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 near the coasts of all

temperate and tropical regions. Geologically they appear first in the

chalk.

GOBIUS.--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.

[Illustration: Fig. 220.--Gobius lentiginosus, from New Zealand.]

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 especially on rocky coasts, attaching

themselves firmly with their ventrals to a rock in almost any position,

and thus withstanding 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 acclimatised in fresh water, especially

lakes. The males of some species construct nests for the eggs, which

they jealously watch, and defend even for some time after the young are

hatched. Several species are found on the British coast: _G. niger_,

_paganellus_, _auratus_, _minutus_, _ruthensparri_. Fossil species of

this genus have been found at Monte Bolca.

A very small Goby, _Latrunculus 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 eggs 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 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

_Euctenogobius_, _Lophiogobius_, _Doliichthys_, _Apocryptes_,

_Evorthodus_, _Gobiosoma_ and _Gobiodon_ (with scaleless body)

_Triænophorichthys_.

SICYDIUM.--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 _Sicydium_.

PERIOPHTHALMUS.--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, immediately

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.

Gill-openings narrow.

The fishes of this genus, and the closely-allied _Boleophthalmus_,

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 crustaceans, and other small animals

disporting themselves on the ground 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 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 singularly enough one species reappears

on the West African coast. About seven species are known (including

_Boleophthalmus_), _P. koelreuteri_ being one of the most common fishes

of the Indian Ocean.

[Illustration: Fig. 221.--Periophthalmus koelreuteri.]

ELEOTRIS.--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

the Indo-Pacific and Atlantic. Others have even penetrated into the

inland-waters of the African continent.

TRYPAUCHEN.--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 _T. vagina_ is common.

CALLIONYMUS.--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

protractile. Eyes rather large, more or less directed upwards.

Teeth very small, palate smooth. A strong spine at the angle of

the præoperculum. 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 (_C. draco_) is

very common, and locally called “Skulpin.” About thirty species are

known, many of which have the præopercular 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_.

TENTH DIVISION--ACANTHOPTERYGII BLENNIIFORMES.

_Body low, sub-cylindrical or compressed, elongate. Dorsal fin 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 fins thoracic or jugular,

if present._

FIRST FAMILY--CEPOLIDÆ.

_Body very elongate, compressed, covered with very small cycloid

scales; eyes rather large, lateral. Teeth of moderate size. No bony

stay for the angle of the præoperculum. 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 vertebræ

exceedingly numerous._

The “Band-fishes” (_Cepola_) are small marine fishes, belonging

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 examples 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--TRICHONOTIDÆ.

_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 præoperculum. 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 vertebræ much exceeding that of the abdominal._

Small marine fishes, belonging to two genera only, _Tricho__notus_

(_setigerus_) from Indian Seas, with some of the anterior dorsal rays

prolonged into filaments; and _Hemerocoetes_ (_acanthorhynchus_) from

New Zealand, and sometimes found far out at sea on the surface.

THIRD FAMILY--HETEROLEPIDOTIDÆ.

_Body oblong, compressed, scaly; eyes lateral; cleft of the mouth

lateral; dentition feeble. The angle of the præoperculum connected by a

bony stay with the infraorbital ring. Dorsal long, with the spinous and

soft portions equally developed; anal elongate. Ventrals thoracic, with

one spine and five rays._

[Illustration: Fig. 222.--Scale from the lateral line of

Hemerocœtes acanthorhynchus, with lacerated margin.]

[Illustration: 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

CHIRUS, which is distinguished by the presence of several

lateral lines;

OPHIODON, with one lateral line only, cycloid scales, and

slightly armed præoperculum;

AGRAMMUS, with one lateral line only, ctenoid scales, and

unarmed præoperculum; and

ZANIOLEPIS, with one lateral line and minute comb-like scales.

FOURTH FAMILY--BLENNIIDÆ.

_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 rudimentary or entirely absent.

Pseudobranchiæ generally present._

Littoral forms of great generic variety, occurring abundantly 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 pseudobranchiæ (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; _Pterygocephalus_ 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.

The “Sea-wolf,” or “Sea-cat” (_A. lupus_), is a gigantic 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.

[Illustration: Fig. 224.--Teeth of the Wolf-fish, _Anarrhichas

lupus_.]

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 which they

even propagate their species. All species readily accustom themselves

to fresh water, and some (_B. 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.

[Illustration: Fig. 225.--Petroscirtes bankieri, from Hong-Kong.]

PETROSCIRTES.--Body moderately elongate, naked. Snout generally

short. A single dorsal fin; ventrals composed of two or three

rays. Cleft of the mouth narrow; a single series of immovable

teeth in the jaws; a strong curved canine tooth behind this

series, that of the lower jaw much stronger than that of the

upper. Head sometimes with tentacles. Gill-opening reduced to a

small fissure above the root of the pectoral.

Thirty species, from the tropical Indo-Pacific, of small size.

[Illustration: Fig. 226.--Dentition of the same, enlarged.]

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

detached anterior part. Ventral fins with two or three rays. A

tentacle above the orbit. Gill-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 in 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 is also the case in _Blennius_.

CLINUS.--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 fin; and _Tripterygium_, with

three distinct dorsal fins, of which the two anterior are spinous. The

species of these genera are as numerous as those of _Clinus_, occurring

in many parts of tropical seas, in the Mediterranean, and being

especially well represented in South Australia and New Zealand.

STICHÆUS.--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.

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 distinct.

Gill-openings of moderate width, the gill-membranes coalescent

across the isthmus.

