very wide. The number of caudal 
vertebra: much exceeding that of the abdominal. 

Small marine fishes, belonging to two genera only, Z'richo- 


o 


HETEROLEPIDOTID. 491 


notus (setigerus) from Indian Seas, with some of the anterior 
dorsal rays prolonged into fila- 
ments; and Hemerocoetes (acan- 
thorhynchus) from New Zealand, 
and sometimes found far out at 
sea on the surface. 


THIRD FAMILY—HETERO- 
LEPIDOTID.&. 


Body oblong, compressed, scaly ; 


‘ Fig. 222.—Scale from the lateral 
eyes lateral ; cleft of the mouth line of Hemeroceetes acantho- 


lateral © dentition Jeeble. The  vhynchus, with lacerated margin. 
angle of the preoperculum connected by a bony stay with the 
infraorbital ring. Dorsal long, with the spinous and soft por- 
tions equally developed; anal elongate. Ventrals thoracie, with 
one spine and five rays. 


Fig. 223.—Chirus hexagrammus, from Japan. 


Small shore-fishes, characteristic of the fauna of the 
Northern Pacific,some of the species occurring on the American 
as well as Asiatic side. They have been referred to several 
genera, as 

Currus, which is distinguished by the presence of several 
lateral lines ; 

OPHIODON, with one lateral line only, cycloid scales, and 
slightly armed preeoperculum ; 

AGRAMMUS, with one lateral line only, ctenoid scales, and 
unarmed preeoperculum ; and 

ZANIOLEPIS, with one lateral line and minute comb-lke scales. 


492 FISHES. 


FourtH FAMILY—BLENNUIDA. 


Body elongate, low, more or less cylindrical, naked or covered 
with scales, which generally are small. One, two, or three dorsal 
fins occupying nearly the whole length of the back, the spinous 
portion, if distinct, being as much developed as the soft, or more; 
sometimes the entire fin is composed of spines; anal fin long. 

Ventrals jugular, composed of a few rays, and sometimes rudi- 
mentary or entirely absent. Pseudobranchiee generally present. 

Littoral forms of great generic variety, occurring abund- 
antly in all temperate and tropical seas. Some of the species 
have become acclimatised in fresh water, and many inhabit 
brackish water. With very few exceptions they are very 
small, some of the smallest fishes belonging to the family of 
“Blennies.” One of the principal characteristics of the 
Blennies is the ventral fin, which is formed by less than five 
rays, and has a jugular position. The Blennies have this in 
common with many Gadoids, and it is sometimes difficult to 
decide to which of these two families a fish should be referred. 
In such doubtful cases the presence of the pseudobranchiz 
(which are absent in Gadoids) may be of assistance. 

In many Blennies the ventral fins have ceased to have 
any function, and become rudimentary, or are even entirely 
absent. In others the ventral fins, although reduced to 
cylindrical stylets, possess a distinct function, and are used 
as organs of locomotion, by the aid of which the fish moves 
rapidly over the bottom. 

The fossil forms are scarcely known; Plerygocephalus from 
Monte Bolca appears to have been a Blennioid. 

ANARRHICHAS.—Body elongate, with rudimentary scales ; 
snout rather short ; cleft of the mouth wide ; strong conical teeth 
in the jaws, those on the sides with several pointed tubercles ; 
a biserial band of large molar teeth on the palate. Dorsal fin 


long, with flexible spines; caudal separate. Ventrals none. 
Gill-openings wide. 


BLENNIES. 493 


The “Sea-wolf,” or “Sea-cat” (A. lupus), is a gigantic 


Fig. 224.—Teeth of the Wolf-fish, Anarrhichas lupus. 


Blenny, attaining to a length of more than six feet. With 
its enormously strong tubercular teeth it is able to crush the 
hardest shells of Crustaceans or Mollusks, on which it feeds 
voraciously, It is an inhabitant of the northern seas, like 
two other allied species, all of which are esteemed as food by 
the inhabitants of Iceland and Greenland. Two other species 
of Sea-wolves occur in the corresponding latitudes of the 
North Pacific. 


BLENNIUS.—Body moderately elongate, naked ; snout short. 
A single dorsal, without detached portion; ventrals jugular, 
formed by a spine and two rays. Cleft of the mouth narrow ; 
a single series of immovable teeth in the jaws; generally a 
curved tooth behind this series in both jaws, or in the lower 
only. A more or less developed tentacle above the orbit. Gill- 
opening wide. 

About forty species of Blennius (in the restricted generic 
sense) are known from the northern temperate zone, the 
tropical Atlantic, Tasmania, and the Red Sea. But in the 
tropical Indian Ocean they are almost entirely absent, and 
replaced by other allied genera. Three species, found near 
the Sandwich Islands, are immigrants into the Pacific from 
the American Continent. They generally live on the coast, 
or attach themselves to floating objects, some species leading 
a pelagic life, hiding themselves in floating seaweed, in 


494. FISHES. 


which they even propagate their species. All species readily 
accustom themselves to fresh water, and some (4. vulgaris) 
have become entirely acclimatised in inland lakes. British 
species are B. gattorugine (growing to a length of twelve 
inches), B. ocellaris, B. galerita, and B. pholis, the common 
“« Shanny.” 

Chasmodes is a genus allied to Blennius, from the Atlantic 
coasts of temperate North America. | 


PETROSCIRTES.—Body moderately elongate, naked. Snout 


225,—Petroscirtes bankieri, from Hong-Kong. 


generally short. A single dorsal fin ; ventrals composed of two 
or three rays. Cleft of the mouth 
narrow ; a single series of immov- 
able teeth in the jaws; a strong 
curved canine tooth behind this 
,, series, that of the lower jaw much 
gr stronger than that of the upper. 
Head sometimes with tentacles. Gill- 
Fig. 226.—Dentition of the same, opening reduced to a small fissure 
aes above the root of the pectoral. 


Thirty species, from the tropical Indo-Pacific, of small 


size. 


SALARIAS.—Body moderately elongate, naked ; snout short, 
with transverse cleft of the mouth ; a series of numerous small 
teeth in the jaws, implanted in the gum and movable ; generally 
a curved canine tooth on each side of the lower jaw, behind the 
series of small teeth. Dorsal fin continuous, sometimes divided 
into two portions by a more or less deep notch without a de- 


BLENNIES. 495 


tached anterior part. Ventral fins with two or three rays. A 
tentacle above the orbit. Gull-openings wide. 

Sixty species are known from the tropical zone, extending 
northwards to Madeira, southwards to Chile and Tasmania. 
In certain individuals of some of the species a longitudinal 
cutaneous crest is developed; all young individuals lack it, 
and in some other species it is invariably absent. Singularly 
enough this crest is not always a sexual character, as one 
might have supposed from analogy, but im some species at 
least it is developed in both sexes. Mature males, however, 
have generally higher dorsal fins and a more intense and 
variegated coloration than females and immature males, as 1s 


also the case in Bleninius. 


Ciinus—Body moderately elongate, covered with small scales ; 
snout rather short ; a narrow band or series of small teeth in the 
jaws and on the palate. Dorsal fin formed by numerous spines 
and a few soft rays, without a detached anterior portion ; anal 
spines two. Ventrals with two or three rays. A tentacle above 
the orbit. Gill-opening wide. 

Thirty species, from the coasts of tropical America and 
the southern temperate zone. Three other genera are closely 
allied to Clinus, viz. Cristiceps and Cremnobates, in which the 
three anterior dorsal spines are detached from the rest of the 
bale 


which the two anterior are spinous. The species of these 


and Tripterygium, with three distinct dorsal fins, of 


genera are as numerous as those of Clinus, occurring in many 
parts of tropical seas,in the Mediterranean, and being espe- 
cially well represented im South Australia and New Zealand. 


SticH£uUS.—Body elongate, covered with very small scales ; 
lateral line more or less distinct, sometimes several lateral lines. 
Snout short ; very small teeth in the jaws, and generally on the 
palate. Dorsal fin long, formed by spines only. Ventrals with 
two or three rays. Caudal fin distinct. Gill-openings rather 
wide. 


496 FISHES. 


Small fishes, peculiar to the coasts near the arctic circle, 
ranging southwards to the coasts of Japan and Scandinavia. 
Ten species. 

BLENNIOPS.—Body moderately elongate, covered with very 
small scales ; lateral line none. Snout short ; small teeth in the 
jaws, none on the palate. Dorsal fin long, formed by spines 
only. Ventrals with one spine and three rays. Caudal dis- 
tinct. Guill-openings of moderate width, the gill-membranes 
coalescent across the isthmus. 

A fine but not common kind of Blenny (2. ascanii), from 
the British and Scandinavian coasts. 

CENTRONOTUS.—Body elongate, covered with very small 
scales ; lateral line none. Snout short ; very small teeth in the 


jaws. Dorsal fin long, formed by spines only. Ventrals none 
or rudimentary ; caudal separate. Gill-openings of moderate 
width, gill-membranes coalescent. 

Ten species are known from the northern coasts; south- 
wards the genus extends to the coasts of France, New York, 
California, and Japan. C. gunellus, or the “ Gunnel-fish ” 
or “ Butter-fish,” is common on the British coasts. Apo- 
dichthys is allied to Centronotus, but the vertical fins are 
confluent ; and a very large, excavated, pen-like spine lies 
hidden in a pouch in front of the anal fin. This spine is 
evidently connected in some way with the generative organs, 
as a furrow leads from the orifice of the oviduct to the groove 
of the spine. One species from the Pacific coast of North 
America. Xiphidion is another closely allied genus from the 
sane locality. 

CRYPTACANTHODES. — Body very elongate, naked, with a 
single lateral line. Head with the muciferous system well 
developed. Eye rather small. Conical teeth in the jaws, on 
the vomer and palatine bones. One dorsal formed by spines 
only ; caudal connected with dorsal and anal. Ventrals none. 


Gillopening of moderate width, with the gill-membranes joined 
to the isthmus. 


BLENNIES. 497 


One species (C. maculatus) from the Atlantic coasts of 
North America. 


Paracus.—Body oblong, elevated anteriorly ; snout short, 
with sub-vertical anterior profile ; minute teeth in the jaws and 


Fig. 227. 


Patzcus fronto. 


on the vomer. Dorsal fin with the anterior spines strong and 
long, continuous with the caudal; ventrals none. Gill-openings 
wide. , 

Three species of this singular form are known from South 
and West Australia. 


ZOARCES.—Body elongate, with the scales rudimentary ; 
conical teeth in the jaws. Dorsal fin long, with a depression on 
the tail, which is formed by a series of spines much shorter than 
the rays. No other fin-spines. No separate caudal fin. Ven- 
trals short, formed by three or four rays. Gull-openings wide. 


Two species are known, one from the European, and the 
other from the North American side of the Atlantic. The 
former, Z viviparus, is well known by the name of “ Viviparous 
Blenny;” as is signified by this name it produces its young 
alive. These are so matured at the time of their birth that 
on their first exclusion they swim about with the utmost 
agility. No fewer than from two to three hundred young 
are sometimes produced by one female, and the abdomen of 
the mother is so distended before parturition that it is impos- 
sible to touch it without causing them to be extruded. Full 
grown individuals are about twelve inches long, but the 

2K 


498 FISHES. 


American species (7 anguillaris) attains to a length of two 
or three feet. 

Other genera of the family of Blennoids are :—Llennophis, 
Nemophis, Plagiotremus, Neoclinus, Cebidichthys, Myxodes, 
LHeterostichus, Dictyosoma, Lepidoblennius, Dactyloscopus, Gunel- 
lichthys, Urocentrus, Stichwopsis, Sticharvum, Notograptus, 
Pholidichthys, and Pseudoblennius, 


FirtH FAMILY—ACANTHOCLINID&, 


Body elongate, low, compressed, covered with small scales, 
One dorsal fin, occupying nearly the whole of the back, and 
chiefly composed of spines. Anal fin long, with numerous spines. 
Ventrals jugular, composed of a few rays only. 


Of this family one fish only is known (Acanthoclinus 
littoreus), a small Blenny abundant on the coast of New 
Zealand. 


SIXTH FAMILY—MASTACEMBELIDA. 


Body elongate, cel-like, covered with very small scales. 
Mandible long, but little moveable. Dorsal fin very long, the 
anterior portion composed of numerous short isolated spines ; 
anal fin with spines anteriorly. Ventrals none. The humeral 
arch is not suspended from the skull.  Gill-openings reduced 
to a slit at the lower part of the side of the head. 

Freshwater-fishes characteristic of and almost confined to 
the Indian region. The structure of the mouth and of the 
branchial apparatus, the separation of the humeral arch from 
the skull, the absence of ventral fins, the anatomy of the 
abdominal organs, affords ample proof that these fishes are 
Acanthopterygian eels. Their upper jaw terminates in a 
pointed moveable appendage, which is concave and transversely 
striated inferiorly in Rhynchobdella, and without transverse 
strie in Mastacembelus: the only two genera of this family. 


BARRACUDA. 499 


Thirteen species are known, of which Rh. aculeata, M. pancalus 
and I. armatus are extremely common, the latter attaining 


Fig. 228.—Mastacembelus argus, from Siam. 


to a length of two feet. Outlying species are JZ. aleppensis 
from Mesopotamia and Syria, and JZ. eryptacanthus, M. marchei, 
and M. niger, from West Africa, 


ELEVENTH DIVISION— ACANTHOPTERYGII MUGILIFORMES. 


Two dorsal fins more or less remote from each other ; the 
anterior either short, like the posterior, or composed of feeble 


spines, Ventral fins with one spine and five rays, abdominal, 


First FAMILY—SPHYRANID&. 


Body elongate, sub-cylindrical, covered with small eycloid 
scales ; lateral line continuous, Cleft of the mouth wide, 
arned with strong teeth. Eye lateral, of moderate size. 
Vertebre. twenty-four. 

This family consists of one genus only, Sphyrwna, gene- 
rally called “ Barracudas,” large voracious fishes from the 
tropical and sub-tropical seas, which prefer the vicinity of the 
coast to the open sea. They attain to a length of eight feet, 
and a weight of forty pounds ; individuals of this large size are 
dangerous to bathers. They are generally used as food, but 
sometimes (especially in the West Indies) their flesh assumes 
poisonous qualities, from having fed on smaller poisonous 
fishes. Seventeen species. 

The Barracudas existed in the tertiary epoch, their remains 
being frequently found at Monte Bolea. Some other fossil 
genera have been associated with them, but as they are known 
from jaws and teeth or vertebre only, their position in the 


500 FISHES. 


system cannot be exactly determined; thus Sphyrewnodus and 
Hypsodon from the chalk of Lewes, and the London clay of 
Sheppey. The American Portheus is allied to Hypsodon. 
Another remarkable genus from the chalk, Sawrocephalus, 


has been also referred to this family.’ 


SECOND FAMILY—ATHERINID~. 


Body more or less elongate, sub-cylindrical, covered with 
scales of moderate size; lateral line indistinct. Cleft of the 
mouth of moderate width, with the dentition feeble. Hye lateral, 
large or of moderate size. Cill-openings wide. Vertebroe very 
NUMETOUS. 

Sinall carnivorous fishes inhabiting the seas of the tem- 
perate and tropical zones; many enter fresh water, and some 
have been entirely acclimatised in it. This family seems to 
have been represented in the Monte Bolca formation by 
Mesogaster. 

ATHERINA.—Teeth very small; scales cycloid. The first 
dorsal is short and entirely separated from the second. Snout 
obtuse, with the cleft of the mouth straight, oblique, extending 
to or beyond the anterior margin of the eye. 

The Atherines are littoral fishes, living in large shoals, 
which habit has been retained by the species acclimatised in 
fresh water. They rarely exceed a length of six inches, but 
are nevertheless esteemed as food. From their general 
resemblance to the real Smelt they are often thus misnamed, 
but may always be readily recognised by their small first 
spinous dorsal fin. The young, for some time after they are 
hatched, cling together in dense masses, and in numbers 
almost incredible. The inhabitants of the Mediterranean 

1 The systematic affinities of these extinct genera are very obscure. Cope 
places them, with others (for instance Protosphyrana, which has a sword-like 


prolongation of the ethmoid), in a distinct family, Sawrodontide: see * Ver- 
tebrata of the Cretaceous Formations of the West,” 1875. 


GREY MULLETS. 501 


coast of France call these newly hatched Atherines “ Nonnat ” 
(unborn). Some thirty species are known, of which A. pres- 
byter and A. boyert occur on the British coast. - 


ATHERINICHTHYS, distinguished from Atherina in having the 
snout more or less produced ; and the cleft of the mouth gene- 
rally does not extend to the orbit. 


These Atherines are especially abundant on the coasts 
and in the fresh waters of Australia and South America. Of 
the twenty species known, several attain a length of eighteen 
inches and a weight of more than a pound. All are highly 
esteemed as food; but the most celebrated is the “Pesce 
Rey ” of Chile (A. laticlavia). 


TETRAGONURUS.—Body rather elongate, covered with strongly 
keeled and striated scales. The first dorsal fin is composed of 
numerous feeble spiries, and continued on to the second. Lower 
jaw elevated, with convex dental margin, and armed with com- 
pressed, triangular, rather small teeth, in a single series. 


This very remarkable fish is more frequently met with in 
the Mediterranean than in the Atlantic, but generally scarce. 
Nothing is known of its habits; when young it is one of the 
fishes which accompany Medusee, and, therefore, it must be 
regarded as a pelagic form. Probably, at a later period of its 
life, it descends to greater depths, coming to the surface at 
night only. It grows to a length of eighteen inches. 


THIRD FAMILY—MUGILID. 


Body more or less oblong and compressed, covered with eycloid 
scales of moderate size ; lateral line none. Cleft af the mouth 
narrow or of moderate width, without or with feeble teeth. Hye 
lateral, of moderate size. Guill-opening wide. The anterror 
dorsal fin composed of four stiff spines. Vertebroe twenty-four. 

The “Grey Mullets” inhabit in numerous species and in 
ereat numbers the coasts of the temperate and tropical 


502 FISHES. 


zones. They frequent brackish waters, in which they find an 
abundance of food which consists chiefly of the organic sub- 
stances mixed with mud or sand; in order to prevent larger 
bodies from passing into the stomach, or substances from 
passing throueh the gill-openings, these fishes have the organs 
of the pharynx modified into a filtering apparatus. They 
take in a quantity of sand or mud, and, after having worked 
it for some time between the pharyngeal bones, they eject the 
roughest and indigestible portion of it. The upper pharyn- 
geals have a rather irregular form; they are slightly arched, 
the convexity being directed towards 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, at least on its interior posterior portion ; 
this membrane is studded all over with minute horny cilia. 
The pharyngeal bone rests upon a large fatty mass, giving 
it a considerable degree of elasticity. There is a very large 
venous sinus between the anterior portion of the pharyngeal 
and the basal portion of the branchial arches. Another mass 
of fat, of elliptical form, occupies the middle of the roof of the 
pharynx, between the two pharyngeal bones. Each branchial 
arch is provided on each side, in its whole length, with a 
series of closely-set gill-rakers, which are laterally bent 
downwards, each series closely fitting into the series of the 
adjoining arch; they constitute together a sieve, admirably 
adapted to permit a transit for the water, retaining at 
the same time every other substance in the cavity of the 
pharynx. 

The lower pharyngeal bones are elongate, crescent-shaped, 
and broader posteriorly than anteriorly. Their imner surface 
is concave, corresponding to the convexity of the upper 
pharyngeals, and provided with a single series of lamelle, 
similar to those of the branchial arches, but reaching across 
the bone from one margin to the other. 


GREY MULLETS., 503 


The intestinal tract shows no less peculiarities. The 
lower portion of the cesophagus is provided with numerous 
long thread-like papille, and continued into the oblong-ovoid 
membranaceous ccecal portion of the stomach, the mucosa of 
which forms several longitudinal folds. The second portion 
of the stomach reminds one of the stomach of birds; it 
communicates laterally with the other portion, is globular, 
and surrounded by an exceedingly strong muscle. This 
muscle is not divided into two as in birds, but of great thick- 
ness in the whole circumference of the stomach, all the 
muscular fasciculi being circularly arranged. The internal 
cavity of this stomach is rather small, and coated with a 
tough epithelium, longitudinal folds running from the entrance 
opening to the pyloric, which is situated opposite to the other. 
A low circular valve forms a pylorus. There are five rather 
short pyloric appendages. The intestines make a great num- 
ber of circumvolutions, and are seven feet long in a specimen 
thirteen inches in length. 

Some seventy species of Grey Mullets are known, the 
majority of which attain to a weight of about four pounds, but 


Fig. 229.—Mugil proboscideus. 


there are many which grow to ten and twelve pounds. All are 
eaten, and some even esteemed, especially when taken out of 
fresh water. If attention were paid to their cultivation, great 
profits could be made by fry being transferred into suitable 


504 FISHES. 


backwaters on the shore, in which they rapidly grow to a 
marketable size. Several species are more or less abundant 
on the British coasts, as Mugil octo-radiatus (Fig. 105, p. 254), 
M. capito, M. auratus (Fig. 106, p. 254), and JL. septentrionalis 
(Fig. 107, p. 254), which, with the aid of the accompanying 
figures, and by counting the rays of the anal fin, may be 
readily distinguished—J. octo-radiatus having eight, and MV. 
capito and M. auratus nine soft rays. A species inhabiting 
fresh waters of Central America (JZ proboscideus) has the snout 
pointed and fleshy, thus approaching certain other fresh- 
water and littoral Mullets, which, on account of a modifica- 
tion of the structure of the mouth, have been formed into a 
distinct genus, Agonostoma. Myxus comprises Mullets with 
teeth more distinct than in the typical species. 

This genus existed in the tertiary epoch, remains of a 
species having been found in the gypsum of Aix, in Provence. 


TWELFTH DIVISION—ACANTHOPTERYGIIL GASTROSTEIFORMES. 


The spinous dorsal is composed of isolated spines uf present ; 
the ventrals are either thoracic or have an abdominal position 
in consequence of the prolongation of the pubie bones which are 
attached to the humeral arch. Mouth small, at the end of the 
snout which is generally more or less produced. 


First FAMILY—GASTROSTEIDA. 


Body elongate, compressed. Cleft of the mouth oblique ; 
villiform teeth im the jaws. Opercular bones not armed ; in- 
fraorbitals covering the cheek; parts of the skeleton forming 
incomplete external mails. Scales none, but generally large 
scutes along the side. Isolated spines in front of the soft dorsal 
jin. Ventral fins abdominal, joined to the pubic bone, com- 
posed of a spine and a small ray. Branchiostegals three, 


STICKLEBACKS. 505 


Of “Sticklebacks” (Gastrosteus) about ten species are 
satisfactorily known, one of which (G. spinachia) lives in salt 
and brackish water, whilst the others mhabit principally 
fresh waters, although they all are able to exist in the sea. 
They are confined to the Temperate and Arctic zones of the 
northern hemisphere. The British freshwater species are 
the Three-spined Stickleback (G@. aculeatus), which sometimes, 
especially in Central Europe, lacks scutes, sometimes has a 
series of scutes along the side of the body ; the Four-spined 
Stickleback (GL spinulosus) and the Nine-spined Stickleback 
(G. pungitius). The commonest North American species is 
G. noveboracensis. The habits of all the freshwater species 


Fig. 230.—Gastrosteus noveboracensis. 


are very similar. The common European species (G. aculeatus) 
is an active and greedy little fish, extremely destructive to the 
fry of other species, and consequently injurious in ponds 
where these are sought to be preserved. It is scarcely to be 
conceived what damage these little fishes do, and how greatly 
detrimental they are to the increase of all the fishes in general 
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. A small Stickleback, 
kept in an aquarium, devoured, in five hours’ time, seventy- 
four young dace, which were about a quarter of an inch long, 
and of the thickness of a horse hair. ‘Two days after it swal- 
lowed sixty-two ; and would, probaby, have eaten as many 
every day could they have been procured. The Stickleback 


506 FISHES. 


sometimes swarms in prodigious numbers. Pennant states 
that at Spalding, in Lincolnshire, there was once in seven 
years amazing shoals, which appear in the Welland, coming 
up the river in the form of a vast column. The quantity may, 
perhaps, be conceived from the fact that a man employed in 
collecting them, gained, for a considerable time, four shillings 
a-day by selling them at the rate of a halfpenny a bushel. 
Costa, who studied the manners of these small fishes, relates 
that, on the approach of spawning time, the male builds 
a nest of stalks of grass and other matters in a hollow 
of the bottom, a little above three inches wide and about 
six inches and a half deep, creeping over the materials on 
his belly, and cementing them with the mucus that exudes 
from his skin. The bottom of the nest is first laid, then 
the sides are raised, and lastly the top is covered over. A 
small hole is left on one side for an entrance. When the 
erection is complete, he seeks out a female, and conduct- 
ing her, Costa says, with many caresses, to the nest, intro- 
duces her by the door into the chamber. In a few minutes 
she has laid two or three eggs, after which she bores a hole 
on the opposite side of the nest to that by which she 
entered, and makes her escape. The nest has now two doors, 
and the eges are exposed to the cool stream of water, which, 
entering by one door flows out at the other. Next day the 
male goes again in quest of a female, and sometimes brings 
back the same, sometimes finds anew mate. This is repeated 
until the nest contains a considerable number of eggs, and 
each time the male rubs his side against the female and 
passes over the eggs. Next the male watches a whole month 
over his treasure, defending it stoutly against all invaders, 
and especially against his wives, who have a great desire to 
get at the eggs. When the young are hatched and able to 
do for themselves his cares cease. 

The Sea-Stickleback (G. spinachia) is likewise a nest 


FLUTE-MOUTHS. 507 


builder, choosing for its operations especially the shallows of 
brackish water, which are covered with Zostera. 


SECOND FAMILY—FISTULARIID&. 


Fishes of greatly elongated form ; the anterior bones of the 
skull are much produced, and form a long tube, terminating in 
a narrow mouth. Teeth small ; scales none, or small. The 
spinous dorsal fin is either formed by feeble isolated spines or 
entirely absent ; the soft dorsal and anal of moderate length, ven- 
tral fins thoracic or abdominal, composed of five or six rays, 
without spine ; uf abdominal, they are separate from the pubic 
bones, which remain attached to the humeral arch. Branchio- 
stegals five. 

The “Flute-mouths” are also frequently called “ Pipe- 
fishes,” a name which they have in common with the Syn- 
enathide. They are gigantic marine Sticklebacks, living 
near the shore, from which they are frequently driven into 
the open sea; some of the species, therefore, have a wide geo- 
graphical range. Probably all enter brackish water. They 
are distributed over the whole of the tropical and sub-tropical 
parts of the Atlantic and Indo-Pacific. The species are few 
in number, but some of them are very common. 

This family is well represented in Eocene formations ; 
some of the remains belonging to the existing genera, 
Fistularia, Aulostoma, and Auliscops, the two former of 
which occur not rarely at Monte Bolea and in the schists of 
Glaris. Well-preserved remains of Auliscops have been found 
in the Marl-slates of the highlands of Padang in Sumatra. 
Extinct genera from Monte Bolca are Urosphen, the eylindri- 
cal body of which is terminated by a large cuneiform fin ; 
and Rhamphosus, which has an immense spinous ray, denticu- 
lated behind, inserted on the nape. 


508 FISHES. 


FISTULARIA.— Body scaleless ; caudal fin forked, with the 
two middle rays produced into a filament ; no free dorsal spines. 

Three species are known, common on the shores of the 
Tropical Atlantic (#7. tabaccaria) and Indian Oceans (fF. 
serrata and F. depressa); they attain to a leneth of from four 
to six feet. 

The anterior portion of the vertebral column shows the 
same peculiarity as in Dactylopterus ; 1t is a long compressed 
tube, composed of four elongate vertebrae, which are per- 
fectly anchylosed ; each of them has a pair of small foramina 
for blood-vessels. The neural spines and parapophyses of 
this tubiform portion are confluent into thin lamine, the 
lateral of which are wing-like, and expanded in their anterior 
half. 


AULOSTOMA.—Body covered with small scales. Caudal fin 
rhombic, without prolonged rays; a series of isolated feeble 
dorsal spines. ‘Teeth rudimentary. 

Two species from the Tropical Atlantic and Indian 
Oceans. 

AULISCOPS.—Body naked. Ventrals thoracic. Numerous 
spines in front of the dorsal fin. 

One species (A. spinescens) from the Pacific coast of North 
America. Aulorhynchus from the same sea, and Auwlichthys 
from Japan, are allied genera. 


THIRTEENTH DIVISION—ACANTHOPTERYGIL CENTRISCIFORMES. 


Two dorsal fins ; the spinous short, the soft and the anal of 
moderate extent. Ventral fins truly abdominal, imperfectly 
developed. 

This division consists of one family, Centriscida, with two 
genera. The fishes belonging to it are very small, marine, 
and, in consequence of their limited power of swimming, 
often driven out into the open sea. They have the same 


CENTRISCID A. 509 


structure of the mouth and snout as the Fistulariude, but 
combine with it peculiarities of the shape of body, of the 
structure of the vertical fins, and of the relations between 
endo- and exo-skeleton, which render them altogether a 
singular and interesting type. -Amphisile has been found in 
a fossil state at Monte Bolca. 

CENTRISCUS.—Body oblong or elevated, compressed, covered 
with small rough scales ; lateral line none ; some bony strips on 
the side of the back, and on the margin of the thorax and 
abdomen ; the former, in one species, are confluent and form a 
shield. Teeth none. Two dorsal fins, the first with one of the 
spines very strong. Ventral fins small, abdominal, composed of 
five soft rays. Four branchiostegals. 


Of the four species the most generally known is C. 
scolopax, the “Trumpet-fish” or “ Bellows-fish,” which rarely 
occurs on the south coast of England, is more common farther 


Fig. 231.—Centriscus humerosus. 


south, and reappears in Tasmania. The allied CY gracilis is 
one of the fishes common to the Mediterranean and Japanese 
Seas. The species figured, C. humerosus, occurs on the coast 
of South Australia, and is very scarce. 

AMPHISILE.—Body elongate, strongly compressed, provided 
with a dorsal cuirass, which is formed by portions of the skele- 
ton; the longitudinal axis of the tail is not in the same line 
with that of the trunk. Scales none. Teeth none. Two dorsal 
fins situated on the hindmost part of the back; ventral fins 
rudimentary, abdominal. Three or four branchiostegals. 


510 FISHES, 


The three species known of this genus are found in the 
tropical Indo-Pacific. Their body is so thin that it has the 
appearance of being artificially compressed between two 
sheets of paper; it is semi-transparent, especially in the 
region of the air-bladder. The structure of the vertebral 
column is extremely singular and unique among Acanthop- 
terygians. The abdominal portion is more than four times 
as long as the caudal; nevertheless it is composed of only 
six vertebree, whilst the latter consists of fourteen. The 
abdominal vertebree are extremely slender, the third alone 
being nearly as long as the whole caudal portion; they have 
a slight ridge superiorly and inferiorly, and on each side ; the 
whole portion lying in the uppermost concavity of the dorsal 
cuirass. The caudal vertebree are extremely short, and the 
strength of their neural and hemal spines is in proportion to 
their size. The dorsal cuirass is not a dermal production, 
but formed by modified parts of the endoskeleton ; its com- 
position, the number and condition of its single parts, and, 
finally, the first dorsal spine, which in A. punctulata is so 
singularly attached to it, favour this opinion. The plates, 
which occupy the vertebral line, would correspond to the 
neural spines, and the lateral plates on which the ribs are 
suspended to the parapophyses. Amphisile may be con- 
sidered as a Chelonian form among fishes. 


FOURTEENTH DIVISION—ACANTHOPTERYGII GOBIESOCIFORMES. 


No spinous dorsal; the soft and the anal short or of 
moderate length, situated on the tail; ventral fins subjugular, 
with an adhesive apparatus between them. Body naked. 

These fishes are well characterised by their single dorsal 
fin, and by their adhesive ventral apparatus, which has only 
an external similarity to the organ observed in Cyclopterus 
and Liparis; its structure is typically different from it. 


GOBIESOCID, bit 


Whilst in those genera the ventral fins occupy the centre of 
the disk forming its base, these fins are here widely apart 
from each other, as in Callionymus, forming only a portion of 
the periphery of the disk, which is completed by a cartila- 
ginous expansion of the coracoid bones. The following 
description of its structure is taken from Sicyases sanguineus, 
but it is essentially the same in all the genera. 

The whole disk is exceedingly large, subcircular, longer 
than broad, its length being 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 
‘four 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 each side the 
rudimentary ventral spine, but no cartilage. The posterior 
peripheric portion is suspended on each side from the 
coracoid, the upper bone of which is exceedingly broad, be- 
coming a free movable plate behind the pectoral. A broad 
cartilage is firmly attached to it. 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, Five processes of the cartilage are continued into the 
soft striated margin in which the disk terminates posteriorly. 
The surface of the disk is coated with thick epidermis, like 
the sole of the foot of higher animals. The epidermis is 
divided into many polygonal plates; there are no such plates 
between the roots of the ventral fins. 

Not less unique is the structure of the bones which have 
some relation to this external adhesive apparatus. As exempli- 
fied by Chorismochismus dentex the coracoid is well developed, 


512 FISHES. 


and, as usual, composed of two pieces, the upper of which is 
not suspended from the humerus, but fixed by a hgament to 
the hinder margin of the carpal bones. It is a broad lamella, 
dilated posteriorly into the cartilage, which is externally 
visible; the lower piece is narrower, and fixed to the extremity 
of the pubic bone of its side. The pubic bones are united by 
suture, and form together a heart-shaped disk, the point of 
which is produced backwards. The anterior portion .of the 
disk is concave, with a bony longitudinal bridge and a feeble 
transverse ridge. The disk is fixed to the humeral bones by 
the convex portions of its anterior margin, whilst the convex 
portions of the lateral margins serve as base for the ventral 
fins. The latter are composed of one spine, which is trans- 
formed into a broad, thin, and curved plate, hidden below the 
skin, and apparently of four rays; but on closer examination 
we find that the hidden ray has a longitudinal groove 
anteriorly, in which another thinner ray lies concealed. 
This ray is quite free, and not joined to the pubic bone. 

The fishes belonging to the single family of this division, 
Gobiesocide, are strictly marine but littoral fishes. They are 
seattered over the temperate zones of both hemispheres, 
and more numerous than between the Tropics. All are of 
small or very small size. 

The adhesive disk consists of an anterior and posterior 
division. In some of the genera the posterior division has no 


Fig. 232.—Gobiesox cephalus. 


free anterior margin, the teeth being either all conical, as in 
Chorisochismus (Cape of Good Hope) and Cotylis (Red Sea 


| ee 


OPHIOCEPHALID.A, GRE 


and Indian Ocean) ; or incisor-like in both jaws, as in Sicyases 
(coast of Chili and West Indies); or incisor-like at least in 
the lower jaw, as in Gobiesox (West Indies and Pacific coasts 
of South America). In other genera the posterior portion of 
the adhesive disk has a free anterior margin. Only one of 
these genera has incisor-like teeth, viz. Diplocrepis from New 


Fig. 233.—Diplocrepis puniceus. 


Zealand. In the remaining genera, Crepidogaster (from Tas- 
mania and South Australia), Trachelochismus (from New 
Zealand and the Fiji Islands), Lepadogaster, and Leptoptery- 
gius, the teeth are very small and fine. The two last genera 
are European, and Lepadogaster at least is common on the 
Southern British coasts. The three species known as British 
—L. gouanu, L. candolli, and L. bimaculatus—are prettily 
coloured, but subject to great variation. 


FIFTEENTH DIVISION—ACANTHOPTERYGII CHANNIFORMES. 


Body elongate, covered with scales of moderate size; no 
spine mm any of the fins; dorsal and anal long. No super- 
branchial organ, only a bony prominence on the anterior sur- 
Jace of the hyomandibular. 

These fishes belong to the single family Ophiocephalida, 
Freshwater-fishes characteristic of the Indian region, which, 
however, have found their way into Africa, where they are 
represented by one or two species. Thirty-one species are 
known altogether, most of which are extremely abundant ; 
some attain to a length of more than two feet. Like other 

21 


514 FISHES, 


tropical freshwater fishes, they are able to survive droughts, 
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 
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 oxygenised. This habit has 
been observed in some species to continue also to the period 


Fig. 234.—Ophiocephalus striatus, India. 


of the year in which the fish lives in normal water, and indi- 
viduals 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. 


SIXTEENTH DIVISION—ACANTHOPTERYGII LABYRINTHI- 
BRANCHII, 


Body compressed, oblong or elevated, with scales of moderate 
size. A superbranchial organ in a cavity accessory to that of 
the gulls. 

First FAMILY—LABYRINTHICI. 


Dorsal and anal spines present, but im variable numbers ; 
ventrals thoracic. Lateral line absent, or more or less distinctly 
interrupted. Gill-opening rather narrow, the gull-membranes 


LABYRINTHICI. bil 


of both sides coalescent below the isthmus, and scaly ; gills four ; 
pseudobranchie rudimentary or absent. 

Freshwater-fishes of the Cyprinoid division of the Equa- 
torial zone. They possess the faculty of being able to live 
for some time out of the water, or in thick or hardened mud, 
in a still greater degree than the fishes of the preceding 
family. In the accessory branchial cavity there is lodged a 
laminated organ which evidently has the function of assist- 
ing in the oxygenisation of the blood. In Anabas it is formed 
by several exceedingly ’ 
thin bony lamine, similar 
in form to the auricle, 
and concentrically situ- 
ated one above the other, 
the innermost being the 
largest. The degree in 
which these lamin are 
developed is dependent 


on age. In specimens 
Cece incl © anche ta Fig. 235.—Superbranchial organ of Anabas. 
half to two inches and a half long there are only two 
such lamine, a third being indicated by a small protuber- 
ance at the central base of the second or outer lamine. In 
specimens of from three to four inches in leneth the third 
lamina is developed, covering one-half of the second. The 
edges of all the laminz are straight, not valanced. In speci- 
mens of from four to five inches a fourth lamina makes its 
appearance in the basal centre of the third lamina. The 
other laminze continue to grow in their circumference, and 
their edges now become undulated and slightly frilled. 
Cuvier and Valenciennes have examined still larger speci- 
mens. The figure given by them and reproduced here was 
taken from a specimen six or seven inches long, and shows 
the superbranchial organ composed of six lamine. 


~ 


d16 FISHES. 


The air-bladder of the majority of these fishes is very 
large, extending far into the tail, and, therefore, divided behind 
by the heemal spines into two lateral portions. 

The Labyrinthici are generally of small size; they are 
capable of being domesticated, and some of them deserve 
particular attention on account of the dazzling beauty of their 
colours or the flavour of their flesh. 


ANABAS.—Body compressed, oblong ; preeorbital and orbitals 
serrated. Small teeth in the jaws and on the vomer ; none on 
the palatines. Dorsal and anal spines numerous. Lateral line 
interrupted. 

The “Climbing Perch” (A. scandens) is generally distri- 
buted over the Indian Region, and well known from its 
faculty of moving for some distance over land, and even up 
inclined surfaces. In 1797 Daldorf, in a memoir communi- 
cated to the Linnean Society of London, mentions that in 
1791 he had himself taken an Anabas in the act of ascending 
a palm tree which grew near a pond. The fish had reached 
the height of five feet above the water, and was going still 
higher. In the effort to do this it held on to the bark of the 
tree by the preopercular spines, bent its tail, and stuck in the 
spines of the anal; then released its head, and, raising it, took 
a new hold with the preoperculum higher up. The fish is 
named in the Malayan language the “Tree Climber.” It 
rarely attains a leneth of seven inches. 

Spirobranchus from the Cape, and Ctenopoma from Tropical 
Africa, represent Anabas in that continent. 


POLYACANTHUS.—Body compressed, oblong; operculum with- 
out spines or serrature ; cleft of the mouth small, more or less 
oblique, not extending beyond the vertical from the orbit, and 
little protractile. Small fixed teeth in the jaws, none on the 
palate. Dorsal and anal spines numerous; the soft dorsal and 
anal, the caudal, and the ventral, more or less elongate in mature 
specimens, Caudal rounded. Lateral line interrupted or absent. 


GOURAMI. 517 


This genus is represented chiefly in the East Indian 
Archipelago; seven species are known; some of them have 
been domesticated on account of the beauty of their colours, 
and several varieties have been produced. One of them is to 
be mentioned, as, under the name of “ Paradise-fish,” it has 
been introduced into the aquaria of Europe, where it readily 
breeds. It was known already to Lacépede, and has been 
mentioned since his time in all ichthyological works as 
Macropus viridi-auratus. In adult males some of the rays, 
and especially the caudal lobes, are much prolonged. 

OsPHROMENUS.— Body compressed, more or less elevated ; 
operculum without spine or serrature. Small fixed teeth in the 
jaws, none on the palate. Dorsal spines in small or moderate 
number ; anal spines in moderate or great number; ventral fins 
with the outer ray very long, filiform. Lateral line not inter- 
rupted or absent. 

To this genus belongs the celebrated “Gourami” (Osphro- 
menus olfax), reputed to be one of the best flavoured Fresh- 


bbl 


Fig. 236.—Osphromenus olfax. 


water-fishes in the East-Indian Archipelago. Its original 
home is Java, Sumatra, Borneo, and several other islands; 
but thence it has been transported to, and acclimatised in, 
Penang, Malacca, Mauritius, and even Cayenne. Being an 
almost omnivorous fish and tenacious of life, it seems to 
recommend itself particularly for acclimatisation in other 


518 FISHES. 


tropical countries, and specimens kept in captivity become as 
tame as carps. It attains the size of a large turbot. A second, 
but much smaller, species of this genus, O. trichopterus, is 
frequently kept in vessels on account of the exquisite beauty 
of its varying iridescent metallic tints; like other fishes of 
this family it is very pugnacious. 

Trichogaster, a very common Bengalese fish, differs from 
Osphromenus in having the ventral fins reduced to a single 
long filament. 


Berra.—Body compressed, oblong ; operculum without spine 
or serrature. Small fixed teeth in the jaws, none on the palate. 
Dorsal fin short, on the middle of the back, without any pungent 
spine ; anal fin long. Ventral fin with five soft rays, the outer 
one being produced. Lateral line interrupted or absent. 


A species of this genus (B. pugnaz) is, on account of its 
pugnacious habits, reared by the Siamese. Cantor gives the 
following account :—* When the fish is in a state of quiet, 
its dull colours present nothing remarkable; but if two be 
brought together, or if one sees its own image in a looking- 
glass, the little creature becomes suddenly excited, the raised 
fins and the whole body shine with metallic colours of dazzling 
beauty, while the projected gill membrane, waving like a black 
frill round the throat, adds something of grotesqueness to the 
general appearance. In this state it makes repeated darts at 
its real or reflected antagonist. But both, when taken out of 
each other’s sight, instantly become quiet. This description 
was drawn up in 1840, at Singapore, by a gentleman who had 
been presented with several by the King of Siam. They were 
kept in glasses of water, fed with larvee of mosquitoes, and 
had thus lived for many months. The Siamese are as in- 
fatuated with the combats of these fish 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 con- 


LUCIOCEPHALID. 519 


siderable 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 ;’ 
but the kind kept especially for fighting is an artificial variety 
cultivated for the purpose.” 

Micracantuus.—This genus represents the three last- 
named genera in Africa, where it has been recently discovered 
in tributaries of the river Ogooue. It seems to differ from 
the Indian genera chiefly by its more elongate body, the 


structure of the fins being scarcely different (D. 2, A. 45, Ve). 


SECOND FAMILY—LUCIOCEPHALIDA. 


Body elongate, covered with scales of moderate size. Late- 
ral line present. Teeth small. Cull-opening wide ; pseudo- 
branchiw none. The superbranchial organ is formed by two 
branchial arches, which are dilated into a membrane. One 
short dorsal fin; dorsaland anal spines none ; ventrals com- 
posed of one spine and five rays. Air-bladder none. 

A small Freshwater-fish (Luciocephalus pulcher), from the 
East-Indian Archipelago. 


SEVENTEENTH DIVISION—ACANTHOPTERYGII LOPHOTIFORMES. 


Body riband shaped, with the vent near its extremity; a 
short anal behind the vent ; dorsal fin as long as the body. 

Only one species is known of this division or family, 
Lophotes cepedianus. It is most probably a deep-sea fish, but 
does not descend to so great a depth as the 7rachypterida, 
its bony and soft parts being well coherent. It is a scarce 
fish, hitherto found in the Mediterranean, off Madeira, and in 
the Sea of Japan; its length is known to exceed five feet. 
The head is elevated into a very high crest, and the dorsal 
fin commences with an exceedingly strong and long spine on 
the head. Silvery, with rose-coloured fins. 


520 FISHES. 


EIGHTEENTH DIVISION—ACANTHOPTERYGIL TANIIFORMES. 


Body riband shaped ; dorsal jin as long as the body ; anal 
absent ; caudal rudimentary, or not in the longitudinal axis of 
the fish. 

The “ Ribbon-fishes ” are true deep-sea fishes, met with in 
all parts of the oceans, generally found when floating dead on 
the surface, or thrown ashore by the waves. Their body is like 
a band, specimens of from fifteen to twenty feet long being 
from ten to twelve inches deep, and about an inch or two 
broad at their thickest part. The eye is large and lateral; 
the mouth small, armed with very feeble teeth; the head 
deep and short. A ligh dorsal fin runs along the whole 
length of the back, and is supported by extremely numerous 


Fig. 237.—Trachypterus teenia. 


rays ; its foremost portion, on the head, is detached from the 
rest of the fin, and composed of very elongate flexible spines. 
The anal fin is absent. The caudal fin (if preserved, which 
is rarely the case, in adult specimens) has an extra-axial posi- 
tion, being directed upwards like a fan. The ventrals are 
thoracic, either composed of several rays or reduced to a single 


RIBBON-FISHES. 521 


long filament. The coloration is generally silvery, with rosy 
fins. 

When these fishes reach the surface of the water the 
expansion of the gases within their body has so loosened all 
parts of their muscular and bony system, that they can be 
lifted out of the water with difficulty only, and nearly always 
portions of the body and fins are broken and lost. The bones 
contain very little bony matter, are very porous, thin and 
light. At what depths Ribbon-fishes live is not known; pro- 
bably the depths vary for different species; but although 
none have been yet obtained by means of the deep-sea 
dredge, they must be abundant at the bottom of all oceans, as 
dead fishes or fragments of them are frequently obtained. 
Some writers have supposed from the great length and nar- 
row shape of these fishes that they have been mistaken for 
“Sea-serpents ;’ but as these monsters of the sea are always 
represented by those who have had the good fortune of meet- 
ing with them as remarkably active, it is not likely that 
harmless Ribbon-fishes, which are either dying or dead, have 
been the objects described as “ Sea-serpents.” 

Young hibbon-fishes (from two to four inches) are not 


Fig. 238.—Young Trachypterus. 


rarely met with near the surface; they possess the most 


522 FISHES. 


extraordinary development of fin rays observed in the whole 
class of fishes, some of them being several times longer than 
the body, and provided with lappet-lke dilatations. There is 
no doubt that fishes with such delicate appendages are bred 
and live in depths where the water is absolutely quiet, as a 
sojourn in the disturbed water of the surface would deprive 
them at once of organs which must be of some utility for 
their preservation. 
tibbon-fishes are divided into three genera :— 


TRACHYPTERUS.—In which the ventral rays are well deve- 
loped, and composed of several more or less branched rays. 
Specimens of this genus have been taken in the Mediter- 
ranean, Atlantic, at Mauritius, and in the Eastern Pacific. 
The “ Deal-fish” (7. arcticus) is often met with in the North 
Atlantic, and specimens are generally found after the equi- 
noctial gales on the coasts of the Orkneys and North Britain. 


STYLOPHORUS.— Without ventrals, and with the tail termin- 
ating in an exceedingly lone cord-like appendage. Known 
from one specimen only, found at the beginning of this cen- 
tury between Cuba and Martinique. It is eleven inches long, 
and preserved in the Museum of the Royal College of Sur- 
geons in London. 

Regalecus.—Each ventral fin is reduced to a long filament, 
dilated at the extremity; caudal fin rudimentary or absent. 
These are the largest of all Ribbon-fishes, specimens being on 
record the length of which exceeded twenty feet. They have 
been taken in the Mediterranean, North and South Atlantic, 
Indian Ocean, and on the coast of New Zealand. They are 
frequently called “ Kings of the herrings,” from the erroneous 
notion that they accompany the shoals of herrings; or “ Oar- 
fishes,” from their two ventral fins, which have a dilatation 
at their extremity not unlike the blade of an oar. One or 
more species (2. banksii) are sometimes found on the British 


NOTACANTHIDA. 523 


coasts, but they are very scarce, not more than sixteen cap- 
tures having been recorded between the years 1759 and 
1878. 


NINETEENTH DIVISION—ACANTHOPTERYGIL NOTACANTHI- 
FORMES. 


Dorsal fin short, composed of short, isolated spines, without 
a soft portion. Anal fin very long, anteriorly with many 
spines ; ventrals abdominal, with more than five soft and several 
unarticulated rays. 

Notacanthus is the most aberrant type of Acanthoptery- 
gians. Of the characteristics of this order the development 
of spines in the vertical fins is the only one preserved in the 
fishes of this genus. Their body is elongate, covered with 
very small scales; the snout protrudes beyond the mouth. 
Eyes lateral, of moderate size ; dentition feeble. Five species 
are known from the Arctic Ocean, Mediterranean, Atlantic, 
and Southern Pacific. They inhabit considerable depths, 
probably from 100 to 400 fathoms, and during the “Chal- 
lenger” expedition specimens have been obtained from an 
alleged depth of 1875 fathoms. 


SECOND ORDER: 
ACANTHOPTERYGIT PHARYNGOGNATHI. 
Part of the rays of the dorsal, anal, and ventral fins are 


non-articulated spines. The lower pharyngeals coalesced. Aitr- 
bladder without pneumatic duct. 


Fig. 239.—Coalescent Pharyngeals of Scarus cretensis. 
a, upper ; b, lower pharyngeals. 


524 FISHES. 


First FAMILY—POMACENTRID. 


Body short, convpressed, covered with ctenoid scales. Den- 
tition feeble ; palate smooth. The lateral line does not extend 
to the caudal fin, or is interrupted. One dorsal fin, with the 
spinous portion as well developed as the soft, or more. Two, 
sometimes three, anal spines; the soft anal similar to the soft 
dorsal. Ventral fins thoracic, with one spine and five soft rays. 
Gills three and a half ; pseudobranchie and air-bladder pre- 
sent. Vertebra, twelve abdominal and fourteen caudal. 