A fine but not common kind of Blenny (_B. 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; southwards 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. _Apodichthys_ 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 same 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. Gill-opening of

moderate width, with the gill-membranes joined to the isthmus.

One species (_C. maculatus_) from the Atlantic coasts of North America.

PATÆCUS.--Body oblong, elevated anteriorly; snout short, with

subvertical anterior profile; minute teeth in the jaws and on

the vomer. Dorsal fin with the anterior spines strong and long,

continuous with the caudal; ventrals none. Gill-openings wide.

[Illustration: Fig. 227.--Patæcus fronto.]

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. Ventrals

short, formed by three or four rays. Gill-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 impossible to touch it without

causing them to be extruded. Full grown individuals are about twelve

inches long, but the American species (_Z. anguillaris_) attains to a

length of two or three feet.

Other genera of the family of Blennoids are:--_Blennophis_,

_Nemophis_, _Plagiotremus_, _Neoclinus_, _Cebidichthys_, _Myxodes_,

_Heterostichus_, _Dictyosoma_, _Lepidoblennius_, _Dactyloscopus_,

_Gunellichthys_, _Urocentrus_, _Stichæopsis_, _Sticharium_,

_Notograptus_, _Pholidichthys_, and _Pseudoblennius_.

FIFTH FAMILY--ACANTHOCLINIDÆ.

_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--MASTACEMBELIDÆ.

_Body elongate, eel-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 striæ in

_Mastacembelus_: the only two genera of this family. Thirteen species

are known, of which _Rh. aculeata_, _M. pancalus_ and _M. armatus_

are extremely common, the latter attaining to a length of two feet.

Outlying species are _M. aleppensis_ from Mesopotamia and Syria, and

_M. cryptacanthus_, _M. marchei_, and _M. niger_, from West Africa.

[Illustration: Fig. 228.--Mastacembelus argus, from Siam.]

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--SPHYRÆNIDÆ.

_Body elongate, sub-cylindrical, covered with small cycloid scales;

lateral line continuous. Cleft of the mouth wide, armed with strong

teeth. Eye lateral, of moderate size. Vertebræ twenty-four._

This family consists of one genus only, _Sphyræna_, generally 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 Bolca. Some other fossil genera have been

associated with them, but as they are known from jaws and teeth

or vertebræ only, their position in the system cannot be exactly

determined; thus _Sphyrænodus_ 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, _Saurocephalus_,

has been also referred to this family.[44]

SECOND FAMILY--ATHERINIDÆ.

_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. Eye lateral, large or of moderate

size. Gill-openings wide. Vertebræ very numerous._

Small carnivorous fishes inhabiting the seas of the temperate 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 coast of France call

these newly hatched Atherines “Nonnat” (unborn). Some thirty species

are known, of which _A. presbyter_ and _A. boyeri_ occur on the British

coast.

ATHERINICHTHYS, distinguished from _Atherina_ in having the

snout more or less produced; and the cleft of the mouth

generally 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 spines, and continued on to the second.

Lower jaw elevated, with convex dental margin, and armed with

compressed, 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

Medusæ, 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--MUGILIDÆ.

_Body more or less oblong and compressed, covered with cycloid scales

of moderate size; lateral line none. Cleft of the mouth narrow or of

moderate width, without or with feeble teeth. Eye lateral, of moderate

size. Gill-opening wide. The anterior dorsal fin composed of four stiff

spines. Vertebræ twenty-four._

The “Grey Mullets” inhabit in numerous species and in great numbers the

coasts of the temperate and tropical zones. They frequent brackish

waters, in which they find an abundance of food which consists chiefly

of the organic substances mixed with mud or sand; in order to prevent

larger bodies from passing into the stomach, or substances from passing

through 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 pharyngeals 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 inner surface is concave,

corresponding to the convexity of the upper pharyngeals, and provided

with a single series of lamellæ, similar to those of the branchial

arches, but reaching across the bone from one margin to the other.

The intestinal tract shows no less peculiarities. The lower portion

of the œsophagus is provided with numerous long thread-like papillæ,

and continued into the oblong-ovoid membranaceous cœcal 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 thickness 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 number of circumvolutions, and are seven

feet long in a specimen thirteen inches in length.

[Illustration: Fig. 229.--Mugil proboscideus.]

Some seventy species of Grey Mullets are known, the majority of

which attain to a weight of about four pounds, but 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 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 _M.

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--_M. octo-radiatus_ having eight, and _M. capito_

and _M. auratus_ nine soft rays. A species inhabiting fresh waters of

Central America (_M. proboscideus_) has the snout pointed and fleshy,

thus approaching certain other freshwater and littoral Mullets, which,

on account of a modification 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--ACANTHOPTERYGII GASTROSTEIFORMES.

_The spinous dorsal is composed of isolated spines if present;

the ventrals are either thoracic or have an abdominal position in

consequence of the prolongation of the pubic 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--GASTROSTEIDÆ.

_Body elongate, compressed. Cleft of the mouth oblique; villiform

teeth in the jaws. Opercular bones not armed; infraorbitals 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 fin. Ventral fins abdominal, joined to

the pubic bone, composed of a spine and a small ray. Branchiostegals

three._

[Illustration: Fig. 230.--Gastrosteus noveboracensis.]

Of “Sticklebacks” (_Gastrosteus_) about ten species are satisfactorily

known, one of which (_G. spinachia_) lives in salt and brackish water,

whilst the others inhabit 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 (_G.

spinulosus_) and the Nine-spined Stickleback (_G. pungitius_). The

commonest North American species is _G. noveboracensis_. The habits

of all the freshwater species 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

swallowed sixty-two; and would, probably, have eaten as many every day

could they have been procured. The Stickleback 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

conducting her, Costa says, with many caresses, to the nest, introduces

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 eggs 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 a new 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 builder,

choosing for its operations especially the shallows of brackish water,

which are covered with _Zostera_.

SECOND FAMILY--FISTULARIIDÆ.

_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, ventral fins thoracic or abdominal,

composed of five or six rays, without spine; if abdominal, they are

separate from the pubic bones, which remain attached to the humeral

arch. Branchiostegals five._

The “Flute-mouths” are also frequently called “Pipe-fishes,” a name

which they have in common with the Syngnathidæ. 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 geographical 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

Bolca 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

cylindrical body of which is terminated by a large cuneiform fin; and

_Rhamphosus_, which has an immense spinous ray, denticulated behind,

inserted on the nape.

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

(_F. tabaccaria_) and Indian Oceans (_F. serrata_ and _F. depressa_);

they attain to a length of from four to six feet.

The anterior portion of the vertebral column shows the same peculiarity

as in _Dactylopterus_; it is a long compressed tube, composed of four

elongate vertebræ, which are perfectly 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 laminæ,

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 _Aulichthys_ from Japan, are

allied genera.

THIRTEENTH DIVISION--ACANTHOPTERYGII 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, _Centriscidæ_, 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 structure of the mouth and snout as the

Fistulariidæ, 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.

[Illustration: Fig. 231.--Centriscus humerosus.]

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 south, and reappears in

Tasmania. The allied _C. 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 skeleton; 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.

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 Acanthopterygians. The abdominal portion is more than four

times as long as the caudal; nevertheless it is composed of only

six vertebræ, whilst the latter consists of fourteen. The abdominal

vertebræ 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 vertebræ are

extremely short, and the strength of their neural and hæmal spines

is in proportion to their size. The dorsal cuirass is not a dermal

production, but formed by modified parts of the endoskeleton; its

composition, 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 considered 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. 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 cartilaginous 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,

becoming 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 exemplified by

_Chorismochismus dentex_ the coracoid is well developed, and, as

usual, composed of two pieces, the upper of which is not suspended from

the humerus, but fixed by a ligament 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 transformed 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,

_Gobiesocidæ_, are strictly marine but littoral fishes. They are

scattered over the temperate zones of both hemispheres, and more

numerous than between the Tropics. All are of small or very small size.

[Illustration: Fig. 232.--Gobiesox cephalus.]

The adhesive disk consists of an anterior and posterior division. In

some of the genera the posterior division has no free anterior margin,

the teeth being either all conical, as in _Chorisochismus_ (Cape of

Good Hope) and _Cotylis_ (Red Sea 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

Zealand. In the remaining genera, _Crepidogaster_ (from Tasmania and

South Australia), _Trachelochismus_ (from New Zealand and the Fiji

Islands), _Lepadogaster_, and _Leptopterygius_, 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. gouanii_, _L. candollii_, and _L. bimaculatus_--are

prettily coloured, but subject to great variation.

[Illustration: Fig. 233.--Diplocrepis puniceus.]

FIFTEENTH DIVISION--ACANTHOPTERYGII CHANNIFORMES.

_Body elongate, covered with scales of moderate size; no spine in any

of the fins; dorsal and anal long. No superbranchial organ, only a bony

prominence on the anterior surface of the hyomandibular._

These fishes belong to the single family _Ophiocephalidæ_,

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 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 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

of the year in which the fish lives in normal water, and individuals

which are kept in a basin and prevented from coming to the surface

and renewing the air for respiratory purposes, are suffocated. The

particular manner in which the accessory branchial cavity participates

in respiratory functions is not known. It is a simple cavity, without

an accessory branchial organ, the opening of which is partly closed by

a fold of the mucous membrane.

[Illustration: Fig. 234.--Ophiocephalus striatus, India.]

SIXTEENTH DIVISION--ACANTHOPTERYGII LABYRINTHIBRANCHII.

_Body compressed, oblong or elevated, with scales of moderate size. A

superbranchial organ in a cavity accessory to that of the gills._

FIRST FAMILY--LABYRINTHICI.

_Dorsal and anal spines present, but in variable numbers; ventrals

thoracic. Lateral line absent, or more or less distinctly interrupted.

Gill-opening rather narrow, the gill-membranes of both sides

coalescent below the isthmus, and scaly; gills four; pseudobranchiæ

rudimentary or absent._

[Illustration: Fig. 235.--Superbranchial organ of Anabas.]

Freshwater-fishes of the Cyprinoid division of the Equatorial 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 assisting in the oxygenisation of the blood. In _Anabas_ it is

formed by several exceedingly thin bony laminæ, similar in form to the

auricle, and concentrically situated one above the other, the innermost

being the largest. The degree in which these laminæ are developed

is dependent on age. In specimens from one inch and a half to two

inches and a half long there are only two such laminæ, a third being

indicated by a small protuberance at the central base of the second

or outer laminæ. In specimens of from three to four inches in length

the third lamina is developed, covering one-half of the second. The

edges of all the laminæ are straight, not valanced. In specimens of

from four to five inches a fourth lamina makes its appearance in the

basal centre of the third lamina. The other laminæ continue to grow in

their circumference, and their edges now become undulated and slightly

frilled. Cuvier and Valenciennes have examined still larger specimens.

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 laminæ.

The air-bladder of the majority of these fishes is very large,

extending far into the tail, and, therefore, divided behind by the

hæmal 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; præorbital 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 distributed 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 communicated 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 length of seven inches.