The fishes of this family are marine; they resemble the 
Cheetodonts with regard to their mode of life, living chiefly in 
the neighbourhood of coral formations. Like them they are 
beautifully coloured, the same patterns being sometimes 
reproduced in members of both families, proving that the 


Fig. 240.—Dascyllus aruanus. Natural size, from the Indo-Pacific, 


development and distribution of colours is due to the agencies 
of climate, of the surroundings and of the habits of animals. 
The geographical range of the Pomacentride is co-extensive 
with that of the Cheetodonts, the species being most numer- 
ous in the Indo-Pacific and Tropical Atlantic, a few extend- 
ing northwards to the Mediterranean and Japan, southwards 


WRASSES. 525 


to the coasts of South Australia, They feed chiefly on small 
marine animals, and such as have compressed teeth appear to 
feed on the small Zoophytes covering the banks, round which 
these “ Coral-fishes” abound. In a fossil state this family is 
known from a single genus only, Odonteus, from Monte Bolea, 
allied to Heliastes. The recent genera belonging to this 
family are:—Amphiprion, Premnas, Dascyllus, Lepidozyqus, 
Pomacentrus, Glyphidodon, Parma, and Heliastes. About 120 
species are known. 


SECOND FAMILY—LABRIDA. 


Body oblong or elongate, covered with cycloid scales. The 
lateral line extends to the caudal, or is interrupted. One dorsal 
jin, with the spinous portion as well developed as, or more than, 
the soft. The soft anal similar to the soft dorsal. Ventral fins 
thoracic, with one spine and five soft rays. Palate without 
teeth.  Branchiostegals five or six; gills three and a half ; 
pseudobranchie and air-bladder present. Pylorie appendages 
none ; stomach without ceecal sac. 

The “ Wrasses” are a large family of littoral fishes, very 
abundant in the temperate and tro- 
pical zones, but becoming scarcer to- 
wards the Arctic and Antarctic circles, 
where they disappear entirely. Many 
of them are readily recognised by 
their thick lips, which are sometimes 


internally folded, a pecuharity which 
has given to them the German term Fig. 241.—Lips of a Wrasse, 
of “Lip-fishes.” They feed chiefly Libris Nepiiis 

on mollusks and crustaceans, their dentition being admirably 
adapted for crushing hard substances. Many species have 
a strong curved tooth at the posterior extremity of the 


intermaxillary, for the purpose of pressing a shell against 


526 FISHES. 


the lateral and front teeth by which it is crushed. Other 
Wrasses feed on corals, others on zoophytes; a few are 
herbivorous. In all Wrasses the upper pharyngeal bones 
seem to be jointed to the basi-occipital; but whilst in 
Labrus the basi-occipital is raised on each side into a large 
flattish condyle, fittmg into a concavity of the upper 
pharyngeals, in Scarus the mode of articulation is reversed, 
the basi-occipital having a pair of long grooves, in which 
the oblong condyles of the upper pharyngeals slide for- 
wards and backwards. Beautiful colours prevail in this 
family, permanent pigmentary colours as. well as passing 
iridescent reflections of the scales. Some species remain very 
small, others grow to a weight of fifty pounds. The larger 
kinds especially are prized as food, the smaller less so. 

Remains of Labridee, recognised by their united pharyn- 
geals, which bear molar-like teeth, are not scarce in tertiary 
formations of France, Germany, Italy, and Eneland, Such 
remains from Monte Bolca and the Swiss Molasse have been 
referred to the genus Labrus. Others, Nummopalatus and 
Phyllodus, are allied, but cannot be assigned, to one of 
the recent genera; the latter genus is first represented in 
cretaceous formations of Germany. Another genus, Tawrinich- 
thys, from the Miocene of France, represents the Odacina of 
the living fauna. Hyertonia, from the Isle of Sheppey, differs 
so much from all recent Labroid genera that its pertinence to 
this family appears doubtful. 

[See J. Cocchi, Monografia dei Pharyngodopilide, 1866; and £. Sauvage, 
Sur le genre Nummopalatus, in Bull. Soc. Geol. France, 1875.] 

Laprus.—Body compressed, oblong, covered with scales of 
moderate size, in more than forty transverse series ; snout more 
or less pointed; imbricate scales on the cheeks and opercles ; 
none or only a few on the interoperculum. Teeth in the jaws 
conical, in a single series. Dorsal spines numerous, thirteen or 
twenty-one, none of which are prolonged; anal spines three. 
Lateral line not interrupted. 


WRASSES, 527. 


Young “ Wrasses ” differ from mature specimens in having 
the preoperculum serrated. The headquarters of this genus 
are the Mediterranean, whence it ranges, gradually diminish- 
ing towards the north, along all the shores of Europe. Nine 
species are known; British are the “Ballan Wrasse” (Z. 
maculatus), and the “Striped or Red Wrasse” or “Cook” 
(LZ. mixtus). The two sexes of the latter species are very 
differently coloured; the male being generally ornamented 
with blue streaks, or a blackish band along the body, whilst 
the female has two or three large black blotches across the 
back of the tail. 


CRENILABRUS are Labrus with serrated preeoperculum ; the 
number of their dorsal spines varies from thirteen to eighteen, 
and the scales are arranged in less than forty transverse series. 

The range of this genus is coextensive with Labrus. C. 
melops, the “ Gold-sinny,” or “ Cork-wing,” is common on the 
British coasts. 


TauToGA.—Body compressed, oblong, covered with small 
scales ; scales on the cheek rudimentary, opercles naked. Teeth 
in the jaws conical, in double series ; no posterior canine tooth. 
Dorsal spines seventeen, anal spines three, Lateral line not 
interrupted. 

The “ Tautog,” or “ Black-fish,’ 1s common on the Atlantic 
coasts of temperate North America, and much esteemed as 


food. 


CTENOLABRUS.—Body oblong, covered with scales of moder- 
ate size ; imbricate scales on the cheeks and opercles. Teeth in 
the jaws in a band, with an outer series of stronger conical teeth ; 
no posterior canine tooth. Dorsal spines from sixteen to eighteen ; 
anal spines three. Lateral line not interrupted. 

Four species, from the Mediterranean and the temperate 
parts of the North Atlantic, Ct. rupestris being common on 
the British, and C¢. bwrgall on the North American coasts. 


Or 
bo 
ioe) 


FISHES. 


ACANTHOLABRUS.—A Wrasse with five or six anal spines, 
and with the teeth in a band. 
From the Mediterranean and British coasts (A. palloni). 


CENTROLABRUS.—Wrasses with four or five anal spines, and 
with the teeth in a single series. 

Two species are known from Madeira and the Canary 
Islands, and one from northern Europe and Greenland. The 
latter is scarce on the British coasts, but bears a distinct 
name on the south coast, where it is called “ Rock-cook.” 


LACHNOLAEMUS from the West Indies, and MALACOPTERUS 
from Juan Fernandez, are Labroids, closely allied to the pre- 
ceding North Atlantic genera. 


CossypHus.—Body compressed, oblong, with scales of moder- 
ate size; snout more or less pointed ; imbricate scales on the 
cheeks and opercles; basal portion of the vertical fins scaly. 
Lateral line not interrupted. Teeth in the jaws in a single 
series ; four canine teeth in each jaw anteriorly ; a posterior 

12 


canine tooth. Formula of the fins: D. j244, A. 


nee 

Twenty species are known from the tropical zone and 
coasts adjoining it; some, like C. gouwldia from Tasmania, 
attain a leneth of three or four feet. 


CuILInus.—Body compressed, oblong, covered with large 
scales ; lateral line interrupted ; cheeks with two series of scales; 
preoperculum entire ; teeth in a single series, two canines in 
each jaw ; no posterior canine tooth; lower jaw not produced 
backwards. Dorsal spines subequal in length ; formula of the 
fins: D. 2575, A. 2. 


Common in the tropical Indo-Pacific, whence more than 


twenty species are known. Hybrids between the different 
species of this genus are not uncommon. 


EprpuLus.—Closely allied to the preceding genus, but with 
a very protractile mouth, the ascending branches of the inter- 
maxillaries, the mandibles, and the tympanic being much pro- 
longed. 


WRASSES. 529 


This fish (Z. insidiator) is said to seize marine animals 
by suddenly thrusting out its mouth and engulphing those 
that come within the reach of the elongated tube. It attains 
a length of twelve inches, is common in the tropical Indo- 
Pacific, and varies much in coloration. 

ANAMPSES.—Distinguished by its singular dentition, the two 


front teeth of each jaw being prominent, directed forwards, com- 
pressed, with cutting edge. D. 5%, A. 7%. 

Beautifully coloured fishes from the tropical Indo-Pacific. 
Ten species. 

PLATYGLOSSUS.—Scales in thirty or less transverse series ; 
lateral line not interrupted. A posterior canine tooth. Dorsal 
spines nine. 

Small beautifully coloured Coral-fishes, abundant in the 
equatorial zone and the coasts adjoining it. Some eighty 
species are known (inclusive of the allied genera Stethojulis, 
Leptojulis, and Pseudojulis). 

NovacuLa.—Body strongly compressed, oblong, covered 
with scales of moderate size ; head compressed, elevated, obtuse, 
with the supero-anterior profile more or less parabolic ; head 
nearly entirely naked. Lateral line interrupted. No posterior 
canine tooth. D. 7%, A. 3%; the two anterior dorsal spines 
sometimes remote or separate from the others, 

Twenty-six species are known from the tropical zone, and 
the warmer parts of the temperate zones. They are readily 
recognised by their compressed, knife-shaped body, and 
peculiar physiognomy; they scarcely exceed a length of 
twelve inches. 

JULIS.—Scales of moderate size ; lateral line not interrupted. 
Head entirely naked. Snout of moderate extent, not produced ; 
no posterior canine tooth. Dorsal spines ten. 


Co-extensive with Platyglossus in their geographical dis- 
tribution, and of like beautiful coloration and similar habits. 
Some of the most common fishes of the Indo-Pacific, as -/. 
lunaris, trilobata, and dorsalis, belong to this genus, 

2M 


530 FISHES. 


Coris.—Seales small, in fifty or more transverse series ; 
lateral line not interrupted. Head entirely naked. Dorsal 
spines nine. 

Twenty-three species, distributed like Platyglossus ; two 
reach the south coast of England, Coris julis and C. giofredi, 
said to be male and female of the same species. Some 
belong to the most gorgeously coloured kinds of the whole 
class of fishes. 

Genera allied to the preceding Labroids are—Choerops, 
Xiphochilus, Semicossyphus, Trochocopus, Decodon, Pteragogus, 
Clepticus, Labrichthys, Labroides, Duymeria, Cirrhilabrus, 
Dovratonotus, Pseudochilinus, Hemigymnus, Gomphosus, Cheilio, 
and Cymolutes. 

PsEUDODAX.—NScales of moderate size ; lateral line continu- 
ous ; cheeks and opercles scaly. Each jaw armed with two pairs 
of broad incisors, and with a cutting lateral edge; teeth of the 
lower pharyngeal confluent, pavement-like. Dorsal spines eleven. 


One species (P. moluccensis) from the East Indian Archi- 
pelago. 


Scarus.—Jaws forming a sharp beak, the teeth being 
soldered together. The lower jaw projecting beyond the upper. 
A single series of scales on the cheek; dorsal spines stiff, pun- 
gent ; the upper lip double in its whole circuit. The dentigerous 
plate of the lower pharyngeal is broader than long. 


The fishes of this genus, and the three succeeding, are 
known by the name of “ Parrot-wrasses.” Of Scavws one 
species (S. eretensis) occurs in the Mediterranean, and nine 
others in the tropical Atlantic. The first was held in high 
repute by the ancients, and Aristotle has several pass- 
ages respecting its rumination. It was most plentiful and 
of the best quality in the Carpathian Sea, between Crete 
and Asia Minor, but was not unknown even in early times 
on the Italian coasts, though Columella says that it seldom 
passed beyond Sicily in his day. But in the reign of 
Claudius, according to Pliny, Optatus Elipentius brought it 


PARROT-WRASSES. 531 


from the Troad, and introduced it into the sea between 
Ostium and Campagna. For five years all that were caught 
in the nets were thrown into the sea again, and from that 
time it was an abundant fish in that locality. In the time of 
Pliny it was considered to be the first of fishes (Wune Scaro 
datur principatus) ; and the expense incurred by Elipentius 
was Justified, in the opinion of the Roman gourmands, by the 
extreme delicacy of the fish. It was a fish, said the poets, 
whose very excrements the gods themselves were unwilling 
to reject. Its flesh was tender, agreeable, sweet, easy of 
digestion, and quickly assimilated ; yet if it happened to have 
eaten an Aplysia, it produced violent diarrhcea. In short, 
there is no fish of which so much has been said by ancient 
writers. In the present day the Scarus of the Archipelago is 
considered to be a fish of exquisite flavour; and the Greeks 
still name it Searo, and eat it with a sauce made of its liver 
and intestines. It feeds on fucus; and Valenciennes thinks 
that the necessity for masticating its vegetable diet thoroughly, 
and the working of it with that intent backwards and _ for- 
wards in the mouth, may have given rise to the notion of its 
being a ruminant; and it is certain that its aliment is very 
finely divided when it reaches the stomach. 


ScCARICHTHYS.—Differing from Scarus only in having flexible 
dorsal spines. 


Fig. 242.—Scarichthys auritus. 


Two species from the Indo-Pacitic. 


5o2 FISHES. 


CALLYODON.— Differing from Scarichthys in having the upper 
lip double posteriorly only. 


Nine species from the tropical zone. 


PSEUDOSCARUS, — Jaws forming a strong beak, the teeth 
being soldered together. The upper jaw projecting beyond the 
lower. Two or more series of scales on the cheek. The denti- 
gerous plate of the lower pharyngeal longer than broad, 


This tropical genus contains by far the greatest number 
of Scaroid Wrasses, some seventy species being known, and 
a still greater number of names beimg introduced into the 
various Ichthyological works. They are beautifully coloured, 
but the colours change with age, and vary in an extraordinary 
degree in the same species. They rapidly fade after death, so 
that it is almost impossible to recognise in preserved speci- 
mens the species described from living individuals. Many 
attain to a rather large size, upwards of three feet in length. 
The majority are eaten, but some acquire poisonous properties 
from their food; which consists either of corals or of fucus. 

OpAx.—The edge of each jaw is sharp, without distinct 
teeth. The dentigerous plate of the lower pharyngeal triangular, 
much broader than long. Cheeks and opercles scaly ; scales of 


the body small or rather small ; lateral line continuous. Snout 
conical. Dorsal spines rather numerous, flexible. 


Six species from the coasts of Australia and New Zea- 


Fig. 243.—Odax radiatus. 


land. Small. The species figured (0. radiatus) is from 
Western Australia. 


EMBIOTOCID A. 533 


CorIDODAX.—Jaws as in Odazv, head naked. Seales of the 
body small ; lateral line continuous. Snout of moderate extent. 
Dorsal spines numerous, flexible. 


The “ Butter-fish,” or “ Kelp-fish” of the colonists of New 
Zealand (C. pullus), is prized as food, and attains to a weight 
of four or five pounds. It feeds on zoophytes, scraping them 
from the surface of the kelp, with its curiously formed teeth. 
Its bones are green, like those of Lelone. 

OLISTHEROPS, from Kine George’s Sound, has scales of 
moderate size, but agrees otherwise with Coridodaz. 


SIPHONOGNATHUS.—Head and body very elongate, snout long, 
as in Fistularia ; wpper jaw terminating in a long, pointed, skinny 
appendage ; opercles and cheeks scaly ; scales of moderate size ; 
lateral line continuous. Dorsal spines numerous, flexible. Jaws 
as in Odax ; the dentigerous plate of the lower pharyngeal very 
narrow. 

S. argyrophanes, from King George’s Sound, is the most 
aberrant type of Wrasses, whose principal characters are re- 
tained, but united with a form of the body which resembles 
that of a Pipe-fish. 


THIRD FAMILY—EMBIOTOCIDA. 


Body compressed, elevated or oblong, covered with cycloid 
scales ; lateral line continuous. One dorsal fin, with a spinous 
portion, and with a scaly sheath along the base, which 1s 
separated by a groove from the other scales; anal with three 
spines and numerous rays; ventral fins thoracic, with one 
spine and five rays. Small teeth in the jaws, none on the palate. 
Pseudobranchie present. Stomach siphonal, pyloric appendages 
none. Viviparous. 

Marine Fishes characteristic of the fauna of the temperate 
North Pacific, the majority living on the American side, and 
only a few on the Asiatic. All are viviparous (see Fig. 70, 
p. 159). Agassiz describes the development of the embryoes 


534 FISHES. 


as a normal ovarian gestation, the sac containing the young 
not being the oviduct but the ovarian sheath, which fulfils 
the functions of the ovary. This organ presents two modes 
of arrangement: in one there is a series of triangular mem- 
branous flaps communicating with each other, between which 
the young are arranged, mostly longitudinally, the head of 
one to the tail of another, but sometimes with the bodies 
curved, to the number of eighteen or twenty; in the other, 
the cavity is divided by three membranes converging to a 
point, into four compartments, not communicating with each 
other except towards the genital opening, the young being 
arranged in the same longitudinal manner. The propor- 
tionate size of the young is very remarkable. In a female 
specimen 104 inches long, and 43 inches high, the young 
were nearly 3 inches long and 1 inch high. Seventeen 
species are known, the majority of which belong to Ditrema, 
and one to Hysterocarpus. They do not attain to a large size, 
varying from three-quarters to three pounds in weight. 


FourtTH FAMILY—CHROMIDES. 


Body elevated, oblong or elongate, scaly, the scales being 
generally ctenoid. Lateral line interrupted or nearly so. One 
dorsal fin, with a spinous portion ; three or more anal spines ; 
the soft anal similar to the soft dorsal. Ventral fins thoracic, 
with one spine and five rays. Teeth in the jaws small, palate 
smooth. Pseudobranchie none. Stomach coecal ; pyloric ap- 
pendages none. 

Freshwater-fishes of rather small size from the tropical 
parts of Africa and America; one genus from Western India. 
The species with lobate teeth, and with many circumvolu- 
tions of the intestines, are herbivorous, the other carnivorous. 


ETropLus.—Body compressed, elevated, covered with ctenoid 
scales of moderate size. Lateral line indistinct. Dorsal and anal 


oP 


CHROMIDES, 7935 


spines numerous. Teeth compressed, lobate, in one or two 
series, Anterior prominences of the branchial arches not 
numerous, short, conical, hard. Dorsal fin not scaly. 


Two species from Ceylon and Southern India. 


CHRoMIS.—Body compressed, oblong, covered with cycloid 
scales of moderate size. Dorsal spines numerous, anal spines 
three. Teeth compressed, more or less lobate, in one series. 
Anterior prominences of the branchial arches short, thin, lamelli- 
form, non-serrated. Dorsal fin not scaly. 

Some twenty species are known from the fresh waters of 
Africa and Palestine; the most celebrated is the “ Bulti,” or 
“ Bolty,” of the Nile, one of the few well-flavoured fishes of 


yy 
My” 


y 
Ry 
A> 


= 


<= 


Fig. 244.—Chromis andrec, from the Lake of Galilee. 


that river; it grows to the length of twenty inches. Two or 
three species of this genus occur in the Jordan and Lake of 
Galilee. 


HEMICHROMIS, differing from Chromis in having conical teeth 
in one or two series. 


Ten species, the range of which is coextensive with that 
of Chromis. One species, H. sacra, is abundant in the Lake 
of Galilee. 


PARETROPLUS, differing from Hemichromis in having nine 
anal spines. 


One species from Madagascar. 


536 FISHES. 


AcARA.—Body compressed, oblong, covered with ctenoid 
scales of moderate size. Dorsal spines numerous, anal spines 
three or four; base of the soft dorsal nearly uncovered by 
scales. Teeth in a band, small, conical. Anterior prominences 
of the first branchial arch very short tubercles. 


Some twenty species are known from the fresh waters of 
Tropical America, A. bimaculata being one of the most com- 
mon fishes of that region. All are very small. 

Heros.—Differing from Acara in having more than four 
anal spines. 

Some fifty species are known from the fresh waters of 
Tropical America, especially Central America, where almost 
every large lake or river is tenanted by one or more peculiar 


AU 


ans 


SZ 


Fig. 245.—Hevos salvini, from Central America. 


species. They are of rather small size, rarely exceeding a 
leneth of twelve inches. 

* Genera allied to Heros, and likewise from Tropical 
America, are Neetroplus, Mesonauta, Petenia, Varu, and Hygro- 
gonus. 

CicHLA.—Form of the body perch-like. Scales small; the 
spinous and soft portions of the dorsal fin of nearly equal extent, 
and separated by a notch; anal spines three. Each jaw with 
a broad band of villiform teeth. The outer branchial arch with 
lanceolate crenulated prominences along its concave side. Dorsal 
and anal fins scaly. 


Four species from Brazil, Guyana, and Peru. 


LYCODIDA. 537 


CRENICICHLA.— Body low, sub-cylindrical ; scales small or 
rather small. The spinous portion of the dorsal is much more 
developed than the soft, both being continuous, and not separated 
by a notch; anal spines three. Praopercular margin serrated. 
Each jaw with a band of conical teeth. The outer branchial 
arch with short tubercles. Dorsal and anal fins naked. 


Ten species from Brazil and Guyana. 

The following genera complete the list of South American 
Chromides: Chatobranchus, Mesops, Satanoperca, Geophagus, 
Symphysodon, and Pterophyllum. 


THIRD ORDER—ANACANTHINI. 


Vertical and ventral fins without spinous rays. The ventral 
fins, if present, are jugular or thoracic. Air-bladder, of present, 
without preumatic duct. 

These characters are common to all the members of this 
order, with the exception of a freshwater-fish from Tasmania 
and South Australia (Gadopsis), which has the anterior por- 
tion of the dorsal and anal fins formed of spines. 


First DIvIsloN—ANACANTHINI GADOIDEI. 


Head and body symmetrically formed. 


First FAMILY—LYCODIDA. 


Vertical fins confluent. Ventral fin, if present, small, 
attached to the humeral arch, jugular. Gill-opening narrow, 
the gill-membrane being attached to the isthmus. 

Marine littoral fishes of small size, resembling Blennies, 
chiefly represented in high latitudes, but a few living within 
the tropical zone. 

LycopEs.—Body elongate, covered with minute scales im- 


bedded in the skin, or naked ; lateral line more or less indistinct. 
Eye of moderate size. Ventral small, short, rudimentary, jugular, 


538 FISHES. 


composed of several rays. Upper jaw overlapping the lower. 
Conical teeth in the jaws, on the vomer, and on the palatine 
bones. Barbel none. Five or six branchiostegals ; gill-opening 
narrow, the gill+membranes being attached to the isthmus. 
Pseudobranchize present. Air-bladder none. fPyloric appen- 
dages two, or rudimentary, or entirely absent. No prominent 
anal papilla. 


Fig, 246.—Lycodes mucosus, from Northumberland Sound. 


Nine species are known from the Arctic Ocean, four from 
the southern extremity of the American continent. 


GyYMNELIS.—Body elongate, naked. Eye of moderate size 
or rather small. Ventrals none. Vent situated at some dis- 
tance backwards from the head. Small conical teeth in the jaws, 
on the vomer and palatine bones. Jaws equal anteriorly. 
Barbel none. Six branchiostegals; gill-opening narrow, the 
gill membranes being attached to the isthmus. Pseudobranchie 
present ; air-bladder none.  Pyloric appendages two; no pro- 
minent anal papilla. 


Fig. 247.—Gymuelis viridis. 


One species (G. viridis) from Greenland, the other (G. 
pictus) from the Straits of Magelheen. 

The other genera belonging to this family are Uronectes 
from Baffin’s Bay, Microdesmus from Panama, Blennodesmus 
from the coast of North-Eastern Australia, and Maynea from 
the Straits of Magelheen. 


\ 


COD-FISHES. 539 


SECOND FAMILY—GADID&. 


Body more or less elongate, covered with small smooth scales. 
One, two, or three dorsal fins, occupying nearly the whole of the 
back ; rays of the posterior dorsal well developed ; one or two 
anal fins. Caudal free from dorsal and anal, or, of they are 
united, the dorsal with a separate anterior portion. Ventrals 
jugular, composed of several rays, or, if they are reduced to a 
filament, the dorsal is divided into two. Gill-opening wide ; 
the gill-membranes generally not attached to the isthmus. 
Pseudobranchie none, or glandular, rudimentary. An ar- 
bladder and pyloric appendages generally present. 

The family of “Cod-fishes” consists partly of littoral and 
surface species (and they form the majority), partly of deep- 


sea forms. The former are almost entirely confined to the 


temperate zones, extending beyond the Arctic Circle; the 
latter have, as deep-sea fishes generally, a much wider range, 
and hitherto have been found chiefly at considerable depths 
of rather low latitudes. Only two or three species inhabit 
fresh waters. They form one of the most important articles 
of food and subsistence to the fishermen in Europe and North 
America, and to whole tribes bordering upon the Arctic 
Ocean. 

Fossil remains are scarce. Nemopteryx and Palwogadus 
have been described from the schists of Glaris, a formation 
believed to have been the bottom of a very deep sea. In the 
clay of Sheppey species occur allied to Gadus, Merluccius, and 
Phyeis ; others, not readily determinable, have been found at 
Licata in Sicily (Miocene). 


Gapus.—Body moderately elongate, covered with small 
scales. A separate caudal, three dorsal, and two anal fins ; 
ventrals narrow, composed of six or more rays. Teeth in the 
upper jaw in a narrow band ; vomerine teeth ; none on the pala- 
tines. 


540 FISHES. 


Arctic and temperate zones of the Northern Hemisphere. 
Eighteen species are known, of which the following are the 
most important :— 

Gadus morrhua, the common “ Cod-fish”—in German 
called “ Kabeljau” when fresh and old, “ Dorsch” when young 
and fresh, “ Stock-fish” when dried, “ Labberdan ” when salted 
—imeasures from two to four feet, and attais to a weight 
of one hundred pounds. On the British coasts and in the 
German Ocean it is generally of a greenish or brownish-olive 
colour, with numerous yellowish or brown spots. Farther 
northwards darker-coloured specimens, frequently without 
any spots, predominate; and on the Greenland, Iceland, and 
North Scandinavian coasts the Cod have often a large irregular 
black blotch on the side. The Cod-fish occurs between 50° 
and 75° lat. N., in great profusion, to a depth of 120 fathoms, 
but is not found nearer the Equator than 40° lat. Close to 
the coast it is met with singly all the year round, but towards 
the spawning-time it approaches the shore in numbers, which 
happens in January in England and not before May on the 
American coasts. The English resorted to the cod-fisheries 
of Iceland before the year 1415, but since the sixteenth 
century most vessels go to the banks of Newfoundland, and 
almost all the preserved Cod consumed during Lent in the 
various continental countries is imported from across the 
Atlantic. At one time the Newfoundland cod-fishery rivalled 
in importance the whale-fishery and the fur trade of North 
America. Cod-liver oil is prepared from the liver on the 
Norwegian coast, but also other species of this genus contri- 
bute to this most important drug. 

Gadus tomcodus abundantly occurs on the American coasts ; 
it remains within smaller dimensions than the common Cod- 
fish. Gadus eglefinus, the “ Haddock” (“Schell-fisch ” of the 
Germans, “ Hadot” of the French), is distinguished by a black 
lateral line and a blackish spot above the pectoral fin. It 


COD-FISHES. 541 


attains to a leneth of three feet in the higher latitudes, but 
remains smaller on more southern coasts; like the Cod it ex- 
tends across the Atlantic. The largest specimens are taken 
on the British coast in winter, because at that time they leave 
the deep water to spawn on the coast. Gadus merlangus, the 
“Whiting,” with a black spot in the axil of the pectoral fin. 
Gadus luscus, the “Bib,” “ Pout,” or “ Whiting-pout,” with cross- 
bands during life, and with a black axillary spot, rarely ex- 
ceeding a weightof five pounds. Gadus fabricii,a small species, 
but occurring in incredible numbers on the shores near the 
Arctic circle, and ranging to 80° lat. N. Gadus pollachius, the 
“ Pollack,” without a barbel at the chin, and with the lower 
jaw projecting beyond the upper. Gadus virens, the “ Coal-fish,” 
valuable on account of its size and abundance, and therefore 
preserved for export like the Cod. 

The fishes of the genus Gadus are bathymetrically suc- 
ceeded by several genera, as Gadiculus, Mora, and Strinsia ; 
however these do not descend to sufficiently great depths to 
be included into the deep-sea Fauna; the two following are 
true deep-sea fishes. 


HALARGYREUS.—Body elongate, covered with small scales. 
Two dorsal and two anal fins ; ventrals composed of several rays. 
Jaws with a band of minute villiform teeth ; vomer and palatines 
toothless. No barbel. 


The single species known, H. johnsonii, proves to be a 
deep-sea fish by its organisation as well as geographical dis- 
tribution. Originally known from a single specimen, which was 
obtained at Madeira, it has since been found off the coast of 
New Zealand. There is no doubt that it will be discovered 
also in intermediate seas. 


MELANONUS.—Head and body rather compressed, covered 
with cycloid scales of moderate size, and terminating in a long 
tapering tail, without caudal. Eye of moderate size. Villiform 
teeth in the jaws, on the vomer and palatine bones. Barbel 


542 FISHES. 


none. A short anterior dorsal, the second extending to the end 
of the tail, and the anal being of similar length. Ventrals com- 
posed of several rays. Bones soft and flexible. 

This is one of the discoveries made during the expedition 
of the “Challenger.” The single specimen obtained is of a 
deep-black colour, and was dredged up at a depth of 1975 
fathoms in the Antarctic Ocean. 

Meruuccius.—Body elongate, covered with very small scales. 
A separate caudal ; two dorsal fins and one anal; ventrals well 
developed, composed of seven rays. Teeth in the jaws and on 
the vomer rather strong, in double or triple series. No barbel. 


Two species are known of this genus, widely separated in 
their distribution. The European species, JZ. vulgaris, the 
“Hake,” is found on both sides of the Atlantic, and grows to 
a leneth of four feet. It is caught in great numbers, and 
preserved as “Stock-fish.”. The second species JZ. gayi, is 
common in the Straits of Magelhzn and on the coast of 
Chili, less so in New Zealand. 

The vertebral column of this genus shows a singular modi- 
fication of the apophyses. The neural spines of all the 
abdominal vertebra are extremely strong, dilated, wedged into 
one another. The parapophyses of the third to sixth verte- 
bra are slender, styliform, whilst those of all the following 
abdominal vertebrae are very long and broad, convex on the 
upper and concave on the lower surface; the two or three 
anterior pairs are, as it were, inflated. The whole forms 
a strong roof for the air-bladder, reminding us of a simi- 
lar structure in Kurtus. 

PSEUDOPHYCIS.—Body of moderate length, covered with rather 
small scales. A separate caudal, two dorsals, and one anal; ven- 
tral fins very narrow and styliform, but composed of several rays. 


Jaws with a band of small teeth ; vomer and palatines toothless. 
Chin with a barbel. 


Two species, of which Ps. bachus is common on the coast 
of New Zealand. 


Ne 


COD-FISHES. 543 


Allied genera are Lotella, Physiculus, Uraleptus, and 
Lemonema, from moderate depths, obtained chiefly off 
Madeira and the Southern Temperate Zone. 


Hinnca 
se 


. 
: nage Dae i 
ne oe 


Fig. 248.—Pseudophycis bachus. 


Puycts.—Body of moderate length, covered with small scales. 
Fins more or less enveloped in loose skin. A separate caudal ; 
two dorsal fins and one anal; the anterior dorsal composed of 
from eight to ten rays; ventrals reduced to a single long ray, 
bifid at its end. Small teeth in the jaws and on the vomer ; 
palatine bones toothless. Chin with a barbel. 


Six species from the temperate parts of the North At- 
lantic and the Mediterranean, one, Ph. blennioides, is occa- 
sionally found on the British coast. 


HALOPORPHYRUS.— Body elongate, covered with small scales. 
A separate caudal, two dorsal fins, and one anal; the first dorsal 
with four rays; ventrals narrow, composed of six rays. Jaws 
and vomer with villiform teeth ; palatine bones toothless, Chin 
with a barbel. 


A small genus of deep-sea fishes, of which three species 
are known. They offer a striking instance of the extraordinary 
distribution of deep-sea fishes ; H. /epidion occurs in from 100 
to 600 fathoms in the Mediterranean and the neighbouring 
parts of the Atlantic, off the coast of Japan, and various parts 
of the South Atlantic; H. australis in from 55 to 70 fathoms 
in the Straits of Magelhzn; and finally H. rostratus in from 
600 to 1375 fathoms, midway between the Cape of Good 
Hope and Kerguelen’s Land, and in the South Atlantic. 


544 FISHES. 


Lora.—Body elongate, covered with very small scales. A 
separate caudal, two dorsal fins, and one anal ; ventrals narrow, 
composed of six rays. Villiform teeth in the jaws and on the 
vomer ; none on the palatines, The first dorsal with from ten 
to thirteen well-developed rays. Chin with a barbel. 


The “ Burbot,” or “ Eel-pout” (LZ. vulgaris, Fig. 8, p. 43), 
is a Freshwater-fish which never enters salt water. It is 
locally distributed im Central and Northern Europe and 
North America; it is one of the best Freshwater-fishes, and 
exceeds a length of three feet. 

Motva.—Differs from Lofa in having several large teeth in 
the lower jaw and on the vomer. 

The “Ling” (MZ vulgaris) is a very valuable species, 
common on the northern coasts of Europe, Iceland, and 
Greenland; and generally found from three to four feet long. 
The larger number of the specimens caught are cured and 
dried. 

More._ua.—Body elongate, covered with minute scales. A 
separate caudal. “Two dorsal fins, the anterior of which is 
reduced to a narrow rayed fringe, more or less concealed in a 
longitudinal groove ; the first ray is prolonged. One anal fin. 
Ventrals composed of from five to seven rays. <A band of teeth 
in the jaws and on the vomer. 


Eight species of “ Rocklings” are known from the 
coasts of Europe, Iceland, Greenland, Japan, the Cape of 
Good Hope, and New Zealand. They are of small size, and 
chiefly distinguished by the number of their barbels. British 
are the Five-bearded Rockling (AZ mustela), the Three-bearded 
Rocklings UL tricirrhata, macrophthalma, and maculata), and 
the Four-bearded Rockling (JZ. cimbria). M. macrophthalma 
comes from a depth of from 80 to 180 fathoms. The young 
are known as “ Mackerel Midge” (Couchia), and sometimes 
met with in large numbers at some distance from the coast. 


RANICEPS.—Head large, broad, and depressed ; body of 
moderate length, covered with minute scales. A separate caudal. 


COD-FISHES. 545 


Two dorsal fins, the anterior of which is very short, rudimentary. 
One anal fin. Ventrals composed of six rays. Card-like teeth in 
the jaws and on the vomer. 

The “ Trifurcated Hake,” 2. trifureus, not uncommon 
on the coasts of Northern Europe. 


BREGMACEROS. — Body fusiform, compressed posteriorly, 
covered with cycloid scales of moderate size. Two dorsal fins ; 
the anterior reduced to a single long ray on the occiput ; the 
‘second and the anal much depressed in the middle ; ventrals 
very long, composed of five rays. Teeth small. 


A dwarf Gadoid, the only one found at the surface between 


> 


SN 
S 


Fig. 249.—Bregmaceros macclellandii. 


the Tropics. .B. macclellandii scarcely exceeds three inches in 
length, is not uncommon in the Indian Ocean, and has found 
its way to New Zealand; specimens have been picked up in 
mid-ocean. 


MURANOLEPIS.—Body covered with lanceolate epidermoid 
productions, intersecting each other at right angles like those of 
a Freshwater-eel. Vertical fins confluent, no caudal being dis- 
cernible ; an anterior dorsal fin is represented by a single fila- 
mentous ray ; ventral fins narrow, composed of several rays. A 

2N 


546 FISHES. 


barbel. Jaws with a band of villiform teeth ; palate tooth- 
less. 


One species (JZ. marmoratus) from Kerguelen’s Land. 

CHIASMODUS.—Body naked ; stomach and abdomen disten- 
sible. ‘Two dorsal fins and one anal; a separate caudal; ven- 
tral fins rather narrow, with several rays. Upper and lower 
jaws with two series of large pointed teeth, some of the anterior 
being very large and movable ; teeth on the palatine bones, 
but none on the vomer. Chin without barbel. 


This Gadoid (Ch. niger, Fig. 111, p, 311), inhabits great 
depths in the Atlantic (to 1500 fathoms). The specimen 
ficured was taken with a large Scopeloid in its stomach. 


Brosmius.—Body moderately elongate, covered with very 
small scales. A separate caudal, one dorsal, and one anal ; ven- 
trals narrow, composed of five rays. Vomerine and palatine 
teeth. A barbel. 


The “Torsk” (B. brosme) is confined to the northern parts 
of the temperate zone, and probably extends to the arctic 
circle. 

THIRD FAMILY—OPHIDIIDA, 


Body more or less elongate, naked, or scaly. Vertical fins 
generally wnited ; no separate anterior dorsal or anal ; dorsal 
oecupying the greater portion of the back. Ventral fins rudi- 
mentary or absent, jugular. Gull-openings wide, the gill-mem- 
branes not attached to the isthmus. 

Marine fishes (with the exception of ZLucifuga), partly 
littoral, partly bathybial. They may be divided into five 
groups. 


I. Ventral fins present, attached to the humeral arch: 
BROTULINA. 


BrotuLa.—Body elongate, covered with minute scales. Hye 
of moderate size, Hach ventral reduced to a single filament, 
sometimes bifid at its extremity. Teeth villiform; snout with 
barbels. One pyloric appendage. 


OPHIDIID®. 547 


Five species of small size from the Tropical Atlantic and 
Indian Ocean. 

Lucifuga are Brotula organised for a subterranean life, 
The eye is absent, or quite rudimentary, and covered by the 
skin; the barbels of Brotula are replaced by numerous minute 


Fig. 250.—Lucifuga dentata, from caves in Cuba. 


ciliz or tubercles. They inhabit the subterranean waters of 
caves in Cuba, and never come to the light. 


BATHYNECTES.—Body produced into a long tapering tail, 
without caudal. Mouth very wide, villiform teeth in the jaws, 
on the vomer and palatine bones. Barbel none. Ventral fins 
reduced to simple or bifid filaments, placed close together, and 
near to the humeral symphysis. Gill-membranes not united ; 
gill-laminze remarkably short. Bones of the head soft and 
cavernous ; operculum with a very feeble spine above. 


Deep-sea fishes, inhabiting depths varying from 1000 to 
2500 fathoms. Three species are known, the largest specimen 
obtained being seventeen inches long. 

ACANTHONUS.—Head large and thick, armed in front and on 


the opercles with strong spines ; trunk very short, the vent being 
below the pectoral; tail thin, strongly compressed, tapering, 


Fig. 251.—Acanthonus armatus. 


without caudal. Eye small. Mouth very wide; villiform teeth 
in the jaws, on the vomer and palatine bones. Barbel none. 


548 FISHES. 


Ventrals reduced to simple filaments placed close together on the 
humeral symphysis. Scales extremely small. Bones of the 
head soft. 


Only two specimens, thirteen inches long, of this remark- 
able deep-sea form have been obtained, at a depth of 1075 
fathoms, in the Indian Ocean. 


TypHLOoNUS.— Head large, compressed, with most of the 
bones in a cartilaginous condition ; the superficial bones with 
large muciferous cavities, not armed. Snout a thick protuberance 
projecting beyond the mouth, which is rather small and inferior. 
Trunk very short, the vent being below the pectoral ; tail thin, 
strongly compressed, tapering, without separate caudal. Eye 
externally not visible. Villiform teeth in the jaws, on the vomer 
and palatine bones. Barbel none. Scales thin, deciduous, 
small. 

Also of this deep-sea fish two specimens only are known, 
10 inches long, from a depth of 2200 fathoms in the Western 
Pacific. 


APHYONUS.—Head, body, and tapering tail strongly com- 
pressed, enveloped in a thin, scaleless, loose skin. Vent far 
behind the pectoral. Snout swollen, projecting beyond the wide 
mouth. No teeth in the upper jaw, small ones in the lower. 
No externally visible eye. Barbel none. Head covered with a 
system of wide muciferous channels, the dermal bones being 
almost membranaceous, whilst the others are in a semi-cartila- 
ginous condition. Notochord persistent, but with a superficial 
indication of vertebral segments. 


Fig. 252,—Aphyonus gelatinosus. 


One specimen only of this most remarkable form is 
known; it is 54 inches long, and was obtained at a depth of 
1400 fathoms south of New Guinea. 


OPHIDIID®. 549 


Of the remaining genera belonging to this group, Brotu- 
lophis, Halidesmus, Dinematichthys, and Bythites are surface 
forms; Sirembo and Pteridiwm inhabit moderate depths ; 
Lhinonus is a deep-sea fish. 


Il. Ventral fins replaced by a pair of bifid filaments 
(barbels) inserted below the glosso-hyal : OPHIDIINA. 
OpHIDIUM.—Body elongate, compressed, covered with very 
small scales. Eye of moderate size. All the teeth small. 
Small fishes from the Atlantic and Pacific. Seven species 
are known, differing from one another in the structure of the 
air-bladder (see p. 145). . 
GENYPTERUS is a larger form of Ophidiwm, in which the 


outer series of teeth in the jaws and the single palatine series 
contains strong teeth. 


Three species from the Cape of Good Hope, South 
Australia, New Zealand, and Chili are known. They grow to 
a length of five feet, and have an excellent flesh, like cod, 
well adapted for curing. At the Cape they are known by the 
name of “ Klipvisch,” and in New Zealand as “ Ling” or 
“Cloudy Bay Cod.” 

Ill. No ventral fins whatever ; vent at the throat: FIERAS- 
FERINA. 


These fishes (Fierasfer and Encheliophis) are of very small 
size and eel-like in shape; the ten species known are found 
in the Mediterranean, Atlantic, and Indo-Pacific. As far as 
is known they live parasitically in cavities of other marine 
animals, accompany Medusz, and more especially penetrate 
into the respiratory cavities of Star-fishes and Holothurians. 
Not rarely they attempt other animals less suited for their 
habits, as, for instance, Bivalves; and cases are known in 
which they have been found imprisoned below the mantle of 
the Mollusk, or covered over with a layer of the pearly sub- 
stance secreted by it. They are perfectly harmless to their 


550 FISHES. 


host, and merely seek for themselves a safe habitation, feeding 
on the animalcules which enter with the water the cavity 
inhabited by them. 


IV. No ventral fins whatever ; vent remote from the head ; 
gul-openings very wide, the gill-membranes not being united : 
AMMODYTINA. 


The “Sand-eels” or “Launces” (Ammodytes) are ex- 
tremely common on sandy shores of Europe and North 
America. They live in large shoals, rising as with one accord 
to the surface, or diving to the bottom, where they bury them- 
selves with incredible rapidity in the sand. They are much 
sought after for bait by fishermen, who discover their pre- 
sence on the surface by watching the action of Porpoises 
which feed on them. These Cetaceans, when they meet with 
a shoal, know how to keep it on the surface by diving below 
and swimming round it, thus destroying large numbers of 
them. The most common species on the British coast is the 
Lesser Sand-eel (A. tobianus); the Greater Sand-eel (A. 
lanceolatus), which attains to a leneth of eighteen inches; A. 
siculus, from the Mediterranean, scarcer in British seas. Two 
species live on the American coasts, A. americanus and A. 
dubius ; one in California, A. personatus. Bleekeria from 
Madras is the second genus of this group. 


V. No ventral fins whatever ; vent remote from the head ; 


Fig. 253.—Congrogadus subducens. 


gill-openings of moderate width, the gill-membranes being united 
below the throat, not attached to the isthmus: CONGROGADINA. 

Only two fishes belong to this group—Congrogadus from 
the Australian coasts, and Haliophis from the Red Sea. 


MACRURID&. 551 


FourtH FAMILY—MACRURID&A. 


Body terminating in a long, compressed, tapering tail, 


Fig. 255.—Scale of Macrurus ecelorhynchus. 


Fig. 254.—Scale of Macrurus 
trachyrhynchus. 


WY a 
A 


HU 


i 


Mth 


HD 
iy 
Y, Yypy 


Fig. 256.—Scale from the lateral line of Macrurus australis. 


covered with spiny, keeled, or striated scales. One short ante- 


552 FISHES. 


rior dorsal ; the second very long, continued to the end of the 
tail, and composed of very feeble rays ; anal of an extent similar 
to that of the second dorsal; no caudal. Ventral fins thoracic 
or jugular, composed of several rays. 

This family, known a few years ago from a limited number 
of examples, representing a few species only, proves to be one 
which is distributed over all oceans, occurring in considerable 
variety and great abundance at depths of from 120 to 2600 
fathoms. They are, in fact, Deep-sea Gadoids, much resemb- 
lng each other in the general shape of their body, but differ- 
ing in the form of the snout and in the structure of their 
scales. About forty species are known, of which many attain 
a length of three feet. They have been referred to the fol- 
lowing genera :— 


Fig. 257.—-Macrurus australis. 


Macrurus.—Scales of moderate size; snout produced, 
conical ; mouth inferior. 

CoRYPHANOIDES.—Scales of moderate size; snout obtuse, 
obliquely truncated ; cleft of the mouth lateral. 

MAcruRONUS.—NSeales of moderate size, spiny ; snout pointed ; 
mouth anterior ands lateral, with the lower jaw projecting. 

MALACOCEPHALUS.—NSeales very small, ctenoid ; snout short, 
obtuse, obliquely truncated, 

BatuyGapus.—Scales small, cycloid ; snout not projecting 
beyond the mouth ; mouth wide, anterior, and lateral. 


FLAT-FISHES, 553 


Ateleopus from Japan and Xenocephalus from New Ire- 
land are genera belonging to the Gadoid Anacanths, but are 
very imperfectly known. 


SECOND DIVISION—ANACANTHINI PLEURONECTOIDEI. 


Head and part of the body unsymmetrically formed. 


This division consists of one family only : 


PLEURONECTIDA. 


The fishes of this family are called “ Flat-fishes,” from their 
strongly compressed, high, and flat body; in consequence of the 
absence of an air-bladder, and of the structure of their paired 
fins, they are unable to maintain their body in a vertical posi- 
tion, resting and moving on one side of the body only. The side 
turned towards the bottom is sometimes the left, sometimes 
the right, colourless, and termed the “blind” side; that 
turned upwards and towards the light is variously, and in 
some tropical species even vividly, coloured. Both eyes are 
on the coloured side, on which side also the muscles are more 
stronely developed. The dorsal and anal fins are exceedingly 
long, without division. All the Flat-fishes undergo remark- 
able changes with age, which, however, are very imperfectly 
known and not yet fully understood, from the difficulty of 
referring larval forms to their respective parents. The larve 
are, singularly enough, much more frequently met in the open 
ocean than near the coast; they are transparent, like Lepto- 
cephalt ; perfectly symmetrical, with an eye on each side of 
the head, and swim in a vertical position like other fishes. 
The manner in which one eye is transferred from the blind 
to the coloured side is subject to discussion. Whilst some 
naturalists believe that the eye turning round its axis pushes 
its way through the yielding bones from the blind to the 


054 FISHES. 


upper side, others hold that, as soon as the body of the fish 
commences to rest on one side only, the eye of that side, in 
its tendency to turn towards the light, carries the surround- 
ing parts of the head with it; in fact, the whole of the fore- 
part of the head is twisted towards the coloured side, which is 
a process of but little difficulty as lone as the framework of 
the head is still cartilaginous. 

Flat-fishes when adult live always on the bottom, and 
swim with an undulating motion of their body. Sometimes 
they rise to the surface; they prefer sandy bottom, and do 
not descend to any considerable depth. They occur in all 
seas, except in the highest latitudes and on rocky, precipi- 
tous coasts, becoming most numerous towards the equator ; 
those of the largest size occur in the temperate zone. Some 
enter fresh water freely, and others have become entirely 
acclimatised in ponds and rivers. All are carnivorous. 

Flat-fishes were not abundant in the tertiary epoch; the 
only representative known is a species of Rhombus from 
Monte Bolca. 

The size and abundance of Flat-fishes, and the flavour of 
the flesh of the majority of the species, render this family one 
of the most useful to man; and especially on the coasts of 
the northern temperate zone, their capture is one of the most 
important sources of profit to the fishermen. 


PseTTopEs.—Mouth very wide, the maxillary being more 
than one-half of that of the head. Each jaw armed with two 
series of long, slender, curved, distant teeth, the front teeth of 
the inner series of the lower jaw being the longest, and received 
in a groove before the vomer; vomerine and palatine teeth. 
The dorsal fin commences on the nape of the neck. 

This genus fitly heads the list of Flat-fishes, having 
retained more of symmetrical structure than the other mem- 
bers of the family, and, therefore, their eyes are as often found 
on the right as on the left side. It seems to swim, not un- 


FLAT-FISHES. 555 


frequently, in a vertical position. Only one species is known, 
Ps. erumet, common in the Indian Ocean. 


HrppoGLossus.—Eyes on the right side; mouth wide, the 
length of the maxillary being one-third of that of the head. 
Teeth in the upper jaw in a double series; the anterior of the 
upper jaw and the lateral of the lower strong. The dorsal fin 
commences above the eye. 


The “ Holibut” (4. vulgaris) is the largest of all Flat- 
fishes, attaining to a length of five and six feet, and a weight 
of several hundredweights. It is found along the northern 
coasts of Europe, on the coasts of Kamtschatka and Cali- 
fornia, particularly frequenting banks situated at some 
distance from the coast, and at a depth of 50 to 120 fathoms. 

Other genera, with nearly symmetrical mouth, in which 
the dorsal fin commences above the eye, are Hippoglossoides 
(the “Rough Dab”) and Zephritis. 


RuHomMBuUS.—Hyes on the left side. Mouth wide, the length 
of the maxillary being more than one-third of that of the 
head. Each jaw with a band of villiform teeth, without canines ; 
vomerine teeth, none on the palatines, The dorsal fin. com- 
mences on the snout. Scales none or small. 


Seven species from the North Atlantic and Mediterranean, 
of which the most noteworthy are the “ Turbot,’ RA. maximus, 
one of the most valued food-fishes, and growing to a length 
of three feet; the “Turbot of the Black Sea,” Rh. meoticus, 
the body of which is covered with bony, conical tubercles, 
which are as large as the eye; the “ Brill,” Ah. levis, repre- 
sented on the North American coasts by Lh. aquosus ; the 
“Whiff,” or “ Mary-sole,” or “Sail-fluke,” Rh. megastoma ; 
“Bloch’s Top-knot,” Lh. punctatus (described by Yarrell as 
Lh. hirtus, and often confounded with the following species). 


PHRYNORHOMBUS, differing from Lhombus in lacking vomer- 
ine teeth. The scales are very small and spiny. 


The “Top-knot” (Ph. wnimaculatus) occurs occasionally 


556 FISHES. 


on the south coast of England, and is more common in the 
Mediterranean ; it is a small species. 

ARNOGLOSSUS.— Mouth wide, the length of the maxillary 
being more or not much less than one-third of that of the head. 
Teeth minute, in a single series in both jaws; vomerine or 
palatine teeth none. The dorsal fin commences on the snout. 
Scales of moderate size, deciduous ; lateral line with a strong 
curve above the pectoral, Eyes on the left side. 

Seven species from European and Indian Seas. The 
“Scald-fish” (A. laterna) is common in the Mediterranean, and 
extends to the south coast of England; it is a small species. 


PSEUDORHOMBUS.—Mouth wide, the length of the maxillary 
being more than one-third of that of the head. Teeth in both 
jaws in a single series, of unequal size ; vomerine or palatine teeth 
none. ‘The dorsal fin commences on the snout. Scales small ; 
lateral line with a strong curve anteriorly. Eyes on the left side. 
Interorbital space not concave. 

A tropical genus with a few outlying species, represented 
chiefly in the Indo-Pacific, and also in the Atlantic. Seven- 
teen species. 

VHOMBOIDICHTHYS. — Mouth of moderate width or small. 
Teeth minute, in a single or double series ; vomerine or palatine 
teeth none. Eyes separated by a concave more or less broad 
space. The dorsal fin commences on the snout. Seales ciliated ; 
lateral line with a strong curve anteriorly, Eyes on the left side. 

A tropical genus, but also represented in the Mediterranean 
and on the coast of Japan. Sixteen species, the majority of 
which are prettily coloured and ornamented with ocellated 
spots; in some species the adult males have some of the fin- 
rays prolonged into filaments. 

Other genera with nearly symmetrical mouth, in which 
the dorsal fin commences before the eye, on the snout, are 
Citharus, Anticitharus, Brachyplewra, Samarts, Psettichthys, 
Citharichthys, Hemirhombus, Paralichthys, Liopsetta, Lopho- 
nectes, Lepidopsetta, and Thysanopsetta. 


FLAT-FISHES. 557 


PLEURONECTES.—Cleft of the mouth narrow, with the denti- 
tion much more developed on the blind side than on the coloured. 
Teeth in a single or in a double series, of moderate size ; palatine 
and vomerine teeth none. The dorsal fin commences above the 
eye. Scales very small or entirely absent. Eyes generally on 
the right side. 


This genus is characteristic of the littoral fauna of the 
northern temperate zone, a few species ranging to the Arctic 
circle. ‘Twenty-three species are known, of which the fol- 
lowing are the most noteworthy: P. platessa, the “ Plaice,” 
ranging from the coast of France to Iceland; P. glacialis, 
from the Arctic coasts of North America; P. americanus, the 
transatlantic representative of the Plaice; P. limanda, the 
common “Dab;” P. microcephalus, the “Smear-dab;” P. 
cynoglossus, the “ Craig-fluke ;” P. flesus, the “ Flounder.” 


RHOMBOSOLEA.—Eyes on the right side, the lower in advance 
of the upper. Mouth narrower on the right side than on the 
left ; teeth on the blind side only, villiform; palatine and 
vomerine teeth none. The dorsal fin commences on the fore- 
most part of the snout. Only one ventral which is continuous 
with the anal. Scales very small, cycloid ; lateral line straight. 

This genus represents Plewronectes in the Southern Hemi- 
sphere, but consists of three species only, which occur on the 
coasts of New Zealand, and are valued as food-fishes. 

Other genera, with narrow unsymmetrical mouth, in which 
the upper eye is not in advance of the lower, and which have 
pectoral fins, are Parophrys, Psammodiscus, Ammotretis, Pel- 
torhamphus, Nematops, Leops, and Poecilopsetta. 


SoLeA.—Eyes on the right side, the upper being more or less 
in advance of the lower. Cleft of the mouth narrow, twisted 
round to the left side. Villiform teeth on the blind side only ; 
vomerine or palatine teeth none. The dorsal fin commences on 
the snout, and is not confluent with the caudal. Scales very 
small, ctenoid ; lateral line straight. 


“Soles” are numerously represented in all suitable locali- 


558 FISHES, 


ties within the temperate and tropical zones, with the excep- 
tion of the southern parts of the southern temperate zone, in 
which they are absent. Some enter or live in fresh water. 
Nearly forty species are known. British are S. vulgaris, the 
common “Sole;” S. awrantiaca, the “Lemon-sole,” which is 
rather a southern species, and inhabits, on the south coast of 
England, deeper water than the common Sole; S. variegata, 
the “ Banded Sole,” with very small pectoral fins; and 8S. 
minuta, the “ Dwarf-Sole.’—Allied to Solea are Pardachirus 
and Liachirus from the Indian coasts. 


SyNAPTuRA.—Eyes on the right side, the upper in advance of 
the lower. Cleft of the mouth narrow, twisted round to the left 
side ; minute teeth on the left side only. Vertical fins confluent. 
Scales small, ctenoid ; lateral line straight. 

Twenty species; with the exception of two from the 
Mediterranean and coast of Portugal, all belong to the fauna 
of the Indian Ocean.—Closely allied is Aesopia. 


GYMNACHIRUS.—Mouth very small, toothless. Scales none, 
lateral line straight. Eyes on the right side. The dorsal fin 
commences on the snout ; caudal free. Pectorals rudimentary or 
entirely absent. 

Two species from the Tropical Atlantic. 


CyNoGLossus.—Kyes on the left side; pectorals none ; ver- 
tical fins confluent. Scales ctenoid ; lateral line on the left 
side double or triple ; upper part of the snout produced back- 
wards into a hook; mouth unsymmetrical, rather narrow. 
Teeth minute, on the right side only. 


Abundant in the Indian seas, and especially on the flat 
sandy shores of China. About thirty-five species are known, 
which rarely exceed a length of eighteen inches. They are 
easily recognised by their long narrow shape (which has 
been compared to a dog’s tongue) and the peculiar form of 
their snout. 

To complete the list of Pleuronectoid genera, the following 


CAT-FISHES, 5d9 


have to be mentioned: Soleotalpa and Apionichthys, Soles 
with rudimentary eyes; -Ammopleurops, Aphoristia, and 
Plagusia, which are closely allied to Cynoglossus, the latter 
genus having the lips provided with tentacles. 


FOURTH ORDER—PHYSOSTOMI. 


All the fin-rays articulated, only the first of the dorsal and 
pectoral fins ws sometimes ossified. Ventral fins, if present, 
abdominal, without spine. Atr-bladder, of present, with a pneu- 
matic duct (except in Scombresocide). 


First FAMILY—SILURIDA, 


Skin naked or with osseous scutes, but without scales. 
Larbels always present ; maxillary bone rudimentary, almost 
always forming a support to a maxillary barbel. Margin of 
the upper jaw formed by the intermaxillaries only. Suboper- 
culum absent. Air-bladder generally present, communicating 
with the organ of hearing by means of the auditory ossicles, 
Adipose fin present or absent. 

A large family, represented by numerous genera, which 
exhibit a great variety of form and structure of the fins; they 
inhabit the fresh waters of all the temperate and tropical 
regions ; a few enter the sea but keep near the coast. The 
first appearance of Siluroids is indicated by some fossil remains 
in tertiary deposits of the highlands of Padang in Sumatra, 
where Pseudeutropius and Bagarius, types well represented in 
the living Indian fauna, have been found. Also in North 
America spines referable to Cat-fishes have been found in 
tertiary formations. 

The skeleton of the typical Siluroids shows many peculia- 
rities, The cranial cavity is not membranous on the sides, 


560 FISHES. 


but closed as in the Cyprinids, by the orbitosphenoids and 
the ethmoid that unite with the pre-frontals, carrying forward 
the cranial cavity to the nasal bone, without leaving a mem- 
branous septum between the orbits. But the supraoccipital 
is greatly developed, and in many the post-temporal is united 
by suture to the sides of the cranium. In numerous members 
of the family the skull is enlarged posteriorly, by dermal 
ossifications, to form a kind of helmet which spreads over the 
nape; the lateral angles of this production are formed by the 
suprascapule, augmented and fixed by suture, and the median 
part is the extension of the supraoccipital, which is generally 
very large, is connected anteriorly with the frontal, and pass- 
ing backwards between the post-frontals, the parietals, the 
mastoids, and the suprascapulee, goes past them all on to the 
nape. The mastoids interpose between the post-frontals and 
the parietals, so as to come in contact with the supraoccipital, 
and the parietals but little developed are pressed to the back 
part of the cranium, and in some instances wholly disappear. 

The suprascapula most frequently unites to the mastoid 
by an immovable suture, which includes the parietal when 
that bone is present, and extends even to the supraoccipital. 
It gives out besides two processes, one of them resting on the 
exoccipital and basioccipital, or wedging itself between them, 
and the other going to the first vertebra; sometimes a plate 
from the exoccipital supports the same vertebra. This verte- 
bra, though it presents a pretty continuous centrum beneath, 
is in reality composed of three or four coalescent vertebrae, as 
we ascertain by its diapophyses, by the circular elevations of 
the neural canal, and by the holes for the exit of the pairs of 
spinal nerves. There is great variety in the development of 
the various processes of the bones we have mentioned, and 
there is no less in the magnitude and connections of the first 
three interneurals. 

In general in the species which have a strong dorsal 


ee 


ee 


CAT-FISHES. 561 


spine the second and third interneurals unite to form a single 
plate, the “buckler;” the great spine is articulated to the 
third interneural, and there is only the vestige of a spine on 
the second interneural in form of a small oval bone, forked 
below, whose function is to act as a bolt or fulcrum to the 
ereat spine when the fish wishes to use it as an offensive 
weapon. The great spine itself is jomed by a ring to a 
second spine, which belongs to the third interneural. This 
articulation by ring exists in Lophius and a few other fishes 
not of this family. 

The first interneural does not carry a ray, and it varies 
much in the species whose helmet is continuous with the 
buckler, as in many of the Bagri and Pimelodi. In these 
cases the supraoccipital, extending backwards, conceals the 
first nterneural, passing over it to touch with its poimt the 
buckler formed by the second and third interneurals. In 
other instances, as in Synodontis and Auchenipterus, the supra- 
occipital and second interneural, forking and expanding, in- 
close and join themselves to the first interneural, but leave 
a larger or smaller space in the middle of the nuchal armour 
which they contribute to form. When the point of the supra- 
occipital does not reach quite to the second interneural, the 
first interneural remains free from connection, and occasion- 
ally shows as a narrow plate interposed between the other 
two; in such a case the helmet is not continuous with the 
buckler. 

The neural spines of the coalescent centra, which form the 
apparently single first vertebra, concur also in sustaining the 
nuchal plate-armour and the first great dorsal spine. They 
carry the interneurals, are joined to them by suture, and one 
of them is often inclined towards the occiput to assist in sus- 
taining the head; in fact, this part of the skeleton is con- 
structed to give firm mutual support. 

The shoulder-girdle of the Siluroids is also formed to give 

20 


562 FISHES. 


resistance to the strong weapon with which it is frequently 
armed. The post-temporal, as we have said above, is often 
united by suture to the cranium, and it obtains support below 
by one or two processes that are fixed on the basioccipitals 
and on the diapophysis of the first vertebra. 

In most osseous fishes the clavicle completes the lower 
key of the scapular arch in joining its fellow by suture or 
synchondrosis without the intervention of the coracoid; but 
in the Siluroids the coracoid descends to take part in this 
joint, and sometimes even to occupy the half of the suture, 
which is not unfrequently constructed of very deep inter- 
locking serratures. The solidity of this base of the pectoral 
spine is further augmented by the intimate union of the 
coracoid and scapula, which often extends to junction by 
suture, or even to coalescence; and these bones, moreover, 


give off two bony arches—the first a slender one, arising from 
the salient edge of the coracoid near the pectoral fin, and 
going to the interior face of the scapular that is applied to 
the interior surface of the ascending branch of the clavicle ; 
the second and broader supplementary arch is often perforated 
by a large hole; it also emanates from the same salient edge 
of the radius, but proceeds in opposite direction to the inferior 
edge of the clavicle, a little before the insertion of the pectoral 
spine. The two arches give attachments to the muscles that 
move this spine; in the Synodontes and many Bagri the 
upper arch remains in a cartilaginous or Lgamentous condi- 
tion, while in Malapterurus it is the lower arch that does not 
ossify, but both are fully formed in the Siluri and many other 
Siluroids more closely allied to that typical genus. The 
post-clavicle is also wanting in the Siluroids. The pterygoid 
and entopterygoid are reduced to a single bone, the symplectic 
is wholly wanting, and the palatine is merely a slender cylin- 
drical bone. The sub-operculum is likewise constantly absent 
in all the Siluroids. 


rT ee a ee oe 


Oy aN 


CAT-FISHES. 563 


The great number of different generic types has necessi- 
tated a further division of this family into eight subdivisions : 


I. Siturip& Homaoprera&.— The dorsal and anal fins are 
very long, nearly equal in extent to the corresponding parts of 
the vertebral column. 

a, CLARIINA. 


CLARIAS.—Dorsal fin extending from the neck to the caudal, 
without adipose division. Cleft of the mouth transverse, 
anterior, of moderate width ; barbels eight ; one pair of nasal, 
one of maxillary, and two pairs of mandibulary barbels. Eyes 
small. Head depressed ; its upper and lateral parts are osseous, 
or covered with only a very thin skin. A dendritic accessory 
branchial organ is attached to the convex side of the second and 
fourth branchial arches, and received in a cavity behind the gill- 
cavity proper. Ventrals six-rayed; only the pectoral has a 
pungent spine. Body eel-like. 


Twenty species from Africa, the East Indies, and the inter- 
mediate parts of Asia; some attain to a length of six feet. 
They inhabit muddy and marshy waters; the physiological 
function of the accessory branchial organ is not known. Its 
skeleton is formed by a soft cartilaginous substance covered 
by mucous membrane, in which the vessels are imbedded. 
The vessels arise from branchial arteries, and return the blood 
into branchial veins. The vernacular name of the Nilotic 
species is “ Carmoot.” 


HETEROBRANCHUS differs from Clarias only in the structure 
of the dorsal fin, the posterior portion of which is adipose. 


The geographical range of this genus is not quite co- 
extensive with that of Clarias, inasmuch as it is hmited to 
Africa and the East-Indian Archipelago. Six species. 


b. PLOTOSINA. 


Piorosus.—A short dorsal fin in front, with a pungent 
spine ; a second long dorsal coalesces with the caudal and anal. 
Vomerine teeth molar-like. Barbels eight or ten; one immedi- 


564. FISHES. 


ately before the posterior nostril, which is remote from the | 


Fig. 258. —Mouth of Cnidoglanis megastoma, Australia. 


anterior, the latter being quite in front of the snout. Cleft of 
the mouth transverse. Eyes small. The gill-membranes are not 
confluent with the skin of the isthmus. Ventral fins many- 
rayed. Head depressed ; body elongate. 


Three species are known from brackish waters of the 
Indian Ocean freely entering the sea. Plotosus anguillaris is 
distinguished by two white longitudinal bands, and is one of 
the most generally distributed and common Indian fishes — 


—— 


Fig, 259.—Cnidoglanis microcephalus. 


Copidoglanis and Cnidoglanis are two very closely allied forms, 


———— 


chiefly from rivers and brackish waters of Australia. None 
of these Siluroids attain to a considerable size. Chaca, from 
the East Indies, belongs likewise to this sub-family. 


CAT-FISHES. 565 


Il. Stturma HETEROPTERA— The rayed dorsal fin is 
very little developed, and, if rt is present, it belongs to the 
abdoninal portion of the vertebral column; the adipose fin is 
exceedingly small or absent. The extent of the anal ts not 
much inferior to that of the caudal vertebral column. The 
gul-membranes overlap the isthmus, remaining more or less 
separate: SILURINA. 


SACCOBRANCHUS.—Adipose fin none ; dorsal very short, 
without pungent spine, placed above the ventrals. Cleft of the 
mouth transverse, anterior, of moderate width ; barbels eight. 
Eyes rather small. The upper and lateral parts of the head 
osseous or covered with a very thin skin. Gill-cavity with an 
accessory posterior sac, extending backwards between the muscles 
along each side of the abdominal and caudal portions of the 
vertebral column. Ventrals six-rayed. 

Small fishes from East Indian rivers; four species are 
known. The lung-like extension of the branchial cavity 
receives water, and is surrounded by contractile transverse 
muscular fibres by which the water is expelled at intervals. 
The vessels of the sac take their origin in the last branchial 
artery, and pass into the aorta. 

Smturus.—No adipose fin; one very short dorsal, without 
pungent spine. Barbels four or six, one to each maxillary, and 
one or two to each mandible. Nostrils remote from each other. 
Head and body covered with soft skin. The eye is situated 
above the level of the angle of the mouth. The dorsal fin is 
anterior to the ventrals which are composed of more than eight 
rays. Caudal rounded. 


This genus, of which five species are known, inhabits 
the temperate parts of Europe and Asia. The species which 
has given the name to the whole family, is the “ Wels” of 
the Germans, Silurus glanis. It is found in the fresh waters 
east of the Rhine, and is, besides the Sturgeons, the largest 
of European Freshwater-fishes, and the only species of this 
family which occurs in Europe. Barbels six. It attains to 


566 FISHES. 


a weight of 300 or 400 Ibs. and the flesh, especially of 
smaller specimens, is firm, flaky, and well flavoured. Aris- 


M Hil) 


Fig. 260.—The ‘‘ Wels,” Siluris glanis. 
totle described it under the name of Glanis. Its former 
occurrence in Scotland has justly been denied. In China it 
is represented by a similar species, S. asotus, which, however, 
has four barbels only. 

This sub - family is well represented by various other 
genera in the fresh waters of the African as well as Indian 
region. African genera are Schilbe and Futropius ; East 
Indian : Silwrichthys, Wallago, Belodontichthys, Eutropiuichthys, 
Cryptopterus, Callichrous, Hemisilurus, Siluranodon, Ailia, 
Schilbichthys, Lais, Pseudeutropius, Pangasius, Helicophaqus, 
and Stilondia. 


Ill. SiruripA ANOMALOPTERA. 
very short, the former belonging to the caudal vertebral column ; 


‘sal and adipose fins 


anal very long. Ventrals in front of the dorsal. Gall- 
membranes entirely separate, overlapping the isthmus: (Hy- 
POPHTHALMINA. 


HyYPorpHTHALMUS.—Dorsal fin with seven rays, the first of 
which is slightly spinous. The lower jaw is rather the longer. 
Barbels six, those of the mandible long. No teeth; inter- 
maxillaries very feeble. Head covered with skin. Eye of mode- 
rate size, situated behind and below the angle of the mouth. 
Ventrals small, six-rayed. 


CAT-FISHES. 567 


Four species from tropical America. The second genus 
of this sub-family is Helogenes from the Essequibo. 


IV. Situripz PROTEROPTERZ.— The rayed dorsal fin is 
always present, short, with not more than twelve short rays, 
and belongs to the abdominal portion of the vertebral column, 
being placed in advance of the ventrals. The adipose fin is always 
present and well developed, although frequently short. The 
extent of the anal is much inferior to that of the caudal verte- 
bral column. The gill-membranes are not confluent with the 
skin of the isthmus, their posterior margin always remaining 
Sree even if they are united with each other. Whenever the 
nasal barbel is present it belongs to the posterior nostril. 


a. BAGRINA. 


Baarus.—Adipose fin long; a short dorsal with a pungent 
spine and nine or ten soft rays; anal fin short, with less than 
twenty rays. Barbels eight. The anterior and posterior nostrils 
are remote from each other, the posterior being provided with a 
barbel. Teeth on the palate in a continuous band. Eyes with 
a free orbital margin. Caudal forked ; ventrals six-rayed. 


This genus consists of two species only, common in the 
Nile, viz. the “ Bayad,” B. bayad, and B. docmac. Both grow 
to a large size, exceeding a length of five feet, and are eaten. 
Chrysichthys and Clarotes are two other Siluroid genera from 
African rivers, closely allied to Bagrus. Similar Siluroids are 
common in the East Indies, and have been referred to the 
following genera: Macrones, Pseudobagrus, Liocassis, Bagroides, 
Bagrichthys, Rita, Acrochordonichthys, Akysis. 


b. AMIURINA. 


Amiurus.—Adipose fin of moderate length ; a short dorsal 
with a pungent spine and six soft rays; anal fin of moderate 
length. Barbels eight. The anterior and posterior nostrils are 
remote from each other, the posterior being provided with a bar- 


568 FISHES. 


bel. Palate edentulous. Head covered with skin above. Ven- 
trals eight-rayed. 

The “Cat-fishes” of North America, of which about a 
dozen different species are known. One species occurs in 
China, Allied, but smaller forms are Hopladelus and Notu- 
rus, likewise from North America. 


c. PIMELODINA. 


PLATYSTOMA.—Adipose fin of moderate length ; a short dor- 
sal fin with a pungent spine and six or seven soft rays; anal fin 
rather short. Snout very long, spatulate, with the upper jaw 
more or less projecting ; the upper surface of the head not 
covered by the skin. Barbels six; the anterior and posterior 
nostrils remote from each other, none with a barbel. Palate 
toothed. Caudal forked; ventrals six-rayed, inserted behind 
the dorsal. 

Twelve species from South America, some attaining a 
length of six feet, the majority being ornamented with deep- 
black spots or bands. Allied genera from South America, 
hkewise distinguished by a long spatulate snout, are Sorubim, 
Hemisorubim, and Platystomatichthys, whilst Phractocephalus, 
Piramutana, Platynematichthys, Piratinga, Bagropsis, and 
Sciades, have a snout of ordinary length. The barbels of some 
are of extraordinary length, and not rarely dilated and 
bandlike. 


PrmELopus.—Adipose fin well developed ; dorsal fin short, 
with a more or less pungent spine and six rays; anal fin short. 
Barbels six, cylindrical or slightly compressed, none of them 
belonging to either of the nostrils, which are remote from each 
other. Palate edentulous. Ventrals six-rayed, inserted behind 
the dorsal. 

Of all South American genera this is represented by the 
ereatest number of species, more than forty being well 
characterised ; they differ chiefly with regard to the length of 


the adipose fin and barbels, and the streneth of the dorsal 


CAT-FISHES. 569 


spine. Singularly, two species (P. platychir and P. balayi), 
are found in West Africa. The majority are of but moderate 
size and plain coloration.—Alhled South American genera (also 
without teeth on the palate), are Pirinampus, Conorhynchus, 
Notoglanis, Callophysus, Lophiosilurus. 


AUCHENOGLANIS.—Adipose fin rather long, dorsal short, with 
a pungent spine and seven rays; anal short. Snout produced, 
pointed, with narrow mouth. Barbels six, none of which belongs 
to either of the nostrils, which are remote from each other. The 
teeth of each jaw form a pair of small elliptic patches which are 
longer than broad; palate edentulous. Eyes of moderate size. 
Ventrals six-rayed. 

One species, Aw. biscutatus, from the Nile, Senegal, and 


other West African rivers. 


d. ARIINA. 


Arius.—Adipose fin of moderate length or short ; a short 
dorsal fin with a pungent spine and seven soft rays; anal fin 
rather short. Head osseous above; barbels six, four at the 
mandible, none at either of the nostrils which are close together. 
Eyes with a free orbital margin. Caudal fin forked ; ventrals 
six-rayed, behind the dorsal. 


Of all Siluroid genera this has the greatest number of 
species (about seventy), and the widest distribution, being 
represented in almost all tropical countries which are drained 
by large rivers; some of the species prefer brackish to fresh 
water, and a few enter the sea, but keep near to the coast. 
Some of the species are of small size, whilst others exceed a 
length of five feet. The extent of the armature of the neck 
and the dentition vary much in the different species, and 
affords two of the principal characters by which the species 
are separated.—The following genera are allied to Artus, 
Galeichthys from South Africa ; Genidens and Paradiplomystax 
from Brazil; Diplomystax from Chile; <Aelurichthys from 
Central and South America ; Hemipimelodus, Ketengus, Osteo- 


570 FISHES. 


genwosus, and Batrachocephalus from the East Indies; and 
Aitopochilus from West Africa. 


12 92 


99°99, 


° 
9 oD 
2 
2 3832 


3. 
52 
AR 300 39 ie 
47.90:0509 


o 
2: 


=o “Gonos 


Fig. 261.—Arius australis, from Queensland. 


é. BAGARIINA. 


BacArius.—Adipose fin rather short ; a short dorsal with 
one spine and six rays; anal fin of moderate length. Barbels 
eight, of which one pair stands between the anterior and posterior 
nostrils which are close together. Head naked above. Caudal 
fin deeply forked ; ventrals rays six. Thorax without longitu- 
dinal plaits of the skin. 


CAT-FISHES. BTL 


A large Siluroid (B. bagarius) from rivers of India and 
Java; exceeding a length of six feet. 


EUGLYPTOSTERNUM.— Adipose fin of moderate length ; a short 
dorsal with a pungent spine and six rays; anal fin short. Bar- 
bels eight, of which one pair is placed between the anterior and 


Fig. 262.—Euglyptosternum coum, thoracic adhesive apparatus. 


posterior nostrils which are close together. Teeth on the palate 
villiform, in two separate patches. Eyes small, below the skin. 
Caudal forked ; ventral rays six. Pectorals horizontal, with a 
thoracic adhesive apparatus between, which is formed by longitu- 
dinal plaits of the skin. 

This fish (Zw. cowm) inhabits the river Coic in Syria, and 
is about twelve inches long. The plaited structure on the 
thorax probably increases the capability of the fish of main- 
taining its position in the rapid current of the stream, a func- 
tion which appears to be chiefly performed by the horizontally 
expanded pectoral fins. A similar structure is found in 


Die FISHES. 


Glyptosternum, a genus represented by eight species in moun- 
tain streams of the East Indies, and differing from the Syrian 
species in lacking the teeth on the palate. 


V. SmuRIDA STENOBRANCHIZ.— The rayed dorsal fin 1s 
short, if present, belonging to the abdominal portion of the verte- 
bral column, the ventrals being inserted behind it (except im 
Lhinoglanis). The gill-membranes are confluent with the skin 
of the isthnvus. 


a. DORADINA. 


Some of the genera have no bony shields along the lateral 
line, and a small adipose fin or none whatever; all of these 
are South American— A geniosus, Tetranematichthys, Euane- 
mus, Auchenipterus, Glanidium, Centromochlus, Trachelyopterus, 
Cetopsis, and Astrophysus. 

Others have a series of bony scutes along the middle of 
the side; they form the genus Doras with two closely allied 
forms, Oxydoras and Rhinodoras. Some twenty-five species 
are known, all from rivers of tropical America, flowing into 
the Atlantic. These fishes have excited attention by their 
habit of travelling, during the dry season, from a piece of water 
about to dry up, m 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 travellers 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 supposed 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 


CAT-FISHES. 573 


the beginning of the rainy season, of leaves, and is sometimes 
placed in a hole scooped out in the beach. 

Finally, in the last genus, the lateral scutes are likewise 
absent, v1z. 1n 


SYNODONTIS.—The adipose fin is of moderate length or 
rather long; the dorsal fin has a very strong spine and seven 
soft rays. The teeth in the lower jaw are movable, long, very 
thin at the base, and with a slightly-dilated brown apex. Mouth 
small. Barbels six, more or less fringed with a membrane or 
with filaments. Neck with broad dermal bones. 

Synodontis is characteristic of the fauna of tropical 


Africa, where it is represented by fifteen species. Several 


Fig. 263.—Synodontis xiphias. 


occur in the Nile, and are known by the vernacular name 
“Schal.” Some attain a length of two feet. The species 
figured is from West Africa, and characterised by its long 
upper jaw. 


b. RHINOGLANINA. 


RHINOGLANIS.—Two dorsal fins, both composed of rays, the 
first with a strong spine; anal rather short. Barbels six; 
anterior and posterior nostrils close together, the posterior very 
large, open. Neck with broad dermal bones. Ventrals with 
seven rays, inserted below the posterior rays of the first dorsal 
fin. 

This Siluroid is known from a single example only one and 
a half inches long, obtained at Gondokoro on the Upper Nile. 
Callomystax represents this type in the Ganges and Indus. 


574 FISHES. 


c, MALAPTERURINA. 


MALAPTERURUS.—One dorsal fin only, which is adipose and 
situated before the caudal; anal of moderate length or short ; 
caudal rounded ; ventrals six-rayed, inserted somewhat behind 
the middle of the body; pectorals without pungent spine. 
Barbels six: one to each maxillary and two on each side of the 
mandible. The anterior and posterior nostrils are remote from 
each other. No teeth on the palate. The entire head and 
body covered with soft skin. Eyes small. Gill-opening very 
narrow, reduced to a slit before the pectoral. 

The “ Electric Cat- or Sheath-fishes ” are not uncommon in 
the fresh waters of tropical Africa; three species have been 
described, of which J. electricus occurs in the Nile; they 


Fig. 264.—Malapterurus electricus. 


erow to a length of about four feet. Although the first 
dorsal fin is absent, its position Gf it had been developed) is 
indicated by a rudimentary interneural spine, which rests in 
the cleft of the neural process of the first vertebra. The 
electric organ extends over the whole body, but is thickest 
on the abdomen; it les between two aponeurotic membranes, 
below the skin, and consists of rhomboidal cells which con- 
tain a rather firm gelatinous substance. The electric nerve 
takes its origin from the spinal chord, does not enter into 
connection with ganglia, and consists of a single enormously- 
strong primitive fibre, which distributes its branches in the 


electric organ. 


. 


VI. Srturtp& PROTEROPODES.— The rayed dorsal fin is 
always present and rather short; the ventrals are inserted below 


CAT-FISHES, 575 


(very rarely in front of) the dorsal. The gill-membranes are 
confluent with the skin of the isthmus, the gill-opening being 
reduced to a short slit. Pectorals and ventrals horizontal. 
Vent before, or not much behind, the middle of the length of the 
body. ' 


a. HYPOSTOMATINA. 


STYGOGENES.—Adipose fin short ; dorsal and anal short ; 
the outer fin-rays somewhat thickened and rough ; palate tooth- 
less ; cleft of the mouth of moderate width, with a maxillary 
barbel on each side; a short broad flap on each side between 
the nostrils, which are close together. Lower lip very broad, 
pendent. Eyes small, covered with transparent skin. Head 
covered with soft skin. Ventrals six-rayed. 


These small Siluroids, which are called “ Prefiadillas” by 
the natives, together with the allied Avges, Brontes, and Astro- 
plebus, have received some notoriety through Humboldt’s 
accounts, who adopted the popular belief that they live in 
subterranean waters within the bowels of the active voleanoes 
of the Andes, and are ejected with streams of mud and 
water during eruptions. Humboldt himself considers it very 
singular that they are not cooked and destroyed whilst they 
are vomited forth from craters or other openings. The ex- 
planation of their appearance during volcanic eruptions is, 
that they abound in the numerous lakes and torrents of 
the Andes, that they are killed by the sulphuretted gases 
escaping during an eruption, and swept down by the torrents 
of water issuing from the volcano. 


CALLICHTHYS.—Adipose fin. short, supported anteriorly by 
a short movable spine; dorsal with a feeble spine and seven or 
eight rays; anal short. Teeth minute or entirely absent ; cleft 
of the mouth rather narrow, with a pair of maxillary barbels on 
each side, which are united at the base. Eyes small. Head 
covered with osseous plates; body wholly protected by two 
series of large imbricate shields on each side. Ventrals six-rayed. 


576 FISHES. 


Twelve species of this genus are known; they are small, 
and similarly distributed as Doras, with which they have 


Fig. 265.—Callichthys armatus, from the Upper Amazon. Natural size. 


much in common as regards their mode of life. They like- 
wise are able to travel over land, and construct nests for 
their ova. 


CuatTostomus.—A short adipose fin, supported anteriorly 
by a short, compressed, curved spine; dorsal fin of moderate 
length, with from eight to ten rays, the first of which is simple ; 
anal fin short ; ventral six-rayed ; pectoral with a strong spine. 
Head and body completely cuirassed, the lower parts being 
sometimes naked ; body rather short, with four or five longi- 
tudinal series of large imbricate scutes on each side; tail not 
depressed. Snout produced, obtuse in front ; mouth inferior, 
transverse, with a single series of generally very fine bent teeth 
in both jaws. Interoperculum very movable and armed with 
erectile spines. 

This genus, with the allied Plecostomus, Liposarcus, Ptery- 
goplichthys, Rhinelepis, Acanthicus, and Xenomystus, is well 
represented in the fresh waters of South America, whence 
about sixty species are known. The majority do not exceed 
a length of twelve inches, but some attain to more than 
double that size. In some of the species the male is provided 


CAT-FISHES. 577 


with long bristles round the margin of the snout and inter- 
operculum. 


Fig. 266.—-Upper and Lower side of the head of Chetostomus 
heteracanthus, Upper Amazons. 


578 FISHES. 


Hypoptopoma. — Differing from Chetostomus in the peculiar 
formation of the head, which is depressed, spatulate, the eyes 


Fig. 267.—Hypoptopoma thoracatum, Upper Amazons. Natural size. 


being on the lateral edge of the head. The movable gill-covers 
are reduced to two bones, neither of which is armed, viz.—the 
operculum small and placed as in Chetostomus, and a second, 
larger one, separated from the eye by the narrow sub-orbital 
ring, and placed at the lower side of the head. 


LORICARIA.—One short dorsal fin ; anal short ; the outer 
ray of each fin thickened, but flexible. Head depressed, with 
the snout more or less produced and spatulate. Mouth situated 
at the lower side of the snout, remote from its extremity, trans- 
verse, surrounded by broad labial folds which are sometimes 
fringed ; a short barbel at each corner of the mouth. Teeth in 
the jaws small, bent, with a dilated, notched apex, in a single 


ts 


CAT-FISHES, 579 


series, sometimes absent. Head and body cuirassed; tail de- 
pressed, long ; eye rather small or of moderate size. 


Fig. 268.—Loricaria lanceolata, Upper Amazons. Natural size. 


Small fishes from rivers of tropical America; about 
twenty-six species are known. The male of some species has 
a bearded or bristly snout. 


AceEsTRA differs from Loricaria in having the snout much 
prolonged. 


580 FISHES. 


Sisor.—Head depressed, spatulate ; trunk depressed ; tail 
long and thin. One short dorsal fin; anal short ; ventrals 
seven-rayed. Head partially osseous, rough ; a series of bony 
plates along the median line of the back ; lateral line rough. 
Eyes very small, Mouth inferior, small, transverse, with bar- 
bels ; teeth none. 

A single species, S. rhabdophorus, from rivers of northern 
Bengal. Allied to this genus is Hrethistes from Assam. 


PSEUDECHENEIS.—Adipose fin of moderate length ; a short 
dorsal with one spine and six rays; anal fin rather short. Bar- 
bels eight. Mouth small, inferior. Head depressed, covered 
with soft skin above ; eyes small, superior. Caudal fin forked ; 
pectorals horizontal, with a thoracic adhesive apparatus between, 
formed by transverse plaits of the skin. Ventrals six-rayed. 

A very small species, inhabiting the mountain-streams 
of Khassya; by means of the adhesive apparatus it is enabled 
to hold on to stones, thus preventing the current from sweep- 
ing it away. vostoma is a similar small Siluroid from Indian 
mountain-streams, but without the thoracic apparatus ; pro- 


bably its mouth performs the same function. 


b. ASPREDININA. 


ASPREDO.— Adipose fin none ; dorsal short, without pungent 
spine ; anal very long, but not united with the caudal. Head 
broad, much depressed ; tail very long and slender. Barbels 
not less than six, one of which is attached to each intermaxillary ; 
none at the nostrils. Eyes very small. Head covered with soft 
skin; the anterior and posterior nostrils are remote from each 
other. Ventrals six-rayed. 

Six species are known from Guyana; the largest grows to 
a length of about eighteen inches. The remarkable mode of 
taking care of their ova has been noticed above (p. 161, Fig. 
72).  Bunocephalus, Bunocephalichthys, and Harttia, from 
tropical America, are other genera of this sub-family which 
remain to be mentioned. 


CAT-FISHES. 581 


VIL SmLurIpA OPISTHOPTERX.— The rayed dorsal fin is 
always present, short, and placed above or behind the middle 
of the length of the body, above or behind the ventrals which, 
however, are sometimes absent ; anal short. Nostrils remote 
from each other ; uf a nasal barbel is present, it belongs to the 
anterior nostril. Lower lip not reverted. The gill-membranes 
are not confluent with the skin of the isthinus : NEMATOGENYINA 
and 'TRICHOMYCTERINA,. 

The genera Heptapterus, Nematogenys, Trichomycterus, E're- 
mophilus, and Pariodon, belong to this sub-family. They 
are small South American Siluroids, the majority of which 
inhabit waters at high altitudes, up to 14,000 feet above 
the level of the sea. In the Andes they replace the Loaches 
of the Northern Hemisphere, which they resemble in appear- 
ance and habits, and even in coloration, offerme a striking 
example of the fact that similar forms of animals are pro- 
duced under similar external physical conditions. 


VIII. Stturipa BraNncuicoLa.—The rayed dorsal fin is 
present, short, and placed behind the ventrals ; anal short. Vent 
far behind the middle of the length of the body.  Gull-mem- 
branes confluent with the skin of the isthmus. 

Stegophilus and Vandellia, two genera from South America, 
comprising the smallest and least developed Siluroids. Their 
body is narrow, cylindrical, and elongate; a small barbel at 
each maxillary ; the operculum and inter-operculum are 
armed with short stiff spines. The natives of Brazil accuse 
these fishes of entering and ascending the urethra of persons 
while bathing, causing inflammation and sometimes death. 
This requires confirmation, but there is no doubt that they 
live parasitically in the gill-cavity of larger fishes (Platy- 
stoma), but probably they enter these cavities only for places 
of safety, without drawing any nourishment from their 
host. 


582 FISHES. 


SrEconp FAMILY—SCOPELID. 


Body naked or scaly. Margin of the upper jaw formed by 
the intermaxillary only ; opercular apparatus sometimes w- 
completely developed. Barbels none. ill-opening very wide ; 
pseudobranchie well developed, Air-bladder none. Adipose 
Jin present. The eggs are enclosed in the sacs of the ovary, and 
excluded by oviducts. Pyloric appendages few im number or 
absent. Intestinal tract very short. 

Exclusively marine, the majority being either pelagic or 
deep-sea forms. Of fossil remains the following have been 
referred to this family :—Osmeroides, from Mount Lebanon, 
which others believe to be a marine salmonoid ; Hemisaurida, 
from Comen, allied to Saurus ; Parascopelus and Anapterus, 
from the miocene of Licata, the latter genus allied to 
Paralepis. 


SAuURUS (inclus. Sawrida).—Body sub-cylindrical, rather elong- 
ate, covered with scales of moderate size; head oblong ; cleft of 
the mouth very wide ; intermaxillary very long, styliform, taper- 
ing; maxillary thin, long, closely adherent to the intermaxillary. 
Teeth card-like, some being elongate, slender; all can be laid 
downwards and inwards. Teeth on the tongue, and palatine 
bones. Eye of moderate size. Pectorals short ; ventrals eight- 
or nine-rayed, inserted in advance of the dorsal, not far behind 
the pectorals. Dorsal fin nearly in the middle of the length of 
the body, with thirteen or less rays; adipose fin small; anal 
short or of moderate length ; caudal forked. 

Fifteen species of small size, from the shores of the 
tropical and sub-tropical zones. The species figured on 
p. 42, Fig. 5, occurs on the north-west coast of Australia and 


in Japan. 


BATHYSAURUS,—Shape of the body similar to that of Saurus, 
sub-cylindrical, elongate, covered with small scales. Head de- 
pressed, with the snout produced, flat above. Cleft of the mouth 


SCOPELID A. 583 


very wide, with the lower jaw projecting ; intermaxillary very long, 
styliform, tapering, not movable. Teeth in the jaws, in broad 
bands, not covered by lips, curved, unequal in size and barbed at 
the end. A series of similar teeth runs along the whole length of 
each side of the palate. Eye of moderate size, lateral. Pectoral 
of moderate length. Ventral eight-rayed, inserted immediately 
behind the pectoral. Dorsal fin in the middle of the length of 
the body, with about eighteen rays. Adipose fin absent or pre- 
sent. Anal of moderate length. Caudal emarginate. 

Deep-sea fishes, obtained in the Pacific at depths varying 
from 1100 to 2400 fathoms. The largest example is twenty 
inches long. ‘Two species. 


BATHYPTEROIS.—Shape of the body like that of an Aulopus. 
Head of moderate size, depressed in front, with the snout pro- 
jecting, the large mandible very prominent beyond the upper 
jaw. Cleft of the mouth wide ; maxillary developed, very mov- 
able, much dilated behind. Teeth in narrow villiform bands in 
the jaws. On each side of the broad vomer a small patch of 
similar teeth ; none on the palatines or on the tongue. Eye very 
small. Scales cycloid, adherent, of moderate size. Rays of the 
pectoral fin much elongated, some of the upper being separate 
from the rest, and forming a distinct division. Ventrals ab- 
dominal, with the outer rays prolonged, eight-rayed. Dorsal fin 
inserted in the middle of the body, above or immediately behind 
the root of the ventral, of moderate length. Adipose fin present 
or absent. Anal short. Caudal forked. 

This very singular form is one of the discoveries of thie 
“Challenger ;” it is widely distributed over the seas of the 
Southern Hemisphere, in depths varying from 520 to 2600 
fathoms. The elongate pectoral rays are most probably 
organs of touch. Four species were discovered, the largest 
specimen being thirteen inches long. 


HARPODON.—Body elongate, covered with very thin, dia- 
phanous, deciduous scales. Head thick, with very short snout ; 
its bones are very soft, and the superficial ones are modified into 
wide muciferous cavities ; the lateral canal of the body is also 


584 FISHES. 


very wide, and a pair of pores corresponds to each scale of the 
lateral line, one being above, the other below the scale. Cleft 
of the mouth very wide; intermaxillary very long, styliform, 
tapering; maxillary absent. Teeth card-lke, recurved, unequal 
in size; the largest are in the lower jaw, and provided with a 
single barb at the posterior margin of the point. Eye small, 
Ventral fins long, nine-rayed, inserted below the anterior dorsal 
rays; dorsal fin in the middle of the length of the body ; adi- 
pose fin small; anal of moderate length ; caudal fin three-lobed, 
the lateral line being continued along the central lobe. Centre 
of the vertebre open in the middle. 

Two species only are known of this singular genus ; both 
are evidently inhabitants of considerable depths, and periodi- 
cally come nearer to the surface. One (//. nehereus) is well 
known in the East Indies, being of excellent flavour. When 
newly taken its body is brilliantly phosphorescent. When 
salted and dry it is known under the names of “ Bombay- 
ducks” or “Bummaloh,” and exported in large quantities 
from Bombay and the coast of Malabar. The second species 
(H. microchir) exceeds the other in length, and has been 
found in the sea off Japan. 


ScopELus.—Body oblong, more or less compressed, covered 
with large scales. Series of phosphorescent spots run along the 
lower side of the body, and a similar glandular substance some- 
times occupies the front of the snout and the back of the tail. 


Fig. 269.—Scopelus boops. 


Cleft of the mouth very wide. Intermaxillary very long, styli- 
form, tapering ; maxillary well developed. Teeth villiform. Eye 
large. Ventrals eight-rayed, inserted immediately in front of or 


SCOPELID &. 585 


below the anterior dorsal rays. Dorsal fin nearly in the middle 
of the length of the body; adipose fin small; anal generally 
long ; caudal forked. Branchiostegals from eight to ten. 


The fishes of this genus are small, of truly pelagic habits, 
and distributed over all the temperate and tropical seas ; 
they are so numerous that the surface-net, when used during 
a night of moderate weather, scarcely ever fails to enclose 
some specimens. They come to the surface at night only ; 
during the day and in very rough weather they descend to 
depths where they are safe from sunlight or the agitation of 
the water. Some species never rise to the surface; indeed, 
Scopeli have been brought up in the dredge from almost any 
depth to 2500 fathoms. Thirty species are known. Gymno- 
scopelus differs from Scopelus in lacking scales. 


Ipnops.—Body elongate, sub-cylindrical, covered with large, 
thin, deciduous scales, and without phosphorescent organs. Head 
depressed, with broad, long, spatulate snout, the whole upper 
surface of which is occupied by a most peculiar organ of vision 
(or luminosity), longitudinally divided in two symmetrical halves. 
Bones of the head well ossified. Mouth wide, with the lower 
jaw projecting; maxillary dilated behind. Both jaws with 
narrow bands of villiform teeth; palate toothless. Pectoral 
and ventral fins well developed, and, owing to the shortness of 
the trunk, close together. Dorsal fin at a short distance behind 
the vent; adipose fin none; anal fin moderately long; caudal 
subtruncated, Pseudobranchiz none. 


This singular genus, one of the “ Challenger ” discoveries, 
is known from four examples, obtained at depths varying 
between 1600 and 2150 fathoms, off the coast of Brazil, near 
Tristan d’Acunha and north of Celebes. All belong to one 
species, J. murrayi. The eye seems to have lost its function 
of vision and assumed that of producing light. The speci- 
mens are from 4 to 54 inches long. 


PARALEPIS.—Head and body elongate, compressed, covered 
with deciduous scales. Cleft of the mouth very wide ; maxillary 


586 FISHES. 


developed, closely adherent to the intermaxillary. Teeth in a 
single series, unequal in size. Eye large. Ventrals small, in- 
serted opposite or nearly opposite the dorsal. Dorsal fin short, 
on the hinder part of the body; adipose fin small; anal 
elongate, occupying the end of the tail ; caudal emarginate. 

Three species; small pelagic fishes from the Mediter- 
ranean and Atlantic.—Sudis, from the Mediterranean, has a 
dentition slightly different from that of Paralepis. 


PLaGyopus.—Body elongate, compressed, scaleless ; snout 
much produced, with very wide cleft of the mouth. Intermax- 
illary very long and slender; maxillary thin, immovable. 
Teeth in the Jaws and of the palate very unequal in size, the 


Fig. 270.—Plagyodus ferox. 


majority pointed and sharp, some very large and lanceolate. 
Eye large. Pectoral and ventral fins well developed; the 
rayed dorsal fin occupies the whole length of the back from the 
occiput to opposite the anal fin; adipose and anal fins of 
moderate size. Caudal forked. Branchiostegals six or seven. 


This is one of the largest and most fermidable deep-sea 
fishes. One species only is well known, P.’ ferox, from 
Madeira and the sea off Tasmania; other species have been 
noticed from Cuba and the North Pacific, but it is not evi- 
dent in what respects they differ specifically from P. feroz. 
This fish grows to a length of six feet, and from the stomach 
of one example have been taken several Octopods, Crusta- 


CARPS. 587 


ceans, Ascidians, a young. Brama, twelve young Boar-fishes, 
a Horse-mackerel, and one young of its own species. The 
stomach is coecal; the commencement of the intestine has 
extremely thick walls, its inner surface being cellular, like 
the lung of a reptile; a pyloric appendage is absent. All 
the bones are extremely thin, light, and flexible, containing 
very little earthy matter; singular is the development of a 
system of abdominal ribs, symmetrically arranged on both 
sides, and extending the whole length of the abdomen. 
Perfect specimens are rarely obtained on account of the 
want of coherence of the muscular and osseous parts, caused 
by the diminution of pressure when the fish reaches the 
surface of the water. The exact depth at which Plagyodus 
lives is not known; probably it never rises above a depth of 
300 fathoms. 


The other less important genera belonging to this family 
are Aulopus, Chlorophthalmus, Scopelosaurus, Odontostomus, 


and Nannobrachium. 


THIRD FAMILY—CYPRINIDA. 


Body generally covered with scales; head naked. Margin 


Fig. 271.—Pharyngeal bones and teeth of the Bream, Abramis brama. 


of the upper jaw formed by the intermaxillarics. Belly rounded, 
or, f trenchant, without ossifications. No adipose fin. Stomach 


588 FISHES. 


without blind sac. Pyloric appendages none. Mouth tooth- 
less; lower pharyngeal bones well developed, falciform, sub- 
parallel to the branchial arches, provided with teeth, which are 
arranged in one, two, or three series. Air-bladder large, divided 
into an anterior and posterior portion by a constriction, or into 
a right or left portion, enclosed in an osseous capsule. Ovarian 
sacs closed, 

The family of “ Carps” is the one most numerously repre- 
sented in the fresh waters of the Old World and of North 
America. Also numerous fossil remains are found in tertiary 
freshwater-formations, as in the limestones of Oeningen and 
Steinheim, in the legnites of Bonn, Stéchen, Bilin, and Menat, 
in the marl slates and carbonaceous shales of Licata in Sicily, 
and of Padang in Sumatra, in corresponding deposits of Idaho 
in North America. The majority can be referred to existing 
genera: Barbus, Thynnichthys, Gobio, Leuciscus, Tinea, Ambly- 
pharyngodon, Rhodeus, Cobitis, Acanthopsis, only a few show- 
ing characters different from those of living genera: Cyclurus, 
Hexapsephus, Mylocyprinus (tertiary of North America). 

Most Carps feed on vegetable and animal substances ; 
a few only are exclusive vegetable feeders. There is much 
less diversity of form and habits in this family than in the 
Siluroids; however, the genera are sufficiently numerous to 
demand a further subdivision of the family into groups. 


I. CaTostoMINA.—Pharyngeal teeth in a single series, ex- 
ccedingly numerous and closely set. Dorsal fin elongate, oppo- 
site to the ventrals ; anal short, or of moderate length. Barbels 
none. 

These fishes are abundant in the lakes and rivers of North 
America, more than thirty species having been described, and 
many more named, by American ichthyologists. Two species 
are known from North-Eastern Asia. They are generally 
called “ Suckers,” but their vernacular nomenclature is very 


CARPS. 589 


arbitrary and confused. Some of the species which inhabit 
the large rivers and lakes grow to a length of three feet and 
a weight of fifteen pounds. The following genera may be 
distinguished :—Catostomus, “Suckers,” “Red-horses,” “Stone- 
rollers,” “ White Mullets ;” Moxostoma ; Sclerognathus, “ But- 
faloes,” “Black Horses ;” and Carpiodes, “Spear-fish,” “ Sail- 
fish.” 


Il. Cyprinina.—Anal fin very short, with not more than 
Jive or six, exceptionally seven, branched rays. Dorsal fin oppo- 
site ventrals. Abdomen not compressed. Lateral line running 
along the median line of the tail. Mouth frequently with 
_barbels, never more than four in number. Pharyngeal teeth 
generally in a triple series in the Old World genera; in a 
double or single serves in the North American forms, which are 
small and feebly developed. Arr-bladder present, without osseous 
COvering. 