_Spirobranchus_ from the Cape, and _Ctenopoma_ from Tropical Africa,

represent _Anabas_ in that continent.

POLYACANTHUS.--Body compressed, oblong; operculum without 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.

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 Lacépède, 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 interrupted or absent.

[Illustration: Fig. 236.--Osphromenus olfax.]

To this genus belongs the celebrated “Gourami” (_Osphromenus olfax_),

reputed to be one of the best flavoured Freshwater-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 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.

BETTA.--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. pugnax_) 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 larvæ of mosquitoes, and had thus lived for

many months. The Siamese are as infatuated 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 considerable

annual revenue to the King of Siam. The species abounds in the rivulets

at the foot of the hills of Penang. The inhabitants name it ‘Pla-kat,’

or the ‘Fighting-fish;’ but the kind kept especially for fighting is an

artificial variety cultivated for the purpose.”

MICRACANTHUS.--This genus represents the three last-named genera in

Africa, where it has been recently discovered in tributaries of the

river Ogooué. It seems to differ from the Indian genera chiefly by its

more elongate body, the structure of the fins being scarcely different

(D. 3/7, A. 4/23, V. 1/4).

SECOND FAMILY--LUCIOCEPHALIDÆ.

_Body elongate, covered with scales of moderate size. Lateral line

present. Teeth small. Gill-opening wide; pseudobranchiæ none. The

superbranchial organ is formed by two branchial arches, which are

dilated into a membrane. One short dorsal fin; dorsal and anal spines

none; ventrals composed 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 _Trachypteridæ_, 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.

EIGHTEENTH DIVISION--ACANTHOPTERYGII TÆNIIFORMES.

_Body riband shaped; dorsal fin as long as the body; anal absent;

caudal rudimentary, or not in the longitudinal axis of the fish._

[Illustration: Fig. 237.--Trachypterus tænia.]

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 high dorsal fin runs along the whole length of

the back, and is supported by extremely numerous 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 position, being directed upwards like a fan. The

ventrals are thoracic, either composed of several rays or reduced to a

single 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; probably

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 narrow 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 meeting 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.”

[Illustration: Fig. 238.--Young Trachypterus.]

Young Ribbon-fishes (from two to four inches) are not rarely met with

near the surface; they possess the most 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-like

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.

Ribbon-fishes are divided into three genera:--

TRACHYPTERUS.--In which the ventral rays are well developed, and

composed of several more or less branched rays. Specimens of this genus

have been taken in the Mediterranean, Atlantic, at Mauritius, and in

the Eastern Pacific. The “Deal-fish” (_T. arcticus_) is often met with

in the North Atlantic, and specimens are generally found after the

equinoctial gales on the coasts of the Orkneys and North Britain.

STYLOPHORUS.--Without ventrals, and with the tail terminating in an

exceedingly long cord-like appendage. Known from one specimen only,

found at the beginning of this century between Cuba and Martinique. It

is eleven inches long, and preserved in the Museum of the Royal College

of Surgeons 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

(_R. banksii_) are sometimes found on the British coasts, but they

are very scarce, not more than sixteen captures having been recorded

between the years 1759 and 1878.

NINETEENTH DIVISION--ACANTHOPTERYGII NOTACANTHIFORMES.

_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 Acanthopterygians. 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 “Challenger”

expedition specimens have been obtained from an alleged depth of 1875

fathoms.

SECOND ORDER:

ACANTHOPTERYGII PHARYNGOGNATHI.

_Part of the rays of the dorsal, anal, and ventral fins are

non-articulated spines. The lower pharyngeals coalesced. Air-bladder

without pneumatic duct._

[Illustration: Fig. 239.--Coalescent Pharyngeals of Scarus

cretensis. _a_, upper; _b_, lower pharyngeals.]

FIRST FAMILY--POMACENTRIDÆ.

_Body short, compressed, covered with ctenoid scales. Dentition

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; pseudobranchiæ

and air-bladder present. Vertebræ, twelve abdominal and fourteen

caudal._

[Illustration: Fig. 240.--Dascyllus aruanus. Natural size, from

the Indo-Pacific.]

The fishes of this family are marine; they resemble the Chætodonts

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 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 _Pomacentridæ_ is co-extensive

with that of the Chætodonts, the species being most numerous in

the Indo-Pacific and Tropical Atlantic, a few extending northwards

to the Mediterranean and Japan, southwards 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

Bolca, allied to _Heliastes_. The recent genera belonging to this

family are:--_Amphiprion_, _Premnas_, _Dascyllus_, _Lepidozygus_,

_Pomacentrus_, _Glyphidodon_, _Parma_, and _Heliastes_. About 120

species are known.

SECOND FAMILY--LABRIDÆ.

_Body oblong or elongate, covered with cycloid scales. The lateral

line extends to the caudal, or is interrupted. One dorsal fin, 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; pseudobranchiæ and air-bladder present. Pyloric

appendages none; stomach without cæcal sac._

[Illustration: Fig. 241.--Lips of a Wrasse, _Labrus

festivus_.]

The “Wrasses” are a large family of littoral fishes, very abundant in

the temperate and tropical zones, but becoming scarcer towards 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 peculiarity which has given to them the German

term of “Lip-fishes.” They feed chiefly 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 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, fitting 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 forwards 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 Labridæ, recognised by their united pharyngeals, which bear

molar-like teeth, are not scarce in tertiary formations of France,

Germany, Italy, and England. 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, _Taurinichthys_, from

the Miocene of France, represents the _Odacina_ of the living fauna.