CyprINUS.—Scales large. Dorsal fin long, with a more or 
less strong serrated osseous ray; anal short. Snout rounded, 
obtuse, mouth anterior, rather narrow, Pharyngeal teeth, 
3. 1. 1-1. 1. 3, molar-like. Barbels four. 


Fig. 272.—The Carp, Cyprinus carpio. 


The “Carp” (C. carpio, “ Karpfen,” “La carpe,”) is originally 
a native of the East, and abounds in a wild state in China, 
where it has been domesticated for many centuries; thence it 


590 FISHES. 


was transported to Germany and Sweden, and the year 1614 
is assigned as the date of its first introduction into England. 
It delights in tranquil waters, preferrmg such as have a 
muddy bottom, and the surface partially shaded with plants. 
Its food consists of the larvee of aquatic insects, minute 
testacea, worms, and the tender blades and shoots of plants. 
The leaves of lettuce, and other succulent plants of a similar 
kind, are said to be particularly agreeable to them, and to 
fatten them sooner than any other food. Although the Carp 
eats with great voracity when its supply of aliment is 
abundant, it can subsist for an astonishing length of time 
without nourishment. In the winter, when the Carps as- 
semble in great numbers, and bury themselves among the 
mud and the roots of plants, they often remain for many 
months without eating. They can also be preserved alive 
for a considerable length of time out of the water, especially 
if care be taken to moisten them occasionally as they become 
dry. Advantage is often taken of this circumstance to trans- 
port them alive, by packing them among damp herbage or 
damp linen ; and the operation is said to be unattended with 
any risk to the animal, especially if the precaution be taken 
to put a piece of bread in its mouth steeped in brandy! 

The fecundity of these fishes is very great, and their 
numbers consequently would soon become excessive but for 
the many enemies by which their spawn is destroyed. No 
fewer than 700,000 eges have been found in the ovaries of a 
sinele Carp, and that, too, by no means an individual of the 
largest size. Their growth is very rapid, more so perhaps 
than that of any other Freshwater fish, and the size which 
they sometimes attain is very considerable. In certain lakes 
in Germany individuals are occasionally taken weighing 
thirty or forty pounds; and Pallas relates that they occur 
in the Volga five feet in length, and even of greater weight 
than the examples just alluded to. The largest of which we 


CARPS. 591 


have any account is that mentioned by Bloch, taken near 
Frankfort-on-the-Oder, which weighed seventy pounds, and 
measured nearly nine feet in length,—a statement the accu- 
racy of which is very much open to doubt. 

Like other domesticated animals the Carp is subject to 
variation ; some individuals, especially when they have been 


bred under unfavourable circumstances, have a lean and low 


body; others are shorter and higher. Some have lost every 
trace of scales, and are called “ Leather-carps;” others retain 
them along the lateral line and on the back only (“Spiegel- 
karpfen” of the Germans). Finally, in some are the fins 
much prolonged, as in certain varieties of the Gold-fish. 
Cross-breeds between the Carp and the Crucian Carp are of 
common occurrence. The Carp is much more esteemed as 
food in inland countries than in countries where the more 
delicate kinds of sea fishes can be obtained. 


Carassius differs from Cyprinus in lacking barbels;_ its 
pharyngeal teeth are compressed, in a single series, 4—4. 


Two well-known species belong to this genus. The 
“Crucian Carp” (C. carasswus, “Karausche”) is generally 
distributed over Central and Northern Europe, and extends 
into Italy and Siberia. It inhabits stagnant waters only, 
and is so tenacious of life that it will survive a lengthened 
sojourn in the smallest pools, where, however, it remains 
stunted ; whilst in favourable localities it attains to a length 
of twelve inches. It is much subject to variation of form ; 
very lean examples are commonly called “ Prussian Carps.” 
Its usefulness consists in keepime ponds clean from a super- 
abundance of vegetable growth, and in serving as food for 
other more esteemed fishes. The second species is the “ Gold- 
fish,” Carassius auratus. It is of very common occurrence in 
a wild state in China and the warmer parts of Japan, being 
entirely similar in colour to the Crucian Carp. In a domes- 


592 FISHES. 


ticated state it loses the black or brown chromatophors, and 
becomes of a golden-yellow colour; perfect Albinos are com- 
paratively scarcer. Many varieties and monstrosities have 
been produced during the long period of its domestication ; 
the variety most highly priced at present being the so-called 
“ Telescope-fish,” of which a figure is annexed. The Gold-fish 


Fig. 273.—Cyprinus auratus, var. 


is said to have been first brought to England in the year 1691,. 
and is now distributed over nearly all the civilised parts of 
the world. 


CaTLA.—Scales of moderate size. Dorsal fin without osseous 
ray, with more than nine branched rays, commencing nearly 
opposite to the ventrals. Snout broad, with the integuments very 
thin; there is no upper lip, the lower with a free continuous 
posterior margin. Symphysis of the mandibulary bones loose, 
with prominent tubercles. Mouth anterior. Barbels none. 
Gill-+rakers very long, fine, and closely set. Pharyngeal teeth, 
5. 3. 2-2. 3. 5. 

The “Catla” (C. buchanani), one of the largest Carps of 
the Ganges, growing to a length of more than three feet, and 


esteemed as food. 


CARPS. 593 


LABEO.—NScales of moderate or small size. Dorsal fin with- 
out osseous ray, with more than nine branched rays, commenc- 
ing somewhat in advance of the ventrals. Snout obtusely 
rounded, the skin of the maxillary region being more or less 
thickened, forming a projection beyond the mouth. Mouth 
transverse, inferior, with the lips thickened, each or one of 
them being provided with an inner transverse fold, which is 
covered with a deciduous horny substance forming a sharp edge, 
which, however, does not rest upon the bone as base, but is soft 
and movable. Barbels very small, two or four; the maxillary 
barbels more or less hidden in a groove behind the angle of the 
mouth. Anal scales not enlarged. Pharyngeal teeth uncinate, 
5. 4. 2.-2. 4.5. Snout generally more or less covered with 
hollow tubercles. 


About thirteen species are known from rivers of tropical 
Africa and the East Indies. 


DISCOGNATHUS.—Scales of moderate size. Dorsal fin with- 
out osseous ray, with not more than nine branched rays, com- 
mencing somewhat in advance of the ventrals. Snout obtusely 
rounded, more or less depressed, projecting beyond the mouth, 
more or less tubercular. Mouth inferior, transverse, crescent- 
shaped ; lips broad, continuous, with an inner sharp edge of the 
jaws, covered with horny substance on the lower jaw ; upper lip 
more or less distinctly fringed ; lower lip modified into a suc- 
torial disk, with free anterior and posterior margins. Barbels 
two or four; if two, the upper are absent. Anal scales not 
enlarged. Pectoral fins horizontal. Pharyngeal teeth, 5, 4. 2.- 
PhD: 


A small fish (D. lamta), extremely abundant in almost 
all the mountain streams from Abyssinia and Syria to 
Assam. 


CAPoETA.—NScales small, of moderate or large size. Dorsal 
fin with or without a strong osseous ray, with not more than 
nine branched rays. Snout rounded, with the mouth transverse 
and at its lower side; each mandible angularly bent inwards 
in front, the anterior mandibular edge being nearly straight, 
sharpish, and covered with a horny brown layer. No lower 

2Q 


594. FISHES. 


labial fold. Barbels two (rarely four), or entirely absent. Anal 
scales not conspicuously enlarged. Pharyngeal teeth compressed, 
truncated, 5 or 4. 3. 2.-2. 3. 4 or 5. 


Characteristic of the fauna of Western Asia; one species 
from Abyssinia. Of the fifteen species known C. damascina 
deserves to be specially mentioned, being abundant in the 
Jordan and other rivers of Syria and Asia Minor. 


Barpus.—Scales of small, moderate, or large size. Dorsal 
fin generally with the (third) longest simple ray ossified, enlarged, 
and frequently serrated ; never, or only exceptionally, with more 
than nine branched rays, commencing opposite or nearly opposite 
to the root of the ventral fin. Eyes without adipose eyelid. Anal 
fin frequently very high. Mouth arched, without inner folds, 
inferior or anterior; lips without horny coverimg.  Barbels 
short, four, two, or none. Anal scales not enlarged. Pharyngeal 


9 


teeth 5. 4 or 3. 3 or 2.-2 or 3. 3 or 4. 5. Snout but rarely 
with tubercles or pore-like grooves. 

No other genus of Cyprinoids is composed of so many 
species as the genus of “ Barbels,” about 200 being known 
from the tropical and temperate parts of the Old World; it 
is not represented in the New World. Although the species 
differ much from each other in the form of the body, number 
of barbels, size of the scales, strength of the first dorsal ray 
or spine, etc., the transition between the extreme forms is so 
perfect that no further generic subdivision should be at- 
tempted. Some attain a length of six feet, whilst others 
never exceed a length of two inches. The most noteworthy 
are the large Barbels of the Tigris (B. subguincunciatus, B. 
esocinus, B. scheich, B. sharpeyi); the common Barbel of 
Central Europe and Great Britain (B. vulgaris) ; the “ Bynni” 
of the Nile (B. bynni); B. canis from the Jordan; the 
“ Mahaseer” of the mountain streams of India (£. mosal), pro- 
bably the largest of all species, the scales of which are some- 
times as large as the palm of a hand. The small, large-scaled 


PP 


aa 


CARPS. 595 


Species are especially numerous in the East Indies and the 
fresh waters of Tropical Africa. 


THYNNICHTHYS.—Scales small. Dorsal fin without an os- 
seous ray, with not more than nine branched rays, commencing 
nearly opposite the ventrals. Head large, strongly com- 
pressed ; eye without well-developed adipose membrane, in the 
middle of the depth of the head. Snout with the integuments 
very thin ; there is no upper lip, and the lower jaw has a thin 
labial fold on the sides only. Mouth anterior and lateral ; bar- 
bels none. Gill-rakers none; lamine branchiales long, half as 
long as the postorbital portion of the head; pseudobranchiz 
none. Pharyngeal teeth lamelliform, with flat oblong crown, 
5. 3 or 4, 2-2. 4 or 3. 5, the teeth of the three series being 
wedged into one another. 


Three species from the East Indies. 


OREINUS.—Scales very small. Dorsal fin with a strong 
osseous serrated ray, opposite to the ventrals. Snout rounded, 
with the mouth transverse, and at its lower side ; mandibles 
broad, short, and flat, loosely joined together ; margin of the 
jaw covered with a thick horny layer ; a broad fringe-like lower 
lip, with free posterior margin. Barbels four. Vent and anal 
fin in a sheath, covered with enlarged tiled scales. Pharyngeal 
teeth pointed, more or less hooked, 5. 3. 2—2. 3. 5. 


Three species from mountain streams of the Himalayas. 


ScHIZOTHORAX.—Hill-barbels, with the same singular sheath 
on each side of the vent, as in the preceding genus; but they 
differ in having the mouth normally formed, with mandibles of 
the usual length and width. 


Seventeen species are known from fresh waters of the 
Himalayas, and north of them. Other genera from the same 
region, and with the anal sheath, are Ptychobarbus, Gymnocy- 
pris, Schizopygopsis, and Diptychus. 

Gopio.—Scales of moderate size ; lateral line present. Dor- 


sal fin short, without spine. Mouth inferior; mandible not 
projecting beyond the upper jaw when the mouth is open; both 


596 FISHES. 


jaws with simple lips; a small but very distinct barbel at the 
angle of the mouth, quite at the extremity of the maxillary. 
Gill-rakers very short ; pseudobranchiz. Pharyngeal teeth, 5. 3 
or 2.-2 or 3. 5, hooked at the end. 

The “Gudgeons” are small fishes of clear fresh waters of 
Europe ; they are, like the barbels, animal feeders. In Eastern 
Asia they are represented by two closely allied genera, Ladis- 
lavia and Pseudogobio. 


CERATICHTHYS.—Scales of moderate or small size ; lateral 
line present. Dorsal fin short, without spine, not or but slightly 
in advance of the ventrals. Mouth subinferior; the lower jaw 
does not project beyond the upper when the mouth is open ; in- 
termaxillaries protractile from below the maxillaries ; both jaws 
with thickish lips ; a small barbel at the angle of the mouth, 
quite at the extremity of the maxillary. Gill-rakers very short 
and few in number: pseudobranchie. Pharyngeal teeth 4—4. 
hooked at the end (sometimes 4, 1-1. 4). 

About ten species are known from North America; they 
are small, and called “ Chub” in the United States. (C. bigut- 
tatus is, perhaps, the most widely-diffused Freshwater-fish in 
the United States, and common everywhere. Breeding males 
have generally a red spot on each side of the head. 

Other similar genera from the fresh waters of North 
America, and generally called “Minnows,” are Pimephales 
(the “ Black Head”), Hyborhynchus, Hybognathus, Campostoma 
(the “Stone-ligger”), Ericymba, Cochlognathus, Exoglossum (the 
“Stone Toter” or “ Cut-lips”), and Rhinichthys (the “ Long- 
nosed Dace”). 

The remaining Old World genera belonging to the group 
Cyprinina are Cirrhina, Dangila, Osteochilus, Barynotus, 
Tylognathus, Abrostomus, Crossochilus, Epalzeorhynchus, 
Barbichthys, Amblyrhynchichthys, Albulichthys, Aulopyge, 


Lungia, and Pseudorashora. 


III. Ronretcuruyina.—Anal fin very short, with not more 


CARPS. 597 


than six branched rays. Dorsal fin behind ventrals, Abdomen 
compressed. Lateral line running along the median line of the 
tail. Mouth without barbels. Pharyngeal teeth in a triple 
serves. 

One genus and species only, Rohteichthys microlepis, from 
Borneo and Sumatra. 


IV. Leproparsina—Anal fin very short, with not more 
than six branched rays. Dorsal fin opposite to ventrals. Ab- 
domen not compressed. Lateral line running in the lower half 
of the tail. Barbels present, not more than four in number. 
Pharyngeal teeth in a triple series. 

One genus and species only, Leptobarbus hoevenii, from 
Borneo and Sumatra. 


V. Rassortna.—Anal fin very short, with not more than 
six branched rays. Dorsal fin inserted behind the origin of the 
ventrals. Abdomen not compressed. Lateral line running along 
the lower half of the tail, if complete. Mouth sometimes with 
barbels, which are never more than four in number. Pharyngeal 
teeth in a triple or single serves. Air-bladder present, without 
OSSCOUS COVETING. 

RASBORA.—Scales large, or of moderate size, there being 
generally four and a half longitudinal series of scales between 
the origin of the dorsal fin and the lateral line, and one between 
the lateral line and the ventral. Lateral line curved downwards. 
Dorsal fin with seven or eight branched rays, not extending to 
above the anal, which is seven-rayed. Mouth of moderate 
width, extending to the front margin of the orbit, with the lower 
jaw slightly prominent, and provided with three prominences in 
front, fitting into grooves of the upper jaw ; barbels none, in one 
species two. Gillrakers short, lanceolate. Pseudobranchie. 
Pharyngeal teeth in three series, uncinate. 

Thirteen species of small size from the East Indian Con- 
tinent and Archipelago, and from rivers on the east coast of 
Africa. 


598 FISHES. 


AMBLYPHARYNGODON.— Scales small; lateral line incom- 
plete. Dorsal fin without an osseous ray, with not more than 
nine branched rays, commencing a little behind the origin of the 
ventrals. Head of moderate size, strongly compressed ; eye with- 
out adipose membrane ; snout with the integuments very thin ; 
there is no upper lip, and the lower jaw has a short labial fold 
on the sides only. Mouth anterior, somewhat directed upwards, 
with the lower jaw prominent. Barbels none. Gill-rakers ex- 
tremely short; pseudobranchiw. Pharyngeal teeth molar-like, 
with their crowns concave, 3. 2. 1.—l. 2. 3. Intestinal tract 

narrow, with numerous convolutions. 


Three species of small size from the Gontinent of India. 
To the same group belong Luciosoma, Nuria, and Aphyo- 
cypris, from the same geographical region. / 


VI. SemipLotina.—Anal jin short, with seven branched 
rays, not extending forwards to below the dorsal. Dorsal fin 
elongate, with an osseous ray. Lateral line running along the 
middle of the tail. Mouth sometimes with barbels. 

Two genera: Cyprinion, from Syria and Persia, and Sem- 
plotus from Assam. 

VII. XenocypripiIna.—Anal jin rather short, with seven 
or more branched rays, not extending forwards to below the 
dorsal fin. Dorsal short, with an osseous ray. Lateral line 
running along the middle of the tail. Mouth sometimes with 
barbels. Pharyngeal teeth in a triple or double series. 

Three genera: Yenocypris and Paracanthobrama from 
China; and Afystacoleucus from Sumatra. 


VIII. Levuciscina.—Anal jin short or of moderate length, 
with from eight to eleven branched rays, not extending forwards 
to below the dorsal. Dorsal fin short, without osseous ray. 
Lateral line, if complete, running along, or nearly in, the middle 
of the tail. Mouth generally without barbels. Pharyngeal teeth 
in a single or double series. 


LEUCISCUS, 


Body covered with imbricate scales. Dorsal 


ae 


CARPS. 599 


fin commencing opposite, rarely behind, the ventrals. Anal fin 
generally with from nine to eleven, rarely with eight (in small 
species only), and still more rarely with fourteen rays. Mouth 
without structural peculiarities ; lower jaw not trenchant ; bar- 
bels none. Pseudobranchiz. Pharyngeal teeth conical or com- 
pressed, in a single or double series. Intestinal tract short, with 
only a few convolutions. 

The numerous species of this genus are comprised under 
the name of “ White-fish ;” they are equally abundant in the 
northern temperate zone of both hemispheres, about forty 
species being known from the Old World, and about fifty 
from the New. The most noteworthy species of the former 
Fauna are the “ Roach” (LZ. rutilus, see Fig. 21, p. 50), com- 
mon all over Europe north of the Alps; the “Chub” (JZ. 
cephalus), extending into Northern Italy and Asia Minor; the 
“Dace” (L. leweiscus), a companion of the Roach ; the “ Id” 
or “ Nerfling” (Z. idus), from the central and northern parts 
of Continental Europe, domesticated in some localities of 
Germany, in this condition assuming the golden hue of semi- 
albinism, hke a Gold-fish, and then called the “ Orfe;” the 
“ Rudd,” or “ Red-eye” (ZL. erythrophthalmus), distributed all 
over Europe and Asia Minor, and distinguished by its scarlet 
lower fins; the “Minnow” (ZL. phoxwinus), abundant every- 
where in Europe, and growing to a length of seven inches in 
favourable localities. The North American species are much 
less perfectly known; the smaller ones are termed “ Min- 
nows,” the larger “Shiner” or “Dace.” The most common 
are L.. cornutus (Red-fin, Red Dace) ; LZ. neogeus, a minnow 
resembling the European species, but with incomplete lateral 
line ; LZ. hudsonius, the “ Spawn-eater” or “Smelt.” 


Tinca.—Scales small, deeply embedded in the thick skin ; 
lateral line complete. Dorsal fin short, its origin being opposite 
the ventral fin; anal short; caudal subtruncated. Mouth an- 
terior ; jaws with the lips moderately developed ; a barbel at the 
angle of the mouth. Gill-rakers short, lanceolate ; pseudobran- 


600 FISHES. 


chie rudimentary. Pharyngeal teeth 4 or 5-5, cuneiform, 
slightly hooked at the end. 


o 


Fig. 274.—The Tench (Tinea tinea). 


Only one species of “Tench” is known (7. tinca), found 
all over Europe in stagnant waters with soft bottom. The 
“Golden Tench” is only a variety of colour, an incipient 
albinism like the Gold-fish and Id. Like most other Carps 
of this group it passes the winter in a state of torpidity, 
during which it ceases to feed. It is extremely prolific, 
297,000 ova having been counted in one female; its spawn 


is of a greenish colour. 


Lrucosomus.—NScales of moderate or small size ; lateral line 
present. Dorsal fin commencing opposite, or nearly opposite, to 
the ventral. Anal fin short. Mouth anterior or sub-anterior ; 
intermaxillaries protractile. A very small barbel at the ex- 
tremity of the maxillary. Lower jaw with rounded margin, 
and with the labial folds well developed laterally. Gull-rakers 
short ; pseudobranchie. Pharyngeal teeth in a double series. 

A North American genus, to which belong some of the 
most common species of the United States. ZL. pulchellus 
(the “ Fall-fish,” “Dace,” or “ Roach”), one of the largest 
White-fishes of the Eastern States, attaining to a length of 
18 inches, and abundant in the rapids of the larger rivers. 
L. corporalis (the “ Chub”), common everywhere from New 
Eneland to the Missouri region. 


CHONDROSTOMA.—Scales of moderate size or small. Lateral 


CARPS. 601 


line terminating in the median line of the depth of the tail. 
Dorsal fin with not more than nine branched rays, inserted above 
the root of the ventrals. Anal fin rather elongate, with ten or 
more rays. Mouth inferior, transverse, lower jaw with a cutting 
edge, covered with a brown horny layer. Barbels none.  Gill- 
rakers short, fine; pseudobranchiz. Pharyngeal teeth 5 or 6 
or 7.-7 or 6 or 5, knife-shaped, not denticulated. Peritoneum 
black. 

Seven species from the Continent of Europe and Western 
Asia. 

Other Old World genera belonging to the Lewciscina are 
Myloleucus, Ctenopharyngodon, and Paraphoxinus ; from North 
America: Mylopharodon, Meda, Orthodon, and Acrochilus. 


IX. Ruopewa.—Anal jin of moderate length, with from 
nine to twelve branched rays, extending forwards to below the 
dorsal. Dorsal fin short, or of moderate length. Lateral line, 
uf complete, running along or nearly in the middle of the taal. 
Mouth with very small, or without any barbels. Pharyngeal 
teeth in a single serves. 

Very small roach-lke fishes inhabiting chiefly Eastern 
Asia and Japan, one species (RA. amarus) advancing into 
Central Europe. The thirteen species known have been dis- 
tributed among four genera, Achilognathus, Acanthorhodeus, 
Rhodeus, and Pseudoperilampus. In the females a long 
external urogenital tube is developed annually during the 
spawning season. The European species is known in Ger- 
many by the name of “ Bitterline.” 


X. Dantontna.—Anal jin of moderate length or elongate, 
with not less, and generally more, than eight branched rays. 
Lateral line running along the lower half of the tail. Mouth 
with small, or without any, barbels, Abdomen not trenchant. 
Pharyngeal teeth in a triple or double series. 

Small fishes from the East Indian Continent, Ceylon, 
the East Asiatic Islands, and afew from East African Rivers, 


602 FISHES. 


The genera belonging to this group are Danio, Pteropsarion, 
Aspidoparia, Barilius, Bola, Scharca, Opsariichthys, Squalio- 
barbus, and Ochetobius: altogether about forty species. 


XI. HypopuTHaLMicutTuyina.— Anal jin elongate. Lateral 
line running nearly along the median line of the tail. Mouth 
without barbels. Abdomen not trenchant. No dorsal spine. 
Pharyngeal teeth in a single series. 

One genus (Hypophthalmichthys) with two species from 
China. 


XII. Apramipina.—Anal jin elongate. Abdomen, or part 
of the abdomen, compressed. 


ABRAMIS.—Body much compressed, elevated, or oblong. 
Scales of moderate size. Lateral line present, running in the 
lower half of the tail. Dorsal fin short, with spine, opposite to 
the space between ventrals and anals. Lower jaw generally 
shorter, and rarely longer than the upper. Both jaws with 
simple lips, the lower labial fold being interrupted at the sym- 
physis of the mandible. Upper jaw protractile. Gill-rakers 
rather short ; pseudobranchie. The attachment of the branchial 
membrane to the isthmus takes place at some distance behind 
the vertical from the orbit. Pharyngeal teeth in one or two 


oe 
Sa 
pia: 
EUR e ae 
4 {9 a3) i sae p 
“y) ‘i YES = 


Fig. 275.—The Bream (Abramis brama). 


series, with a notch near the extremity. Belly behind the 
ventrals compressed into an edge, the scales not extending 
across it. 


The “ Breams” are represented in the temperate parts of 


CARPS. 603 


both northern hemispheres ; in Europe there occur the “Com- 
mon Bream, A. brama ; the “Zope,” A. ballerus ; A. sapa; the 
“ Zarthe,” A. vimba ; A. elongatus ; the “ White Bream,” A. 
blicca ; A. bipunctatus. Of these A. brama and A. blicca are 
British; the former being one of the most common fishes, 
and sometimes attaining to a length of two feet. Crosses 
between these two species, and even with other Cyprinoids, 
are not rare. Of the American species A. americanus 
(“ Shiner,’ “Bream’’) is common and widely distributed ; 
like the European Bream it lives chiefly in stagnant waters 
or streams with a slow current. 


Aspius.—Body oblong ; scales of moderate size ; lateral line 
complete, terminating nearly in the middle of the depth of the tail. 
Dorsal fin short, without spine, opposite to the space between 
the ventrals and anal; anal fin elongate, with thirteen or more 
rays. Lower jaw more or less conspicuously projecting beyond 
the upper. Lips thin, simple, the lower labial fold being at the 
symphysis ; upper jaw but little protractile. Guill-rakers short 
and widely set; pseudobranchie. The attachment of the branchial 
membrane to the isthmus takes place below the hind margin of 
the orbit. Pharyngeal teeth hooked, 5. 3.-3 or 2.5 or 4 Belly 
behind the ventrals compressed, the scales covering the edge. 


Four species from Eastern Europe to China. 


ALBURNUS.—Body more or less elongate ; scales of moderate 
size ; lateral line present, running below the median line of the 
tail. Dorsal fin short, without spine, opposite to the space 
between ventrals and anal; anal fin elongate, with more than 
thirteen rays. Lower jaw more or less conspicuously projecting 
beyond the upper. Lips thin, simple, the lower labial fold being 
interrupted at the symphysis of the mandible. Upper jaw pro- 
tractile. Gill-rakers slender, lanceolate, closely set ; pseudo- 
branchie. The attachment of the branchial membrane to the 
isthmus takes place below the hind margin of the orbit. Pharyn- 
geal teeth in two series, hooked. Belly behind the ventrals 
compressed into an edge, the scales not extending across it. 


604 FISHES. 


“Bleak” are numerous in Europe and Western Asia, 
fifteen species being known. The common Bleak (A. albur- 
nus) 1s found north of the Alps only, and represented by 
another species (A. alburnellus, “ Alborella,” or “ Avola”’) in 
Italy. 

Of the other genera referred to this group, Leucaspius 
and Pelecus belong to the European Fauna; Pelotrophus is 
East African; all the others occur in the East Indies or the 
temperate parts of Asia, viz. Rasborichthys, Hlopichthys, 
Acanthobrama (Western Asia), Osteobrana, Chanodichthys, 
Hemiculter, Smiliogaster, Toxabramis, Culter, Eustira, Chela, 
Pseudolabuca, and Cachius. 


XIII. Homanoprertna.—Dorsal and anal fins short, the 
Jormer opposite to ventrals. Pectoral and ventral fins hori- 
zontal, the former with the outer rays simple. Barbels sia or 
none. <Air-bladder absent. Pharyngeal teeth in a single series, 
Jrom ten to sixteen in number. 

Inhabitants of hill-streams in the East Indies; they are 
of small size and abundant where they occur, Thirteen 
species are known belonging to the genera Homaloptera, 
Gastromyzon, Crossostoma, and Psilorhynchus. 

XIV. Copirmina.—Mouth surrounded by siz or more 
barbels. Dorsal jin short or of moderate length; anal fin 
short. Scales small, rudimentary, or entirely absent. Pharyn- 
geal teeth in a single series, in moderate number. Air-bladder 
partly or entirely enclosed in a bony capsule. Pseudobranchie 
none : Loaches. 


Miscurnus.—Body elongate, compressed. No sub-orbital 
spine. Ten or twelve barbels, four belonging to the mandible. 
Dorsal fin opposite to the ventrals ; caudal rounded, 


Four species from Europe and Asia. Jf. fossilis is the 
largest of European Loaches, growing to a length of ten 
inches ; it occurs in stagnant waters of eastern and southern 


LOACHES. 605 


Germany and northern Asia. In China and Japan it is re- 
placed by an equally large species, IZ anguillicaudatus. 


NEMACHILUS.—No erectile sub-orbital spine. Six barbels, 
none at the mandible. Dorsal fin opposite to the ventrals. 

The greater number of Loaches belong to this genus ; 
about fifty species are known from Europe and temperate 
Asia; such species as extend into tropical parts inhabit 
streams of high altitudes. Loaches are partial to fast-runnine 
streams with stony bottom, and exclusively animal feeders. 
In spite of their small size they are esteemed as food where 
they occur in sufficient abundance. The British species, WV. 
barbatulus, is found all over Europe except Denmark and 
Scandinavia. 


Copitis.—Body more or less compressed, elongate ; back not 
arched. <A small, erectile, bifid sub-orbital spine below the eye. 
Six barbels only on the upper jaw. Dorsal fin inserted opposite 
to ventrals. Caudal rounded or truncate. 

Only three species are known, of which C. tenia occurs 
in Europe. It is scarce and very local in Great Britain. 


Botta.—Body compressed, oblong ; back more or less arched. 
Eyes with a free circular eyelid ; an erectile bifid sub-orbital 
spine. Six barbels on the upper jaw, sometimes two others at 
the mandibulary symphysis. Dorsal fin commencing in advance 
of the root of the ventrals ; caudal fin forked. Air-bladder con- 
sisting of two divisions: the anterior enclosed in a partly osseous 
capsule, the posterior free, floating in the abdominal cavity. 

This genus is more tropical 
than any of the preceding, and 
the majority of the species 
(eight in number) are finely 


coloured. The more elevated 
form of their body, and the Fig. 276.—Botia rostrata. From 
imperfect ossification of the Bengal: 

capsules of the air-bladder, the divisions of which are not side 


606 FISHES. 


by side, but placed in the longitudinal axis of the body, indi- 
cate likewise that this genus is more adapted for still waters 
of the plains than for the currents of hill-streams. 

Other genera from tropical India are Lepidocephalichthys, 
Acanthopsis, Oreonectes (hills near Hong-Kong), Paramisqur- 
nus (Yan-tse-Kiang), Lepidocephalus, Acanthophthalmus, and 
Apua. 


FourtH FAMILY—K NERIID 4. 


Body scaly, head naked. Margin of the upper jaw formed 
by the intermaxdlaries. Dorsal and anal fins short, the former 
belonging to the abdominal portion of the vertebral column. 
Teeth none, either in the mouth or pharyna. Barbels none. 
Stomach siphonal ; no pyloric appendages.  Pseudobranchie 
none. Branchiostegals three; air-bladder long, not divided. 
Ovaries closed. 

Small loach-hke fishes from fresh waters of tropical 
Africa; two species only, Kneria angolensis and K. spekii, are 
known. 


Firth FAMILY—CHARACINIDA. 


Body covered with scales, head naked ; barbels none. Mar- 
gin of the wpper jaw formed by the intermaxillaries in the 
middle and by the maxillaries laterally. Generally a small 
adipose fin behind the dorsal. Pyloric appendages more or 
less numerous ; atr- bladder transversely divided into two 
portions, and communicating with the organ of hearing by 
means of the auditory ossicles. Pseudobranchice none. 

The fishes of this family are confined to the fresh waters 
of Africa, and especially of tropical America, where they 
replace the Cyprinoids, with which family, however, they 
have but little in common as far as their structural charac- 
teristics are concerned. Their co-existence in Africa with 


\ 


CHARACINID A. 607 


Cyprinoids proves only that that continent is nearer to the 
original centre, from which the distribution of Cyprinoids 
commenced than tropical America. The family includes 
herbivorous as well as strictly carnivorous forms; some are 
toothless, whilst others possess a most formidable dentition. 
The family contains so many diversified forms as to render 
a subdivision into groups necessary. They have not yet 
been obtained in fossiliferous strata. 


I. ERYTHRININA.—Adipose jin absent. 


The sixteen species of this group belong to the fauna of 
tropical America, and are referred to the genera Macrodon, 
Erythrinus, Lebiasina, Nannostomus, Pyrrhulina, and Cory- 
nopoma. 


Il. Curmmatina.—A_ short dorsal and an adipose fin; 
dentition imperfect. Tropical America. 

CurIMATUS.—Dorsal fin placed nearly in the middle of the 
body ; anal rather short or of moderate length ; ventrals below 
the dorsal. Body oblong or elevated, with the belly rounded or 
flattened before the ventrals. Cleft of the mouth transverse, 
lips none, margins of the jaws trenchant. No teeth whatever, 
Intestinal tract very long and narrow. 

About twenty species are known, of rather small size. 

The, other genera of this group have teeth, but they are 
either rudimentary or absent in some part of the jaws : Pro- 
chilodus, Cenotropus, Hemiodus, Saccodon, Parodon. 


III. CrrHartnina.—A rather long dorsal and an adipose 
jin; minute labial teeth. Tropical Africa. 

One genus only, Citharinus, with two species, is known. 
Common in the Nile, attaming to a leneth of three feet. 


TV. ANASTOMATINA.—A short dorsal and an adipose fin ; 
teeth in both jaws well developed ; the gill-membranes grown to 


608 FISHES. 


the isthmus ; nasal openings remote from each other. Tropical 
America. 

LEPORINUS.—Dorsal fin placed nearly in the middle of the 
length of the body; anal short; ventrals below the dorsal. 
Body oblong, covered with scales of moderate size ; belly rounded. 
Cleft of the mouth small, with the lips well developed ; teeth 
in the intermaxillary and mandible, few in number, flattened, 
with the apex more or less truncated, and not serrated; the 
middle pair of teeth is the longest in both jaws ; palate toothless, 


This genus is generally distributed in the rivers east of 
the Andes ; about twenty species are known, some of which, 
like ZL. frederici, L. megalepis, are very common. They are 
well marked by black bands or spots, and rarely grow to a 
length of two feet, being generally much smaller—The other 
genera belonging to this group are Anastomus and Rhytrodus. 


V. NannocHaracina.—aA short dorsal and an adipose fin ; 
teeth in both jaws well developed ; notched incisors. The gull- 
membranes are grown to the isthmus. Nostrils close together. 

One genus, Vannocharax, with two species only, from the 
Nile and Gaboon; very small. 


VI. TerraGonoprerIna.—A._ short dorsal and an adipose 
fin; the teeth in both jaws well developed, compressed, notched, 
or denticulated ; the gill-membranes free from the isthmus, and 
the nasal openings close together. South America and Tropical 


Africa. 


AEstEs.—The dorsal fin is placed in the middle of the length 
of the body, above or behind the ventrals ; anal fin rather long. 
Body oblong, covered with scales of moderate or large size ; 
belly rounded. Cleft of the mouth rather small. Maxillary 
teeth none ; intermaxillary teeth in two series; those of the 
front series more or less compressed, more or less distinctly 
tricuspid ; the teeth of the hinder series are broad, molar-like, 
each armed with several pointed tubercles. Teeth in the lower 
jaw in two series; those in the front series laterally compressed, 


CHARACINIDA. 609 


broader behind than in front; the hinder series is composed 

of two conical teeth. All the teeth are strong, few in number. 
Fourteen species from Tropical Africa; several inhabit 

the Nile, of which the “ Raches” (A. dentex and A. kotschyi) 


are the most common. 


TETRAGONOPTERUS.—The dorsal fin is placed in the middle of 
the length of the body, above or immediately behind the ventrals ; 
anal fin long. Body oblong or elevated, covered with scales of 
moderate size; belly rounded. Cleft of the mouth of moderate 
width. Anterior teeth strong, lateral teeth small. Intermaxil- 
lary and mandibulary teeth sub-equal in size, with a compressed 
and notched crown, the former in a double, the latter in a single 
series ; maxillary with a few teeth near its articulation, rarely 
with the entire edge denticulated. 

Of all the genera of this family Tetragonopterus is repre- 
sented by the greatest number of species; about fifty are 
known. Some of them seem to have a very wide range, 
whilst others are merely local. All are of small size, rarely 
exceeding a length of eight inches. 


Cur1RoDON.—Dorsal fin placed in the middle of the length of 
the body, behind the ventrals ; anal long or of moderate length. 
Body oblong, covered with scales of moderate size ; lateral line 
not continued to the tail. Belly rounded before the ventrals. 
Cleft of the mouth narrow, maxillary short. A single series of 
small serrated teeth in the intermaxillary and mandibulary ; 
maxillary teeth none. 


Fig. 277.—Chirodon alburnus. 


Three species of small size from various parts of South 
America; the species figured is represented of the natural 
size, and comes from the Upper Amazons. 

2k 


610 FISHES, 


MEGALOBRYCON.—Dorsal fin placed in middle of the length 
of the body, immediately behind 
the ventrals. Anal long. Ab- 
domen rounded in front of, and 
somewhat compressed behind, 
the ventrals. Cleft of the mouth 
of moderate width. Teeth 
notched, in a triple series in 
the intermaxillary, and in a 
single in the maxillary and man- 
dible ; no other teeth behind 
the mandibulary teeth or on the 
palate. Scales of moderate size, 
with the free portion striated. 


One species from the Upper Amazons (JZ. cephalus). Speci- 
mens more than one foot long have been obtained. 


GASTROPELECUS.—Dorsal fin placed behind the middle of the 
length of the body, above the anal; anal long ; pectoral long ; 
ventrals very small or rudimentary. Body strongly compressed, 
with the thoracic region dilated into a sub-semicircular disk. 
Scales of moderate size. Lateral line descending obliquely 
backwards towards the origin of the anal fin. The lower profile 
compressed into an acute ridge. Cleft of the mouth of moderate 
width ; teeth compressed, tricuspid, in one or two series in the 
intermaxillary, and in a single in the mandible ; maxillary with 
a few minute conical teeth ; palate toothless. 

Three specimens of this singular form are known from 
Brazil and the Guyanas; they are of very small size. 

The majority of the other genera belonging to this group 
are South American, viz. Piabucina, Scissor, Pseudochalceus, 
Aphyocharax, Chalceus, Brycon, Chaleinopsis, Bryconops, Crea- 
grutus, Chaleinus, Piabuea, Paragoniates, and Agoniates ; two 
only are African, viz. Vanneethiops, which represents the South 
American Z'etragonopterus, and Bryconethiops, which is allied 
to Brycon. 


VII. Hyprocyonina.—A short dorsal and an adipose jin ; 


CHARACINIDA, 611 


teeth in both jaws well developed and conical ; gill membranes 
Sree from the isthmus ; nasal openings close together. South 
America and Tropical Africa. Fishes of prey. 


Hyprocyon.—The dorsal fin is in the middle of the length 
of the body, above the ventrals ; anal of moderate length. Body 
oblong, compressed, covered with scales of moderate size; belly 
rounded, Cleft of the mouth wide, without lips; the inter- 
maxillaries and mandibles are armed with strong pointed teeth, 
widely set and few in number ; they are received in notches of 
the opposite jaw, and visible externally when the mouth is . 
closed. Palate toothless. Cheeks covered with the enlarged 
suborbital bones. Orbit with an anterior and posterior adipose 
eyelid. Intestinal tract short. 

Four species from Tropical Africa; two occur in the Nile, 
HT. forskaliw being abundant, and well known by the names 
“Kelb el bahr” and “Kelb el moyeh.” Their formidable 
dentition renders them most destructive to other fishes ; they 
erow to a length of four feet. 


Cynopon.—Dorsal fin placed behind, or nearly in, the middle 
of the length of the body, behind the ventrals; anal long. 
Head and body compressed, oblong, the latter covered with very 
small scales; belly compressed, keeled. Teeth in the inter- 
maxillary, maxillary, and mandible in a single series, conical, 
widely set, of unequal size; a pair of very large canine teeth 
anteriorly in the lower jaw, received in two grooves on the 
palate ; palate with patches of minute granulated teeth. The 
outer branchial arch without gill-rakers, but with very short 
tubercles, 

Four species from Brazil and the Guyanas; they are as 
formidable fishes of prey as the preceding, and grow to the 
same size. 

With the exception of Sarcodaces, all the remaining genera 
of this group belong to the fauna of Tropical America, viz. 
Anacyrius, Hystricodon, Salminus, Oligosarcus, Xiphorhamphus, 
and Xiphostoma. 


612 FISHES. 


VIII. Disticnopontiwa.— Dorsal jin rather elongate ; adi- 
pose fin present. Gull-membranes attached to the isthinus ; 
belly rounded. Tropical Africa. 

The species, ten in number, belong to one genus only 
(Distichodus), well known on the Nile under the name of 
“ Nefasch.” They grow to a considerable size, being some- 
times four feet long and one and a half foot deep. They are 
used as food. 


IX. IcuTHyporiInaA.— An adipose fin; number of dorsal 
rays inereased (12-17); gill-membranes free from the isthmus. 
belly rounded ; canine teeth. Tropical Africa. 

Two genera only: chthyborus from the Nile, and Phago 
from West Africa. Small fishes of very rare occurrence. 


X. CRENUCHINA.—Dorsal jin rather elongate; an adipose 
jin. Gill-membranes free from the isthmus, with the belly 
rounded, and without canine teeth. 

This small group is represented in the Essequibo by a 
single species, Crenuchus spilurus, and by another in West 
Africa, Xenocharax spilurus. 


XI. SERRASALMONINA.— Dorsal fin rather elongate; an 
adipose fin. Cill-membranes free from the isthmus; belly 
serrated. Tropical America. 

Although the fishes of this family do not attain any con- 
siderable size, the largest scarcely exceeding two feet in 
length, their voracity, fearlessness, and number renders them 
a perfect pest in many rivers of tropical America. In all, the 
teeth are strong, short, sharp, sometimes lobed incisors, ar- 
ranged 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 fishes abound is immedi- 
ately attacked and cut in pieces in an incredibly short time. 
They assail persons entering the water, inflicting dangerous 
wounds before the victims are able to make their escape. 


CYPRINODONTIDA. 613 


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 fishes 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 a spot. They are most abundant 
in the Brazils and Guyanas ; some forty species are known, 
and referred to the genera Mylesinus, Serrasalmo, Myletes, and 
Catoprion. 


Fig. 279.—Serrasalmo scapularis, from the Essequibo. 


SrxtH FAMILY—CYPRINODONTID. 


Head and body covered with scales ; barbels none. Margin 
of the upper jaw formed by the intermaxillaries only. Teeth in 
both jaws; upper and lower pharyngeals with cardiform teeth. 
Adipose fin none ; dorsal fin situated on the hinder half of the 
body. Stomach without blind sac; pyloric appendages none. 
Pseudobranchie none; air-bladder simple, without ossicula 
auditus. 

Small fishes, inhabiting fresh, brackish, and salt water of 
Southern Europe, Africa, Asia, and America. The majority 


614 FISHES. 


are viviparous; and to facilitate copulation the anal fin of 
the adult male of many species is modified into a copulatory 
organ, Which is probably (partially at least) introduced into 
the vulva of the female; but it is uncertain whether it serves 
to conduct the semen, or merely to give the male a firmer 
hold of the female during the act. Also secondary sexual 
differences are developed in the Cyprinodonts; the males are 
always the smaller, sometimes several times smaller than the 
females, quite diminutive; and they are perhaps the smallest 
fishes in existence. The fins generally are more developed 
in the males, and the coloration is frequently different also. 
Some species are carnivorous; others live on the organic 
substances mixed with mud. Fossil remains have been found 
in tertiary strata, all apparently referable to the existing 
genus Cyprinodon ; they occur near Aix in Provence, in the 
marl of Gesso, St. Angelo, in the Brown coal near Bonn, 
near Frankfort, and in the freshwater-chalk of Oeningen. 
In the latter locality a Poecilia occurs likewise. 

The genera can be divided into two groups: 


I. CYPRINODONTIDA CARNIVORA. 


The bones of each ramus 
of the mandible are firmly united ; intestinal tract short, or 
but little convoluted. Carnivorous or insectivorous. 

CyPpRINODON.—Cleft of the mouth small, developed laterally 
and horizontally. Snout short. Teeth of moderate size, incisor- 
like, notched, in a single series. Scales rather large. Origin of 
the anal fin behind that of the dorsal in both sexes, both fins 
being larger in the male than in the female. Anal not modified 
into a sexual organ. 

Seven species occur in the Mediterranean region, all of 
which seem able to live in briny springs or pools, the water 
of which contains a much greater percentage of salts than 
sea-water, as the brine-springs near the Dead Sea or in the 
Sahara. They are as little affected by the high temperature 
of some of these springs (91°), for instance of that at Sidi 


CYPRINODONTID. 615 


Ohkbar in the Sahara. Like other fishes living in hmited 
localities or concealing themselves in mud, Cyprinodonts 
lose sometimes their ventral fins; such specimens have 
been described as TYellia. The species of the New World 
are less known than those of the Old, but not less numerous. 

Allied to Cyprinodon are /itzroyia from Monte Video, 
and Characodon from Central America. 


HAPLOcHILUS.—Snout flat, both jaws being much depressed, 
and armed with a narrow band of villiform teeth. Body oblong, 
depressed anteriorly, compressed posteriorly. Dorsal fin short, 
commencing behind the origin of the anal, which is more or less 
elongate. 

Twenty species from the East Indies, tropical Africa, and 
temperate and tropical America. 


FunpuLUS.—Cleft of the mouth of moderate width, developed 
laterally and horizontally. Snout of moderate length. Teeth 
in a narrow band, those of the outer series being largest, conical. 
Scales of moderate size. Dorsal fin commencing before or 
opposite the origin of the anal. Sexes not differentiated. 

“ Killifish,” abundant in the New World, where about 
twenty species have been found; F. heteroclitus, majalis, 
diaphanus, being common on the Atlantic coast of the United 
States; from the Old World two species only are known, viz. 
F. hispanicus from Spain, and F. orthonotus from the east 
coast of Africa. Allied to Fundulus are the South American 
Limnurgus, Lucania, Rwvulus, and Cynolebias. 


OrESTIAS.—Ventral fins none. Cleft of the mouth of moderate 
width, directed upwards, with the lower jaw prominent, and 
with the upper protractile. Both jaws with a narrow band 
of small conical teeth. Scales rather small or of moderate 
size, those on the head and upper part of the trunk frequently 
enlarged, plate-like, and granulated. Dorsal and anal fins 
moderately developed, opposite to each other. Sexes not differ- 
entiated by modification of the anal fin. The gill-membranes of 


616 FISHES. 


both sides are united for a short distance, and not attached to 
the isthmus. 


Inhabitants of Lake Titicaca and other elevated sheets of 
water on the Cordilleras of Peru and Bolivia, between the 
14th and 19th degrees of latitude, at an elevation of 13,000 
and 14,000 feet above the level of the sea. Singularly, the 
fishes of this outlying genus attain to a greater size than any 
other members of this family, being about eight inches long 
and comparatively bulky. They are considered a delicacy. 
Six species. 

JENYNSIA.—Cleft of the mouth small, developed laterally 
and horizontally ; snout not produced. Both jaws with a series 
of tricuspid teeth of moderate ‘size. Scales of moderate size. 
The origin of the anal fin is, in both sexes, behind that of the 


dorsal, although the anal of the male is modified into an intro- 
mittent organ, in which scarcely any of the rays remain distinct. 


One species from Maldonado. 


GAMBUSIA.—Cleft of the mouth developed laterally and 
horizontally. Snout not produced, with the lower jaw more or 


Fig. 280.—Gambusia punctata, from Cuba. A. Male; B. Female. 


less prominent. Both jaws with a band of teeth, those of the 
outer series being strongest and conical. Scales rather large. 
Origin of the anal fin more or less in advance of that of the 
dorsal. Anal fin of the male modified into an intromittent 
organ and much advanced. 


de 


CYPRINODONTID A. 617 


Eight species from the West Indies and the southern 
parts of South America.—Allied genera are the Central 
American Pseudoxiphophorus and Belonesox. 


ANABLEPS.—Head broad and depressed, with the supraorbital 
part very much raised. Body elongate, depressed anteriorly and 
compressed posteriorly. Cleft of the mouth horizontal, of mode- 
rate width, the mandible being short; upper jaw protractile. 
Both jaws armed with a band of villiform teeth, those of the 
outer series being largest and somewhat movable. The integu- 
ments of the eye are divided into an upper and lower portion 
by a dark-coloured transverse band of the conjunctiva ; also the 
pupil is completely divided into two by a pair of lobes projecting 
from each side of the iris. Scales rather small or of moderate 
size. Dorsal and anal fins short, the former behind the latter. 
The anal fin of the male is modified into a thick and long scaly 
conical organ with an orifice at its extremity. 


Three species from tropical America, They are the 
longest Cyprinodonts, attaining to the length of nearly 
twelve inches. Their peculiar habit of swimming with part 
of the head out of the water has been noticed above (p. 113). 


II. Cyprinopontipa LimnopHaca&.— The bones of each 
ramus of the mandible are but loosely joined ; intestinal tract 
with numerous circumvolutions. Sexes differentiated. Mud- 
eating. Tropical America. 

PorcittA.—Cleft of the mouth small, transverse ; mandible 
very short. Both jaws with a narrow band of minute teeth. 
Seales rather large. Origin of the anal fin generally nearly 
opposite to that of the dorsal fin in the female, but in the male 
it is modified into an intromittent organ and much advanced. 
Dorsal fin short, with not more than eleven rays. 


Sixteen species. 

Mo.LuieNnEsiA.— Differing from Poccilia in having A larger 
dorsal fin, with twelve or more rays. 

Five species. The males are most beautifully coloured, 
and their dorsal fin is much enlarged. In one species (Jf. 


618 FISHES. 


hellerit), besides, the lower caudal rays of the mature male 
are prolonged into a long, sword-shaped, generally black and 
yellow.appendage. 

Two other genera belong to this group : Platypoecilus and 
Girardinus. 


SEVENTH FAMILY—HETEROPYGIL 


ead naked ; body covered with very small scales ; barbels 
none. Margin of the upper jaw formed by the intermazillaries. 
Villiform teeth in the jaws and on the palate. Adipose fin 
none. Dorsal fin belonging to the caudal portion of the vertebral 
column, opposite to the anal. Ventral fins rudimentary or 
absent. Vent situated before the pectorals. Stomach coecal ; 
pyloric appendages present. Pseudobranchic none ; air-bladder 
deeply notched anteriorly. 

To this small family, which is closely allied to the 
Cyprinodonts and Umbride, belongs the famous Blind Fish 
of the Mammoth Cave in Kentucky, Amblyopsis speleus. It 
is destitute of external eyes, and the body is colourless; 
although the eyes, with the optic nerve, are quite rudimentary, 
the optic lobes are as much developed as in fishes with per- 
fect eyes. The loss of vision is compensated by the acute- 
ness of its sense of hearing, as well as by a great number of 
tactile papille, arranged on transverse ridges on the head, and 
provided with nervous filaments coming from the fifth pair. 
The ovary is single, and the fish is viviparous, like the 
Cyprinodonts. It seems to occur in all the subterranean 
rivers that flow through the ereat limestone region under- 
lying the carboniferous rocks in the central portion of the 
United States. As in Cyprinodon, so in this genus, specimens 
occur without ventral fins; they have been called Typhlich- 
thys. The largest size to which Amblyopsis grows is five 
inches. 

Chologaster is closely allied, but provided with small 


> 7a 


SCOMBRESOCID A. 619 


external eyes; its body is coloured, but it is destitute of 
ventrals. It was found once in a rice field in South Carolina. 


[See Tellkampf, Mill. Arch. 1844, p. 381; Packard and Putnam, ‘‘ The 
Mammoth Cave and its Inhabitants.” Salem. 1872. 8°.] 


EIGHTH FAMILY—UMBRID&. 


Head and body covered with scales ; barbels none. Margin 
of the upper jaw formed by the intermaxillaries mesially, and 
by the maxillaries laterally. Adipose fin none ; the dorsal fin 
belongs partly to the abdominal portion of the vertebral column. 
Stomach siphonal ; pyloric appendages none ; pscudobranchice 
glandular, hidden ; air-bladder simple. 

Two small species only are known: Umbra krameri from 
Austria and Hungary, and Umbra limi, locally distributed in 
the United States ; called “ Hunds-fish” in Germany, “ Dog- 
fish ” or “ Mud-fish ” in America. 


NINTH FAMILY—SCOMBRESOCID. 


Body covered with scales ; a series of keeled scales along each 
side of the belly. Margin of the upper jaw formed by the inter- 
maxtlaries mesially, and by the maxillaries laterally. Lower 
pharyngeals united into a single bone. Dorsal fin opposite the 
anal, belonging to the caudal portion of the vertebral column. 
Adipose fin none. Air-bladder generally present, simple, some- 
times cellular, without pneumatic duct. Pseudobranchie hidden, 
glandular. Stomach not distinct from the intestine, which as 
quite straight, without appendages. 

The fishes of this family are chiefly marine, some living in 
the open ocean, whilst others have become acclimatised in fresh 
water; many of the latter are viviparous, all the marine 
forms being oviparous. They are found in all the temperate 
and tropical zones. Carnivorous. 

This family is represented in the strata of Monte Bolea 
by rare remains of a fish named /olosteus, allied to Belone or 


620 FISHES, 


Scombresoz, and by a species of Belone in the miocene of 
Licata. 


BeELONE.—Both jaws are prolonged into a Jong slender beak. 
All the dorsal and anal rays connected by membrane. 

The long upper jaw of the “Gar-pike” is formed by the 
intermaxillaries, which are united by a longitudinal suture. 
Both jaws are beset with asperities, and with a series of 
longer, conical-pointed, widely-set teeth. Skimming along 
the surface of the water, the Gar-pike seize with these long 
jaws small fish as a bird would seize them with its beak; 
but their gullet is narrow, so that they can swallow small 
fish only. They swim with an undulating motion of the 
body ; although they are in constant activity, their progress 
through the water is much slower than that of the Mackerels, 
the shoals of which sometimes appear simultaneously with 
them on our coasts. Young specimens are frequently met in 
the open ocean; when very young their jaws are not pro- 
longed, and during growth the lower jaw is much in advance 
of the upper, so that these young fishes resemble a Hemi- 
rhamphus. About fifty species are known from tropical and 
temperate seas, Lelone belone being a common fish on the 
British coast. Its bones, like those of all its congeners, are 
green; and therefore the fish, although good eating, is dis- 
liked by many persons. Some species attain a length of five 
feet. 


SCOMBRESOX.—Both jaws are prolonged into along slender 
beak. A number of detached finlets behind the dorsal and anal 
fins. 

The “Saury” or “Skipper” resemble the Gar-pike, but 
the teeth in the jaws are minute; they seem to feed chiefly 
on soft pelagic animals. In their habits they are still more 
pelagic; and the young, in which the beak is still unde- 
veloped, are met with everywhere in the open ocean, in the 


FLYING-FISH. 621 


Atlantic as well as in the Pacific. The European species, Se. 
saurus, is not rare on the british coast; four other species 
have been described, closely allied to Sc. sawrus. 

HemirHAMPHUS.—The lower jaw only is prolonged into a 
long slender beak. 

In the young both jaws are short; the upper is never 
prolonged, the intermaxillaries forming a triangular, more or 
less convex, plate. The “ Half-beaks” are common between 
and near the tropics ; some forty species are known, none of 
which attain to the same length as the Gar-pike, scarcely 
ever exceeding a length of two feet. Some of the tropical 
species live in fresh water only ; they are of small size and 
viviparous. 

ARRHAMPHUS.—Mouth formed as in Hemirhamphus, except 
that the lower jaw is not produced into a beak. Pectoral fins 
of moderate length. 

One species (A. sclerolepis) from the coast of Queensland 
(not New Zealand); it may be regarded as a Hemirhamphus, 
with retarded development of the lower jaw. 

Exocortus.—Jaws short, intermaxillaries and maxillaries 
separate. Teeth minute, rudimental, and sometimes absent. 
Body moderately oblong, covered with rather large scales. 
Pectorals very long, an organ of flying. 

Forty-four different kinds of “Flying-fishes” are known 


Fig, 281.—Flying Fish ; Exocoetus callopterus. 


from tropical and sub-tropical seas; some have a very wide 
range, whilst others seem to remain within one particular 


622 FISHES. 


part of the ocean; thus, the species figured, . callop- 
terus, has been hitherto found on the Pacific side of the 
isthmus of Panama only. Their usual leneth is about 10 or 
12 inches, but specimens of 18 inches have been caught. 
They always live in shoals, and their numbers at certain 
times and localities are immense ; thus, at Barbadoes many 
boats engage in their capture, as they are excellent eating. 
The pectorals are in the various species of unequal length; 
in some they extend to the anal fin only; in others (and 
these are the best fliers) to the caudal. A few have curious, 
barbel-like appendages at the lower jaw, which may disappear 
with age or be persistent throughout life. The literature on 
the subject of Flying-fishes is very extensive, and great diver- 
sity of opmion exists among observers as regards the mode 
and power of their flight; but the most relable agree that 
the fishes do not leave the water for the purpose of catching 
insects (!), and that they are unable to move their fins in the 
manner of a bat or bird, or to change voluntarily the direc- 
tion of their flight, or to fly beyond a very limited distance. 
The most recent enquiries are those of K. Mobius (“Die 
Beweeungen der Fliegenden Fische durch die Luft,” Leip. 
1878, 8vo), the chief results of which may be summed up 
thus: Flying-fish are more frequently observed in rough 
weather and in a disturbed sea than during calm; they dart 
out of the water when pursued by their enemies, or frightened 
by an approaching vessel, but frequently also without any 
apparent cause, as is also observed in many other fishes; 
and they rise without regard to-the direction of the wind or 
waves. The fins are kept quietly distended, without any 
motion, except an occasional vibration caused by the air 
whenever the surface of the wing is parallel with the cur- 
rent of the wind. Their flight is rapid, but gradually de- 
creasing in velocity, greatly exceeding that of a ship going 
10 miles an hour, and a distance of 500 feet. Generally, it 


q 


PIKE. 623 


is longer when the fishes fly against than with or at an angle 
to the wind. Any vertical or horizontal deviation from a 
straight line is not caused at the will of the fish, but by cur- 
‘rents of the air; thus they retain a horizontally ‘straight 
course when flying with or against the wind, but are carried 
towards the right or left whenever the direction of the wind 
is at an angle with that of their flight. However, it some- 
times happens that the fish during its flight immerses its 
caudal fin in the water, and by a stroke of its tail turns 
towards the right or left. In a calm the line of their flight 
is always also vertically straight, or rather parabolic, hke the 
course of a projectile, but it may become undulated in a 
rough sea, when they are flying against the course of the 
waves; they then frequently overtop each wave, beimg car- 
ried over it by the pressure of the disturbed air. Flying- 
fishes often fall on board of vessels, but this never happens 
during a calm, or from the lee side, but during a breeze only, 
and from the weather side. In daytime they avoid a ship, 
flying away from it; but during the night, when they are 
unable to see, they frequently fly against the weather-board, 
where they are caught by the current of air, and carried 
upwards to a height of 20 feet above the surface of the 
water, while, under ordinary circumstances, they keep close to 
it. All these observations point clearly to the fact that any 
deflection from a straight course is due to external cireum- 
stances, and not to voluntary action-on the part of the fish. 


TENTH FAMILY—ESOCIDA. 


Body covered with scales; barbels none. Margin of the 
upper jaw formed by the intermaxillaries mesially, and by the 
maxillaries laterally. Adipose fin none; the dorsal fin belongs 
to the caudal portion of the vertebral column. Stomach without 
blind sac ; pyloric appendages none. LPseudobranchice glandu- 
lar, hidden ; avr-bladder simple ; gill-opening very wide. 


624 FISHES. 


This family includes one genus only, Esoz, the “ Pikes,” in- 
habitants of the fresh waters of the temperate parts of Europe, 
Asia, and America, The European species, Z. lucius, inhabits 


Fig. 282.—The Pike. (Esox lucius.) 


all three continents, but the North American waters harbour 
five, or perhaps more, other species, of which the “ Muskel- 
lunge,” or “ Maskinonge” (£. estor) of the Great Lakes attains 
to the same large size as the common Pike. The other species 
are generally called “ Pickerell” in the United States. 

Fossil Pike, belonging to the existing genus, have been 
found in the freshwater-chalk of Oeningen, and in the diluvial 
marl of Silesia. Remains of the common Pike occur in 
abundance in quaternary deposits. 


ELEVENTH FAMILY—GALAXIIDA. 


Body naked, barbels none. Margin of the upper jaw chiefly 
formed by the intermaxillaries, which are short, and continued 
by a thick lip, behind which are the maaillaries. Belly 
rounded ; adipose fin none ; dorsal opposite to anal. Pyloric 
appendages tn small number. Air-bladder large, simple; pseudo- 
branchie none. The ova fall into the cavity of the abdomen 
before exclusion. 

Small freshwater fishes of the southern hemisphere, be- 
longing to two genera, Galaxias and Neochanna. Of the 


z: hie Fee 


MORMYRID&. 625 


former genus five species are found in New Zealand, where 
this type is most developed, three in New South Wales, two 


Fig. 283.—Galaxias truttaceus, from Tasmania. 


in Tasmania, and four in the southern extremity of South 
America. Their native name in New Zealand is “ Kokopu,” 
and they were dignified with the name of “Trout” by the 
settlers before the introduction of true Salmonide. They 
rarely exceed a length of eight inches. Neochanna is a de- 
eraded form of Galaxias, from which it differs by the absence 
of ventral fins. This fish has hitherto been found only in 
burrows, which it excavates in clay or consolidated mud, 
at a distance from water. 


TWELFTH FAMILY—MORMYRIDA. 


Body and tail scaly ; head scaleless ; barbels none. The 
margin of the upper jaw is formed in the middle by the inter- 
maaxillaries, which coalesce into a single bone, and laterally by 
the maxillaries, Sub- and inter-operculum present, the latter 
very small. On each side of the single parietal bone a cavity 
leading wnto the interior of the skull, and covered with a thin 
bony lamella. All the fins are well developed, in Mormyrus ; 
or caudal, anal, and ventral fins are absent, in Gyronarchus. 
No adipose fin. Pseudobranchie none ; gill-openings reduced 
to a short slit. Air-bladder simple. Two coeca pylorica 
behind the stomach. 

This family is characteristic of the freshwater fauna of 
tropical Africa. Of Mormyrus (including Hyperopisus and 

28 


626 FISHES. 


Mormyrops), fifty-one species are known, of which eleven 
occur in the Nile. Some attain a length of three or four feet, 
others remain small. Their flesh is said to have an excellent 
flavour. The species figured (and probably other alhed 


Fig. 284.—Mormyrus oxyrhynchus. 


species) was an object of veneration to the ancient Egyptians, 


and, therefore, frequently occurs in their emblematic inscrip-- 


tions. They abstained from eating it because it was one of 
three different kinds of fishes accused of having devoured a 
member of the body of Osiris, which, therefore, Isis was unable 
to recover when she collected the rest of the scattered mem- 
bers of her husband. 

The Mormyri possess a singular organ on each side of the 
tail, without electric functions, but evidently representing a 
transitional condition from muscular substance to an electric 
organ. It is an oblong capsule divided into numerous com- 
partments by vertical transverse septa, and containing a gela- 
tinous substance. The Mormyri differ much with regard to 
the extent of the dorsal and anal fins, the former sometimes 
occupying the greater portion of the leneth of the back, 
sometimes being much shorter and limited to the tail. In 
some the snout is short and obtuse, in others long and 
decurved, with or without appendage. 

Of Gymnarchus one species only is known, G. niloticus, 
which occurs in the Nile and West African rivers, and 
attains a length of six feet. The form of its body is eel-like, 
and each jaw is armed with a series of incisor-like teeth. 


7 
: 


STERNOPTYCHID A. 627 


Like Mormyrus, Gymnarchus posseses a pseudo-electric organ, 
thickest on the tail, tapering in front, and extending nearly 
to the head. It consists of four membranaceous tubes inti- 
mately connected with the surrounding muscles, and con- 
taining prismatic bodies arranged in the manner of a pater- 
noster. The air-bladder of Gymnarchus is cellular, very 
extensible, and communicates with the dorsal side of the 
cesophagus by a duct possessing a sphincter. 


[See #rdi, Miinchner Gelehrte Anzeigen, 1846, xxiii, and Hyrid, 
Denkschr, Akad. Wiss. Wien. 1856. xii. ] 


THIRTEENTH FAMILY—STERNOPTYCHIDA. 


Body naked, or with very thin deciduous scales; barbels 
none. Margin of the upper jaw formed by the maaillary and 
intermaxillary, both of which are toothed ; opercular apparatus 
not completely developed. Gill-opening very wide; pseudo- 
branchie present or absent; air-bladder simple, if present. 
Adipose fin present, but generally rudimentary. Serres of phos- 
phorescent bodies along the lower parts. The eggs are enclosed 
in the sacs of the ovarium, and excluded by oviduets. 

Pelagic and Deep-sea fishes of small size. 


STERNOPTYX.—Trunk much elevated and compressed, with 
the trunk of the tail very short. Body covered with a silvery pig- 
ment, without regular scales ; series of phosphorescent spots run 
along the lower side of the head, body, and tail. Cleft of the 
mouth wide, vertical, with the lower jaw prominent. Jaws 
armed with small teeth. Eyes rather large, and although lateral, 
directed upwards and placed close together. Ventral fins very 
small. A series of imbricate scutes runs along the abdomen, 
forming a kind of serrature. The dorsal fin is short, and occu- 
pies about the middle of the length of the fish ; it is preceded by 
the first commencement of the formation of a spinous dorsal, 
several neural spines being prolonged beyond the dorsal muscle 
forming a triangular osseous plate. Adipose fin rudimentary ; 
anal short ; caudal forked. 


628 FISHES. 


These small fishes are now and then picked up in the 
Mediterranean and Atlantic. According to the dredging- 
records of the “ Challenger,” they and the allied genera Argy- 
ropelecus and Polyipnus would descend to depths of respectively 
1100 and 2500 fathoms; but the form of their body and their 
whole organisation render this statement very improbable ; 
they most likely live at a small depth during the day-time, 
coming to the surface at night, hke many Scopelus. 

Coccia and Maurolicus are two other genera allied to the 
preceding. 

CHAULIODUS.—Body elongate, compressed, covered with ex- 
ceedingly thin and deciduous scales; series of luminous (phos- 
phorescent) spots run along the lower side of the head, body, 
and tail. Head much compressed and elevated, with the bones 
thin, but ossified, and with the opercular portion very narrow, 
the interoperculum being rudimentary. Cleft of the mouth ex- 


Fig. 285.—Chauliodus sloanii. 


ceedingly wide, the intermaxillary forming one half of the upper 
jaw. Each intermaxillary with four long canine teeth ; edge of 
the maxillary finely denticulated ; mandible with pointed, widely 
set teeth, the anterior of which are exceedingly long; none of 
the large teeth are received within the mouth. Palatine with a 
single series of small pointed teeth; no teeth on the tongue. 
Eye of moderate size. Pectoral and ventral fins well developed. 
Dorsal fin anteriorly on the trunk, before the ventrals ; adipose 
fin small, sometimes fimbriated ; anal short, rather close to the 
caudal, which is forked. Gill-opening very wide, the outer 
branchial arch extending forward to behind the symphysis of 
the lower jaw ; it has no gill-rakers. Branchiostegals numerous. 


ca” ee 


+e hee reer Ss Sr eee 


STOMIATIDAL. 629 


This genus, of which one species only (Ch. sloanii) is 
known, is generally distributed over the great depths of the 
oceans, and does not appear to be scarce; it attains to a 
length of 12 inches, and must be one of the most formidable 
fishes of prey of the deep-sea. 

Allied genera are Conostoma, Photichthys, and Diplophos, 
all of which have the teeth of much smaller size. 


FOURTEENTH FAMILY—STOMIATIDA. 


Skin naked, or with exceedingly delicate scales; a hyoid 
barbel. Margin of the upper jaw formed by the intermaxillary 
and maxillary which are both toothed; opercular apparatus 
but little developed. Cull-opening very wide ; pseudobranchie 
none. The eggs are enclosed in the sacs of the ovarium, and 
excluded by oviducts. 

Deep-sea fishes, descending to the greatest depths, charac- 
terised by their barbel and their formidable dentition. 


Fig. 286.—Astronesthes niger. The white spots in front of the eye are 

phosphorescent organs. 

Some have two dorsal fins, the posterior of which is adi- 
pose; they belong to the genus Astronesthes, are the smallest 
of the family, and frequently met with in the Atlantic. 

The others—viz. Stomias, Echiostoma, Malacosteus, and 
Bathyophis, lack the adipose fin, the rayed dorsal being 
opposite to the anal. Of these the one longest known is 


Srom1As.—Body elongate, compressed, covered with exceed- 


650 FISHES. 


ingly fine and deciduous scales, which are scarcely imbricate, 
lying in subhexagonal impressions; vent situated at no great 
distance from the caudal fin. Head compressed, with the snout 
very short, and with the cleft of the mouth very wide. Teeth 
pointed, unequal in size, those of the intermaxillaries and of the 
mandible being the longest; maxillary finely denticulated ; 
vomer with a pair of fangs; palatine bones and tongue with 
smaller pointed teeth. Eye of moderate size. Opercular portion 
of the head narrow. A fleshy barbel in the centre of the hyoid 
region. Dorsal opposite the anal, close to the caudal; pectoral 
and ventral fins feeble, the latter inserted behind the middle of 
the length of the body. Series of phosphorescent dots run along 
the lower side of the head, body, and tail. Gill-opening very 
wide. Pyloric appendages none. 

Three species are known; beside specimens which were 
found floating on the surface, others have been dredged from 


depths varying between 450 and 1800 fathoms. 


FIFTEENTH FAMILY—SALMONIDA. 


Body generally covered with scales; head naked ; barbels 
none. Margin of the upper jaw formed by the intermaxillarves 
mesially, and by the maxillaries laterally. Belly rounded. A 
small adipose fin behind the dorsal. Pylorie appendages gener- 
ally numerous, rarely absent. Atrr-bladder large, simple ; 
pseudobranchia present. The ova fall into the cavity of the 
abdomen before exclusion. 

Inhabitants of the sea and freshwater; the majority of 
the marine genera are deep-sea forms. The freshwater forms 
are peculiar to the temperate and arctic zones of the Northern 
Hemisphere, one occurring in New Zealand; many fresh- 
water species periodically or occasionally descending to the 
sea. One of the most valuable families of the class of 
fishes. No fossils of the freshwater forms are known; but of 
the marine genera, Osmerus occurs in the greensand of Ibben- 
busen, and in the schists of Glaris and Licata; a species of 


SALMONIDA. 631 


Mallotus, indistinguishable from the living JM. villosus, occurs 
abundantly in nodules of clay of unknown geological age in 
Greenland. Other genera, as Osmeroides, Acrognathus, and 
Aulolepis, from the chalk of Lewes, belong to the same fauna 
as species of Beryx, and were probably deep-sea Salmonoids. 


SatmMo.—Body covered with small scales. Cleft of the 
mouth wide, the maxillary extending to below or beyond the 
eye. Dentition well developed ; conical teeth in the jaw bones, 
on the vomer and palatines, and on the tongue, none on the 
pterygoid bones. Anal short, with less than fourteen rays. 
Pyloric appendages numerous; ova large. Young specimens 
with dark cross-bands (Parr-marks). 


We know of no other group of fishes which offers so many 
difficulties to the ichthyologist with regard to the distinction 
of the species as well as to certain points in their life-history, 
as this genus, although this may be partly due to the unusual 
attention which has been given to their study, and which has 
revealed an almost greater amount of unexplained facts than 
of satisfactory solutions of the questions raised. The almost 
infinite variations of these fishes are dependent on age, sex 
and sexual development, food, and the properties of the 
water. Some of the species interbreed, and the hybrids mix 
again with one of the parent species, thus producing an off- 
spring more or less similar to the pure breed. The colora- 
tion is, first of all, subject to variation; and consequently 
this character but rarely assists in distinguishing a species, 
there being not one which would show in all stages of de- 
velopment the same kind of coloration. The young of all 
the species are barred ; and this is so constantly the case that 
it may be used as a generic or even as a family character, not 
being peculiar to Salmo alone, but also to Zhymallus and 
probably to Coregonus. The number of bars is not quite 
constant, but the migratory Trout have two (and even three) 
more than the River-Trout. In some waters River-trout 


632 FISHES. 


remain small, and frequently retain the Parr-marks all their 
lifetime ; at certain seasons a new coat of scales overlays the 
Parr-marks, rendering them invisible for a time; but they 
reappear in time, or are distinct as soon as the scales are 
removed. When the Salmones have passed this “ Parr” 
state, the coloration becomes much diversified. The males, 
especially during and immediately after the spawning time, 
are more intensely coloured and variegated than the females ; 
specimens which have not attained to maturity retaiming a 
brighter silvery colour, and being more similar to the female 
fish. Food appears to have less influence on the coloration 
of the outer parts than on that of the flesh; thus the more 
variegated specimens are frequently out of condition, whilst 
well-fed individuals with pinkish flesh are of a more uniform 
though bright coloration. Chemistry has not supplied us yet 
with an analysis of the substance which gives the pink colour 
to the flesh of many Salmonoids; but there is little doubt 
that it is identical with, and produced by, the red pigments 
of many salt- and fresh-water Crustaceans, which form a 
favourite food of these fishes. The water has a marked 
influence on the colours; Trout with intense ocellated spots 
are generally found in clear rapid rivers, and in small open 
Alpine pools; in the large lakes with pebbly bottom the fish 
are bright silvery, and the ocellated spots are mixed with or 
replaced by X-shaped black spots; in pools or parts of lakes 
with muddy or peaty bottom, the trout are of a darker colour 
generally, and when enclosed in caves or holes, they may 
assume an almost uniform blackish coloration. 

The change of scales (that is, the rapid reproduction of 
the worn part of the scales) coincides in the migratory species 
with their sojourn in the sea. The renovated scales give 
them a bright silvery appearance, most of the spots disappear- 
ing or being overlaid and hidden by the silvery scales. Now, 
some of the species, ike S. fario, inhabit all the different 


SALMONID. 633 


waters indicated, even brackish water, and, in consequence, 
we find a great variation of colour in one and the same species ; 
others are more restricted in their habitat, like S. salar, 
S. ferox, etc., and, therefore, their coloration may be more 
precisely defined. 

With regard to size the various species do not present an 
equal amount of variation. Size appears to depend on the 
abundance of food and the extent of the water. Thus, the 
Salmon and the different kinds of great Lake-trout do not 
appear to vary considerably im size, because they find the 
same conditions in all the localities inhabited by them. <A 
widely spread species, however, like S. fario, when it inhabits 
a small mountain pool with scanty food, may never exceed a 
weight of eight ounces, whilst in a large lake or river, where 
it finds an abundance and variety of food, it attains to a 
weight of fourteen or sixteen pounds. Such large River-trout 
are frequently named and described as Salmon-trout, Bull- 
trout, etc. Further, in Salmones, as in the majority of fishes 
and tailed Batrachéans, there is an innate diversity of growth 
in individuals hatched from the same spawn. Some grow 
rapidly and normally, others more slowly, and some remain 
dwarfed and stationary at a certain stage of development. 

The proportions of the various parts of the body to one 
another vary exceedingly in one and the same species. Be- 
side the usual changes from the young to the sexually 
mature form observed in all fishes, the snout undergoes an 
extraordinary amount of alteration of shape. In the mature 
male the intermaxillaries and the mandible are produced in 
various degrees, and the latter is frequently more or less bent 
upwards. Hence the males have the snout much more 
pointed and produced, and the entire head longer, than the 
females; with the intermaxillary bone the teeth, with which 
it is armed, are also enlarged, sometimes to four times the 
size of those of the females. And if this development of the 


634 FISHES. 


front part of the head happens to be going on while the 
individual is able to obtain only a scanty supply of food, the 
usual proportions of the head and trunk are so altered that 
the species is very difficult to recognise. Barren male fish 
approach the females in the proportions of the head and 
body, but hybrid fishes do not differ in this respect from their 
parents. The abundance or scarcity of food, and the disposi- 
tion or indisposition of the Salmonoids to feed, are other 
causes affecting the growth or fulness of the various parts of 
the body. In well-fed fishes the head is proportionally not 
only smaller but also shorter, and vice versa. 

The fins vary to a certain degree. The variation in the 
number of the rays is inconsiderable and of no value for 
specific distinction. The caudal fin undergoes considerable 
changes of form with age, and dependently upon the sexual 
development. Young specimens of all species have this fin 
more or less deeply excised, so that the young of a species 
which has the caudal emarginate throughout life, is distin- 
guished by a deeper incision of the fin, from the young of a 
species which has it truncate in the adult state. As the 
individuals of a species do not all attain to maturity at the 
same age and at the same size, and as mature individuals 
generally have the caudal less deeply excised than immature 
ones of the same age and size, it is evident that the varia- 
tions in the form of the caudal are considerable and numerous, 
and that it is a very misleading character if due regard be not 
paid to the age and sexual development of the fish. Further, 
species inhabiting rapid streams as well as still waters show 
considerable variations in the form and length of all the fins ; 
those individuals which live in rapid streams, being in almost 
constant motion and wearing off the delicate extremities of 
the fins, have the fin-rays comparatively shorter and stouter, 
and the fins of a more rounded form, particularly at the 
corners, than individuals inhabiting ponds or lakes. More- 


SALMONIDA. 635 


over, one and the same individual may pass a part of its 
life in a lake, and enter a river at certain periods, thus 
changing the form of its fins almost periodically. 

Finally, to complete our enumeration of these variable 
characters, we must mention that in old males, during and 
after the spawning-season, the skin on the back becomes 
thickened and spongy, so that the scales are quite invisible, 
being imbedded in the skin. 


After this cursory review of variable characters we pass 
on to those which are more constant, not subject to ready 
modification by external circumstances ; and which, therefore, 
ought to be noticed in every description of a species of Salmo. 

1. The form of the prwoperculum of the adult fish—The 
preeoperculum is composed of a vertical (posterior) and hori- 
zontal (lower) part (limb), both meeting at a more or less 
rounded angle. The development of the lower limb is a very 
constant character; in some species (as in the Salmon) it is 
long, in others (S. ferox, S. brachypoma) exceedingly short. 
The adjoining woodcuts will readily show this difference. 


A 
Fig. 287.—Preoperculum of A. Salmo salar; B. Salmo brachypoma. 


In young specimens of all Salmonoids the preeoperculum 
has a very short lower limb; but whilst in some species it 
lengthens with age, its development in a horizontal direction 
is arrested in others. 


636 FISHES. 


2. The width and strength of the maxillary of the adult 
Jish.—To show this character in two distinct species, we have 
given woodcuts of the maxillaries of females (12 inches long) 
of S. fario and S. levenensis of the same size. 


Fig. 288.—Maxillary of A. Salmo fario; B. Salmo levenensis. 


In young specimens of all Salmonoids the maxillary is com- 
paratively shorter and broader, somewhat resembling that of 
Coregonus ; yet this bone offers a valu- 
able character for the determination of 
the young of some species; for in- 
stance, in a young S. cambricus it ex- 
tends scarcely to below the centre of 
the eye, whilst in S. fario of the same 
size it reaches to, or even beyond, this 
point. 

o. The size of the teeth, those of the 


intermaxillaries excepted. 


4. The arrangement, and the per- 
manence or deciduousness of the vomer- 


ine teecth.—In some species the vomer 


is normally armed with a double or 


single series throughout life, although, 


Fig. 289.—Vomerine teeth of course, some of the teeth are fre- 
of Salmo salar (Salmon), A. 


uently accic lost; 1 r 
Sideyiew. E Lowen Ga ently ace dentally lost; in others, 


these teeth disappear gradually with 
age, the hinder ones first, so that finally the anterior only 
remain. In order to ascertain the arrangement of the teeth, 
it is necessary to remove the gengiva. Frequently the teeth 
stand in a distinctly double or single series, or they are placed 
alternately; but frequent irreeularities occur which render 


SALMONIDA, 637 


the character vague, or even unsafe, so that some zoologists 
have rejected it entirely as unreliable. However, when a 


Fig. 290.—Vomerine teeth of Fig. 291.—Vomerine teeth of 

Salmo fario, lower view. a Charr, side view. 
greater number of individuals really belonging to the same 
species are examined, a pretty safe conclusion may be arrived 
at as regards the arrangement of the teeth. 

5. The form of the caudal fin in specimens of a given size, 
age, and sexual development. 

6. A great development of the pectoral fins, when constant 
in individuals from the same locality. 

7. The size of the scales, as indicated by the number of 
transverse rows above the lateral line: one of the most con- 
stant characters. 

8. The number of vertebre.—Considering the great number 
of vertebree in Salmonoids the constancy of this character is 
truly surprising. An excess or a diminution of the normal 
number by two, is of rare occurrence, and generally to be ex- 
plained by the fact that one vertebra has been abnormally 
divided into two, two such vertebre being considerably 
smaller than the others; or, on the other hand, that two have 
merged into one centrum, which is then unusually large, and 
provided with two neural spines. We have seen one case 
only, in which three vertebree were united. The number of 
vertebrae can be easily ascertained in specimens destined for 
preservation in spirits, by an incision made along one side of 
the fish, a little above the lateral line. 

9. The number of pyloric appendages——There can be no 
doubt that this character may materially assist in fixing a 
species. We shall see that in some species it varies from 30 
to 50; but in others, as in the Salmon and Charr, it has been 


638 FISHES. 


found very constant (see Fig. 56, p. 131). If unexpected 
variations occur, their cause may be found in a partial con- 
fluence of the czca, as we have observed that specimens of 
S. levenensis (a species normally with from 70 to 90 ceca), had 
those appendages of unusual width when the normal number 
was diminished. 


We have mentioned above that many points in the /ife- 
history of the Salmonoids still remain very obscure :— 

1. Johnson, a correspondent of Willughby (“ Hist. Pisc.,” 
p. 194), 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 (S. cambricus) and the River Trout (S. favo) 
were numerous in the Rhymney and other rivers of South 
Wales, before Salmonoids were almost exterminated by the 
pollutions allowed to pass into those 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 be- 
tween S. fario and S. trutta; hybrids between S. fario and 
species of Charr have been abundantly bred by continental 
pisciculturists. In some rivers the conditions appear to be 
more favourable to hybridism than in others, in which 
hybrids are of comparatively rare occurrence. Hybrids be- 
tween the Salmon and some other species are very scarce 
everywhere. The hybrids are sexually as much developed 
as the pure breed, but nothing whatever is known of their 
further propagation and progeny. 

2. Siebold has shown that some individuals of every 
species are not sexually developed, and that such individuals 
differ also externally from those normally developed. How- 


SALMONIDZ. 639 


ever, he appears to have gone too far when he stated that 
this state of sterility extends over the whole existence of such 
individuals, and that, therefore, the external peculiarities also 
remain permanent throughout life. According to Widegren 
this sterility is merely a temporary immaturity, and a part of 
the individuals arrive at a full sexual development at a later 
or much later period than others. To this we may add that 
many Salmonoids cease to propagate their species after a 
certain age, and that all so called overgrown individuals 
(that is, specimens much exceeding the usual size of the 
species) are barren. Externally they retain the normal 
specific characters. 

The Salmon offers a most remarkable instance of irregu- 
larity as regards the age at which the individuals arrive at 
maturity. Shaw has demonstrated, in the most conclusive 
manner, that those small Salmonoids, which are generally 
called Parr, are the offspring of the Salmon, and that many 
males, from 7 to 8 inches long, have their sexual organs fully 
developed, and that their milt has all the impreenating pro- 
perties of the seminal fluid of a much older and larger fish. 
That this Parr is not a distinct species—as has been again 
maintained by Couch—is further proved by the circumstance 
that these sexually mature Parr are absolutely identical in 
their zoological characters with the immature Parr, which are 
undoubtedly young Salmon, and that no Parr has ever been 
found with mature ova. But whether these Parr produce 
normal Salmon, impregnating the ova of female salmon, or 
mingle with the River-trout, or whether they continue to 
grow and propagate their species as fully developed Salmon, 
are questions which remain to be answered. We may only add 
that, as far as we know, barren old Salmon are extremely scarce. 

3. The question whether any of the migratory species 
can be retained by artificial means in fresh water, and finally 
accommodate themselves to a permanent sojourn therein, 


640 FISHES. 


must be negatived for the present. Several instances of suc- 
cessful experiments made for this purpose have been brought 
forward; but all these accounts are open to serious doubts, 
inasmuch as they do not afford us sufficient proof that the 
young fish introduced into ponds were really young migra- 
tory Salmonoids, or that the full-grown specimens were 
identical with those introduced, and not hybrids or non- 
migratory Trout of a somewhat altered appearance in conse- 
quence of the change of their locality. We have seen the 
experiment tried at two places in South Wales, and in both 
cases the Salmon and the pure Sewin died when not allowed 
to return to the sea. On the other hand, hybrid fishes from 
the Sewin and the Trout survived the experiment, and con- 
tinued to grow in a pond perfectly shut up from communica- 
tion with the sea. In that locality neither those hybrids nor 
the trout spawn. 

4, Although the majority of the mature individuals of a 
migratory species ascend a river at a certain fixed time before 
the commencement of spawning, others enter the fresh-water 
at a much earlier period, either singly or in small troops ; 
and many appear to return to the sea before they reascend 
at the time of the regular immigration. It is not improbable 
that one and the same individual may change the salt- or 
fresh-water several times in the year. However, this is the 
ease in certain rivers only, for instance, in those falling into 
the Moray Firth; in others one immigration only is known 
to occur. The cause of the irregular ascents previous to the 
autumnal ascents is unknown. A part, at least, of the hybrid 
fishes retain the migratory instinct; but it is not known 
whether sterile individuals accompany the others in their 
migrations. 

5. It is said that the migratory species invariably return 
to the river in which they are bred. Experiments have 
shown that this is normally the case; but a small proportion 


SALMONIDA, 641 


appear to stray so far away from their native place as to be 
unable to find their way back. Almost every year Salmon 
and Sea-trout in the Grilse-state make their appearance at 
the mouth of the Thames (where the migrating Salmonoids 
have become extinct for many years), ready to reascend and 
to restock this river as soon as its poisoned water shall be 
sufficiently purified to allow them a passage. 

6. There has been much dispute about the time required 
for the growth of Salmonoids. The numerous and apparently 
contradictory observations tend to show that there is a great 
amount of variation even among individuals of the same 
origin living under the same circumstances, some of them 
growing much more quickly than others, and being ready 
to descend to the sea twelve months before their brethren. 
The cause of this irregularity is not explained. On the other 
hand, when we consider the fibrous condition of the Sal- 
monoid skeleton, which is much less solid, and more want- 
ing in calcareous substance, than that of the majority of 
Teleosteous* fishes, we shall be quite prepared to adopt 
the truth of the observation that the young Salmonoids 
return to the fresh water, after a few months sojourn in 
the sea, and after having feasted on nourishing Crustaceans, 
Sand-eels, etc., with their former weight in ounces increased 
to pounds. 

7. Liability to variation in form indicates that an animal 
can adapt itself to a variety of circumstances ; therefore, such 
species as show the greatest pliability in this respect, are 
those which most recommend themselves for domestication 
and acclimatisation within certain climatic limits. Thus, the 
River-trout or Sea-trout were very proper subjects for those 
eminently successful attempts to establish them in similar 
latitudes of the Southern Hemisphere, whilst the attempt of 
transferring them into the low hill-streams of India ended (as 
could be foreseen) in a total failure. Those two species must 

27 


642 FISHES. 


now be considered to be fully acclimatised in Tasmania and 
New Zealand, and with but little protection may be expected 
to hold their own in the freshwaters of those colonies. Whe- 
ther the acclinatisation of the Salmon will be in the end 
equally and permanently successful, remains to be seen. The 
true S. salar is not subject to variation, and is very sensitive 
to any change of external conditions, and to every kind of 
interference with its economy. The fourth species, with 
which attempts of acclimatisation in Southern Australia have 
been made, is a migratory Salmon from the Sacramento river 
in California. This experiment is still im progress, and be- 
heved to be promising of success. It will be a most curious 
problem to ascertain, how much the original characters and 
habits of those species will be affected by their transference 
to so distant a part of the globe. At present it would be too 
hazardous to offer an opinion on this point, especially as it is 
a fact that numerous ecross-breeds have been introduced into, 
and reared in, Tasmania, which must more or less interfere 
with the characters of the pure breeds. 

It is apparent, from the foregoing remarks, that the dis- 
tinction of the various species of Salmonide is a matter of 
considerable difficulty, and that there is scope for great 
diversity of opinion. At any rate it is only by a close, long- 
continued study, and constant comparison of specimens of 
various ages and from various localities, that one is enabled 
to find a guide through the labyrinth of confusing variations. 
However, it is a significant fact that the very same characters 
by which we are enabled to distinguish European species 
occur again, though in an exaggerated form, in American 
Salmonoids (which everybody will admit to be of distinct 
species), and therefore our faith in them necessarily becomes 
strengthened. In accordance with acknowledged principles 
in zoology, forms which differ from their congeners by a com- 
bination of two or more of constant characters, are to be 


SALMONIDA, 643 


distinguished under distinct specific names. Most likely they 
have been derived, at a not very remote period, from common 
ancestors, but the question of their specific distinctness is no 
more affected by this consideration than the question whether 
Salmo and Coregonus are distinct genera. Whenever the 
zoologist observes two forms distinguished by peculiarities of 
organisation, such as cannot be conceived to be the effects of 
an external or internal cause, disappearing with the disap- 
pearance of that cause, and which forms have been propagated 
and are being propagated uniformly through all the genera- 
tions within the limits of our observations, and are yet most 
probably to be propagated during the existence of mankind, 
he is obliged to describe these forms as distinct, and they will 
commonly be called species. 

The species of the genus Salo are inhabitants of the 
temperate and arctic zones of the Northern Hemisphere ; the 
species are most abundant in the northern parts of the tem- 
perate zone, becoming scarcer beyond the Arctic circle, and 
in the warmer parts towards the south. The southernmost 
points in which Salmones are found, are, on the American 
continent, the rivers falling into the head of the Californian 
Gulf, and in the Old World the mountain rivers of the Atlas 
and Hindu Kush. The Salmones from those localities 
are migratory Trout in the New World, non-migratory and 
small in the Old. Those species which range to the highest 
latitudes (lat. 82°) belong to the division of Charr, a group 
which generally are more intolerant of a moderate temperature, 
than real Trout. The genus is subdivided into 


a. Salmones—Salmon and Trout—with teeth on the body of 
the vomer as well as its head (see Figs. 289 and 290), 

b. Salvelini—Charr—with teeth on the head of the vomer 
only (see Fig. 291). 


Of the host of species (the majority of which is unfortu- 


644. FISHES. 


nately very insufficiently characterised) we enumerate the 


following :—? 


a. SALMONES. 


1. 8. salar (Salmon ; Lachs or Salm ; Saumon) (Fig. 6, p. 43). 
The Salmon can generally be readily recognised, but there are 
instances in which the identification of specimens is doubtful, and 
in which the following characters (besides others) will be of great 
assistance. The tail is covered with relatively large scales, there 
being constantly eleven, or sometimes twelve in a transverse series 
running from behind the adipose fin forwards to the lateral line, 
whilst there are from thirteen to fifteen in the different kinds of 
Sea-trout and River-trout. The number of pyloric appendages 
(see Fig. 56, p. 131) is great, generally between 60 and 70, more 
rarely falling to 53 or rising to 77. The body of the vomer 
is armed with a single series of small teeth, which at an early 
age are gradually lost from behind towards the front, so that 
half-grown and old individuals have only a few (1-4) left. 
The Salmon inhabits temperate Europe southwards to 43° 
N. lat., and is not found in any of the rivers falling into the 
Mediterranean. In the New World its southern boundary is 
41° N. lat. 

2. S. trutta (Sea-trout, Salmon-trout).’—Especially numerous 
in North Britain. 

3. S. cambricus (Sewin).—Wales, South of England, Ireland, 
Norway, and Denmark. 

. S. fario (Common River-trout). 
. S. macrostigma (Algeria). 
. S. lemanus (Lake of Geneva). 
. 8. brachypoma—A migratory species from the rivers Forth, 
Tweed, and Ouse. 
8. S. gallivensis (Galway Sea-trout). 


ie 


“I op Ot 


1 For specific characters and detailed descriptions we refer to Giinther, 
‘Catal. of Fishes,” vol. vi. 

2 The names ‘‘ Bull-trout” and ‘‘Peal” are not attributable to definite 
species. We have examined specimens of S. salar, S. trutta, and S. cambricus 
and S. fario, to which the name ‘‘ Bull-trout” had been given ; and that of 
‘*Peal” is given indiscriminately to Salmon-grilse and to S. cambricus. 


SALMONIDA. 645 


9. 8. orcadensis.—A. non-migratory trout from Lough Stennis, 
in the Orkney Islands. 

10. S. ferov.—The great Lake-trout of North Britain, Wales, 
and Ireland. 

11. S. stomachicus (the Gillaroo of Ireland). 

12. S. nigripinnis from mountain-pools of Wales. 

13. S. levenensis (Lochleven Trout). 

14. S. oxi from the rivers of the Hindu Kush. 

15. S. purpuratus from the Pacific coast of Asia and North 
America. 

16. S. macrostoma.—Japan. 

17. S. namaycush.—The great Lake-trout of North America. 


O 


: rie 


>. SF 


DILL 


Fig. 292.—Salmo brachypoma, 


b, SALVELINI: Charr. 


1. S. umbla.—The “ Ombre chevalier” of the Swiss lakes. 

2. S. salvelinus— The “Selbling” of the Alpine lakes of 
Bavaria and Austria. 

3. S. alpinus.—The common Northern Charr, growing to a 
length of four feet, and migratory. 

4, S. killinensis—The Loch Killin Charr, Inverness-shire. 

5, S. willughbii.—The Loch Windermere Charr. 

6. S. perisiiThe “ Torgoch” of Wales. 

7. S. grayii—The “Freshwater Herring” of Lough Melvin, 
Treland. 


646 FISHES. 


8. S. colii—Charr of Loughs Eske and Dan. 

9. 8. hucho.—The “ Huchen” of the Danube, growing to the 
size of the Salmon. 

10. JS. alipes from lakes in Boothia Felix and Greenland. 

11. S. arcturus—The most northern species from 82° lat. 

12. S. fontinalis—The common “Brook - trout” of the 
United States. 

13. S. oquassa—A lake species from the State of Maine. 


Oncorhynchus differs from Salmo only in the increased 
number of anal rays, which are more than fourteen. All the 
species are migratory, ascending American and Asiatic rivers 
flowing into the Pacific. The Californian Salmon (0. guinnat ?) 
belongs to this genus. 

Other allied genera are Brachymystax and Luciotrutta. 

PLEcoGLOssus.—Body covered with very small scales. Cleft 
of the mouth wide; maxillary long. Dentition feeble ; inter- 
maxillaries with a few small, conical, pointed teeth; the teeth 
of the maxillaries and mandibles are broad, truncated, lamellated 
and ‘serrated, movable, seated in a fold of the skin. The man- 
dibles terminate each in a small knob, and are not jointed at the 
symphysis. The mucous membrane in the interior of the mouth 
—between the terminal halves of the mandibles—forms a pecu- 
liar organ, being raised into folds, with a pair of pouches in front 
and a single one behind. Tongue very small, with minute teeth, 
its apical part being toothless ; palate apparently without teeth. 

A small aberrant form of Freshwater-Salmonoids abund- 
antly found in Japan and the Island of Formosa. 


OsMERUS.—Body covered with scales of moderate size. Cleft 
of the mouth wide ; maxillary long, extending to, or nearly to, 
the hind margin of the orbit. Dentition strong ; intermaxillary 
and maxillary teeth small, much smaller than those of the man- 
dible. Vomer with a transverse series of teeth, several of which 
are large, fang-like ; a series of conical teeth along the palatine 
and pterygoid bones. Tongue with very strong fang-like teeth 
anteriorly, and with several longitudinal series of smaller ones 
posteriorly. Pectoral fins moderately developed. Pyloric ap- 
pendages very short, in small number ; ova small. 


SALMONIDA, 647 


The “Smelt ” (0. eperlanus) is common on many places of 
the coasts of Northern Europe and America. In the sea it 
grows to a leneth of eight inches ; but, singularly, it frequently 
migrates from the sea into rivers and lakes, where its growth 
is very much retarded. That this habit is one of very old 
date, is evident from the fact that this small freshwater form 
occurs, and is fully acclimatised, in lakes which have now no 
open communication with the sea. And still more singularly, 
this same habit, with the same result, has been observed in 
the Smelt of New Zealand (Retropinna richardsonii). The 
Smelt is considered a delicacy in Europe, as well as in 
America, where the same species occurs. ‘Two other allied 
genera, Hypomesus and Thaleichthys, are found on the Pacific 
coast of North America, the latter being caught in immense 
numbers,and known bythe name“ Eulachon” and “Oulachan ;” 
it is so fat, that it is equally used as food and as candle. 


Ma.iotus.—Body covered with minute scales, which are 
somewhat larger along the lateral line and along each side of the 
belly ; in mature males these scales become elongate, lanceolate, 
densely tiled, with free projecting points, forming villous bands. 
Cleft of the mouth wide; maxillary very thin, lamelliform, ex- 
tending to below the middle of the eye. Lower jaw the longer, 
partly received between the maxillaries. Dentition very feeble ; 
the teeth forming single series ; only the teeth on the tongue are 
somewhat larger and disposed in an elliptical patch. Pectoral 
fins large, horizontal, with broad base. Pyloric appendages very 
short, in small number; ova small. 

The “ Capelin” (JZ. villosus) is found on the Arctic coasts 
of America and of Kamtschatka. It is caught in immense 
numbers by the natives, who consume it fresh, or dry it for 
use in the winter. Its length does not exceed nine inches. 


CorEGONUS.—Body covered with scales of moderate size. 
Cleft of the mouth small; maxillary broad, short or of moderate 
length, not extending behind the orbit. Teeth, if present, 


648 _ FISHES. 


extremely minute and deciduous. Dorsal fin of moderate length ; 


caudal deeply forked. Ova small. 


NAY a. Mt Wey 
bak Be , me 


Fig. 293.—Coregonus oxyrhynchus. 


The majority of the species, of which more than forty are 
known, are lacustrine species; and comparatively few are 


Fig. 294.—Head of Coregonus oxyrhynchus. 


subject to periodical migrations to the sea, like Salmo. They 
are confined to the northern parts of temperate Europe, Asia, 
and North America. Their distribution is local, but some- 
times three and more species are found in the same lake. 
They abound in every lake and river of the northern parts of 
North America, and are known by the name of “ White-fish.” 


ra 


SALMONIDA. 649 


They are of vital importance to some tribes of the native 
population, The European C. oxyrhynchus is as much a 
marine as a freshwater species. In the British Islands 
several small species occur, viz. C. elupeoides, the “ Gwyniad,” 


Fig. 295.—Coregonus clupeoides. 


“Schelly,” or “Powen” from the great lakes; C. vandesius, 
the “ Vendace” of Lochmaben; and C. pollan, the “ Pollan” 
of the Ivish lakes. The latter is brought in quantities to 
Belfast market during the season, that is, at the time when 
it rises from the depths of Lough Neagh to deposit its spawn 
near the shore. Thomson says that in September 1834 some 
17,000 were taken there at three or four draughts of the net. 
Some of the species of the continent of Europe and America 
attain to a much larger size than the British species, viz. to 
a length of two feet. 


THYMALLUS.—Principally distinguished from Coregonus by 
its long many-rayed dorsal fin. 

“ Graylings ”—five species, inhabiting clear streams of the 
north of Europe, Asia, and North America. The best known 


650 FISHES. 


are the “ Poisson bleu” of the Canadian voyageurs (Zh. sig- 
nifer), and the European Grayling (7. vulgaris). 


SALANX.—Body elongate, compressed, naked or covered with 
small, exceedingly fine, deciduous scales. Head elongate and 
much depressed, terminating in a long, flat, pointed snout. Eye 
small. Cleft of the mouth wide ; jaws and palatine bones with 
conical teeth, some of the intermaxillaries and mandibles being 
enlarged ; no teeth on the vomer; tongue with a single series 
of curved teeth. Dorsal fin placed far behind the ventrals, but 
in front of the anal; anal long ; adipose fin small ; caudal forked. 
Pseudobranchiz well developed ; air-bladder none. The entire 
alimentary canal straight, without bend; pyloric appendages 
none. Ova small. 

This small, transparent, or whitish fish GS. chinensis) is well 
known at Canton and other places of the coast of China as 
“ Whitebait,” and considered a delicacy. It is evidently a fish 
which lives at a considerable depth in the sea, and approaches 
the coast only at certain seasons. 


Finally, this family is represented in the deep sea by three 
genera, Argentina, Microstoma, and Bathylagus, of which the 
two former live at moderate depths, and have been known for 
a long time, whilst the last was discovered during the “ Chal- 
lenger” expedition in the Atlantic and Antarctic Oceans at 
depths of 1950 and 2040 fathoms. As Argentina is sometimes 
found in the North Atlantic, and even near the British coasts, 
we give its principal characters. 