_Egertonia_, 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 Pharyngodopilidæ, 1866; and _E.

Sauvage_, Sur le genre Nummopalatus, in Bull. Soc. Geol. France,

1875.]

LABRUS.--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.

Young “Wrasses” differ from mature specimens in having the præoperculum

serrated. The headquarters of this genus are the Mediterranean, whence

it ranges, gradually diminishing towards the north, along all the

shores of Europe. Nine species are known; British are the “Ballan

Wrasse” (_L. maculatus_), and the “Striped or Red Wrasse” or “Cook”

(_L. 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 præoperculum; 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 co-extensive 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,” is common on the Atlantic coasts of

temperate North America, and much esteemed as food.

CTENOLABRUS.--Body oblong, covered with scales of moderate 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

_Ct. burgall_ on the North American coasts.

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 preceding North Atlantic

genera.

COSSYPHUS.--Body compressed, oblong, with scales of moderate

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 canine tooth.

Formula of the fins: D. 12/9–11, A. 3/12.

Twenty species are known from the tropical zone and coasts adjoining

it; some, like _G. gouldii_ from Tasmania, attain a length of

three or four feet.

CHILINUS.--Body compressed, oblong, covered with large scales;

lateral line interrupted; cheeks with two series of scales;

præoperculum 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. 9–10/10–9, A. 3/8.

Common in the tropical Indo-Pacific, whence more than twenty species

are known. Hybrids between the different species of this genus are not

uncommon.

EPIBULUS.--Closely allied to the preceding genus, but with

a very protractile mouth, the ascending branches of the

intermaxillaries, the mandibles, and the tympanic being much

prolonged.

This fish (_E. 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,

compressed, with cutting edge. D. 9/12, A. 3/12.

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. 9/12, A. 3/12; 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 distribution,

and of like beautiful coloration and similar habits. Some of the most

common fishes of the Indo-Pacific, as _J. lunaris_, _trilobata_, and

_dorsalis_, belong to this genus.

CORIS.--Scales 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_, _Duymæria_, _Cirrhilabrus_, _Doratonotus_,

_Pseudochilinus_, _Hemigymnus_, _Gomphosus_, _Cheilio_, and _Cymolutes_.

PSEUDODAX.--Scales of moderate size; lateral line continuous;

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 Archipelago.

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, pungent; 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 _Scarus_ one species (_S. cretensis_)

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 passages 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 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 _(Nunc 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 diarrhœa. 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 _Scaro_, 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 forwards 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.

[Illustration: Fig. 242.--Scarichthys auritus.]

SCARICHTHYS.--Differing from _Scarus_ only in having flexible

dorsal spines.

Two species from the Indo-Pacific.

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 dentigerous 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 being 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

specimens 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.

ODAX.--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.

[Illustration: Fig. 243.--Odax radiatus.]

Six species from the coasts of Australia and New Zealand. Small. The

species figured (_O. radiatus_) is from Western Australia.

CORIDODAX.--Jaws as in _Odax_, head naked. Scales 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 _Belone_.

OLISTHEROPS, from King George’s Sound, has scales of moderate size, but

agrees otherwise with _Coridodax_.

SIPHONOGNATHUS.--Head and body very elongate, snout long, as in

_Fistularia_; upper 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 retained, but united

with a form of the body which resembles that of a Pipe-fish.

THIRD FAMILY--EMBIOTOCIDÆ.

_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 is 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. Pseudobranchiæ 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 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 membranous 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 proportionate

size of the young is very remarkable. In a female specimen 10½ inches

long, and 4½ 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.

FOURTH 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. Pseudobranchiæ none. Stomach

coecal; pyloric appendages 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 circumvolutions 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 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,

lamelliform, 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 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.

[Illustration: Fig. 244.--_Chromis andreæ_, from the Lake of

Galilee.]

HEMICHROMIS, differing from _Chromis_ in having conical teeth in

one or two series.

Ten species, the range of which is co-extensive 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.

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 common 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 species. They are of rather small

size, rarely exceeding a length of twelve inches.

[Illustration: Fig. 245.--_Heros salvini_, from Central

America.]

Genera allied to _Heros_, and likewise from Tropical America, are

_Neetroplus_, _Mesonauta_, _Petenia_, _Uaru_, and _Hygrogonus_.

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.

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. Præopercular 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:

_Chætobranchus_, _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, if present, without

pneumatic 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 portion of the dorsal and anal

fins formed of spines.

FIRST DIVISION--ANACANTHINI GADOIDEI.

_Head and body symmetrically formed._

FIRST FAMILY--LYCODIDÆ.

_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.

LYCODES.--Body elongate, covered with minute scales imbedded in

the skin, or naked; lateral line more or less indistinct. Eye

of moderate size. Ventral small, short, rudimentary, jugular,

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.

Pseudobranchiæ present. Air-bladder none. Pyloric appendages

two, or rudimentary, or entirely absent. No prominent anal

papilla.

[Illustration: Fig. 246.--Lycodes mucosus, from Northumberland

Sound.]

Nine species are known from the Arctic Ocean, four from the southern

extremity of the American continent.

GYMNELIS.--Body elongate, naked. Eye of moderate size or rather

small. Ventrals none. Vent situated at some distance 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. Pseudobranchiæ present; air-bladder

none. Pyloric appendages two; no prominent anal papilla.

[Illustration: Fig. 247.--Gymnelis viridis.]

One species (_G. viridis_) from Greenland, the other (_G. pictus_) from

the Straits of Magelhæn.

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 Magelhæn.