ARGENTINA.—NScales rather large ; cleft of the mouth small; 
intermaxillaries and maxillaries very short, not extending to 
below the orbit. Eye large. Jaws without teeth; an arched 
series of minute teeth across the head of the vomer and on the 
fore part of the palatines; tongue armed with a series of small 
curved teeth on each side. Dorsal fin short, in advance of the 
ventrals ; caudal deeply forked. Pseudobranchiz well developed. 
Pyloric appendages in moderate numbers. Ova small. 


Four species are known, of which 4. silus and A. hebridica 


HAPLOCHITONIDA, 651 


have been found occasionally on the North British, and, more 
frequently, on the Norwegian coast. The other species are 
from the Mediterranean. Attaining to a length of 18 inches. 


SIXTEENTH FAMILY—PERCOPSIDA. 


Body covered with ctenoid scales ; head naked. Margin of 
the upper yaw formed by the intermaxillaries only ; opercular 
apparatus complete.  Barbels none. Gill - openings wide. 
Adipose fin present. 

One genus and species only (Percopsis guttatus) ; interest- 
ing as having the general characters of Salmonoids, but the 
mouth and scales of a Percoid. Freshwaters of the northern 
United States. 


SEVENTEENTH FAMILY—HAPLOCHITONID. 


Body naked or scaly (eycloid). Margin of the upper jaw 
Jormed by the intermaxillary ; opercular apparatus complete. 
Barbels none. Gul - opening wide; pseudobranchie.  Atr- 
bladder simple. Adipose fin present. Ovaries laminated ; the 
eggs fall into the cavity of the abdomen, there being no oviduct. 
Pyloric appendages none. 

Freshwater-fishes which represent the Salmonoids in the 


Fig. 296.—Prototroctes oxyrhynchus, New Zealand. 


southern hemisphere. Two genera only are known, Hap- 
lochiton (Fig. 104, p. 250) abundant in lakes and the streams 


652 FISHES. 


falling into the Straits of Magelhen and in the rivers of Chile 
and the Falkland Islands, It has the general appearance of a 
Trout, but is naked. Prototroctes, with the habit of a Core- 
gonus, scaly, and provided with minute teeth ; one species (P. 
marena) is common in South Australia, the other (P. ory- 
rhynchus) in New Zealand. The settlers in these colonies call 
them Grayling; the Maori name of the second species is 
“ Upokororo.” 


EIGHTEENTH FAMILY—GONORHYNCHID. 


Head and body entirely covered with spiny scales ; mouth 
with barbels, Margin of the wpper jaw formed by the inter- 
maxillary, which, although short, is continued downwards asa 
thick lip, situated in front of the maxillary. Adipose fin none ; 
the dorsal fin is opposite to the ventrals, and short, like the anal. 
Stomach simple, without blind sac; pyloric appendages in small 
number, Pseudobranchice ; air-bladder absent. Gill-openings 
NATTOW. 


Fig. 298.—Scale of Gonorhynchus greyi. 


One genus and species only (Gonorhynchus greyi) is known ; 
it is a semi-pelagic fish, not very rare off the Cape of Good Hope, 
and in the Australian and Japanese seas. From 12 to 18 inches 


OSTEOGLOSSID A. 653 


long. The colonists in New Zealand name it “ Sand-eel,” as it 
frequents bays with sandy bottom. It is eaten. 


NINETEENTH FAMILY—HYODONTIDA. 


Body covered with cycloid scales ; head naked ; barbels none. 
Margin of the wpper jaw formed by the intermaxillaries mesially, 
and by the maxillaries laterally, the latter being articulated to 
the end of the former. Opercular apparatus complete. Adipose 
jin none ; the dorsal fin belongs to the caudal portion of the 
vertebral column. Stomach horseshoe-shaped, without blind 
sac ; intestine short ; one pyloric appendage. Pseudobranchice 
none ; air-bladder simple. Gill-openings wide. The ova fall 
into the abdominal cavity before exclusion. 

One genus and species only (Hyodon tergisus) is known, 
generally called “Moon-eye.” It is abundant in the western 
streams and great lakes of North America. From 12 to 18 
inches long. 


TWENTIETH FAMILY—PANTODONTIDA. 


Body covered with large cycloid scales; sides of the head 
osseous. Margin of the upper yaw formed by the single inter- 
maxillary mesially, and by the maxillaries laterally. The 
dorsal fin belongs to the caudal portion of the vertebral column, 
is short, opposite and similar to the anal. Gull-openings wide ; 
gill-covers consisting of a preoperculum and operculum only. 
Branchiostegals numerous. Pseudobranchie none ; air-bladder 
simple. Stomach without coecal sac; one pyloric appendage. 
Sexual organs with a duct. 

A small freshwater-fish (Pantodon buchholzi), singularly 
alike to a Cyprinodont, from the west coast of Africa. 


TWENTY-First FAMILY—OSTEOGLOSSIDA. 


Body covered with large hard scales, composed of preces like 


654 FISHES. 


mosaic. Head scaleless ; its integuments nearly entirely replaced 
by bone ; lateral line composed of wide openings of the mucus- 
duct. Margin of the upper jaw formed by the intermaxillaries 
mesially, and by the mazillaries laterally. The dorsal fin 
belongs to the caudal portion of the vertebral column, 1s opposite 
and very similar to the anal fin; both approximate to the 
rounded caudal (with which they are abnormally confluent). 
Gill-openings wide ; pseudobranchie none ; air-bladder simple 
or cellular. Stomach without coecal sac; pyloric appendages 
two. 

Large freshwater-fishes of the tropics, whose singular 
geographical distribution has been noticed above (p. 223). 

OsTEOGLOSSUM.—Cleft of the mouth very wide, oblique, with 
the lower jaw prominent. A pair of barbels at the lower jaw. 
Abdomen trenchant. Bands of rasp-like teeth on the vomer, 


palatine and pterygoid bones, on the tongue and hyoid, Pectoral 
fins elongate. 

O. bicirrhosum from Brazil and Guyana, O. formosuwm from 
Borneo and Sumatra, O. leichardti from Queensland. 

ARAPAIMA.—Cleft of the mouth wide, with the lower jaw 
prominent; barbels none. Abdomen rounded. Jaws with an 
outer series of small conical teeth ; broad bands of rasp-like teeth 
on the vomer, palatines, pterygoids, sphenoid, os linguale, and 
hyoid. Pectoral fins of moderate length. 


« RCC uy 
a ( 
COX ate 

Srelolees 


ue cae raat 


¥ Ma 
ue 
CRY 


MG i { ( 
a i 
a a 


ine RA 
ut ( y) 
ae 


és 


aos : : 
Fig. 299.—Arapaima gigas. 


The largest freshwater Teleostean known, exceeding a 
leneth of 15 feet and a weight of 400 pounds. It is common 
in the large rivers of Brazil and the Guyanas, and esteemed as 
an article of food. When salted it is exported in large 
quantities from the inland fisheries to the seaports. 


HERRINGS. 655 


HETEROTIS.—Cleft of the mouth rather small, with the jaws 
subequal ; barbels none. A single series of small teeth in the 
jaws ; pterygoids and hyoid with a patch of small conical teeth ; 
none on the vomer or palatines. 


This fish (H. niloticus), which is not uncommon in the 
Upper Nile and the West African rivers, exhibits several 
anatomical peculiarities. The fourth branchial arch supports 
a spiral accessory organ, the function of which is still 
unexplained. The air-bladder is cellular, and the stomach 
consists of a membranous and a muscular portion. 


TWENTY-SECOND FAMILY—CLUPEIDZ. 


Body covered with scales; head naked; barbels none, 
Abdomen frequently compressed into a serrated edge. Margin 
of the upper jaw formed by the intermaxillaries mesially, and 
by the maxillaries laterally ; maxillaries composed of at least 
three movable yieces. Opercular apparatus complete. Adipose 
fin none. Dorsal not elongate; anal sometimes very long. 
Stomach with a blind sac ; pyloric appendages numerous.  Gull- 
apparatus much developed, the gill-openings being generally very 
wide. Pseudobranchie generally present. Atr-bladder more 
or less simple. 

The family of “ Herrings” is probably unsurpassed by any 
other in the number of individuals, although others comprise 
a much greater variety of species. The Herrings are princi- 
pally coast-fishes, or, at least, do not go far from the 
shore; none belong to the deep-sea fauna; scarcely any 
have pelagic habits, but many enter or lve in fresh waters 
communicating with the sea. They are spread over all the 
temperate and tropical zones. Fossil remains of Herrings are 
numerous, but the pertinence of some of the genera to this 
family is open to serious doubts, as the remains are too 
fragmentary to allow of determining whether they belong to 
Salmonoids or Clupeoids. Therefore, Agassiz comprised both 


656 FISHES. 


families in one—Halecide. Many of the remains belong to 
recent genera, which are readily recognised, as Clupea, 
Engraulis and Chanos, principally from the schists of Glaris 
and Licata, from Monte Bolea and the Lebanon. Others, like 
Thrissopater, from the Gault at Folkestone, Leptosomus, 
Opisthopteryx, Spaniodon, from the chalk and tertiary forma- 
tions, can be readily associated with recent genera. But the 
majority do not show an apparent affinity to the present fauna. 
Thus, Halee from the chalk of Bohemia, Platinz and Coelogaster 
from Monte Boleca, Rhinellus from Monte Bolca and Mount 
Lebanon, Scombroclupea, with finlets behind the anal, from 
the Lebanon and Comen, and Crossognathus from tertiary Swiss 
formations, allied to Megalops, Spathodactylus from the same 
locality, and Chirocentrites from Mount Lebanon, ete. Finally, 
a genus recently discovered in tertiary formations of Northern 
Italy, Hemitrichas, has been classed with the Clupeoids, from 
which, however, it differs by having two short dorsal fins, so 
that it must be considered, without doubt, to be the represent- 
ative of a distinct family. 


ENGRAULIS (including CETENGRAULIS).—Scales large or of 
moderate size. Snout more or less conical, projecting beyond 
the lower jaw. Teeth small or rudimentary. Intermaxillaries 
very small, hidden ; maxillary long, attached to the cheek by a 
scarcely distensible membrane. Anal fin of moderate or great 
length. Branchiostegals short, from nine to fourteen in number, 


Not less than forty-three different species of “ Anchovies” 
are known from temperate and tropical seas. They exhibit 
marked differences in the length of their maxillary bone, 
which sometimes does not reach the gill-opening, whilst in 
other species it extends far beyond it ; and in the number of 
their anal rays, which varies from 20 to 80. Some have the 
upper pectoral ray prolonged into a filament, thus leading 
towards the succeeding genus, Coilia. The majority are 
recognised, besides, by their peculiar structure, by a broad 


HERRINGS. 657 


silvery, lateral band, similar to that observed in the Atherines. 
The most celebrated Anchovy is £. encrasicholus, very plentiful 
in the Mediterranean, but rarely wandering northwards. It 
is the species which, preserved in salt, is exported to all parts 
of the world, although similarly lucrative fisheries of Anchovies 
might be established in Tasmania where the same species 
occurs, in Chile, China, Japan, California, at Buenos Ayres, 
each of which countries possesses Anchovies by no means 
inferior to the Mediterranean species. 


CorLtA.—Body terminating in a long tapering tail. Scales of 
moderate size. Snout and jaws as in Engraulis, Anal fin 
exceedingly long, confluent with the caudal. The two or three 


Vd tidy yy 


Fig. 300.—Coilia clupeoides. 


upper pectoral rays are much prolonged, and their branches form 
four, six, or seven filaments, 


Ten species from Indian and Chinese seas. 


CHATOESSUS.—Body compressed ; abdomen serrated. Scales 
of moderate size. Snout obtuse, or obtusely conical, more or less 
projecting beyond the cleft of the mouth, which is narrow, more 
or less transverse. Maxillary joined to the ethmoid, its upper 
portion being behind the intermaxillary. Teeth none. Anal fin 
rather long ; dorsal opposite to the ventrals, or to the space 
between ventrals and anal. Gill-membranes entirely separate ; 
branchial arches forming two angles, one pointing forward and 
the other backwards ; the fourth branchial arch with an accessory 
organ; branchiostegals of moderate length, five or six in number, 


Ten species from the coasts, brackish and fresh waters of 
2U 


658 FISHES. 


Central America (one species ranges to New York), Australia, 
the East Indies, and Japan. 


CLUPEA.—Body compressed, with the abdomen serrated, the 
serrature extending forwards to the thorax. Scales of moderate 
or large, rarely of small size. Upper jaw not projecting beyond 
the lower. Cleft of the mouth of moderate width. Teeth, if 
present, rudimentary and deciduous. Anal fin of moderate 
extent, with less than thirty rays; dorsal fin opposite to the 
ventrals. Caudal forked. 

This genus comprises more than sixty different species, 
the geographical distribution of which coincides with that of 
the family. The majority are of greater or less utility to man, 
but a few tropical species (C. thrissa, C. venenosa, and others) 
acquire, probably from their food, highly poisonous properties, 
so as to endanger the life of persons eating them. The most 
noteworthy species are— 

1. C. harengus (the “ Herring”’).—It is readily recognised by 
having an ovate patch of very small teeth on the vomer. D. 
17-20. A.16-18. L. lat. 53-59. Vert.56. Guill-cover smooth, 
without radiating ridges. It inhabits, in incredible numbers, 
the German Ocean, the northern parts of the Atlantic, and the 
seas north of Asia. The Herring of the Atlantic coasts of 
North America is identical with that of Europe. A second 
species has been supposed to exist on the British coast (C 
leachiz), but it comprises only individuals of a smaller size, 
the produce of an early or late spawn. Also the so-called 
“Whitebait ” is not a distinct species, but consists chiefly of 
the fry or the young of herrings, and is obtained “in perfection” 
at localities where these small fishes find an abundance of 
food, as in the estuary of the Thames. 


[Separate accounts on the Herring may be found in Cuvier and Valen- 
ciennes, ‘“‘ Hist. nat. des Poissons,” vol. xx.; J. M. Mitchell, ‘* The 
Herring, its Natural History and National Importance,” Edinb. 
1864, S8vo; P. Neucrantz, ‘‘ De Harengo,” Liibeck, 1654; J. S. 
Dodd, ‘‘ Essay towards a Natural History of the Herring,” Lond. 
1768, 8vo; Bock, “ Versuch einer vollstandigen Natur-und Handels- 
Geschichte des Herings,” Konigsberg, 1769, S8vo.] 


HERRINGS. 659 


2. C. mirabilis——The Herring of the North Pacific. 

3. C. sprattus—The “ Sprat.” Without vomerine teeth. D. 
15-18. A. 17-20. L. lat. 47-48. Vert. 47-49. Gill-cover. 
smooth, without radiating ridges. Abundant on the Atlantic 
coasts of Europe. 

4. (. thrissa.—One of the most common West Indian fishes, 
distinguished by the last dorsal ray being prolonged into a 
filament. Hyrtl has discovered a small accessory branchial 
organ in this species. 

5. C. alosa.—The “Shad ” or “ Allice Shad,” with very fine 
and long gill-rakers, from 60 to 80 on the horizontal part of the 
outer branchial arch, and with one or more black lateral 
blotches. Coasts of Europe, ascending rivers. 

6. C. finta—The “Shad” or “Twaite Shad,” with stout 
osseous gill-rakers, from 21 to 27 on the horizontal part of the 
outer branchial arch, and spotted like the preceding species. 
Coasts of Europe, ascending rivers, and found in abundance 
in the Nile. 

7. CO. menhaden.—The “ Mossbanker,” common on the At- 
lantic coasts of the United States. The economic value of this 
fish is surpassed in America only by that of the Gadoids, and 
derived chiefly from its use as bait for other fishes, and from 
the oil extracted from it, the annual yield of the latter exceed- 
ing that of the whale (from American Fisheries). The refuse 
of the oil factories supplies a material of much value for 
artificial manures. 


[See G. Brown Goode, ‘‘The Natural and Economical History of the 
American Menhaden,” in U.S. Commission of Fish and Fisheries, 
Part V., Washington, 1879, 8vo. ] 

8. C. sapidissima—The American Shad, abundant, and an 
important food-fish on the Atlantic coasts of North America. 
Spawns in fresh water. 

9. C. mattowocca.—The “Gaspereau” or “ Ale-wife,” com- 
mon on the Atlantic coasts of North America, ascending into 


660 FISHES. 


freshwater in early spring, and spawning in ponds and 
lakes. 

10. C. pilchardus.—The “ Pilchard” or the “Sardine,” equally 
abundant in the British Channel, on the coast of Portugal, 
and in the Mediterranean, and readily recognised by radiat- 
ing ridges on the operculum, descending towards the sub- 
operculum. 

11. CO. sagax.—Representing the Pilchard in the Pacific, 
and found in equally large shoals on the coasts of California, 
Chile, New Zealand, and Japan. 

12. C. toli.—The subject of a very extensive fishery 
on the coast of Sumatra for the sake of its roes, which are 
salted and exported to China, the dried fish themselves 
being sent into the interior of the island. The fish is called 
“Trubu” by the Malays, about 18 inches long, and it is 
said that between fourteen and fifteen millions are caught 
annually. 

13. C. scombrina.—The “Oil-Sardine” of the eastern coast of 
the Indian Peninsula. 


Other, but less important genera of Clupeoids with ser- 
rated abdomen, are Clupeoides, Pellonula, Clupeichthys, Pellona, 
Pristigaster, and Chirocentrodon (these three last with very 
small or without any ventral fins). 


ALBuULA.—Body oblong, moderately compressed ; abdomen 
flat. Scales of moderate size, adherent; lateral line distinct. 
Eyes covered with a broad annular adipose membrane. Snout 
pointed, the upper jaw projecting beyond the lower. Mouth 
inferior, of moderate width, with villiform teeth ; intermaxillary 
juxtaposed to the upper anterior edge of the maxillary. Dorsal 
fin opposite to the ventrals ; anal fin shorter than dorsal. Gill- 
membranes entirely separate, with numerous branchiostegals. 

One species only (A. conorhynchus), ranging over all tro- 
pical and sub-tropical seas, and very common in many locali- 


HERRINGS, 661 


ties near the coasts. It grows toa length of from two to 
three feet, and is not valued as food. 


Exops. — Body rather elongate, moderately compressed ; 
abdomen flat. Scales small, adherent; lateral line distinct. A 
narrow osseous lamella, attached to the mandibulary symphysis, 
covers the part between the mandibles. Snout pointed ; mouth 
wide, anterior ; intermaxillary short, maxillary forming the lateral 
part of the mouth. Bands of villiform teeth in the jaws, on the 
vomer, palatine and pterygoid bones, on the tongue, and on the 
base of the skull. Dorsal fin opposite to ventrals ; anal rather 
shorter than dorsal. Gill-membranes entirely separate, with 
very numerous branchiostegals. 


Two species, of which one, Z. sawrus, is, like the preced- 


Fig. 301.—Elops saurus. 


ing fish, spread over all tropical and sub-tropical seas ; it 
exceeds a length of three feet, and is not esteemed as food. 


MecALops.—Body oblong, compressed, abdomen flat. Scales 
large, adherent ; lateral line distinct. A narrow osseous lamella, 
attached to the mandibulary symphysis, between the mandibles. 
Snout obtusely conical ; mouth anterior, lower jaw prominent ; 
intermaxillary short ; maxillary forming the lateral part of the 
mouth. Bands of villiform teeth in the jaws, on the vomer, 
palatine and pterygoid bones, on the tongue and on the base of 
the skull. Dorsal fin opposite to, or immediately behind, the 
ventrals; anal rather larger than dorsal. Gill-membranes en- 
tirely separate, with numerous branchiostegals. Pseudobranchiz 
none. 

Two species, one belonging to the Indo-Pacific (1. eypri- 
noides), the other to the Atlantic (IZ thrissoides) ; they are 
the largest fishes of this family, exceeding a length of five 


662 FISHES. 


feet, and excellent eating. Young specimens enter freely 
fresh waters. 


CHANOS.—Body oblong, compressed ; abdomen-flat. Scales 
small, striated, adherent ; lateral line distinct. Snout depressed ; 
mouth small, anterior, transverse, the lower jaw with a small 
symphysial tubercle. Intermaxillary in juxtaposition to the 
upper anterior edge of maxillary. Teeth none. Dorsal fin 
opposite to the ventrals ; anal small, shorter than dorsal ; caudal 
deeply forked. Gill-membranes entirely united below, and free 
from the isthmus. Branchiostegals four, long. An accessory 
branchial organ in a cavity behind the gill-cavity proper. Air- 
bladder divided by a constriction into an anterior and posterior 
portion. Mucous membrane of the cesophagus raised in a spiral 
fold. Intestine with many convolutions. 

Two species from the Indo-Pacific, of which Ch. salmoneus 
is extremely common; it enters fresh waters, and exceeds a 
leneth of four feet ; its flesh is highly esteemed. The acces- 


Fig. 302.—Chanos salmoneus. 


sory branchial organ and the skeleton have been described by 
Muller, “Bau und Grenzen der Ganoiden,” p. 75 ; and by Hyrtl, 
“ Denksehr. Ak. Wiss. Wien.” xxi. 1883, p. 1. 


The remaining genera belonging to this family are Spra- 
telloides, Dussumieria, and Htrumeus, which together form a 
small group, distinguished by an anterior and lateral mouth, 
by the upper jaw not overlapping the lower, by a rounded 
abdomen, and by lacking the gular plate of some of the pre- 
ceding genera. 


CHIROCENTRIDA. 663 


TWENTY-THIRD FAMILY—BATHYTHRISSID2. 


Body oblong, with rounded abdomen, covered with cycloid 
scales; head naked ; barbels none. Margin of the wpper jaw 
Jormed by the intermaaillaries mesially, and by the maxillaries 
laterally. Opercular apparatus complete. Adipose fin none ; 
dorsal fin much elongate, many rayed ; anal fin short. 
Stomach with a blind sac ; pyloric appendages numerous. Gull- 
apparatus well developed ; pseudobranchie ; gill-openings wide ; 
an air-bladder. Ova very small ; ovaries without duct. 

One genus and species only (Bathythrissa dorsalis) from 
deep water (350. fathoms) off the coast of Japan. This re- 
markable fish has the appearance of a Coregonus, and attains 
to a length of two feet. Nothing is known of its osteology, 
but possibly a fossil genus from the Gyps of Montmartre ; 
Notwus, which has also a long dorsal fin, may prove to belong 
to the same family. 


TWENTY-FouRTH FAMILY—CHIROCENTRID. 


Body covered with thin, deciduous scales; barbels none. 
Margin of the upper jaw formed by the intermaxillaries mesi- 
ally, and by the maxillaries laterally, both bones being firmly 
united, in juxtaposition. Opercular apparatus complete. Adi- 
pose fin none ; the dorsal fin belongs to the caudal portion of 
the vertebral column. Stomach with a blind sac; intestine 
short, the mucous membrane forming a spiral fold ; pylorie 
appendages none. Pseudobranchiw none; air-bladder imeom- 
pletely divided into cells ; gill-opening wide. 

One genus and species only (Chirocentrus dorab) is known, 
which is common in the Indian Ocean, and attains to a 
length of about three feet; it is not esteemed as food. 
Remains of fishes similar to Ohirocentrus are found in the 
marl slates of Padang, in Sumatra. 


664 FISHES. 


TWENTY-FIFTH FAMILY—ALEPOCEPHALID A. 


Body with or without scales; head naked ; barbels none. 
Margin of the upper jaw formed by the intermaxillaries and 
maxillaries, the former being placed along the wpper anterior 
edge of the latter. Opercular apparatus complete. Adipose 
jin none; the dorsal fin belongs to the caudal portion of the 
vertebral column. Stomach curved, without blind sae ; pyloric 
appendages in moderate number. Pseudobranchie ; air-bladder 
absent. Crill-openings very wide. 

Before the voyage of the “Challenger” one species only 
of this family was known, Alepocephalus rostratus, a rare fish 
from the Mediterranean; now, four genera with seven species 
are known, and there is no doubt that this family is one of 
the most characteristic, and will prove to be one of the most 
generally distributed forms, of the deep-sea. Their vertical 
range varies between 345 (Xenodermichthys) and 2150 (Bathy- 
troctes) fathoms. They approach the Salmonoids, but lack 
invariably the adipose fin. Their dentition is very feeble; 
their eye large; bones thin. Coloration black. 

ALEPOCEPHALUS has thin cycloid scales; a mouth of moderate 
width, and no teeth on the maxillary. 

BATHYTROCTES has cycloid scales, a wide mouth, and teeth 
on the maxillary as well as intermaxillary, 

PLATYTROCTES has small keeled scales and no ventrals. 

XENODERMICHTHYS with fine nodules instead of scales. 


TWENTY-SIXTH FAMILY—NOTOPTERIDA. 


Head and body scaly ; barbels none. Margin of the upper 
jaw formed by the intermaxillaries mesially, and by the 
macilaries laterally. Opercular apparatus incomplete. Taal 
prolonged, tapering. Adipose fin none. Dorsal short, belonging 
to the caudal portion of the vertebral column ; anal very long. 
Stomach without blind sac; two pyloric appendages. Pseudo- 


HOPLOPLEURIDA. 665 


branchiw none; air-bladder present, divided in the interior. 
The ova full into the cavity of the abdomen before exclusion. 
On each side a parieto-mastoid cavity leading into the interion 
of the skull. 

One genus only (Notopterus) with five species which 
inhabit fresh waters of the East Indies and West Africa. 
Well-preserved remains of this genus occur in the marl slates 
of Padang, in Sumatra. Their air-bladder is divided into 
several compartments, and terminates in two horns anteriorly 
and posteriorly, the anterior horns being in direct connection 
with the auditory organ. 


TWENTY-SEVENTH FAMILY—HALOSAURIDA. 


Body covered with cycloid scales; head scaly ; barbels none. 
Margin of the upper jaw formed by the intermaxillaries mesially, 
and by the maxillaries laterally. Opercular apparatus incom- 
plete. Adipose fin none. The short dorsal belongs to the 
abdominal part of the vertebral column; anal very long. 
Stomach with a blind sac ; intestine short; pyloric appendages 
in moderate number. Pseudobranchie none. Arr-bladder large, 
simple ; gill-openings wide. Ovaries closed. 

The only genus belonging to this family was discovered 
by the Madeiran ichthyologist Johnson, in 1865; but since 
then the naturalists of the “Challenger” expedition have 
added four other species, showing that this type is a deep-sea 
form and widely distributed; the specimens were dredged in 
depths varying from 560 to 2750 fathoms. 


TWENTY-EIGHTH FAMILY—HOPLOPLEURIDA. 


Body generally with four series of subtriangular scutes, and 
with intermediate scale-like smaller ones. One (?) dorsal only ; 
head long, with the gaws produced. 


666 FISHES. 


Extinct ; developed in the chalk and extending into 
tertiary formations: Dercetis (with the upper jaw longest), 
Leptotrachelus, Pelargorhynchus, Plinthophorus, Saurorhamphus 
(with the lower jaw longest), Hurypholis ; Ischyrocephalus (2). 
The latter genus, from cretaceous formations of Westphalia, 
is said to have two dorsal fins. 


TWENTY-NINTH FAMILY—GYMNOTID&. 


Head scaleless; barbels none. Body elongate, eel-shaped. 
Margin of the upper jaw formed in the middle by the inter- 
maxillaries, and laterally by the maxillartes. Dorsal fin absent 
or reduced to an adipose strip ; caudal generally absent, the tail 
terminating i a point. Anal fin exceedingly long. Ventrals 
none. LHrtremity of the tapering tail capable of being repro- 
duced. Vent situated at, or at a short distance behind, the 
throat. Humeral arch attached to the skull. Ribs well de- 
veloped. Gill-openings rather narrow. Air-bladder present, 
double. Stomach with a cecal sac and pyloric appendages. 
Ovaries with oviducts. 

Kel-like freshwater fishes from Tropical America. 

STERNARCHUS,—Tail terminating in a distinct small caudal 
fin. Teeth small. A rudimentary dorsal fin is indicated by an 
adipose band fitting into a groove on the back of the tail; it is 


easily detached, so as to appear as a thong-like appendage fixed 
in front. Branchiostegals four. 


Eight species, some have the snout compressed and of 
moderate length, like St. Bonapartii from the River Amazons ; 
others have it produced into a long tube, as St. oxyrhynchus 
from the Essequibo. 


RHAMPHICHTHYS.—Caudal fin none; teeth none; no trace 
of a dorsal fin. No free orbital margin. 

Six species, of which, again, some have a tubiform snout, 
whilst in the others it is short. 


ELECTRIC EEL. 667 


STERNOPYGUS.—Caudal fin none; no trace of a dorsal fin. 
Both jaws with small villiform teeth ; similar teeth on each side 
of the palate. Body scaly. 


Four species, very common, and growing to a length of 
30 inches. 


Carapus.—Caudal fin none; no trace of a dorsal fin. A 
series of conical teeth in each jaw. Anterior nostrils, wide in 
the upper lip. Body scaly. 

One species (C. fasciatus) extremely common, and found 
all over tropical America, east of the Andes, from 18 to 24 
inches long. 


Gymnotus.—Caudal and dorsal fins absent ; anal extending 
to the end of the tail. Scales none. Teeth conical, in a single 
series. Eyes exceedingly small. 


The “ Electric Eel” is the most powerful of electric fishes, 
growing to a length of six feet, and extremely abundant in 
certain localities of Brazil and the Guyanas. The electric 
organ consists of two pairs of longitudinal bodies, situated 
immediately below the skin, above the muscles; one pair on 
the back of the tail, and the other pair along the anal fin. 
Each fasciculus is composed of flat partitions or septa, with 
transverse divisions between them. The outer edge of the septa 
appear in nearly parallel lines in the direction of the longitu- 
dinal axis of the body, and consist of thin membranes, which 
are easily torn; they serve the same purpose as the columns 
in the analogous organ of the Torpedo, making the walls or 
abutments for the perpendicular and transverse dissepiments, 
which are exceedingly numerous, and so closely ageregated 
as to seem almost in contact. The minute prismatic cells, 
intercepted between these two sorts of plates, contain a 
gelatinous matter; the septa are about one-thirtieth of an 
inch from each other, and one inch in length contains a series 
of 240 cells, giving an enormous surface to the electric organs. 
The whole apparatus is supphed with more than 200 nerves, 


See 


668 FISHES. 


which are the continuations of the rami anteriores of the 
spinal nerves. In their course they give out branches to the 
muscles of the back, and to the skin of the animal. In the 
Gymnotus, as in the Torpedo, the nerves supplying the electric 
organs are much larger than those bestowed on any part for 
the purposes of sensation or movement. 

The graphic description by Humboldt of the capture of 
Electric Eels by horses driven into the water, which would 
receive the electric discharges and thus exhaust the fishes, 
seems to rest either on the imagination of some person who 
told it to the great traveller or on some isolated incident. 
recent travellers have not been able to verify it even in the 
same parts of the country where the practice was said to 
exist. 

THIRTIETH FAMILY—SYMBRANCHID. 


Body elongate, naked or covered with minute scales ; barbels 
none. Margin of the upper jaw formed by the intermaxillarves 
only, the well developed maaillaries lying behind and parallel 
tothem. Paired fins none. Vertical fins rudimentary, reduced 
to more or less distinct cutaneous folds. Vent situated at a 
great distance behind the head. Ribs present. Cull-openings 
confluent into one slit situated on the ventral surface. Atr- 
bladder none. Stomach without cecal sac or pyloric appen- 
dages. Ovaries with oviducts. 

The fishes of this family consist of freshwater-fishes from 
tropical America and Asia, which, however, enter also 
brackish water; and of a truly marime genus from Australia. 


AMPHIPNOUS.—Vent in the posterior half of the body, which 
is covered with minute scales longitudinally arranged. 


A common fish (A. cuchia) in Bengal, remarkable for its 
singular respiratory apparatus. It has only three branchial 
arches, with rudimentary branchial lamin, and with very 
narrow slits between the arches. To supplement this in- 


EELS. 669 


sufficient respiratory apparatus, a lung-like sac is developed 
on each side of the body behind the head, opening between 
the hyoid and first branchial arch. The interior of the sac 
is abundantly provided with blood-vessels, the arterial coming 
from the branchial arteries, whilst those issuing from it unite 
to form the aorta. A. cwchia approaches the Eels in having 
the humeral arch not attached to the skull. 
MonopTerus.—Vent in the posterior half of the body, which 


is naked. Three branchial arches with rudimentary gills, but 
without breathing sac. 


One species (JZ. javanicus), which is extremely common 
in the East Indian Archipelago and in the eastern parts of 
the Continent. Upwards of three feet long. 

_ SyMBRANCHUS.—Vent in the posterior half of the body, which 
is naked. Four branchial arches with well developed gills. 

Three species, of which one (S. marmoratus) is extremely 
common in tropical America, and the other (S. bengalensis) 
not less so in the East Indies. 


CHILOBRANCHUS.—Vent in the anterior half of the length of 
the body, which is naked. Vertical fins reduced to a simple 
cutaneous fold, without rays. 


A small fish (Ch. dorsalis) from North Western Australia 
and Tasmania. 


THIRTY-FIRST FAMILY—MURANIDA. 


Body elongate, cylindrical or band-shaped, naked or with 
rudimentary scales. Vent situated at a great distance from 
the head. Ventral fins none. Vertical fins, if present, confluent, 
or separated by the projecting tip of the tail. Sides of the upper 
jaw formed by the tooth-bearing maxillaries, the fore part by 
the intermaxillary, which is more or less coalescent with the 
vomer and ethmoid. Humeral arch not attached to the skull. 
Stomach urth a blind sac; no pyloric appendages. Organs of 
reproduction without efferent ducts. 


) 


670 FISHES. 


The “Eels” are spread over almost all fresh waters and 
seas of the temperate and tropical zones; some descend to 
the greatest depths of the oceans. The young of some have 
a limited pelagic existence. (Leptocephali, see p. 179.) At 
Monte Bolca fossil remains are very numerous, belonging to 
recent genera, Anguilla, Sphagebranchus, and Ophichthys ; 
even larval Leptocephales have been preserved. Anguilla 
has been found also in the chalk of Aix and Oeningen. 

In the majority of the species the branchial openings in 
the pharynx are wide shits (Murenide platyschiste) ; in others, 
the true Murene, (Ilurenide engyschiste) they are narrow. 


NeEmMIcHTHYS.—Exceedingly elongate, band-shaped ; tail taper- 
ing into a point. Vent approximate to the pectorals, but the 
abdominal cavity extending far behind the vent. Jaws produced 
into a long slender bill, the upper part being formed by the 
vomer and intermaxillaries. The imner surface of the bill 
covered with small tooth-like asperities. Eye large. The nostrils 
of each side are close together, in a hollow before the eye. Gull- 
openings wide, nearly confluent. Pectoral and vertical fins well 
developed. 

This very singular type is a deep-sea form, occurring at 
depths of from 500 to 2500 fathoms. The two species known 
have hitherto been found in the Atlantic only. 


CyrmMa.—This genus combines the form of the snout of 
Nemichthys, with the soft and shorter body of a Leptocephalus ; 
but the gill-openings are very narrow and close together on the 
abdominal surface. Vent in about the middle of the length of 
the body; vertical fins well developed, confined to, and sur- 
rounding, the tail. Pectoral fins well developed. Eye very 
small. 

Known from two specimens only, 44 inches lone, dredged 
in depths of 1500 and 1800 fathoms in the Pacific and 


Antarctic Oceans. 


SACCOPHARYNX.—Deep-sea Congers, with the muscular system 
very feebly developed, with the bones very thin, soft, and 


EELS. 671 


wanting in inorganic matter. Head and gape enormous. Snout 
very short, pointed, flexible, like an appendage overlapping the 
gape. Maxillary and mandibulary bones very thin, slender, 
arched, armed with one or two series of long, slender, curved, 
widely set teeth, their points being directed inwards; palate 
toothless. Guill-openings wide, at some distance from the head, 
at the lower part of the sides; gills very narrow, free, and ex- 
posed. Trunk of moderate length. Stomach distensible in an 
extraordinary degree. Vent at the end of the trunk. Tail band- 
like, exceedingly long, tapering in a very fine filament. Pectoral 
small, present. Dorsal and anal fins rudimentary. 

This is another extraordinary form of Deep-sea Eels; the 
muscular system, except on the head, is very feebly developed ; 
the bones are as thin, soft, and wanting in inorganic matter, 
as in the Trachypteride. This fish is known from three 
specimens only, which have been found floating on the sur- 
face of the North Atlantic, with their stomachs much dis- 
tended, having swallowed some other fish, the weight of 
which many times exceeded that of their destroyer. © It attains 
to the length of several feet. 


SYNAPHOBRANCHUS.—Gill-openings ventral, united into a 
longitudinal slit between the pectoral fins, separate internally. 
Pectoral and vertical fins well developed. Nostrils lateral, the 
anterior subtubular, the posterior round, before the lower half 
of the eye. Cleft of the mouth very wide ; teeth small; body 
scaly. Stomach very distensible. 

Deep-sea Congers, with well-developed muscular system, 
spread over all oceans, and occurring in depths of from 345 to 
2000 fathoms. Four species are known. Probably attaining 
to the same length as the Conger. 

ANGUILLA.—Small scales imbedded in the skin. Upper jaw 
not projecting beyond the lower. Teeth small, forming bands. 
Gill-openings narrow, at the base of the pectoral fins. The dorsal 
fin commences at a considerable distance from the occiput. 

Some twenty-five species of “Eels” are known from the 
freshwaters and coasts of the temperate and tropical zones ; 


672 FISHES. 


none have been found in South America or the west coast 
of North America and West Africa. The following are the most 
note-worthy : 


The common European species (A. anguilla) is 
spread over Europe to 64° 30’ lat. N., and all round the 
Mediterranean area, but is not found either in the Danube or 
in the Black and Caspian Seas; it extends across the Atlantic 
to North America. The form of the snout varies much, and 
some naturalists have believed that specimens with a broad 
and obtuse snout were specifically distinct from those with 
pointed snout. However, every degree of breadth of the snout 
may be observed; and a much safer way of recognizing this 
species, and distinguishing it from other European Eels, is 
the forward position of the dorsal fin; the distance between 
the commencement of the dorsal and anal fins being as long 
as, or somewhat longer than, the head. Eels grow generally 
to a length of about three feet, but the capture of much 
larger examples is on record. Their mode of propagation is 
still unknown. So much only is certain that they do not 
spawn in fresh water, that many full-grown individuals, but 
not all, descend rivers during the winter months, and that 
some of them at least must spawn in brackish water or in deep 

rater in the sea; for in the course of the summer young 
individuals from three to five inches long ascend rivers in 
incredible numbers, overcoming all obstacles, ascending verti- 
cal walls or floodgates, entering every larger and smaller 
tributary, and making their way even over terra firma to waters 
shut off from all communication with rivers. Such immigra- 
tions have been long known by the name of “ Hel-fairs.” The 
majority of the Eels which migrate to the sea appear to return 
to fresh water, but not in a body, but irregularly, and through- 
out the warmer part of the year. No naturalist has ever 
observed these fishes in the act of spawning, or found mature 
ova; and the organs of reproduction of individuals caught 
in fresh water are so little developed and so much alike, that 


EELS. 673 


the female organ can be distinguished from the male only 
with the aid of a microscope. 

The second species found in Great Britain, on the coasts 
of Europe generally, in China, New Zealand, and the West 
Indies, is (A. latirostris) the “ Grig” or “ Glut,” which prefers 
the neighbourhood of the sea to distant mland-waters, and 
in which the dorsal fin begins farther backwards, the distance 
between the commencement of the dorsal and anal fins being 
shorter than the head; its snout seems to be always broad. 
On the American side of the Atlantic other species, beside 
A. anguilla are found in abundance: A. bostontensis, A. texana. 
The largest Eels occur in lakes of the islands of the Indo- 
Pacific, and they play a conspicuous part in the mythology 
of the South-Sea Islanders and Maories; individuals of from 
eight to ten feet in length have been seen, and referred to several 
species, as A. mauritiana, fidjiensis, obscura, aneitensis, etc. 


ConcER.—Scaleless. Cleft of the mouth wide, extending at 
least to below the middle of the eye. Maxillary and mandibu- 
lary teeth arranged in series, one of which contains teeth of equal 
size, and so closely set as to form a cutting edge. No canine 
teeth. Vomerine band of teeth short. Pectoral and vertical 
fins well developed, the dorsal commencing behind the root of 
the pectoral. Gill-openings large, approximate to the abdomen. 
The posterior nostril opposite to the upper or middle part of the 
orbit, the anterior in a tube. Eyes well developed. 

The “Congers” are marine Eels ; the best known species 
(C. conger) seems to be almost cosmopolitan, and is plentiful 
all round Europe, at St. Helena, in Japan, and Tasmania. It 
attains to a length of eight feet, and thrives and grows rapidly 
even in confinement, which is not the case with the fresh- 
water Eel. Three other species are known, of which @. 
marginatus from the Indian Ocean, is the most common. 
Leptocephalus morrisii is an abnormal larval condition of the 
Conger. 


DEX 


674 FISHES. 


Genera allied to Conger are Poeciloconger, Congromurena, 
Vroconger, and Heteroconger. 


Mur&NESOX. —Scaleless. Snout produced. Jaws with 
several series of small closely set teeth, anteriorly with canines ; 
vomer with several long series of teeth, the middle of which is 
formed by large conical or compressed teeth. Gill-openings wide, 
approximate to the abdomen. Pectoral and vertical fins well 
developed, the dorsal beginning above the gill-opening. Two 
pairs of nostrils, the posterior opposite to the upper part or 
middle of the eye. 

Four species from tropical seas, JZ. cinereus being very 
common in the Indian Ocean, and attaining to a length of six 
feet. 


NETTASTOMA.—Scaleless. Snout much produced, depressed. 
Jaws and vomer with bands of card-like teeth, those along the 
median line of the vomer being somewhat the larger. Vertical 
fins well developed ; pectorals none. Gill-openings of moderate 
width, open. Nostrils on the upper surface of the head, valvular ; 
the anterior near to the end of the snout, the posterior above 
the anterior angle of the eye. 


This genus lives at some depth, the Japanese species 
(N. parviceps) having been obtained at 345 fathoms. J. 
melanurum from the Mediterranean, seems to inhabit a similar 
depth. Hyoprorus is its Leptocephalid form. 


Genera allied to Murenesox are Sawrenchelys, Oxyconger, 
Hoplunnis, and Neoconger ; in all these the nostrils have a 
superior or lateral position. In other genera the nostrils 
perforate the upper lip, as in Myrus, Myrophis, Paramyrus, 
Chilorhinus, Murenichthys, and Ophichthys, the last genus 
deserving of particular mention on account of its great range 
and common occurrence. 


OpHicHtHys.—Nostrils labial; extremity of the tail free, 
not surrounded by a fin. 


More than eighty species are known, many of which are 


EELS. 675 


abundant on the coasts of the tropical and sub-tropical zones. 
They do not attain to a large size, but many must be ex- 
tremely voracious and destructive to other fishes, if we draw 
an inference from the formidable dentition with which their 
jaws and palate is armed. Other species have much more 
feeble, and some even obtuse teeth, better adapted for seizing 
Crustaceans than vigorous and slippery fishes. Some have 
rudimentary pectoral fins or lack them altogether. Many 
are highly ornamented with bands or spots, the coloration 
being apparently very constant in the several species. 


a a a 
Fig. 303.—Ophichthys crocodilinus, from the Indo-Pacific. 


Morincua.— Body scaleless, cylindrical, with the trunk 
much longer than the tail. Pectorals none or small ; vertical 
fins but little developed, limited to the tail. Posterior nostrils 
in front of the small eye. Cleft of the mouth narrow ; teeth 
uniserial, Heart placed far behind the branchiz. Gill-openings 
rather narrow, inferior. 

Six species from freshwaters, brackish water, and the 
coasts of India to the Fiji Islands. 


Mur&NA.—Scaleless. Teeth well developed. Gill-openings 
and clefts between the branchial arches narrow. Pectoral fins 
none; dorsal and anal fins well developed. Two nostrils on 
each side of the upper surface of the snout; the posterior a 
narrow round foramen, with or without tube; the anterior in a 
tube. 


676 FISHES, 


The Murenas are as abundantly represented in the 
tropical and sub-tropical zones, and have nearly the same 
range, as Ophichthys. 'The number of species known exceeds 
eighty. The majority are armed with formidable pointed 
teeth, well suited for seizing other fish on which they prey. 
Large specimens thus armed readily attack persons in and 
out of the water; and as some species attain a length of some 
six or eight feet, they are justly feared by fishermen. The 
minority of species have obtuse and molar-like teeth, their 
food consisting chiefly of Crustaceans and other hard-shelled 


Fig. 304.—Head of a Mureena. 


animals. Most of the Murenas are beautifully coloured and 


Fig. 305.—Murena pavonina, from Southern Seas. 


spotted, some in a reeular and constant manner, whilst in 
others the pattern varies in a most irregular fashion: they 
have quite the appearance of snakes. The Murena of the 


MURZENAS, 677 


Ancient Romans is Murena helena, which is not confined to 
the Mediterranean, but also found in the Indian Ocean and 
on the coast of Australia. Its skin is of a rich brown, beauti- 
fully marked with large yellowish spots, each of which con- 
tains smaller brown spots. 


Fig. 306.—Murena picta, from the Indo-Pacific. 


Gymnomurena differs from Murena in having the fins 
reduced to a short rudiment near the end of the tail. Six 


Fig. 307.—Gymnomurena vittata, from Cuba. 


species are known growing to a length of eight feet. 
Myroconger and Enchelycore belong to the same sub-family 


678 _ FISHES. 


as Murena, but the former is provided with pectoral fins, and 
in the latter the posterior nostril is a long slit, and not round 
as in the other genera. 


FIFTH ORDER—LOPHOBRANCHII. 


The gills are not laminated, but composed of small rounded 
lobes attached to the branchial arches. Gull-cover reduced to a 


Fig. 308.—Gills of Hippocampus abdominalis. 


large simple plate. Avr-bladder simple, without pnewmatie 
duct. A dermal skeleton composed of numerous pieces arranged 
im segments, replaces more or less soft integuments. Muscular 
system not much developed. Snout prolonged. Mouth terminal, 
small, toothless, formed as in Acanthopterygians. 


First FAMILY—SOLENOSTOMID&. 


Gill-openings wide. Two dorsal fins, the rays of the anterior 
not articulated. All the other fins well developed. 

One living genus only is known, which was preceded in 
the tertiary epoch by Solenorhynchus (Monte Postale). 


SoLENOSTOMA.—Snout produced into a long tube. Body 
compressed, with very short tail. All parts covered with thin 
skin, below which there is a dermal skeleton formed by large 
star-like ossifications. The soft dorsal and anal fins on elevated 
bases ; caudal fin long. Ventral fins inserted opposite to the 


PIPE-FISHES. 679 


anterior dorsal, close together, seven-rayed ; they are free in the 
male, but in the female their inner side coalesces with the in- 
teguments of the body, a large pouch for the reception of the 
eggs being formed thereby. Air-bladder and pseudobranchiz 
absent. Branchiostegals four, very thin. Intestinal tract very 
simple, with a stomachic dilatation, without pylorie appendages. 
Ova very small. 

The dermal skeleton of this singular type is formed by 
star-like ossifications, four in each horizontal and vertical 
series on the side of the fore part of the trunk; each consists 
of four or three radiating branches by which it joins the 
neighbouring bones; on the hind part of the trunk and tail 
the series are diminished to two. The dorsal and abdominal 
profiles in front of the fins are protected by similar bones. 
The vertebral column is composed of eighteen abdominal and 
fifteen caudal vertebrae, the vertebree gradually decreasing in 
length backwards, so that the shortness of the tail is caused 
not only by the smaller number of vertebrae, but also by 
their much lesser length. Neural and hemal spines are 
developed. The pelvis consists of two pairs of cartilaginous 
lamine, the convex margin of the anterior fitting into an 
angle of a dermal bone which separates the pelvis from the 
well-ossified humeral arch. 

The singular provision for the retention and protection 
of the eggs has been described above (p. 162, figs. 73 and 74), 
and we have only to repeat here that it is the female which 
takes care of the progeny, and not the male as in the follow- 
ing family. ‘Two or three small species are known from the 
Indian Ocean; they are beautifully marked, especially the 
male, which also appears to be of smaller size in this genus 
than the female. 


SECOND FAMILY—SYNGNATHIDA. 


Gill-openings reduced to a very small opening near the 
upper posterior angle of the gill-cover. One soft dorsal fin ; no 


680 FISHES. 


ventrals, and, sometimes, one or more of the other fins are also 
absent. 

Small marine fishes, which are abundant on such parts of 
the coasts of the tropical and temperate zones as offer by 
their vegetation shelter to these defenceless creatures. They 
are bad swimmers (the dorsal fin being the principal organ 
of locomotion), and frequently and resistlessly carried by cur- 
rents into the open ocean or to distant coasts. All enter 
brackish water, some fresh water. The strata of Monte Bolca 
and Licata (Sicily) have yielded evidence of their existence 
in the tertiary epochs; beside species of Siphonostoma and 
Syngnathus (Pseudosyngnathus), remains of an extinct genus, 
Calamostoma, allied to Hippocampus, but with a distinct 
caudal fin, have been found. On their propagation see 
p. 163, Fig. 76. 

A. SYNGNATHINA.—The tail is not prehensile, and generally 
provided with a caudal fin.—Pipe-Fishes. 

SIPHONOSTOMA.—Body with distinct ridges, the upper caudal 
ridge continuous with the lateral line, but not with the dorsal 
ridge of the trunk. Pectoral and caudal fins well developed ; 
dorsal fin of moderate length, opposite to the vent. Humeral 


bones movable, not united into a “breast-ring.” Males with 


an egg-pouch on the tail, the eggs being covered by cutaneous 
folds. 


Two species, of which S. typhle is common on the British, 
and generally distributed on the European coasts. 

SYNGNATHUS.—Body with the ridges more or less distinct, 
the dorsal ridge of the trunk not being continuous with that of 
the tail. Pectoral fins well developed ; caudal present. Dorsal 


fin opposite or near to the vent. Humeral bones firmly united 
into the breast-ring. Egg-pouch as in Siphonostoma. 


The distribution of this genus nearly coincides with that 
of the family, some fifty species being known. SS. acus, the 
great Pipe-fish (see Fig. 75, p. 163), is one of the most 
common European fishes, extending across the Atlantic and 


PIPE-FISHES. 681 


southwards to the Cape of Good Hope; it attains a length of 
18 inches. Another very common species, frequently met at 
sea, and spread over nearly all the tropical and sub-tropical 
seas, is S. pelagicus, agreeably marked with alternate brown 
and silvery cross-bars. 


DoryicHTHys.—Body with the ridges well developed. Pec- . 
toral and caudal fins present. Dorsal fin long or of moderate 
length, opposite to the vent. Humeral bones firmly united. 
Males with the lower ridges of the abdomen dilated, the dilated 
parts forming a broad groove for the reception of the ova. 