SECOND FAMILY--GADIDÆ.

_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, if 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. Pseudobranchiæ none, or glandular, rudimentary. An air-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 _Palæogadus_ 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 _Phycis_; others, not readily

determinable, have been found at Licata in Sicily (Miocene).

GADUS.--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 palatines.

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--measures from two to four feet, and

attains 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 contribute to this most important drug.

_Gadus tomcodus_ abundantly occurs on the American coasts; it remains

within smaller dimensions than the common Cod-fish. _Gadus æglefinus_,

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 attains to a length of three feet in the higher

latitudes, but remains smaller on more southern coasts; like the Cod

it extends 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 exceeding a weight of 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 succeeded 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 distribution. 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

none. A short anterior dorsal, the second extending to the end

of the tail, and the anal being of similar length. Ventrals

composed 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.

MERLUCCIUS.--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, _M. vulgaris_, the “Hake,” is found

on both sides of the Atlantic, and grows to a length of four feet. It

is caught in great numbers, and preserved as “Stock-fish.” The second

species _M. gayi_, is common in the Straits of Magelhæn and on the

coast of Chili, less so in New Zealand.

The vertebral column of this genus shows a singular modification of

the apophyses. The neural spines of all the abdominal vertebræ are

extremely strong, dilated, wedged into one another. The parapophyses

of the third to sixth vertebræ are slender, styliform, whilst those of

all the following abdominal vertebræ 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 similar structure in _Kurtus_.

PSEUDOPHYCIS.--Body of moderate length, covered with rather

small scales. A separate caudal, two dorsals, and one anal;

ventral 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.

Allied genera are _Lotella_, _Physiculus_, _Uraleptus_, and _Læmonema_,

from moderate depths, obtained chiefly off Madeira and the Southern

Temperate Zone.

[Illustration: Fig. 248.--Pseudophycis bachus.]

PHYCIS.--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 Atlantic and the

Mediterranean, one, _Ph. blennioides_, is occasionally 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. lepidion_ 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 Magelhæn; 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.

LOTA.--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” (_L. vulgaris_, Fig. 8, p. 43), is

a Freshwater-fish which never enters salt water. It is locally

distributed in Central and Northern Europe and North America; it is one

of the best Freshwater-fishes, and exceeds a length of three feet.

MOLVA.--Differs from Lota in having several large teeth in the

lower jaw and on the vomer.

The “Ling” (_M. 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.

MOTELLA.--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 (_M. mustela_),

the Three-bearded Rocklings (_M. tricirrhata_, _macrophthalma_,

and _maculata_), and the Four-bearded Rockling (_M. 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. Two

dorsal fins, the anterior of which is very short, rudimentary.

One anal fin. Ventrals composed of six rays. Cardlike teeth in

the jaws and on the vomer.

The “Trifurcated Hake,” _R. trifurcus_, 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.

[Illustration: Fig. 249.--Bregmaceros macclellandii.]

A dwarf Gadoid, the only one found at the surface between 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.

MURÆNOLEPIS.--Body covered with lanceolate epidermoid

productions, intersecting each other at right angles like those

of a Freshwater-eel. Vertical fins confluent, no caudal being

discernible; an anterior dorsal fin is represented by a single

filamentous ray; ventral fins narrow, composed of several rays.

A barbel. Jaws with a band of villiform teeth; palate toothless.

One species (_M. marmoratus_) from Kerguelen’s Land.

CHIASMODUS.--Body naked; stomach and abdomen distensible. Two

dorsal fins and one anal; a separate caudal; ventral 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 figured 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; ventrals

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--OPHIDIIDÆ.

_Body more or less elongate, naked, or scaly. Vertical fins generally

united; no separate anterior dorsal or anal; dorsal occupying the

greater portion of the back. Ventral fins rudimentary or absent,

jugular. Gill-openings wide, the gill-membranes not attached to the

isthmus._

Marine fishes (with the exception of _Lucifuga_), 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. Eye of

moderate size. Each ventral reduced to a single filament,

sometimes bifid at its extremity. Teeth villiform; snout with

barbels. One pyloric appendage.

Five species of small size from the Tropical Atlantic and Indian Ocean.

[Illustration: Fig. 250.--Lucifuga dentata, from caves in Cuba.]

_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 ciliæ 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-laminæ

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.

[Illustration: Fig. 251.--Acanthonus armatus.]

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,

without caudal. Eye small. Mouth very wide; villiform teeth

in the jaws, on the vomer and palatine bones. Barbel none.

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 remarkable deep-sea

form have been obtained, at a depth of 1075 fathoms, in the Indian

Ocean.

TYPHLONUS.--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 compressed,

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-cartilaginous

condition. Notochord persistent, but with a superficial

indication of vertebral segments.

[Illustration: Fig. 252.--Aphyonus gelatinosus.]

One specimen only of this most remarkable form is known; it is 5½

inches long, and was obtained at a depth of 1400 fathoms south of New

Guinea.

Of the remaining genera belonging to this group, _Brotulophis_,

_Halidesmus_, _Dinematichthys_, and _Bythites_ are surface forms;

_Sirembo_ and _Pteridium_ inhabit moderate depths; _Rhinonus_ is a

deep-sea fish.

II. _Ventral fins replaced by a pair of bifid filaments (barbels)

inserted below the glossohyal_: OPHIDIINÆ.

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 _Ophidium_, 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.”

III. _No ventral fins whatever; vent at the throat_: FIERASFERINA.

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

Medusæ, 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 substance secreted

by it. They are perfectly harmless to their 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; gill-openings

very wide, the gill-membranes not being united_: AMMODYTINA.

The “Sand-eels” or “Launces” (_Ammodytes_) are extremely 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 themselves with incredible rapidity in the sand.

They are much sought after for bait by fishermen, who discover their

presence 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 length 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.

[Illustration: Fig. 253.--Congrogadus subducens.]

V. _No ventral fins whatever; vent remote from the head; 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.

FOURTH FAMILY--MACRURIDÆ.

_Body terminating in a long, compressed, tapering tail, covered with

spiny, keeled, or striated scales. One short ante__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._

[Illustration: Fig. 254.--Scale of Macrurus trachyrhynchus.]

[Illustration: Fig. 255.--Scale of Macrurus cœlorhynchus.]

[Illustration: Fig. 256.--Scale from the lateral line of Macrurus

australis.]

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 resembling each other in the general shape of their body,

but differing 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 following genera:--

[Illustration: Fig. 257.--Macrurus australis.]

MACRURUS.--Scales of moderate size; snout produced, conical;

mouth inferior.

CORYPHÆNOIDES.--Scales of moderate size; snout obtuse, obliquely

truncated; cleft of the mouth lateral.

MACRURONUS.--Scales of moderate size, spiny; snout pointed;

mouth anterior and lateral, with the lower jaw projecting.

MALACOCEPHALUS.--Scales very small, ctenoid; snout short,

obtuse, obliquely truncated.

BATHYGADUS.--Scales small, cycloid; snout not projecting beyond

the mouth; mouth wide, anterior, and lateral.

_Ateleopus_ from Japan and _Xenocephalus_ from New Ireland 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:

PLEURONECTIDÆ.

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 position, 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 strongly developed. The dorsal and anal fins are exceedingly

long, without division. All the Flat-fishes undergo remarkable

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 larvæ are, singularly enough, much

more frequently met in the open ocean than near the coast; they are

transparent, like _Leptocephali_; 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 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 surrounding 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 long 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,

precipitous 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.

PSETTODES.--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 members of the family, and,

therefore, their eyes are as often found on the right as on the left

side. It seems to swim, not unfrequently, in a vertical position. Only

one species is known, _Ps. erumei_, common in the Indian Ocean.

HIPPOGLOSSUS.--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” (_H. 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 California, 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

_Tephritis_.

RHOMBUS.--Eyes 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 commences on the

snout. Scales none or small.

Seven species from the North Atlantic and Mediterranean, of which the

most noteworthy are the “Turbot,” _Rh. maximus_, one of the most valued

food-fishes, and growing to a length of three feet; the “Turbot of the

Black Sea,” _Rh. mæoticus_, the body of which is covered with bony,

conical tubercles, which are as large as the eye; the “Brill,” _Rh.

lævis_, represented on the North American coasts by _Rh. aquosus_; the

“Whiff,” or “Mary-sole,” or “Sail-fluke,” _Rh. megastoma_; “Bloch’s

Top-knot,” _Rh. punctatus_ (described by Yarrell as _Rh. hirtus_, and

often confounded with the following species).

PHRYNORHOMBUS, differing from _Rhombus_ in lacking vomerine teeth. The

scales are very small and spiny.

The “Top-knot” (_Ph. unimaculatus_) occurs occasionally 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. Seventeen species.

RHOMBOIDICHTHYS.--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. Scales 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_,

_Brachypleura_, _Samaris_, _Psettichthys_, _Citharichthys_,

_Hemirhombus_, _Paralichthys_, _Liopsetta_, _Lophonectes_,

_Lepidopsetta_, and _Thysanopsetta_.

PLEURONECTES.--Cleft of the mouth narrow, with the dentition

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 following 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 foremost part of

the snout. Only one ventral which is continuous with the anal.

Scales very small, cycloid; lateral line straight.

This genus represents _Pleuronectes_ in the Southern Hemisphere, 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_, _Peltorhamphus_, _Nematops_,

_Læops_, 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 localities within

the temperate and tropical zones, with the exception 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. aurantiaca_, 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 _S.

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.--Eyes on the left side; pectorals none; vertical

fins confluent. Scales ctenoid; lateral line on the left side

double or triple; upper part of the snout produced backwards

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

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 is sometimes ossified. Ventral fins, if present,

abdominal, without spine. Air-bladder, if present, with a pneumatic

duct (except in Scombresocidæ)._

FIRST FAMILY--SILURIDÆ.

_Skin naked or with osseous scutes, but without scales. Barbels

always present; maxillary bone rudimentary, almost always forming a

support to a maxillary barbel. Margin of the upper jaw formed by the

intermaxillaries only. Suboperculum 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 peculiarities. The

cranial cavity is not membranous on the sides, but closed as in the

Cyprinidæ, by the orbitosphenoids and the ethmoid that unite with

the prefrontals, carrying forward the cranial cavity to the nasal

bone, without leaving a membranous 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 suprascapulæ, 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 passing backwards between the postfrontals, the

parietals, the mastoids, and the suprascapulæ, goes past them all on

to the nape. The mastoids interpose between the postfrontals 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 basi-occipital, or wedging

itself between them, and the other going to the first vertebra;

sometimes a plate from the exoccipital supports the same vertebra. This

vertebra, though it presents a pretty continuous centrum beneath, is in

reality composed of three or four coalescent vertebræ, 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 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 great spine when the fish wishes to use it as an offensive

weapon. The great spine itself is joined 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 interneural, passing over it

to touch with its point the buckler formed by the second and third

interneurals. In other instances, as in Synodontis and Auchenipterus,

the supraoccipital and second interneural, forking and expanding,

inclose 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 supraoccipital does not reach

quite to the second interneural, the first interneural remains free

from connection, and occasionally 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 sustaining the head; in fact,

this part of the skeleton is constructed to give firm mutual support.