In these Pipe-fishes the ova are not received in a com- 
pletely closed pouch, but glued on to the surface of the 
abdomen. ‘Twenty species from tropical seas. 

NeErRopHIS,—Body smooth, rounded, with scarcely any of the 
ridges distinct. Pectoral fin none, caudal absent or rudimentary, 
the tail tapering into a point. Dorsal fin of moderate length, 
opposite to the vent. The ova are attached to the soft integu- 


ment of the abdomen of the male, and are not covered by lateral 
folds of the skin. 


Seven species from the European seas and the Atlantic. 
NV. wequoreus (Ocean Pipe-fish), N. ophidion (Straight-nosed 
Pipe-fish), and WV. lumbriciformis (Little Pipe-fish), are common 
on the British coasts. 

ProrocaAmMpus.—The whole dermal skeleton is covered with 
skin. A broad cutaneous fold runs along the back in front and 


behind the dorsal ; a similar fold along the abdomen. Pectoral 
fin none ; caudal very small. 


The single species of this remarkable genus, P. hymeno- 
lomus, occurs in the Falkland Islands. It may be regarded 
as an embryonal form of Nerophis, the median skin-folds being 
evidently remains of the fringe which surrounds the body of 
the embryo. 

The other genera belonging to this group are, Jchthyo- 
campus, Nannocampus, Urocampus, Leptoichthys, Coelonotus, 
and Stigmatophora. 


682 FISHES. 


HippocaMPInA.—The tail is prehensile, and invariably with- 
out caudal fin.—Sea-horses. 

GASTROTOKEUS.—Body depressed, the lateral line running 
along the margin of the abdomen. Shields smooth. Tail 
shorter than the body. Pectoral fins. No pouch is developed 
for the ova, which are imbedded in the soft integument of the 
abdomen of the male. 

Gastrotokeus biaculeatus,. very common in the Indian 
Ocean to the coasts of Australia. 


SOLENOGNATHUS.—Body compressed, deeper than broad. 
Shields hard, rugose, with round or oval interannular plates ; 
and without elongate processes. Tail shorter than the body. 
Pectoral fins. 

Three species, from the Chinese and Australian Seas ; 
they are the largest of Lophobranchs, S. hardwickiw, attaining 
to a length of nearly two feet. 


PHYLLOPTERYX.—Body compressed, or as broad as deep. 
Shields smooth, but some or ali of them are provided with pro- 


Fig. 309.—Phyllopteryx eques. 


minent spines or processes on the edges of the body ; some of 
the processes with cutaneous filaments. A pair of spines on the 
upper side of the snout and above the orbit. Tail about as long 
as the body. Pectoral fins. The ova are imbedded in soft mem- 


PIPE-FISHES. 683 


brane on the lower side of the tail, without a pouch being 
developed. 

Three species from the coasts of Australia. The protective 
resemblances with which many Lophobranchs are furnished, 
attain to the highest degree of development in the fishes of 
this genus. Not only their colour closely assimilates that 
of the particular kind of seaweed which they frequent, but 
the appendages of their spines seem to be merely part of the 
fucus to which they are attached. They attain a length of 
12 inches. 

HippocaAMpus.—Trunk compressed, more or less elevated. 
Shields with more or less prominent tubercles or spines. Occiput 
compressed into a crest, terminating at its supero-posterior corner 


in a prominent knob (coronet). Pectoral fins. The males carry 
the eggs in a sac at the base of the tail, opening near the vent. 


A singular resemblance of the head and fore part of the 
body to that of a horse, has given to these fishes the name of 
“Sea-horses.” They are abundant between and near the 
tropics, becoming scarcer in higher latitudes. Some twenty 
species are known, some of which have a wide geographical 
range, as they are often carried to great distances with floating 
objects to which they happen to be attached—Acentronura 
is a genus closely allied to Hippocampus. 


SIXTH ORDER—PLECTOGNATHL 


Teleosteous fishes with rough scales, or with ossifications of 
the cutis in the form of scutes or spines ; skin sometimes entirely 
naked. Skeleton incompletely ossified, with the vertebre in 
small number. Gills pectinate ; a narrow gill-opening in front 
of the pectoral fins. Mouth narrow ; the bones of the upper 
jaw generally firmly united. A soft dorsal fin, belonging to the 
caudal portion of the vertebral column, opposite to the anal ; 
sometimes elements of a spinous dorsal besides. Ventral fin 
none, or reduced to spines. Arr-bladder without pneumatic duct. 


684 FISHES. 


First FAMILY—SCLERODERMI. 


Snout somewhat produced ; jaws armed with distinet teeth 
in small number, Skin with scutes or rough. The elements of 
a spinous dorsal and ventral fins generally present. 

Marine fishes of moderate or small size, very common in 
the tropical zone, but scarcer in higher latitudes. They have 
been found in three localities of tertiary strata, viz., at Monte 
Bolca, where a species of Ostracion occurs, and in the Schists 
of Glaris, from which two genera have been described, Acan- 
thoderma and Acanthopleurus, closely allied to Balistes and 
Triacanthus. Glyptocephalus from the Isle of Sheppey has 
the skull of a Balistes, but its body is covered with tuber- 
cles arranged in regular series. The Scleroderms may be 
divided into three very natural groups :— 


A. TRIACANTHINA.—The skin is covered with small, rough, 
scalelike scutes. A spinous dorsal fin with from four to six 
spines. <A pair of strong, movable ventral spines, joined to the 
pelvic bone. 


To this group belong the genera Triacanthodes, Hollardia, 
and Triacanthus, represented by five species, of which Zria- 
canthus brevirostris from the Indian Ocean is the most 
common. 


B. BauistinA. — Body compressed, covered with movable 
scutes or rough. Spinous dorsal reduced to one, two, or three 
spines. Ventral fins reduced to a single pelvic prominence, or 
entirely absent. 

To this group belong the genera alistes, Monacanthus, 
and Anacanthus, the last genus being distinguished by a bar- 
bel at the lower jaw. 

Balistes, or the “ File-fishes” proper, inhabit the tropical 
and sub-tropical seas; shoals of young are not rarely met with 
in mid-ocean. Some thirty species are known, many attaining 
a length exceeding two feet; but the majority are much 


FILE-FISHES, 685 


smaller, and frequently beautifully and symmetrically marked. 
Both jaws are armed with eight strong incisor-like and 


Fig. 310.—Balistes vidua. 


obliquely truncated teeth, by which these fishes are enabled 
to break off pieces of corals on which they feed, or to chisel 
a hole into the hard shell of Mollusca, in order to extract the 
soft parts. They destroy an immense number of Mollusks, 
thus becoming most injurious to the pearl-fisheries. The first 
of their three dorsal spines is very strong, roughened in front 
like a file, and hollowed out behind to receive the second 
much smaller spine, which, besides, has a projection in front, 
at its base, fitting into a notch of the first. Thus these two 
spines can only be raised or depressed simultaneously, and 
the first cannot be forced down, unless the second has been 
previously depressed. The latter has been compared to a 
trigger, hence a second name, “ Trigger-fish,’ has been given 
to these fishes. Some species are armed with a series of short 
spines or tubercles on each side of the tail. Two species (B. 
maculatus and B. capriscus), common in the Atlantic, some- 
times wander to the British coasts. 

The Monacanthus are similarly distributed as the Balistes, 
and still more abundant, some fifty species being known. 
Their dentition is very similar, but they possess one dorsal 
spine only, and their rough scales are so small as to give a 


686 FISHES. 


velvety appearance to the skin (Figs. 17 and 18, p. 48). Adult 
males of some of the species possess a peculiar armature on 
each side of the tail, which in females is much less developed 
or entirely absent. This armature may consist either in 
simple spines arranged in rows, or in the development of the 
minute spines of the scales into long stiff bristles, so that the 
patch on each side of the tail looks like a brush. 

C. OSTRACIONTINA.—The integuments of the body form a hard 
continuous carapace, consisting of hexagonal scutes juxtaposed 


in mosaic-fashion. A spinous dorsal and ventral fins are absent; 
but sometimes indicated by protuberances. 


The “ Coffer-fishes” (Ostracion) are too well known to 
require a lengthened description. Only the snout, the bases 
of the fins, and the hind part of the tail are covered with soft 
skin, so as to admit of free action of the muscles moving these 
parts. The mouth is small, the maxillary and intermaxillary 
bones coalescent, each jaw being armed with a single series 
of small slender teeth. The short dorsal fin is opposite to the 
equally short anal. The vertebral column consists of fourteen 
vertebrae only, of which the five last are extremely short, the 
anterior elongate. Ribs none. The carapaces of some species 
are three-ridged, of others four- and five-ridged, of some 
provided with long spines. Twenty-two species from tropical 
and sub-tropical seas are known. 


SECOND FAMILY—GYMNODONTES. 


Body more or less shortened. The bones of the wpper and 
lower jaw are confluent, forming a beak with a trenchant edge, 
without teeth, with or without median suture. A soft dorsal, 
caudal and anal are developed, approximate. No spinous 
dorsal. Pectoral fins ; no ventrals. 

Marine fishes of moderate or small size from tropical and 
sub-tropical seas. A few species live in fresh water. Fossil 
remains of Diodon are not scarce at Monte Bolea and Licata ; 


GLOBE-FISHES. 687 


a distinct genus, Hnneodon, has been described from Monte 
Postale. The Gymnodonts may be divided into three groups: 


A. TriopontinA.—Tail rather long, with a separate caudal 
fin. Abdomen dilatable into a very large, compressed, pendent 
sac, the lower part of which is merely a flap of skin, into which 
the air does not penetrate, the sac being capable of being ex- 
panded by the very long pelvic bone. The upper jaw divided by 
a median suture, the lower simple. 

A single genus and species (Zriodon bursarius) from the 
Indian Ocean. 


B. TETRODONTINA.—Tail and caudal fin distinct. Part of the 
cesophagus much distensible, and capable of being filled with air. 
No pelvic bone. 


“ Globe-fishes”” have a short, thick, cylindrical body, with 
well developed fins. It is covered with thick scaleless skin, 
in which, however, spines are imbedded of various sizes. The 
spines are very small, and but partially distributed over the 
body in some species, whilst in others they are very large, 
and occupy equally every part of the body. These fishes 
have the power of inflating their body by filling their disten- 
sible cesophagus with air, and thus assume a more or less 
globular form. The skin is, then, stretched to its utmost extent, 
and the spines protrude and form a more or less formidable 
defensive armour, as in a hedgehog; therefore they are fre- 
quently called “ Sea-hedgehogs.” A fish thus blown out turns 
over and floats belly upwards, driving before the wind and 
waves. However, it is probable that the spines are a protec- 
tion not only when the fish is on the surface and able to take 
in air, but also when it is under water. Some Diodonts, 
at any rate, are able to erect the spines about the head by 
means of cutaneous muscles; and, perhaps, all fill their 
stomach with water instead of air, for the same purpose and 
with the same effect. In some Diodonts the spines are fixed, 
erect, not movable. The Gymnodonts generally, when taken, 


688 FISHES. 


produce a sound, doubtless by the expulsion of air from the 
cesophagus. Their vertebral column consists of a small number 
of vertebree, from 20 to 29, and their spinal chord is extremely 
short. All these fishes have a bad reputation, and they are 
never eaten; indeed, some of them are highly poisonous, and 
have caused long continued illness and death. Singularly, 
the poisonous properties of these fishes vary much as regards 
intensity, only certain individuals of a species, or individuals 
from a certain locality, or caught at a certain time of the year, 
being dangerous. Therefore it is probable that they acquire 
their poisonous quality from their food, which consists in 
corals and hard-shelled Mollusks and Crustaceans. Their 
sharp beaks, with broad masticating posterior surface, are 
admirably adapted for breaking off branchlets of coral-stocks, 
and for crushing hard substances. 


TETRODON (including Xenopterus).—Both the upper and lower 
jaws are divided into two by a mesial suture, 


Extremely numerous in tropical and sub- 
tropical zones, more than sixty species being 
known. In some of the species the dermal 
spines are extremely small, and may be absent 
altogether. Many are highly ornamented with 


spots or bands. A few species live in large 
Fig. 311.—Jaws Yivers—thus 7. psittacus from Brazil; JT. 

of Tetrodon. fahaka, a fish well known to travellers on the 
Nile, and likewise abundant in West African rivers; 7. fluvi- 


Fig. 312.—Tetrodon margaritatus, 


GLOBE-FISHES. 689 


atilis from brackish water and rivers of the East Indies. The 
species figured is one of the smallest, about six inches long, 
and common in the Indo-Pacific. 

Diopon.—Jaws without mesial suture, so that there is only 
one undivided dental plate above and one below. 

In these fishes, as well as in some closely allied genera, the 
dermal spines are much more developed than in the Tetro- 
donts; in some the spines are erectile, as in Diodon, Atopo- 
mycterus, Trichodiodon, and Trichocyclus ; in others they are 
stiff and immovable, as in Chilomycterus and Dicotylichthys. 
Seventeen species are known, of which Diodon hystrix is the 
most common as it is the largest, growing to a length of two 
feet. It is spread over the Tropical Atlantic as well as Indo- 


Fig. 313.—Diodon maculatus, 


Pacific, as is also a smaller, but almost equally common 
species, Diodon maculatus. 


Fig. 314.—Diodon maculatus, inflated. 


oY 


690 FISHES. 


C. Morina.—Body compressed, very short; tail extremely 
short, truncate. Vertical fins confluent. No pelvic bone. 


The “Sun-fishes” (Orthagoriscus) are pelagic fishes, found 
in every part of the oceans within the tropical and temperate 
zones. The singular shape of their body and the remarkable 
changes which they undergo with age, have been noticed 
above (p. 175, Figs. 93,94). Their jaws are undivided in the 
middle, comparatively feeble, but well adapted for masticating 
their food, which consists of small pelagic Crustaceans. Two. 
species are known. The common Sun-fish, 0. mola, which 
attains to a very large size, measuring seven or eight feet, and 
weighing as many hundredweights. It has a rough, minutely 
granulated skin. It frequently approaches the southern coasts 
of England and the coasts of Ireland, and is seen basking in 
calm weather on the surface. The second species, 0. truncatus, 
is distinguished by its smooth, tessellated skin, and one of 
the scarcest fishes in collections. The shortness of the ver- 
tebral column of the Sun-fishes, in which the number of 
caudal vertebra is reduced to seven, the total number being 
seventeen, and the still more reduced length of the spinal chord 
have been noticed above (p. 96). 


THIRD SUB-CLASS—CYCLOSTOMATA. 


Skeleton cartilaginous and notochordal, without ribs and 
without real jaws. Skull not separate from the vertebral column. 
No limbs. Gills in the form of fixed sacs, without branchial 
arches, six or seven in number on each side. One nasal aperture 
only. Heart without bulbus arteriosus. Mouth antervor, sur- 
rounded by a circular or sub-circular lip, suctorial. Alimentary 
canal straight, simple, without coecal appendages, pancreas or 
spleen. Generative outlet peritoneal. Vertical fins rayed. 

The Cyclostomes are most probably a very ancient type. 
Unfortunately the organs of these creatures are too soft to be 
preserved, with the exception of the horny denticles with 
which the mouth of some of them is armed. And, indeed, 
dental plates, which are very similar to those of Myxine, are 
not uncommon in certain strata of Devonian and Silurian 
age (see p. 193). The fishes belonging to this sub-class may 
be divided into two families— 


First FAMILY—PETROMYZONTIDA, 


Body eel-shaped, naked. Subject to a metamorphosis ; im 
the perfect stage with a suctorial mouth armed with teeth, 
simple or nulticuspid, horny, sitting on a soft papilla. Mazxil- 
lary, mandibulary, lingual, and suctorial teeth may be dis- 
tinguished. Eyes present (in mature animals). External nasal 
aperture in the middle of the upper side of the head. The nasal 
duct terminates without perforating the palate. Seven branchial 


692 FISHES. 


sacs and apertures on each side behind the head ; the inner 
branchial ducts terminate in a separate common tube. Intestine 
with a spiral valve. Eggs small. The larve without teeth, 
and with a single continuous vertical fin. 

“TLampreys” are found in the rivers and on the coasts of 
the temperate regions of the northern and southern hemi- 
spheres. Their habits are but incompletely known, but so 
much is certain that at least some of them ascend rivers 


periodically, for the purpose of spawning 


e, and that the young 


pass several years in rivers, whilst they undergo a metamor- 
phosis (see p. 170). They feed on other fishes, to which they 
suck themselves fast, scraping off the flesh with their teeth. 
Whilst thus engaged they are carried about by their victim ; 
Salmon have been captured in the middle course of the 
Rhine with the Marine Lamprey attached to them. 


Fig. 315.—Mouth of Larva of — Fig. 316.—Mouth of Petromyzon fluviatilis. 
Petromyzon branchialis. mx, Maxillary tooth; md, Mandibulary 
tooth; Z, Lingual tooth ; s, Suctorial teeth. 


PETROMYZON.—Dorsal fins two, the posterior continuous with 
the caudal, The maxillary dentition consists of two teeth placed 
close together, or of a transverse bicuspid ridge ; lingual teeth 
serrated. . 


The Lampreys belonging to this genus are found in the 
northern hemisphere only; the British species are the Sea- 
Lamprey (P. marinus), exceeding a length of three feet, and 
not uncommon on the European and North American coasts ; 
the River-Lamprey or Lampern (P. fluviatilis), ascending in 


LAMPREYS. 693 


large numbers the rivers of Europe, North America, and 
Japan, and scarcely attaining a length of two feet; the 
“Pride” or “Sand-Piper” or Small Lampern (P. branchialis), 
scarcely twelve inches long, the larva of which has been long 
known under the name of Ammocoetes. 

Ichthyomyzon from the western coasts of North America 
is said to have a tricuspid maxillary tooth. 


MorpactA.—Dorsal fins two, the posterior continuous with 
the caudal. The maxillary dentition consists of two triangular 
groups, each with three conical acute cusps ; two pairs of serrated 
lingual teeth. 

A Lamprey (Jf mordax) from the coasts of Chile and 


Fig, 317.—Mouth of Mordacia mordax, closed and opened. 


Tasmania. This fish seems to be provided sometimes with a 
gular sac, like the following.’ 


Fig. 318.—Mordacia mordax. 


GEOTRIA.—Dorsal fins two, the posterior separate from the 


1 Fig. 317 is taken from a specimen in which the horny covers of the 
dentition were lost, hence it does not represent accurately the shape of the 
teeth. 


694. . FISHES. 


caudal. Maxillary lamina with four sharp flat lobes; a pair of 
long pointed lingual teeth. 

Two species, one from Chile and one from South Australia. 
They grow to a length of two feet, and in some specimens 
the skin of the throat is much expanded, forming a large 
pouch. Its physiological function is not known. The cavity 
is in the subcutaneous cellular tissue, and does not com- 
municate with the buccal or branchial cavities. Probably it 
is developed with age, and absent in young individuals. In 
all the localities in which these Extra-european Lampreys 
are found, Ammocoetes forms occur, so that there is little 
doubt that they undergo a similar metamorphosis as P. 
branchialis. 


SrecoND FAMILY—MYXINID&. 


Body cel-shaped, naked. The single nasal aperture is above 
the mouth, quite at the extremity of the head, which is provided 
with four pairs of barbels. Mouth without lips. Nasal 
duct without cartilaginous rings, penetrating 
the palate. One median tooth on the palate, 
and two comb-like series of teeth on the tongue 
(see Fig. 101). Branchial apertures at a 
great distance from the head; the inner 
branchial ducts lead into the esophagus. A 
sertes of mucous sacs along each side of the 
abdomen. Intestine without spiral valve. 
Leggs large, with a horny case provided with 


threads for adhesion. 
The fishes of this family are known by 
Fig. 319.—Ovum of oun : 53 
Myxine ‘glutinosa, the names of “ Hag-Fish,” “Glutinous Hag, 
enlarged. or “Borer;” they are marine fishes with a 
similar distribution as the Gadidee, being most plentiful in 
the higher latitudes of the temperate zones of the northern 
and southern hemispheres. They are frequently found buried 


LAMPREYS. . 695 


in the abdominal cavity of other fishes, especially Gadoids, 
into which they penetrate to feed on their flesh. They secrete 
a thick glutinous slime in incredible quantities, and are 
therefore considered by fishermen a great nuisance, seriously 
damaging the fisheries and interfermg with the fishing in 
localities where they abound. Myaine descends to a depth 
of 345 fathoms, and is generally met with in the Norwegian 
Fjords at 70 fathoms, sometimes in great abundance. 


MyxINE.—One external branchial aperture only on each side 
of the abdomen, leading by six ducts to six branchial sacs. 


Three species from the North Atlantic, Japan, and Magel- 
heen’s Straits. 


Fig. 320.—Myxine australis. A, Lower aspect of head ; a, Nasal aperture ; 
b, Mouth; g, Branchial aperture ; v, Vent. 


BDELLOSTOMA,—Six or more external branchial apertures on 
each side, each leading by a separate duct to a branchial sac. 


Two species from the South Pacific. 


676 


FOURTH SUB-CLASS—LEPTOCARDII. 


Skeleton membrano-cartilaginous and notochordal, ribless. 
No brain. Pulsating sinuses in place of a heart. Blood 
colourless. Respiratory cavity confluent with the abdominal 
cavity ; branchial elefts in great number, the water being ex- 
pelled by an opening wn front of the vent. Jaws none. 

This sub-class is represented by a single family (Cirro- 
stomt) and by a single genus (Branchiostoma) ;' it is the lowest 
in the scale of fishes, and lacks so many characteristics, not 
only of this class, but of the vertebrata generally, that Heeckel, 
with good reason, separates it into a separate class, that of 
Acrania. The various parts of its organisation have been 
duly noticed in the first part of this work. 

The “ Lancelet” (Branchiostoma lanceolatum, see Fig. 28, 
p. 63), seems to be almost cosmopolitan within the temperate 
and tropical zones. Its small size, its transparency, and the 
rapidity with which it is able to bury itself in the sand, 
are the causes why it escapes so readily observation, even at 
localities where it is known to be common. Shallow, sandy 
parts of the coasts seem to be the places on which it may 
be looked for. It has been found on many localities of the 
British, and generally European coasts, in North America, 
the West Indies, Brazil, Peru, Tasmania, Australia, and 
Borneo. It rarely exceeds a length of three inches. A 
smaller species, in which the dorsal fringe is distinctly higher 
and rayed, and in which the caudal fringe is absent, has been 
described under the name of Epigionichthys pulchellus ; it 
was found in Moreton Bay. 


1 This name is two years older than Amphioxus. 


APPENDIX. 


—— 


DIRECTIONS FOR COLLECTING AND 
PRESERVING FISHES. 


WHENEVER practicable fishes ought to be preserved in spirits. 
To insure success in preserving specimens the best and 
strongest spirits should be procured, which, if necessary, can be 
reduced to the strength required during the journey with water 
or weaker spirit. Travellers frequently have great difficulties in 
procuring spirits during their journey, and therefore it is advis- 
able, especially during sea voyages, that the traveller should take 
a sufficient quantity with him. Pure spirits of wine is best. 
Methylated spirits may be recommended on account of their 
cheapness ; however, specimens do not keep equally well in this 
fluid, and very valuable objects, or such as are destined for 
minute anatomical @xamination, should always be kept in pure 
spirits of wine. If the collector has exhausted his supply of 
spirits he may use arrack, cognac, or rum, provided that the fluids 
contain a sufficient quantity of alcohol. Generally speaking, 
spirits which, without being previously heated, can be ignited by 
a match or taper, may be used for the purposes of conservation. 
The best method to test the strength of the spirits is the use of 
a hydrometer. It is immersed in the fluid to be measured, and 
the deeper it sinks the stronger is the spirit. On its scale the 
number 0 signifies what is called proof spirit, the lowest 
degree of strength which can be used for the conservation of fish 
for any length of time. Spirits, in which specimens are packed 
permanently, should be from 40 to 60 above proof. If the 
hydrometers are made of glass they are easily broken, and there- 
fore the traveller had better provide himself with three or four 
of them, their cost being very trifling. Jurther, the collector 


697 


698 DIRECTIONS 


will find a small distilling apparatus very useful. By its means 
he is able not only to distil weak and deteriorated spirits or any 
other fluid containing alcohol, but also, in case of necessity, to 
prepare a small quantity of drinkable spirits. 

Of collecting vessels we mention first those which the collector 
requires for daily use. Most convenient are four-sided boxes 
made of zinc, 18 in. high, 12 in. broad, and 5 in. wide. They 
have a round opening at the top of 4 in. diameter, which can 
be closed by a strong cover of zinc of 5 in. diameter, the cover 
being screwed into a raised rim round the opening. In order to 
render the cover air-tight, an indiarubber ring is fixed below its 
margin. Each of these zine boxes fits into a wooden case, the 
lid of which is provided with hinges and fastenings, and which 
on each side has a handle of leather or rope, so that the box can 
be easily shifted from one place to another. These boxes are in 
fact made from the pattern of the ammunition cases used in the 
British army, and extremely convenient, because a pair can be 
easily carried strapped over the shoulders of a man or across the 
back of amule. The collector requires at least two, still better four 
or six, of these boxes. All those specimens which are received 
during the day are deposited in them, in order to allow them to 
be thoroughly penetrated by the spirit, which must be renewed 
from time to time. They remain there for some time under the 
supervision of the collector, and are left in these boxes until 
they are hardened and fit for final packing. Of course, other 
more simple vessels can be used and substituted for the collecting 
boxes. For instance, common earthenware vessels, closed by a 
cork or an indiarubber covering, provided they have a wide 
mouth at the top, which can be closed so that the spirit does not 
evaporate, and which permits of the specimens being inspected at 
any moment without trouble. Vessels in which the objects are 
permanently packed for the home journey are zinc boxes of various 
sizes, closely fitting into wooden cases. Too large a size should 
be avoided, because the objects themselves may suffer from the 
superimposed weight, and the risk of injury to the case increases 
with its size. It should hold no more than 18 cubic feet 
at most, and what, in accordance with the size of the specimens, 
has to be added in length should be deducted in depth or breadth. 


FOR COLLECTING. 699 


The most convenient cases, but not sufficient for all specimens, 
are boxes 2 feet in length, 14 foot broad, and 1 foot deep. The 
traveller may provide himself with such cases ready made, 
packing in them other articles which he wants during his 
journey ; or he may find it more convenient to take with him 
only the zine plates cut to the several sizes, and join them into 
boxes when they are actually required. The requisite wooden 
cases can be procured without much difficulty almost everywhere. 
No collector should be without the apparatus and materials for 
soldering, and he should be well acquainted with their use. 
Also a pair of scissors to cut the zinc plates are useful. 

Wooden casks are not suitable for the packing of specimens 
preserved in spirits, at least not in tropical climates. They 
should be used in cases of necessity only, or for packing of the 
largest examples, or for objects preserved in salt or brine. 

Very small and delicate specimens should never be packed 
together with larger ones, but separately, in small bottles. 

Mode of preserving.—All fishes, with the exception of very 
large ones (broad kinds exceeding 3-4 feet in length ; eel-like 
kinds more than 6 feet long), should be preserved in spirits, A 
deep cut should be made in the abdomen between the pectoral 
fins, another in front of the vent, and one or two more, according 
to the length of the fish, along the middle line of the abdomen. 
These cuts are made partly to remove the fluid and easily decom- 
posing contents of the intestinal tract, partly to allow the spirit 
quickly to penetrate into the interior. In large fleshy fishes 
several deep incisions should be made with the scalpel into the 
thickest parts of the dorsal and caudal muscles, to give ready 
entrance to the spirits. The specimens are then placed in one of 
the provisional boxes, in order to extract, by means of the spirit, 
the water of which fishes contain a large quantity. After a few 
days (in hot climates after 24 or 48 hours) the specimens are 
transferred into a second box with stronger spirits, and left 
therein for several days. A similar third and, in hot climates 
sometimes a fourth, transfer is necessary. This depends entirely 
on the condition of the specimens. If, after ten or fourteen 
days of such treatment the specimens are firm and in good con- 
dition, they may be left in the spirits last used until they are 


700 DIRECTIONS 


finally packed. But if they should be soft, very flexible, and 
discharge a discoloured bloody mucus, they must be put back in 
spirits at least 20° over proof. Specimens showing distinct signs 
of decomposition should be thrown away, as they imperil all other 
specimens in the same vessel. Neither should any specimen in 
which decomposition has commenced when found, be received for 
the collecting boxes, unless it be of a very rare species, when the 
attempt may be made to preserve it separately in the strongest 
spirits available. The fresher the specimens to be preserved are, 
the better is the chance of keeping them in a perfect condition. 
Specimens which have lost their scales, or are otherwise much 
injured, should not be kept. Herring-like fishes, and others with 
deciduous scales, are better wrapped in thin paper or linen before 
being placed in spirits. 

The spirits used during this all-important process of preserva- 
tion loses, of course, gradually in strength. As long as it keeps 
10° under proof it may still be used for the first stage of preser- 
vation, but weaker spirits should be re-distilled ; or, if the collector 
cannot do this, it should be at least filtered through powdered 
charcoal before it is mixed with stronger spirits. Many collectors 
are satisfied with removing the thick sediment collected at the 
bottom of the vessel, and use their spirits over and over again 
without removing from it by filtration the decomposing matter 
with which it has been impregnated, and which entirely neutralises 
the preserving property of the spirits. The result is generally 
the loss of the collection on its journey home. The collector can 
easily detect the vitiated character of his spirits by its bad smell. 
He must frequently examine his specimens ; and attention to the 
rules given, with a little practice and perseverance, after the 
possible failure of the first trial, will soon insure to him the safety 
of his collected treasures. The trouble cf collecting specimens 
in spirits is infinitely less than that of preserving skins or dry 
specimens of any kind. 

When a sufficient number of well-preserved examples have 
been brought together, they should be sent home by the earliest 
opportunity. Each specimen should be wrapped separately in a 
piece of linen, or at least soft paper; the specimens are then 
packed as close as herrings in the zine case, so that no free space 


FOR COLLECTING. 701 


is left either at the top or on the sides. When the case is full, 
the lid is soldered on, with a round hole about half an inch in 
diameter near one of the corners. This hole is left in order to 
pour the spirit through it into the case. Care is taken to drive 
out the air which may remain between the specimens, and to 
surround them completely with spirits, until the case is quite 
full. Finally, the hole is closed by a small square lid of tin 
being soldered over it. In order to see whether the case keeps 
in the spirit perfectly, it is turned upside down and left over 
night. When all is found to be securely fastened, the zinc case is 
placed into the wooden box and ready for transport. 

Now and then it happens in tropical climates that collectors 
are unable to keep fishes from decomposition even in the strongest 
spirits without being able to detect the cause. In such cases a 
remedy will be found in mixing a small quantity of arsenic or 
sublimate with the spirits ; but the collector ought to inform his 
correspondent, or the recipient of the collection, of this admix- 
ture having been made. ; 

In former times fishes of every kind, even those of small size, 
were preserved dry as flat skins or stuffed. Specimens thus pre- 
pared admit of a very superficial examination only, and therefore 
this method of conservation has been abandoned in all larger 
museums, and should be employed exceptionally only, for in- 
stance on long voyages overland, during which, owing to the 
difficulty of transport, neither spirits nor vessels can be carried. 
To make up as much as possible for the imperfection of such 
specimens, the collector ought to sketch the fish before it is 
skinned, and to colour the sketch if the species is ornamented 
with colours likely to disappear in the dry example. Collectors 
who have the requisite time and skill, ought to accompany their 
collections with drawings coloured from the living fishes ; but at 
the same time it must be remembered that, valuable as such 
drawings are if accompanied by the originals from which they 
were made, they can never replace the latter, and possess a sub- 
ordinate scientific value only. 

Very large fishes can be preserved as skins only ; and col- 
lectors are strongly recommended to prepare in this manner the 
largest examples obtainable, although it will entail some trouble 


702 DIRECTIONS 


and expense. So very few large examples are exhibited in 
museums, the majority of the species being known from the 
young stage only, that the collector will find himself amply 
recompensed by attending to these desiderata. 

Sealy fishes are skinned thus: with a strong pair of scissors 
an incision is made along the median line of the abdomen from 
the foremost part of the throat, passing on one side of the base 
of the ventral and anal fins, to the root of the caudal fin, the 
cut being continued upwards to the back of the tail close to the 
base of the caudal. The skin of one side of the fish is then 
severed with the scalpel from the underlying muscles to the 
median line of the back; the bones which support the dorsal 
and caudal are cut through, so that these fins remain attached 
to the skin. The removal of the skin of the opposite side 
is easy. More difficult is the preparation of the head and 
scapulary region; the two halves of the scapular arch which 
have been severed from each other by the first incision are 
pressed towards the right and left, and the spine is severed 
behind the head, so that now only the head and shoulder bones 
remain attached to the skin. These parts have to be cleaned 
from the inside, all soft parts, the branchial and hyoid apparatus, 
and all smaller bones, being cut away with the scissors or scraped 
off with the scalpel. In many fishes, which are provided with 
a characteristic dental apparatus in the pharynx (Labroids, Cypri- 
noids), the pharyngeal bones ought to be preserved, and tied 
with a thread to the specimen. The skin being now prepared 
so far, its entire inner surface as well as the inner side of the 
head are rubbed with arsenical soap; cotton-wool, or some 
other soft material is inserted into any cavities or hollows, and 
finally a thin layer of the same material is placed between the 
two flaps of the skin. The specimen is then dried under a 
slight weight to keep it from shrinking. 

The scales of some fishes, as for instance of many kinds of 
herrings, are so delicate and deciduous that the mere handling 
causes them to rub off easily. Such fishes may be covered with 
thin paper (tissue-paper is the best), which is allowed to dry on 
them before skinning. There is no need for removing the paper 
before the specimen has reached its destination. 


FOR COLLECTING. 703 


Scaleless Fishes, as Siluroids and Sturgeons, are skinned in 
the same manner, but the skin can be rolled up over the head ; 
such skins can also be preserved in spirits, in which case the 
traveller may save to himself the trouble of cleaning the head. 

Some Sharks are known to attain to a length of 30 feet, and 
some Rays to a width of 20 feet. The preservation of such 
gigantic specimens is much to be recommended, and although 
the difficulties of preserving fishes increase with their size, the 
operation is facilitated, because the skins of all Sharks and Rays 
can easily be preserved in salt and strong brine. Sharks are 
skinned much in the same way as ordinary fishes. In Rays an 
incision is made not only from the snout to the end of the fleshy 
part of the tail, but also a second across the widest part of the 
body. When the skin is removed from the fish, it is placed into 
a cask with strong brine mixed with alum, the head occupying 
the upper part of the cask; this is necessary, because this part 
is most likely to show signs of decomposition, and therefore 
most requires supervision. When the preserving fluid has 
become decidedly weaker from the extracted blood and water, 
it is thrown away and replaced by fresh brine. After a week’s 
or fortnight’s soaking the skin is taken out of the cask to allow 
the fluid to drain off; its inner side is covered with a thin layer 
of salt, and after being rolled up (the head being inside) it is 
packed in a cask, the bottom of which is covered with salt; all 
the interstices and the top are likewise filled with salt. The 
cask must be perfectly water-tight. 

Of all larger examples of which the skin is prepared, the 
measurements should be taken before skinning so as to guide 
the taxidermist in stuffing and mounting the specimens. 

Skeletons of large osseous fishes are as valuable as their 
skins. To preserve them it is only necessary to remove the soft 
parts of the abdominal cavity and the larger masses of muscle, 
the bones being left in their natural continuity. The remaining 
flesh is allowed to dry on the bones, and can be removed by 
proper maceration at home. The fins ought to be as carefully 
attended to as in a skin, and of scaly fishes so much of the 
external skin ought to be preserved as is necessary for the 
determination of the species, as otherwise it is generally im- 
possible to determine more than the genus. 


704 DIRECTIONS 


A few remarks may be added as regards those Faun, which 
promise most results to the explorer, with some hints as to 
desirable information on the life and economic value of fishes. 

It is surprising to find how small the number is of the fresh- 
water faunz which may be regarded as well explored ; the rivers 
of Central Europe, the Lower Nile, the lower and middle course 
of the Ganges, and the lower part of the Amazons are almost the 
only fresh waters in which collections made without discrimina- 
tion would not reward the naturalist. The oceanic areas are 
much better known ; yet almost everywhere novel forms can be 
discovered and new observations made. Most promising and 
partly quite unknown are the following districts :—the Arctic 
Ocean, all coasts south of 38° lat. S., the Cape of Good Hope, 
the Persian Gulf, the coasts of Australia (with the exception of 
Tasmania, New South Wales, and New Zealand), many of the 
little-visited groups of Pacific islands, the coasts of north-eastern 
Asia north of 35° lat. N., and the western coasts of North and 
South America. 

No opportunity should be lost to obtain pelagic forms, especi- 
ally the young larva-like stages of development abounding on the 
surface of the open ocean. They can be obtained without diffi- 
culty by means of a small narrow meshed net dragged behind 
the ship. ‘The sac of the net is about 3 feet deep, and fastened 
to a strong brass-ring 2 or 24 feet in diameter. The net is 
suspended by three lines passing into the strong main line. It 
can only be used when the vessel moves very slowly, its speed- 
not exceeding three knots an hour, or when a current passes the 
ship whilst at anchor. To keep the net in a vertical position 
the ring can be weighted at one point of its circumference ; and 
by using heavier weights two or three drag-nets can be used 
simultaneously at different depths. This kind of fishing should 
be tried at night as well as day, as many fishes come to the 
surface only after sunset. The net must not be left long in the , 
water, from 5 to 20 minutes only, as delicate objects would be 
sure to be destroyed by the force of the water passing through 
the meshes. 

Objects found floating on the surface, as wood, baskets, sea- 
weed, etc., deserve the attention of the travellers, as they are 
generally surrounded by small fishes or other marine animals. 


FOR COLLECTING. 705 


It is of the greatest importance to note the longitude and 
latitude at which the objects were collected in the open ocean. 

Fishing in great depths by means of the dredge, can be 
practised only from vessels specially fitted out for the purpose ; 
and the success which attended the “Challenger,” and North 
American Deep-sea explorations, has developed Deep-sea fishing 
into such a speciality that the requisite information can be 
gathered better by consulting the reports of those expeditions 
than from a general account, such as could be given in the present 
work. 

Fishes offer an extraordinary variety with regard to their 
habits, growth, etc., so that it is impossible to enumerate in 
detail the points of interest to which the travellers should pay 
particular attention. However, the followmg hints may be 
useful. 

Above all, detailed accounts are desirable of all fishes forming 
important articles of trade, or capable of becoming more generally 
useful than they are at present. Therefore, deserving of special 
attention are the Sturgeons, Gadoids, Thyrsites and Chilodactylus, 
Salmonoids, Clupeoids. Wherever these fishes are found in 
sufficient abundance, new sources may be opened to trade. 

Exact observations should be made on the fishes the flesh of 
which is poisonous either constantly or at certain times and 
certain localities ; the cause of the poisonous qualities as well as 
the nature of the poison should be ascertained. Likewise the 
poison of fishes provided with special poison-organs requires to be 
experimentally examined, especially with regard to its effects on 
other fishes and animals generally. 

All observations directed to sex, mode of propagation, and 
development, will have special interest: thus those relating to 
secondary sexual characters, hermaphroditism, numeric proportion 
of the sexes, time of spawning and migration, mode of spawning, 
construction of nests, care of progeny, change of form during 
growth, ete. 

If the collector is unable to preserve the largest individuals 
of a species that may come under his observation he should note 
at least their measurements. There are but few species of fishes 
of which the limit of growth is known. 

The history of Parasitic Fishes is almost unknown, and any 

22 


706 DIRECTIONS FOR COLLECTING. 


observations with regard to their relation to their host as well 
as to their early life will prove to be valuable ; nothing is known 
of the propagation of fishes even so common as Echeneis and 
Fierasfer, much less of the parasitic Freshwater Siluroids. 

The temperature of the blood of the larger freshwater and 
marine species should be exactly measured. 

Many pelagic and deep-sea fishes are provided with peculiar 
small round organs of a mother-of-pearl colour, distributed in 
series along the side of the body, especially along the abdomen. 
Some zoologists consider these organs as accessory eyes, others 
(and it appears to us with better reason) as luminous organs. 
They deserve an accurate microscopic examination made on fresh 
specimens ; and their function should be ascertained from obser- 
vation of the living fishes, especially also with regard to the 
question, whether or not the luminosity (if such be their function) 
is subject to the will of the fish. 


Fig. 821.—Scopelus boops, a pelagic fish, with luminous organs. 


ABDOMINAL Cavity, 123 
Abdominal fins, 42 
Abramis, 602 
Abrostomus, 596 
Acanthaphritis, 466 
Acanthias, 331 
Acanthicus, 576 
Acanthobrama, 604 
Acanthoclinus, 498 
Acanthodes, 355 
Acanthodini, 355 
Acantholabrus, 528 
Acanthonus, 547 
Acanthophthalmus, 606 
Acanthopsis, 606 
Acanthopterygian, 41 
Acanthopterygii, 374 
Acanthorhodeus, 601 
Acanthurus, 438, 439 
Acanus, 421 

Acara, 536 
Acclimatisation, 185 
Acentronura, 683 
Acerina, 378 
Acestra, 579 
Achilognathus, 601 
Acipenser, 361 
Acipenseride, 360 
Acrochilus, 601 
Acrochordonichthys, 567 
Acrodus, 330 
Acrogaster, 421 
Acrognathus, 631 
Acrolepis, 570 
Acronuride, 438 
Acronurus, 439 
Acropoma, 395 
Acyprinoid division, 218 
Adipose eye-lid, 113 
Adipose fin, 42 
Aegeonichthys, 476 
Aellopos, 325 
Aelurichthys, 569 
Aesopia, 558 
Aétobatis, 345 
African region, 227 


INDEX. 


ee 


Agassiz, 20, 31, 32 
Ageniosus, 572 
Agnus, 463 
Agoniates, 610 
Agonostoma, 504 
Agonus, 480 
Agrammus, 491 
Agriopus, 416 

Ailia, 566 
Aipichthys, 441 
Air-bladder, 142 
Akysis, 567 
Albacore, 458 
Albinism, 183 
Alborella, 604 
Albula, 660 
Albulichthys, 596 
Alburnus, 603 
Alepocephalus, 664 
Alestes, 608 

Ale-wife, 659 
Alisphenoid, 56, 88 
Allice Shad, 659 
Alopecias, 322 
Ambassis, 393 
Amblyopsis, 618 
Amblyopus, 489 
Amblypharyngodon, 598 
Amblypterus, 370 
Amblyrhynchichthys, 596) 
Amia, 372 
Amioidei, 370 
Amiurus, 567 
Ammocoetes, 693 
Ammodytes, 550 
Ammopleurops, 559 
Ammotretis, 557 
Amphioxus, 696 
Amphipnous, 668 
Amphiprion, 525 
Amphisile, 509 
Amphistium, 442 
Anabas, 516 
Anableps, 617 
Anacanthini, 537 
Anacanthus, 684 


Anacyrtus, 611 
Anal fin, 40, 42 
Anampses, 529 
Anapterus, 582 
Anarrhichas, 492 
Anastomus, 608 
Anchovy, 656 
Ancistrodon, 319 
Ancylodon, 430 
Anema, 463 
Anenchelum, 433 
Angel-fish, 334 
Angler, 470 
Anguilla, 671 
Angular bone, 54, 91 
Anomalops, 449 
Anoplogaster, 422 
Antarctic ocean, 289 
Antennarius, 473 
Anthias, 380 
Anticitharus, 556 
Antigonia, 449 
Aphanopus, 434 
Aphareus, 390 
Aphoristia, 559 _ 
Aphredoderus, 396 
Aphritis, 466 
Aphyocharax, 610 
Aphyocypris, 598 
Aphyonus, 548 
Apionichthys, 559 
Apistus, 415 
Aploactis, 417 
Apocryptes, 487 
Apodichthys, 496 
Apogon, 394 
Apophyses, 51 
Appendices pylorice, 131 
Aprion, 397 
Apsilus, 397 
Apua, 606 
Arapaima, 654 
Archeus, 442 
Archipterygium 74 
Arctic ocean, 261 
Arctic zone, 241 


708 


Argentina, 650 
Arges, 575 
Argyropelecus, 628 
Argyriosus, 443 
Aristotle, 1 

Arius, 569 
Arnoglossus, 556 
Arrhamphus, 621 
Arripis, 393 

Artedi, 9 

Artedius, 480 
Arthropterus, 342 
Articulary bone, 54, 90 
Articulated rays, 40 
Asima, 405 
Aspidoparia, 602 
Aspidophoroides, 480 
Aspidorhynchide, 369 
Aspius, 603 
Aspredo, 580 
Aspro, 379 
Astracanthus, 314 
Astrape, 340 
Astrolepis, 354 
Astronesthes, 629 
Astrophysus, 572 
Astroplebus, 575 
Astroptychius, 314 
Ateleopus, 553 
Atherina, 500 
Atherinichthys, 501 
Atlantic, tropical, 278 
Atlantic, northern, 262 
Atopochilus, 570 
Atopomycterus, 689 
Atypichthys, 402 
Auchenaspis, 354 
Auchenipterus, 572 
Auchenoglanis, 569 
Aulacocephalus, 383 
Aulolepis, 631 
Aulichthys, 508 
Auliscops, 507, 508 
Aulopus, 587 
Aulopyge, 596 
Aulorhynchus, 508 
Aulostoma, 507, 508 
Ausonia, 455 
Ausonius, 3 
Autochthont, 214 
Autostylic skull, 71 
Auxis, 459 

Avola, 604 


Bapts, 418 
Baer, 32 
Bagarius, 570 
Bagrichthys, 567 
Bagroides, 567 


INDEX, 


Bagropsis, 568 
Bagrus, 567 

Baird, 29 

Bakker, 82 

Balfour, 32, 33 
Balistes, 684 

Ballan Wrasse, 527 
Band-fish, 490 
Barbel, 594 
Barbels, 37 
Barbichthys, 596 
Barbus, 594 
Barilius, 602 
Barracuda, 437, 499 
Barramunda, 357 
Barynotus, 596 
Basibranchial, 58 
Basihyal, 58 
Basioccipital, 56, 87 
Basisphenoid, 56, 57, 89 
Basking shark, 322 
Bass, 376 

Bastard Dorey, 388 
Bathydraco, 465 
Bathygadus, 552 
Bathylagus, 650 
Bathynectes, 547 
Bathyophis, 629 
Bathypterois, 583 
Bathysaurus, 582 
Bathythrissa, 668 
Bathytroctes, 664 
Batoidei, 335 
Batrachocephalus, 570 
Batrachus, 467 
Bayad, 567 
Bdellostoma, 695 
Becker, 408 
Bellows-fish, 509 
Belodontichthys, 566 
Belon, 3 

Belone, 620 
Belonesox, 617 
Belonostomus, 369 
Bembras, 480 
Benedenius, 370 
Benthophilus, 489 
Beryeidee, 420 
Berycopsis, 421 
Beryx, 422 

Betta, 518 

Bib, 541 

Bichir, 364 
Bitterling, 601 
Black Bass, 393 
Black-fish, 452, 527 
Black Head, 596 
Black Horses, 589 
Black Sea-bream, 406 


Blanchard, 28 

Bleak, 604 

Bleeker, 30 
Bleekeria, 550 
Blenniide, 492 
Blenniops, 496 
Blennius, 493 
Blennodesmus, 538 
Blennophis, 498 
Blenny, 492 
Blepsias, 480 

Blind fish, 618 
Bloch, 13 
Blood-corpuscles, 150 
Blue-fish, 447 
Boar-fish, 388, 449 
Bocage, 28 

Bocourt, 31 

Bola, 602 
Boleophthalmus, 487 
Boleosoma, 379 
Bolty, 535 
Bombay-duck, 584 
Bonaparte, 28 
Bonelli, 7 

Bonito, 458 

Bony Pike, 367 
Borer, 694 

Botia, 605 
Bovichthys, 465 
Bow-tin, 372 

Box, 406 
Brachionichthys, 474 
Brachymystax, 646 
Brachypleura, 556 
Brackish water fishes, 250 
Brain, 97 

Brama, 454 
Branched rays, 40 
Branchie, 1386 
Branchial arches, 58 . 
Branchiostegals, 39, 58, 91 
Branchiostoma, 696 
Bream, 602 
Bregmaceros, 545 
Brill, 555 

British district, 263 
Brontes, 575 
Brook-trout, 646 
Brosmius, 546 
Brotula, 546 
Brotulophis, 549 
Briinnich, 13 
Brycon, 610 
Bryconethiops, 610 
Bryconops, 610 
Bryttus, 396 

Buccal cavity, 123 
Bulbus aorte, 152 


Bull-head, 476 
Bull-trout, 644 
Bulti, 535 

Buffaloe, 589 
Bummaloh, 584 
Bungia, 596 
Bunocephalichthys, 580 
Bunocephalus, 580 
Bunocottus, 480 
Burbot, 544 

Bursa entiana, 128 
Burton Skate, 341 
Butter-fish, 496, 533 
Bynni, 594 

Bythites, 549 


Cacutus, 604 
Cexnotropus, 607 
Cesio, 390 
Calamoichthys, 364 
Californian district, 271 
Calamostoma, 680 
Callanthias, 381 
Callichrous, 566 
Callichthys, 575 
Callionymus, 489 
Callipteryx, 462 
Callomystax, 573 
Callophysus, 569 
Callorhynchus, 350 
Callyodon, 552 
Camper, 16 
Campostoma, 596 
Cantharina, 405 
Cantharus, 405 
Cantor, 30 

Capelin, 647 
Capello, 28 

Cape of Good Hope, 283 
Capitodus, 405 
Capoeta, 593 
Capros, 449 
Carangide, 440 
Carangopsis, 442 
Caranx, 442 
Carapus, 667 
Carassius, 591 
Carboniferous fishes, 196 
Carcharias, 316 
Carchariide, 316 
Carcharodon, 320 
Carcharopsis, 319 
Cardlike teeth, 126 
Caribe, 613 
Carmoot, 563 
Carp, 589 

Carpals, 59 
Carpiodes, 589 
Cartilage-bones, 87 


INDEX. 


Castelnau, 31 
Cataphracti, 480 
Cat-fishes, 568 
Catla, 592 
Catopra, 418 
Catoprion, 613 
Catostomus, 589 
Caturide, 371 
Caudal fin, 40 
Cebidichthys, 498 
Central American district, 
279 
Centrarchus, 396 
Centridermichthys, 477 
Centrina, 331 
Centriscus, 509 
Centrolabrus, 528 
Centrolepis, 370 
Centrolophus, 452 
Centromochlus, 572 
Centronotus, 496 
Centrophorus, 331 
Centropogon, 417 
Centropomus, 379 
Centropristis, 380 
Centroseyllium, 332 
Centrum, 51 
Cephalacanthus, 482 
Cephalaspis, 353 
Cephaloptera, 347 
Cephenoplosus, 368 
Cepola, 490 
Ceratias, 472 
Ceratichthys, 596 
Ceratobranchial, 58 
Ceratodus, 357 
Ceratohyal, 58 
Ceratoptera, 347 
Cerebellum, 97 
Cestracion, 330 
Cestraciontide, 328 
Cetengraulis, 656 
Cetopsis, 572 
Chaca, 564 
Chad, 408 
Chenichthys, 466 
Chetobranchus, 537 
Cheetodon, 398 
Chetopterus, 390 
Cheetostomus, 576 
Chalceus, 610 
Chalcinopsis, 610 
Chalcinus, 610 
Champsodon, 464 
Channa, 513 
Chanodichthys, 604 
Chanos, 662 
Characinidee, 606 
Characodon, 615 


709 


Charr, 645 
Chasmodes, 494 
Chatoéssus, 657 
Chauliodus, 628 
Chaunax, 474 

Cheilio, 530 

Chela, 604 

Chelmo, 399 
Chiasmodus, 546 
Chilian district, 288 
Chilinus, 528 
Chilobranchus, 669 
Chilodactylus, 411 
Chilodipterus, 395 
Chilomycterus, 689 
Chilorhinus, 674 
Chiloscyllium, 326, 327 
Chimera, 349 
Chimeride, 348 
Chimarrhichthys, 466 
Chiracanthus, 355 
Chirocentrites, 656 
Chirocentrodon, 660 
Chirocentrus, 663 
Chirodon, 609 
Chirodus, 370 
Chirolepis, 370 
Chironemus, 411 
Chirus, 491 
Chlorophthalmus, 587 
Cheerops, 530 
Chologaster, 618 
Chomatodus, 329 
Chondropterygii, 313 
Chondrostei, 360 
Chondrosteus, 363 
Chondrostoma, 600 
Chorda dorsalis, 63 
Chorinemus, 446 
Chorismodactylus, 417 
Chorisochismus, 512 
Chromatophors, 183 
Chromides, 534 
Chromis, 535 
Chrysichthys, 567 
Chrysophrys, 409 
Chub, 596, 599, 600 
Cichla, 536 

Cichlops, 466 
Cireulation, organs of, 150 
Cirrhilabrus, 530 
Cirrhina, 596 
Cirrhites, 411 
Cirrhitide, 410 
Cirrostomi, 696 
Citharichthys, 556 
Citharinus, 607 
Citharus, 556 
Cladacanthus, 314 


‘ 


710 


Cladodus, 328 
Clarias, 563 

Clarotes, 567 
Claspers, 167 
Clavicula,. 59, 92 
Clepticus, 530 
Climbing Perch, 516 
Clinus, 495 

Cloudy Bay cod, 549 
Clupea, 658 
Clupeichthys, 660 
Clupeoides, 660 
Cnidoglanis, 564 
Coal-fish, 541 
Cobitis, 605 

Coccia, 628 
Coccosteus, 351 
Cochlognathus, 596 
Cochliodus, 329 
Cock-and-hen Paddle, 484 
Cod-fishes, 539 
Ceecal stomach, 130 
Coelacanthide, 365 
Coelodus, 367 
Coelogaster, 656 
Coelonotus, 681 
Coelorhynchus, 433 
Coffer-fish, 686 
Coilia, 657 
Collichthys, 430 
Commerson, 13 
Conger, 673 
Congrogadina, 550 
Congromureena, 674 
Conodon, 386 
Conodonts, 193 
Conodus, 368 
Conorhynchus, 569 
Conus arteriosus, 151 
Cook, 527 
Copidoglanis, 564 
Coracoid, 59, 92 
Coral-fishes, 397, 525 
Corax, 317 
Coregonus, 647 
Coridodax, 533 
Coris, 530 
Cork-wing, 527 
Cornide, 13 

Corpora quadrigemina, 103, 
Corpora restiformia, 99 
Corpora striata, 100 
Corvina, 430 
Corvo, 429 
Corynopoma, 607 
Coryphena, 452 
Coryphenoides, 552 
Cosmolepis, 370 


Cosmoptychius, 370 


INDEX. 


Cossyphus, 528 
Costa, 28 
Cottoperca, 466 
Cottus, 476 

Cotylis, 512 

Couch, 27 

Couchia, 544 
Craig-fluke, 557 
Creagrutus, 610 
Cremnobates, 495 
Crenicichla, 537 
Crenidens, 406 
Crenilabrus, 527 
Crenuchus, 612 
Crepidogaster, 513 
Cretaceous fishes, 199 
Cricacanthus, 314 
Cristiceps, 495 
Crossochilus, 596 
Crossognathus, 656 
Crossorhinus, 328 
Crossostoma, 604 
Crucian carp, 591 
Crura cerebri, 98 
Cryptacanthodes, 496 
Cryptopterus, 566 
Ctenododipteride, 359 
Ctenodus, 359 
Ctenoid scales, 46 
Ctenolabrus, 527 


Ctenopharyngodon, 601 


Ctenopoma, 516 
Ctenoptychius, 329 
Cubiceps, 456 
Culter, 604 
Curimatus, 607 
Cut-lips, 596 
Cuvier, 17 
Cyathaspis, 354 
Cybium, 459 
Cyclobatis, 340 
Cycloid scales, 46 
Cyclopoma, 375 
Cyclopterus, 484 
Cycloptychius, 370 
Cyclostomata, 691 
Cyclurus, 588 
Cyema, 670 
Cymolutes, 530 
Cynodon, 611 
Cynoglossus, 558 
Cynolebias, 615 
Cyprinide, 587 
Cyprinion, 598 
Cyprinodon, 614 
Cyprinoid division, 217 
Cyprinus, 589 
Cyttidee, 450 
Cyttus, 451 


Das, 557 

Dace, 599, 600 
Dactylopterus, 481 
Dactyloscopus, 498 
Dangila, 596 

Danio, 602 
Daseyllus, 525 
Datnioides, 397 
Daurade, 409 

Day, 30 

Deal-fish, 522 
Decodon, 530 
Deep-sea fishes, 296 
Dekay, 29 
Dendrodus, 365 
Dentary, 54, 91 
Dentex, 389 
Dercetis, 666 
Dermal spines, 53 
Dermoskeleton, 85 
Devil-fishes, 344 
Devonian fishes, 193, 194 
Diagramma, 386 
Diana, 455 
Dibranchus, 475 
Dicerobatis, 347 
Dicotylichthys, 689 
Dicrotus, 437 
Dictyosoma, 498 
Didymaspis, 354 
Digestion, organs of, 121 
Dimeracanthus, 314 
Dinematichthys, 549 
Dinichthys, 352 
Diodon, 689 
Dioecious, 157 
Diplocrepis, 513 
Diplomystax, 569 
Diplophos, 629 
Diploprion, 383 
Diplopterus, 365 
Dipnoi, 855 
Dipterodon, 406 
Dipterus, 359 
Diptychus, 595 
Diretmus, 449 
Discoboli, 483 
Discognathus, 593 
Discopyge, 340 
Distichodus, 612 
Ditrema, 534 
Dog-fishes, 325, 619 
Doliichthys, 487 
Dolphins, 453 
Domesticated fishes, 185 
Domine, 486 
Donovan, 17 

Doras, 572 
Doratonotus, 530 


Dorsal fin, 40 
Dorsch, 540 

Dory, 450 
Doryichthys, 681 
Doydixodon, 406 
Dragonet, 489 
Drepane, 402 
Drepanephorus, 331 
Drum, 427 

Ductor, 442 

Ductus choledochus, 133 
Ductus cysticus, 133 
Duhamel, 13 

Dules, 384 

Duméril, 33 
Dussumieria, 662 
Duverney, 7 
Duymeria, 530 


Haacie-Rays, 344 
Ear, 116 

Echeneis, 460 
Echinorhinus, 333 
Echiostoma, 629 
Ectopterygoid, 90 
Edaphodon, 349 
Eel, 671 

Eel-pout, 544 
Egertonia, 526 
Elacate, 460 
Elasmodus, 349 
Elasmognathus, 349 
Electric Eel, 667 
Electric organs, 94 
Electric Rays, 339 
Electric Sheath-fish, 574 
Eleotris, 488 
Elonichthys, 370 
Elopichthys, 604 
Elops, 661 
Embiotocide, 533 
Encheliophis, 549 
Enchelycore, 677 
Enchodus, 433 
Endoskeleton, 85 
Engraulis, 656 
Enneodon, 687 
Enoplosus, 380 
Entopterygoid, 55, 90 
Epalzeorhynchus, 596 
Ephippus, 402 
Epibranchial, 59 
Epibulus, 528 
Epicoracoid, 59 
Epididymis, 167 
Epigionichthys, 696 
Epihyal, 58 
Epinnula, 436 
Epioticum, 88 


INDEX. 


Epiphysis, 98 
Epitympanie, 55 
Equatorial zone, 218, 272 
Eques, 431 

Equula, 449 
Eremophilus, 581 
Erethistes, 580 
Ericymba, 596 
Erythrichthys, 391 
Erythrinus, 607 
Escholar, 437 

Esox, 624 

Etelis, 397 
Etheostomatide, 379 
Ethmoid, 57, 89 
Etroplus, 534 
Etrumeus, 662 
Euanemus, 572 
Euctenogobius, 487 
Euglyptosternum, 571 
EKugnathus, 368 
Eulachon, 647 
Eulepidotus, 368 
Euoxymetopon, 434 
Euprotomicrus, 334 
Europo-Asiatic region, 243 
Eurynotus, 370 
Eurypholis, 666 
Eurysomus, 370 
Eustira, 604 
EKutropiichthys, 566 
Eutropius, 566 
Evorthodus, 487 
Exoccipital, 56, 87 
Exocoetus, 621 
Exoglossum, 596 
Exostoma, 580 

Eye, 36, 111 


Fasricivs, 13 
Fall-fish, 600 
Fierasfer, 549 
Fighting-fish, 519 
File-fishes, 684 

Fins, 40 
Fishing-Frog, 470 
Fistularia, 507, 508 
Fitzroyia, 615 
Flat-fishes, 553 
Flounder, 557 
Flute-mouth, 507 
Flying-fish, 621 
Flying Gurnard, 482 
Forskal, 13 

Forster, 13 
Freshwater-fishes, 208 
Freshwater-Herring, 645 
Fries and Ekstrom, 27 
Frog-fish, 470 


711 


Frontal bone, 57, 89 
Frost-fish, 436 
Fuegian subregion, 248 
Fundulus, 615 


GapicuLus, 541 
Gadide, 539 
Gadopsis, 537 
Gadus, 539 
Galapagoes district, 280 
Galaxias, 624 
Galeichthys, 569 
Galeocerdo, 317 
Galeoides, 425 
Galeus, 318 

Gallo, 451 
Gambusia, 616 
Ganodus, 349 
Ganoidei, 350 
Ganoid scales, 47 
Gar-pike, 367, 620 
Gaspereau, 659 
Gastrochisma, 455 
Gastrocnemus, 452 
Gastromyzon, 604 
Gastropelecus, 610 
Gastrosteus, 505 
Gastrotokeus, 682 
Gazza, 450 
Gegenbaur, 32 
Gempylus, 437 
Genidens, 569 
Genyoroge, 384 
Genypterus, 549 
Geoffroy, 33 
Geophagus, 537 
Geotria, 693 
Gerres, 388 
Gillaroo, 645 
Gill-cover, 38 
Gill-opening, 38 
Gill-rakers, 59, 139 
Gills, 136 
Gilthead, 409 
Ginglymostoma, 326 
Girardinus, 618 
Girella, 406 
Glanidium, 572 
Glanis, 566 
Glaucosoma, 384 
Globe-fish, 687 
Glossohyal, 58 
Glottis, 149 

Glut, 673 
Glutinous hag, 694 
Glyphidodon, 525 
Glyptauchen, 415 
Glyptolemus, 365 
Glyptolepis, 365 


712 


Glyptopomus, 365 
Glyptosternum, 572 
Gmelin, 13 
Gobiesocide, 510 
Gobiesox, 513 
Gobio, 595 
Gobiodon, 487 
Gobiosoma, 487 
Gobius, 486 

Goby, 486 
Gold-fish, 591 
Gold-Sinny, 527 
Gomphodus, 319 
Gomphosus, 530 
Gonatodus, 370 
Goniognathus, 452 
Gonorhynchus, 652 
Gonostoma, 629 
Gourami, 517 
Grammistes, 382 
Granular teeth, 126 
Graphiurus, 365 
Grayling, 649 
Greenland Shark, 333 
Grey Mullet, 501 
Grig, 673 

Gronow, 12 
Growler, 393 
Growth of Fishes, 170 
Grystes, 392 
Gudgeon, 596 
Gular plates, 80 
Giildenstedt, 13 
Gunellichthys, 498 
Gunnel-fish, 496 
Giinther, 27, 30 
Gurnard, 479 
Gwyniad, 649 
Gymnachirus, 558 
Gymnarchus, 626 
Gymnelis, 538 
Gymnocrotaphus, 406 
Gymnocypris, 595 
Gymnomurena, 677 
Gymnoscopelus, 585 
Gymnotus, 667 
Gyracanthus, 314 
Gyrodus, 367 
Gyropristis, 314 
Gyroptychius, 365 


Happocr, 540 
Hadot, 540 
Heemal arches, 86 
Hemal spine, 52 
Hemapophyses, 51 
Hemulon, 386 
Hag-fish, 694 
Hair-tail, 436 


INDEX. 


Hake, 542 
Halargyreus, 541 
Halec, 656 
Halecidx, 656 
Half-beak, 621 
Halidesmus, 549 
Halieutwa, 475 
Halieutichthys, 475 
Haliophis, 550 
Haller, 16 
Haloporphyrus, 543 
Halosauride, 665 
Hamilton, 17 
Hammerhead, 318 
Hapalogenys, 386 
Haplochilus, 615 
Haplochiton, 651 
Haplodactylina, 406 
Hapuku, 392 
Harpagifer, 467 
Harpodon, 583 
Harttia, 580 

Hasse, 32 
Hasselquist, 13 
Hausen, 361 

Head, 36 

Heart, 150 

Heckel, 28 

Hector, 32 
Heliastes, 525 
Helicophagus, 566 
Heliodus, 359 
Helmichthys, 180 
Helogenes, 567 
Helotes, 385 
Hemerocoetes, 491 
Hemichromis, 535 
Hemiculter, 604 
Hemigaleus, 319 
Hemigymnus, 530 
Hemilepidotus, 480 
Hemiodus, 607 
Hemipimelodus, 569 
Hemipristis, 317 
Hemirhamphus, 621 
Hemirhombus, 556 
Hemirhynchus, 437 
Hemisaurida, 582 
Hemisilurus, 566 
Hemisorubim, 568 
Hemithyrsites, 434 
Hemitrichas, 656 
Hemitripterus, 417 
Heniochus, 399 
Heptanchus, 325 
Heptapterus, 581 
Hermaphroditism, 157 
Heros, 536 
Herring, 658 


Heteracanth, 41 
Heterobranchus, 563 
Heterocercy, 80 
Heteroconger, 674 
Heterognathodon, 389 
Heterolepidotide, 491 
Heteropygii, 618 
Heterostichus, 498 
Heterotis, 655 
Hexanchus, 325 
Hexapsephus, 588 
Himantolophus, 472 
Hippocampus, 683 
Hippoglossoides, 555 
Hippoglossus, 555 
Histiophorus, 431 
Histiopterus, 387 
Holacanthus, 400 
Holibut, 555 
Hollardia, 684 
Holocentrum, 423 
Holocephala, 348 
Holophagus, 365 
Holoptychide, 365 
Holosteus, 619 
Homacanth, 41 
Homaloptera, 604 


Hombron et Jacquinot, 27 


Homelyn Ray, 341 
Homocanthus, 314 
Homocercy, 83 
Homoeolepis, 366 
Homonotus, 421 
Hopladelus, 568 
Hoplichthys, 478 
Hoplognathus, 410 
Hoplopleuride, 665 
Hoplopteryx, 421 
Hoplopygus, 365 
Hoplostethus, 421 
Hoplunnis, 674 
Horse-mackarel, 442 
Hounds, 319 
Huchen, 645 
Humeral arch, 59 
Hunds-fish, 619 
Hunter, 16 

Huro, 393 
Hutton, 32 
Huxley, 33 
Hybernation, 188 
Hybodontide, 328 
Hybognathus, 596 
Hyborhynehus, 596 
Hybridism, 178 
Hydrocyon, 611 
Hygrogonus, 536 
Hyodon, 653 
Hyoid arch, 58 


Hyomandibular, 55, 89 
Hyoprorus, 674 
Hyoptopoma, 578 
Hyostylic skull, 74 
Hypamia, 372 
Hyperoglyphe, 387 
Hyperopisus, 625 
Hypnos, 340 
Hypobranchial, 58 
Hypomessus, 647 
Hypophthalmichthys, 602 
Hypophthalmus, 566 
Hypophysis, 98 
Hypotympanic, 55 
Hypsinotus, 402 
Hypsodon, 500 
Hypural, 53, 84 

Hyrtl, 32 
Hysterocarpus, 534 
Hystricodon, 611 


Icetus, 477 
Ichthyborus, 612 
Ichthyocampus, 681 
Ichthyodorulites, 194 
Ichthyomyzon, 693 
Id, 599 
Ikan sumpit, 403 
Impregnation, artificial, 
186 
Indian region, 220 
Indo-Pacific ocean, 278 
Infraorbital, 54 
Infundibulum, 98 
Interhemals, 53 
Intermaxillary, 53 
Interneurals, 53 
Interoperculum, 38, 55, 91 
Intestine, 127 
Ipnops, 585 
Ischyodus, 349 
Ischyrocephalus, 666 
Isistius, 334 
Isthmus, 39, 58 
Isurus, 457 


JAPANESE DISTRICT, 270 
Jenyns, 27 

Jenynsia, 616 

John Dory, 451 
Jugular fins, 42 

Julis, 529 


KaBELJAv, 540 

Kalm, 13 

Kamtschatkan district, 
269 

Karausche, 591 

Karpfen, 589 


INDEX. 


Kathetostoma, 463 
Kaup, 33 

Kelb el bahr, 611 
Kelb el moyeh, 611 
Kelp-fish, 533 
Keris, 440 
Ketengus, 569 
Kidney, 155 

King of the herrings, 522 
Klein, 12 
Klipvisch, 549 
Klunzinger, 30 
Kner, 27, 28 
Kneria, 606 
Kokopu, 625 
Kolliker, 32 
Kovalevsky, 33 
Kroyer, 27 

Kurtus, 425 


LABBERDAN, 540 
Labeo, 593 
Labials, 64, 69 
Labrax, 376 
Labrichthys, 530 
Labride, 525 
Labroides, 530 
Labrus, 526 
Labyrinthici, 514 
Lachnolemus, 528 
Lachs, 644 
Lacépéde, 15 
Lactarius, 450 
Ladislavia, 596 
Lemargus, 333 
Lemonema, 543 
Lops, 557 

Lais, 566 
Lamine branchiales, 136 
Lamna, 320 
Lamnide, 319 
Lampern, 692 
Lampris, 454 
Lamprey, 692 
Lancelet, 696 
Lanioperca, 397 
Larimus, 431 
Lateral line, 48 
Lates, 377 
Latilus, 466 
Latris, 412 
Latrunculus, 486 
Launce, 550 
Leather-carp, 591 
Lebiasina, 607 
Lemon-sole, 558 
Lentipes, 487 
Lepadogaster, 513 
Lepidoblennius, 498 


713 


Lepidocephalichthys, 606 
Lepidocephalus, 606 
Lepidocottus, 476 
Lepidopsetta, 556 
Lepidopus, 435 
Lepidosiren, 355 
Lepidosteidx, 367 
Lepidotrigla, 479 
Lepidotus, 368 
Lepidozygus, 525 
Leporinus, 608 
Lepracanthus, 314 
Leptacanthus, 314 
Leptobarbus, 597 
Leptocarcharias, 319 
Leptocardii, 696 
Leptocephali, 179 
Leptoichthys, 681 
Leptojulis, 529 
Leptolepide, 371 
Leptopterygius, 515 
Leptoscopus, 463 
Leptosomus, 656 
Leptotrachelus, 666 
Lesson, 26 
Lethrinus, 407 
Leueaspius, 604 
Leuciscus, 598 
Leucosomus, 600 
Liacanthus, 314 
Liachirus, 558 
Liassic fishes, 198 
Lichia, 446 
Ligamentum 
nale, 72 
Limnurgus, 615 
Ling, 544, 549 
Linneus, 10 
Liocassis, 567 
Liopsetta, 556 
Lioscorpius, 415 
Liparis, 485 
Liposarcus, 576 
Liver, 1382 
Loach, 604 
Lobotes, 387 
Lonchurus, 431 
Lophiogobius, 487 
Lophiosilurus, 569 
Lophiostomus, 368 
Lophius, 470 
Lophobranchii, 678 
Lophonectes, 556 
Loricaria, 578 
Lota, 544 
Lotella, 543 
Loxodon, 319 
Lucania, 615 
Lucifuga, 547 


longitudi- 


714 


Luciocephalide, 519 
Luciogobius, 489 
Lucioperca, 378 
Luciosoma, 598 
Luciotrutta, 646 
Lump-sucker, 484 
Liitken, 32 
Lycodes, 537 


MACKEREL, 456, 457 
Mackerel Midge, 544 
Macrodon, 607 
Macrolepis, 421 
Macrones, 567 
Macropoma, 365 
Macropus, 517 
Macrosemius, 368 
Macruride, 557 
Macruronus, 552 
Macrurus, 552 
Mena, 390 
Mahaseer, 594 
Malacanthus, 467 
Malacocephalus, 552 
Malacopterus, 528 
Malacopterygian, 41 
Malacosteus, 629 
Malapterurus, 574 
Mallotus, 647 
Malpighi, 7 
Malpighian corpuscle, 155 
Malthe, 475 
Mandible, 54 
Margrav, 7 
Marine fishes, 254 
Mary sole, 555 
Maskinonge, 624 
Mastacembelus, 498 
Mastoid, 57, 88 
Maurolicus, 628 
Maynea, 538 
Maxillary, 53, 90 
Meagre, 427 
Meckel’s cartilage, 54 
Meda, 601 
Mediterranean 
264 
Medulla oblongata, 98 
Megalichthys, 365 
Megalobrycon, 610 
Megalops, 661 
Meidinger, 13 
Melamphaes, 423 
Melanocetus, 473 
Melanonus, 541 
Membrane-bones, 75, 84 
Mendosoma, 412 
Mene, 455 
Menhaden, 659 


district, 


INDEX. 


Merluccius, 542 
Mesencephalon, 97 
Mesoarium, 158 
Mesodon, 367 
Mesogaster, 500 
Mesolepis, 370 
Mesonauta, 536 
Mesoprion, 384 
Mesops, 537 
Mesopterygium, 70 
Mesotympanie, 55 
Mesturus, 367 
Metacarpals, 59 
Metamorphosis, 170 
Metapterygium, 70 
Metapterygoid, 55, 90 
Metencephalon, 97 
Micracanthus, 519 
Microconodus, 370 
Microdesmus, 538 
Microdon, 367 
Micropogon, 428 
Micropteryx, 443 > 
Micropus, 416 
Microstoma, 650 
Miller’s-thumb, 476 
Minnow, 596, 599 
Minous, 417 
Misgurnus, 604 
Misheup, 408 
Mitchell, 17 
Mixogamous, 177 
Mollienesia, 617 
Molva, 544 
Monacanthus, 684 
Monk-fish, 334 
Monocentris, 421 
Monocirrhus, 418 
Monopterus, 669 
Moon-eye, 653 
Mora, 541 
Mordacia, 693 
Moringua, 675 
Mormyrops, 626 
Mormyrus, 625 
Mossbanker, 659 
Motella, 544 
Mouth, 37, 123 
Moxostoma, 589 
Mud-fish, 372, 619 
Mugil, 501 

Miller, H., 33 
Miiller, J., 22, 32, 33 
Miiller, O. F., 13 
Miller, W., 33 
Mullidae, 403 
Mulloides, 404 
Mullus, 404 
Munro, 16 


Murena, 675 
Mureenesox, 674 
Murenichthys, 674 
Murenolepis, 545 
Murray-Cod, 392 
Muscles, 93 
Muskellunge, 624 
Mustelus, 318 
Mylesinus, 613 
Myletes, 613 
Myliobatis, 344 
Mylocyprinus, 588 
Myloleucus, 601 
Mylopharodon, 601 
Myology, 93 
Myriacanthus, 314 
Myriodon, 383 
Myriolepis, 370 
Myripristis, 423 
Myroconger, 677 
Myrophis, 674 
Myrus, 674 
Mystacoleucus, 598 
Myxine, 695 
Myxodes, 498 
Myxus, 504 


Nanpus, 418 
Nanneethiops, 610 
Nannobrachium, 587 
Nannocampus, 681 
Nannocharax, 608 
Nannostomus, 607 
Narcine, 340 
Naseus, 438, 440 
Nauclerus, 446 
Naucrates, 444 
Nautichthys, 480 
Nealotus, 434 
Nearctic region, 246 
Nebris, 431 

Nebrius, 326 
Neetroplus, 536 
Nefasch, 612 
Nemacanthus, 314 
Nemachilus, 605 
Nemadactylus, 412 
Nematogenys, 581 
Nematops, 557 
Nematoptychius, 370 
Nemichthys, 670 
Nemophis, 498 
Nemopteryx, 434, 539 
Neochanna, 624 
Neoclinus, 498 
Neoconger, 674 
Neophrynichthys, 469 
Neotropical region, 233 
Nerfling, 599 


Nerophis, 681 
Nerves, 103 
Nesiarchus, 434 
Nettastoma, 674 
Neural arches, 85 
Neural spine, 52 
Neurapophyses, 51 
Neurology, 96 
Neuroskeleton, 85 
New Zealand sub-region, 
248 
Nictitating 
113 
Nilsson, 27 
Niphon, 397 
Nomeide, 455 
Nomeus, 456 
Nonnat, 501 
Nordmann, 28 
North American district, 
266 
North 
246 
North Atlantic, 262 
Northern temperate zone, 
262 
Northern zone, 240 
North Pacitic, 268 
Nostrils, 37, 109 
Notacanthus, 523 
Notidanus, 325 
Notochord, 63 
Notoglanis, 569 
Notograptus, 498 
Notopterus, 665 
Notothenia, 466 
Noturus, 568 
Novacula, 529 
Nummopalatus, 526 
Nuria, 598 
Nutrition, organs of, 121 


membrane, 


American region, 


OaR-FISH, 522 
Oblata, 406 
Occipital, 56 
‘ Ochetobius. 602 
Odax, 532 
Odontaspis, 321 
Odonteus, 525 
Odontostomus, 587 
Oil-sardine, 660 
Old Red Sandstone, 194 
Old wife, 406 
Olfactory lobes, 97 
Olfactory organ, 109 
Oligorus, 392 
Oligosarcus, 611 
Olistherops, 533 
Ombre, 429 


INDEX. 


Ombre chevalier, 645 
Omentum, 132 
Onchus, 314 
Oncorhynchus, 646 
Oneirodes, 473 
Oolithic fishes, 199 
Opercular gill, 138 
Operculum, 38, 54, 91 
Ophichthys, 674 
Ophidiidee, 546 
Ophidium, 549 
Ophiocephalide, 513 
Ophiodon, 491 
Ophiopsis, 368 
Opisthognathus, 466 
Opisthopteryx, 656 
Opisthoticum, 88 
Opsariichthys, 602 
Optic lobes, 97 
Oracanthus, 314 
Orbito sphenoid, 57, 88 
Oreinus, 595 
Oreonectes, 606 
Orestias, 615 

Orfe, 599 
Orthacanthus, 334 
Orthagoriscus, 690 
Orthodon, 601 
Orthostomus, 489 
Osbeck, 13 
Osmeroides, 582, 631 
Osmerus, 646 

Os operculare, 91 
Osphromenus, 517 
Osteobrama, 604 
Osteochilus, 596 
Osteogeniosus, 569 
Osteoglossum, 654 
Osteolepis, 365 
Ostracion, 686 

Os transversum, 56 
Otolith, 116 
Otolithus, 430 
Oulachon, 647 
Ovaries, 158, 166 
Ovum, 158, 159, 167 
Owen, 33 
Oxuderces, 489 
Oxyconger, 674 
Oxydoras, 572 
Oxygnathus, 370 
Oxymetopon, 489 
Oxyrhina, 320 
Oxytes, 319 


PACHYCORMUS, 368 
Pachymetopon, 406 
Pachyurus, 430 
Pagellus, 408 


715 


Pagrus, 408 

Paired fins, 42 
Palearctic region, 243 
Paleichthyes, 312 
Paleogadus, 539 
Paleoniscide, 369 
Paleorhynchus, 437 
Paleoscyllium, 326 
Palwospinax, 330 
Palatine, 56, 90 
Palatine arch, 55 
Palimphyes, 457 
Pallas, 13 

Pammelas, 447 
Pancreas, 133 
Pangasius, 566 
Pantodon, 653 
Papilla urogenitalis, 156 
Paracanthobrama, 598 
Paradiplomystax, 569 
Paradise-fish, 517 
Paragoniates, 610 
Paralepis, 585 
Paralichthys, 556 
Paramisgurnus, 606 
Paramyrus, 674 
Paraperca, 375 
Paraphoxinus, 601 
Parapophyses, 51 
Parascopelus, 582 
Parascyllium, 326 
Parasphenoid, 56, 89 
Pardachirus, 558 
Paretroplus, 535 
Parietals, 57, 89 
Pariodon, 581 
Parker, 32 

Parma, 525 

Parnell, 27 
Paroccipital, 56, 88 
Parodon, 607 
Parophrys, 557 
Paropsis, 450 

Parra, 13 
Parr-marks, 631 
Parrot-wrasses, 530 
Patzcus, 497 
Patagonian district, 289 
Peal, 644 

Pectoral arch, 92 
Pectoral fins, 42 
Pediculati, 469 
Pegasus, 482 

Pelagic fishes, 292 
Pelamys, 459 
Pelargorhynchus, 666 
Pelecus, 604 

Pelerin, 322 

Pellona, 660 


716 


Pellonula, 660 
Pelor, 417 
Pelotrophus, 604 
Peltorhamphus, 557 
Pempheris, 425 
Pennant, 13 
Pentaceros, 397 
Pentanemus, 425 
Pentapus, 390 
Pentaroge, 417 
Perea, 375 
Percalabrax, 378 
Perch, 375 
Percichthys, 376 
Percide, 375 
Percilia, 397 
Percis, 464 
Percophis, 466 
Percopsis, 651 


Periophthalmus, 487 


Peristethus, 481 
Permian fishes, 197 


Peruvian district, 280 


Pesce Rey, 501 
Petalopteryx, 480 
Petenia, 536 
Peters, 31 
Petrodus, 329 
Petromyzon, 692 
Petrosal, 56 
Petroscirtes, 494 


Phaneropleuridie, 360 
Pharyngeal bones, 58 
Pharyngognathi, 523 


Pholidichthys, 498 
Pholidophorus, 368 
Photichthys, 629 
Phractocephalus, 56 
5 


Phrynorhombus, 555 


Phycis, 543 
Phyllodus, 526 
Phyllopteryx, 682 
Physiculus, 543 
Physostomi, 559 
Piabuca, 610 
Piabucina, 610 
Pickerell, 624 
Pike, 624 
Pike-perch, 378 
Pilchard, 660 
Pileoma, 379 
Pilot-fish, 444 
Pimelepterus, 410 
Pimelodus, 568 
Pimephales, 596 
Pinguipes, 466 
Pipe-fishes, 680 
Piramutana, 568 
Piratinga, 568 


INDEX. 


Pirinampus, 569 
Piso, 7 

Pituitary gland, 98 
Placodermi, 351 
Placoid scales, 48 
Plagiostomata, 313 
Plagiotremus, 498 
Plagusia, 559 
Plagyodus, 586 
Plaice, 557 
Pla-kat, 519 
Platax, 448 
Platinx, 656 
Platycephalus, 477 
Platycornus, 421 
Platyglossus, 529 
Platynematichthys, 566 
Platypoecilus, 618 
Platyptera, 489 
Platyrhina, 342 
Platysomide, 370 
Platystethus, 450 
Platystoma, 568 
Platystomatichthys, 568 
Platytroctes, 664 
Playfair, 29 
Plecoglossus, 646 
Plecostomus, 576 
Plectropoma, 382 
Plesiops, 418 
Pleurapophyses, 52 
Pleurolepide, 366 
Pleuronectes, 557 
Pleuronectidee, 553 
Pleuropholis, 368 
Plinthophorus, 666 
Plionemus, 442 
Plotosus, 563 
Podabrus, 480 
Podocys, 421 
Poecilia, 617 
Poeciloconger, 674 
Poecilopsetta, 557 
Poey, F., 31 
Pogonias, 427 
Poisonous fishes, 189 
Poisson bleu, 650 
Pollack, 541 
Pollan, 649 
Polyacanthus, 516 
Polycaulus, 480 
Polycentrus, 418 
Polyipnus, 628 
Polymixia, 423 
Polynemus, 425 
Polyodontide, 362 
Polyprion, 582 
Polypteroidei, 363 
Polypterus, 364 


Polyrhizodus, 330 
Pomacanthus, 401 
Pomacentrus, 525 
Pomatomus, 395 
Pomotis, 396 
Pompilus, 444 

Pope, 378 

Porbeagle, 320 

Porgy, 408 

Porichthys, 468 
Portheus, 500 
Porthmeus, 446 

Port Jackson Shark, 330 
Porus abdominalis, 123 
Porus genitalis, 123, 158 
Post-clavicula, 59, 92 
Post-frontal bone, 57, 89 
Post-pliocene fishes, 201 
Post-temporal, 59, 92 
Pout, 541 

Powen, 649 
Preoperculum, 38, 54, 90 
Preorbital, 54 
Prefrontal, 57, 89 
Premaxillary, 53, 90 
Premnas, 525 
Prefiadillas, 575 
Pretympanic, 55 
Priacanthus, 395 
Pride, 693 

Prionotus, 479 
Prionurus, 440 
Pristacanthus, 314 
Pristidae, 336 
Pristigaster, 660 
Pristiophorus, 335 
Pristipoma, 385 
Pristis, 337 

Pristiurus, 326 
Prochilodus, 607 
Prooticum, 88 
Propterus, 368 
Propterygium, 70 
Prosencephalon, 97 
Prosopodasys, 417 
Protamia, 372 
Protocampus, 681 
Protopterus, 356 
Protosphyrena, 500 
Prototroctes, 652 ~ 
Prussian carp, 591 
Psaliodus, 349 
Psammobatis, 342 
Psammodiscus, 557 
Psammodus, 329 
Psammoperca, 378 
Psenes, 456 

Psephurus, 363 
Psettichthys, 556 


Psettodes, 554 
Psettus, 447 
Pseudecheneis, 580 
Pseudeutropius, 566 
Pseudobagrus, 567 
Pseudoberyx, 421 
Pseudoblennius, 498 
Pseudobranchix, 140 
Pseudochalceus, 610 
Pseudochilinus, 530 
Pseudochromis, 466 
Pseudodax, 530 
Pseudoeleginus, 462 
Pseudogobio, 596 
Pseudojulis, 529 
Pseudolabuea, 604 
Pseudoperilampus, 601 
Pseudophycis, 542 
Pseudoplesiops, 466 
Pseudorasbora, 596 
Pseudorhombus, 556 
Pseudoscarus, 532 
Pseudosyngnathus, 680 
Pseudovomer, 442 
Pseudoxiphophorus, 617 
Psilorhynchus, 604 
Psychrolutes, 469 
Pteraclis, 455 
Pteragogus, 530 
Pteraspis, 354 
Pterichthys, 351 
Pteroplatea, 344 
Pteridium, 549 
Pterois, 415 
Pterophyllum, 537 
Pteropsarion, 602 
Pterygocephalus, 492 
Pterygoid, 56 
Pterygoplichthys, 576 
Ptychacanthus, 314 
Ptychobarbus, 595 
Ptychodus, 330 
Ptycholepis, 368 
Ptyonotus, 480 
Pycnodontide, 366 
Pygopterus, 370 
Pyloric appendages, 131 
Pyrrhulina, 607 


QUADRATE Bonz, 55, 89 
Quoy et Gaimard, 26 


Raptus, 59 

Raja, 340 
Raniceps, 544 
Rasbora, 597 
Rasborichthys, 604 
Rathke, 32 

Ray, 8 

Rays of fins, 40 


INDEX. 


Rays, 335, 341 
Red bodies, 147 
Red-dace, 599 
Red-eye, 599 
Red-fin, 599 
Red-horse, 589 
Red mullet, 404 
Regalecus, 522 
Reproduction of lost parts, 
188 
Reproduction, organs of, 
157 
Respiration, organs of, 135 
Rete mirabile, 147 
Retropinna, 647 
Retzius, 32 
Rhabdolepis, 370 
Rhacolepis, 421 
Rhadinichthys, 370 
Rhamphichthys, 666 
Rhamphocottus, 480 
Rhamphosus, 507 
Rhina, 334 
Rhinelepis, 576 
Rhinellus, 656 
Rhinichthys, 596 
Rhinobatus, 338 
Rhinodon, 323 
Rhinodoras, 572 
Rhinoglanis, 573 
Rhinonus, 549 
Rhinoptera, 346 
Rhizodus, 365 
Rhodeus, 601 
Rhomboidichthys, 556 
Rhombosolea, 557 
Rhombus, 555 
Rhynchichthys, 424 
Rhynchobatus, 337 
Rhynchobdella, 498 
Rhynchodus, 349 
Rhypticus, 383 
Rhytiodus, 608 
Rib, 52 
Ribbon-fishes, 520 
Richardson, 27, 28 
Risso, 17 
Rita, 567 
Rivulus, 615 
Roach, 599, 600 
Rock-cook, 528 
Rockling, 544 
Rohteichthys, 597 
Rondelet, 5 
Rosenthal, 32 
Rough Dab, 555 
Rudd, 599 
Ruppell, 29 
Russel, 16 


Saccartus, 474 
Saccobranchus, 565 
Saccodon, 607 
Saccopharynx, 670 
Selbling, 645 
Sail-fish, 589 
Sail-flUuke, 555 
Salanx, 650 
Salarias, 494 
Salivary glands, 124 
Salminus, 611 
Salmo, 631 
Salmon, 644 
Salmon-trout, 644 
Salvelini, 645 
Salviani, 5 
Samaris, 556 
Sand-eel, 550 
Sand-piper, 693 
Sandy Ray, 341 
Sar, 406 

Saragu, 406 
Sareodaces, 611 
Sardine, 660 
Sargina, 406 
Sargo, 406 
Sargodon, 405 
Sargus, 406 
Satanoperca, 537 
Saurenchelys, 674 
Saurichthys, 365 
Saurida, 582 
Sauride, 368 
Saurocephalus, 500 
Saurodipteride, 355 
Saurodontide, 500 
Saurorhamphus, 666 
Saurus, 582 

Saury, 620 
Saw-fishes, 337 
Scabbard-fish, 435 
Seald-fish, 556 
Seales, 45 
Scaphaspis, 354 
Scaphirhynchus, 362 
Scapula, 59, 92 
Scapular arch, 59 
Scarichthys, 531 
Scarus, 526, 530 
Scatharus, 406 
Seatophagus, 401 
Schacra, 602 
Schal, 573 
Schedophilus, 455 
Schell-fisch, 540 
Schelly, 649 
Schilbe, 566 
Schilbichthys, 566 
Schizopygopsis, 595 


717 


718 


Schizothorax, 595 
Schlegel, 29 
Schneider, 15 
Schultze, 33 
Sciades, 568 
Scizna, 429 
Scizvnide, 426 
Scissor, 610 
Sclerodermi, 684 
Sclerognathus, 589 
Scolopsis, 889 
Scomber, 457 
Scombresox, 620 
Scombridee, 456 
Scombroclupea, 656 
Scombrops, 395 
Scopelide, 582 
Scopelosaurus, 587 
Scopelus, 584 
Scorpena, 444 
Scorpenichthys, 480 
Scorpenide, 412 
Scorpis, 402 
Scup, 408 
Seylliodus, 326 
Scylium, 325 
Scymnus, 332 
Sea-bat, 448 
Seabream, 405, 408 
Sea-cat, 493 
Sea-devil, 344, 470 
Sea-hedgehog, 687 
Sea-horses, 682 
Sea-perch, 381 
Seatserpents, 521 
Sea-trout, 644 
Sea-wolf, 493 
Seba, 9 
Sebastes, 413 
Secondary sexual 
acters, 176 
Seingo, 378 
Selache, 322 
Selachoidei, 314 
Semicossyphus, 530 
Semionotus, 368 
Semiophorus, 441, 442 
Semiplotus, 598 
Seriola, 444 
Seriolella, 444, 450 
Seriolichthys, 444 
Serranus, 381 
Serrasalmo, 613 
Setiform teeth, 126 
Sewin, 644 
Sexual characters, 176 
Shad, 659 
Shagreen, 315 
Shagreen Skate, 341 


char- 


INDEX. 


Sharks, 314 
Shark’s fins, 315 
Sheep’s head, 406 
Shiner, 599, 603 
Shore-fishes, 257 
Sicyases, 513 
Sicydium, 487 
Siebold, 28 
Sillago, 464 
Silondia, 566 
Siluranodon, 566 
Silurian fishes, 193 
Silurichthys, 566 
Siluridie, 559 
Silurus, 565 
Siniperca, 376 
Sinus rhomboidalis, 99 
Siphagonus, 481 
Siphonal stomach, 130 
Siphonognathus, 533 
Siphonostoma, 680 
Sirembo, 549 
Sirenide, 355 
Sisor, 580 
Skate, 341 
Skeleton of— 
Amia, 82 
Amphioxus, 63 
Chondropterygians, 66 
Chondrostei, 74 
Cyclostomes, 64 
Dipnoi, 71 
Ganoids, 71 
epidosteus, 80 
olypterus, 77 
~ Teleostei, 83 
Skin, 45 
Skip-jack, 447 
Skipper, 620 
Skull, 51, 85 
Skulpin, 489 
Smaris, 390 
Smear-dab, 557 
Smelt, 647 
Smerdis, 375 
Smiliogaster, 604 
Snapper, 408 
Snock, 437 
Snout, 37 
Solander, 13 
Sole, 557 
Solea, 557 
Solenognathus, 682 
Solenorhynchus, 678 
Solenostoma, 678 
Soleotalpa, 559 
Sonnerat, 13 
Soricidens, 405 
Sorubim, 568 


South Australian district, 
283 
Southern temperate zone, 
281 
Southern zone, 248 
Spaniodon, 656 
Sparide, 405 
Sparnodus, 405 
Sparoid scales, 46 
Spathobatis, 338 
Spathodactylus, 656 
Spatularia, 362 
Spawn-eater, 599 
Spear-fish, 589 
Spherodon, 408 
Spherodontide, 368 
Sphenacanthus, 314 
Sphenocephalus, 421 
Sphenodus, 319 
Sphenoid, 57 
Sphenoideum anterius, 89 
Sphyrena, 499 
Sphyrvenodus, 500 
Spiegel-Karpfen, 591 
Spinacide, 330 
Spinal chord, 96 
Spinal column, 51 
Spinax, 352 
Spines of fins, 40 
Spiracles, 138 
Spiral valve, 128 
Spirobranchus, 516 
Splanchnoskeleton, 85 
Spleen, 133 
Splenial, 54, 91 
Sprat, 659 
Spratelloides, 662 
Squaliobarbus, 602 
Squaloraja, 335 
Squamipinnes, 397 
Squamosal, 88, 89 
Stannius, 32, 33 
Stare-gazer, 462 
Starry Ray, 341 
Stegophilus, 581 
Stegostoma, 326 
Steindachner, 28 
Steller, 13 
Stenostoma, 421 
Sterlet, 361 
Sternarchus, 666 
Sternoptyx, 627 
Sternopygus, 667 
Stethojulis, 529 
Sticheopsis, 498 
Sticheus, 495 
Sticharium, 498 
Stickleback, 505 
Stigmatophora, 681 


Sting Rays, 342 
Stock-fish, 540, 542 
Stomach, 127 
Stomias, 629 
Stone-bass, 382 
Stone-lugger, 596 
Stone-roller, 589 
Stone Toter, 596 
Storer, 29 

Strepsodus, 365 
Strinsia, 541 
Stromateus, 452 
Strophodus, 330 
Sturgeons, 361 
Stygogenes, 575 
Stylodontide, 368 
-Stylohyal, 58 
Stylophorus, 522 
Suboperculum, 38, 55, 91 
Suborbital, 91 
Sucker, 588 
Sucking-fish, 460 
Sudis, 586 

Sun-fishes, 396, 454, 690 
Supraclavicula, 59, 92 
Supraoeccipital, 56, 87 
Supraorbital, 89 
Suprascapula, 59 
Supratemporal, 91 
Surgeon, 439 
Suspensorium of man- 

dible, 55 

Swamimerdam, 7 
Sword-fish, 431 
Symbranchus, 669 
Sympathic nerves, 108 
Symphorus, 390 
Symphysis, 54 
Symphysodon, 537 
Symplectic, 55, 89 
Sympterygia, 342 
Synagris, 390 
Synanceia, 416 
Synaphobranchus, 671 
Synaptura, 558 
Syngnathus, 680 
Synodontis, 573 


TAENIANOTUS, 417 
Taeniura, 343 
Taractes, 454 
Tasmanian subregion, 248 
Taste, organ of, 119 
Taurinichthys, 526 
Tautoga, 527 
Teeth, 121, 124 
Teleostei, 373 
Telescope-fish, 592 
Tellia, 615 


INDEX. 


Temera, 340 
Temmnodon, 446 
Tenacity of life, 186 
Tench, 600 
Tephraeops, 406 
Tephritis, 555 
Tertiary fishes, 200 
Testicles, 162, 167 
Tetragonolepis, 368 
Tetragonopterus, 609 
Tetragonurus, 501 
Tetranematichthys, 572 
Tetraroge, 417 
Tetrodon, 688 
Teuthidide, 418 
Teuthis, 419 
Thalassophryne, 468 
Thalassorhinus, 319 
Thaleichthys, 647 
Thaumas, 334 
Thectodus, 330 
Therapon, 385 
Tholichthys, 172 
Thoracic fins, 42 
Thorn-back, 341 
Thrissonotus, 370 
Thrissopater, 656 
Thrissops, 371 
Thunberg, 13 
Thymallus, 649 
Thynnichthys, 595 
Thynnus, 457 
Thyrsites, 436 
Thysanopsetta, 556 
Tiger-shark, 327 
Tilurus, 180 

Tinea, 599 

Tongue, 124 

Tope, 318 
Top-knot, 555 
Torgoch, 645 
Torpedinide, 338 
Torpedo, 339 
Torsk, 546 

Touch, organ of, 120 
Toxabramis, 604 
Toxotes, 403 
Trachelochismus, 513 
Trachelyopterus, 572 
Trachichthys, 422 
Trachinide, 462 
Trachinops, 418 
Trachinopsis, 462 
Trachinus, 463 
Trachurus, 442 
Trachynotus, 447 
Trachypterus, 522 
Transverse line, 50 
Triacanthodes, 684 


ral 


Triacanthus, 684 
Triacis, 319 
Triznodon, 319 
Trienophorichthys, 487 
Triassic fishes, 197 
Trichiurichthys, 434 
Trichiuride, 433 
Trichiurus, 436 
Trichocyclus, 689 
Trichodiodon, 689 
Trichodon, 466 
Trichogaster, 518 
Trichomycterus, 581 
Trichonotus, 490 
Trichopleura, 417 
Trifureated Hake, 545 
Trigla, 478 
Triglops, 480 
Trigorhina, 338 
Triodon, 687 
Tripterodon, 406 
Tripterygium, 495 
Tristichopterus, 365 
Tristychius, 314 
Trochocopus, 530 
Tropical American region, 
233 
Trout, 644 
Trubu, 660 
Trumpeter, 412 
Trumpet-fish, 509 
Trunk, 39 
Trygon, 343 
Trygonide, 342 
Trygonorhina, 338 
Trypauchen, 489 
Tunny, 458 
Turbinal, 57, 91 
Turbot, 555 
Twaite Shad, 659 
Tyellina, 326 
Tylognathus, 596 
Typhlichthys, 618 
Typhlonus, 548 


Uaru, 536 

Ulna, 59 

Umbra, 429, 619 
Umbrina, 428 
Umbrine, 429 
Undina, 365 
Upeneichthys, 404 
Upeneoides, 404 
Upeneus, 404 
Upokororo, 652 
Uraleptus, 543 
Uranoscopus, 462 
Urinary organs, 155 
Urocampus, 681 


720 


Urocentrus, 498 
Uroconger, 674 
Urogymnus, 343 
Urohyal, 58, 91 
Urolophus, 343 
Uronectes, 538 
Uronemus, 360 
Urosphen, 507 
Urosthenes, 370 
Useful fishes, 189 


VAILLANT, 31 
Valenciennes, 18 
Vandellia, 581 
Velifer, 397 
Vendace, 649 
Ventral fins, 42 
Vertebral column, 51 
Vertical fins, 40 
Villiform teeth, 126 
Viviparous Blenny, 497 
Vogt, 32 


INDEX. 


Vomer (bone), 56, 89 
Vomer (gen.), 441 
Vulsus, 489 


WALLAGo, 566 
Wardichthys, 370 
Weever, 464 
Wels, 565 

Whiff, 555 
White-bait, 658 
White-fish, 599, 648 
Whiting, 541 
Whiting-pout, 541 
Willughby, 8 
Wrasses, 525 


XENOCEPHALUS, 553 
Xenocharax, 612 
Xenocypris, 598 
Xenodermichthys, 664 
Xenomystus, 576 
Xenopterus, 688 


THE END. 


Xiphias, 431 
Xiphidion, 496 
Xiphiide, 431 
Xiphochilus, 530 
Xiphopterus, 434 
Xiphorhampus, 611 
Xiphostoma, 611 


YARRELL, 27 
Yellow-tail, 4 


ZANCHUS, 440 
Zaniolepis, 491 
Zarthe, 603 
Zebra-Shark, 327 
Zeus, 451 
Zoarces, 497 
Zope, 603 
Zuzuki, 378 
Zygaena, 318 
Zygapophyses, 52 
Zygobatis, 346 


Printed by R. & R. Crark, Edinburgh. 


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