The shoulder-girdle of the Siluroids is also formed to give

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

interlocking 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

ligamentous condition, 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 postclavicle

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 cylindrical bone. The sub-operculum is

likewise constantly absent in all the Siluroids.

The great number of different generic types has necessitated a further

division of this family into eight subdivisions:

I. SILURIDÆ HOMALOPTERÆ.--_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 intermediate 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 limited to Africa and the

East-Indian Archipelago. Six species.

_b_. PLOTOSINA.

PLOTOSUS.--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 immediately before

the posterior nostril, which is remote from the 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.

[Illustration: Fig. 258.--Mouth of Cnidoglanis megastoma,

Australia.]

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.--_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.

[Illustration: Fig. 259.--Cnidoglanis microcephalus.]

II. SILURIDÆ HETEROPTERÆ.--_The rayed dorsal fin is very little

developed, and, if it is present, it belongs to the abdominal portion

of the vertebral column; the adipose fin is exceedingly small or

absent. The extent of the anal is not much inferior to that of the

caudal vertebral column. The gill-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.

SILURUS.--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 a weight of 300 or 400 lbs., and the flesh, especially of smaller

specimens, is firm, flaky, and well flavoured. Aristotle 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.

[Illustration: Fig. 260.--The “Wels,” Siluris glanis.]

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 _Eutropius_; East Indian: _Silurichthys_, _Wallago_,

_Belodontichthys_, _Eutropiichthys_, _Cryptopterus_, _Callichrous_,

_Hemisilurus_, _Siluranodon_, _Ailia_, _Schilbichthys_, _Lais_,

_Pseudeutropius_, _Pangasius_, _Helicophagus_, and _Silondia_.

III. SILURIDÆ ANOMALOPTERÆ.--_Dorsal and adipose fins very short,

the former belonging to the caudal vertebral column; anal very long.

Ventrals in front of the dorsal. Gill-membranes entirely separate,

overlapping the isthmus_: (HYPOPHTHALMINA.)

HYPOPHTHALMUS.--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; intermaxillaries very

feeble. Head covered with skin. Eye of moderate size, situated

behind and below the angle of the mouth. Ventrals small,

six-rayed.

Four species from tropical America. The second genus of this sub-family

is _Helogenes_ from the Essequibo.

IV. SILURIDÆ PROTEROPTERÆ.--_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 vertebral column. The gill-membranes are not

confluent with the skin of the isthmus, their posterior margin always

remaining free even if they are united with each other. Whenever the

nasal barbel is present it belongs to the posterior nostril._

_a._ BAGRINA.

BAGRUS.--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 barbel.

Palate edentulous. Head covered with skin above. Ventrals

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 _Noturus_, likewise from North

America.

_c_. PIMELODINA.

PLATYSTOMA.--Adipose fin of moderate length; a short dorsal 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, likewise 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

band-like.

PIMELODUS.--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 greatest

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 strength of the dorsal spine. Singularly, two species

(_P. platychir_ and _P. balayi_), are found in West Africa. The

majority are of but moderate size and plain coloration.--Allied 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, _Au. 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 _Arius_,

_Galeichthys_ from South Africa; _Genidens_ and _Paradiplomystax_ from

Brazil; _Diplomystax_ from Chile; _Aelurichthys_ from Central and

South America; _Hemipimelodus_, _Ketengus_, _Osteo__geniosus_, and

_Batrachocephalus_ from the East Indies; and _Atopochilus_ from West

Africa.

[Illustration: Fig. 261.--Arius australis, from Queensland.]

_e._ BAGARIINA.

BAGARIUS.--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 longitudinal

plaits of the skin.

A large Siluroid (_B. bagarius_) from rivers of India and Java;

exceeding a length of six feet.

[Illustration: Fig. 262.--Euglyptosternum coum, thoracic adhesive

apparatus.]

EUGLYPTOSTERNUM.--Adipose fin of moderate length; a short

dorsal with a pungent spine and six rays; anal fin short.

Barbels eight, of which one pair is placed between the anterior

and 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

longitudinal plaits of the skin.

This fish (_Eu. coum_) 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 maintaining its position

in the rapid current of the stream, a function which appears to be

chiefly performed by the horizontally expanded pectoral fins. A similar

structure is found in _Glyptosternum_, a genus represented by eight

species in mountain streams of the East Indies, and differing from the

Syrian species in lacking the teeth on the palate.

V. SILURIDÆ STENOBRANCHIÆ.--_The rayed dorsal fin is short, if

present, belonging to the abdominal portion of the vertebral column,

the ventrals being inserted behind it (except in Rhinoglanis). The

gill-membranes are confluent with the skin of the isthmus._

_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--_Ageniosus_, _Tetranematichthys_, _Euanemus_,

_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, in quest of a pond of greater capacity.

These journeys are occasionally of such a length that the fish spends

whole nights on the way, and the bands of scaly 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 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,

viz. in

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 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.

[Illustration: Fig. 263.--Synodontis xiphias.]

_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.

_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

_M. electricus_ occurs in the Nile; they grow to a length of about

four feet. Although the first dorsal fin is absent, its position (if 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 lies between two aponeurotic membranes, below the skin, and

consists of rhomboidal cells which contain 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.

[Illustration: Fig. 264.--Malapterurus electricus.]

VI. SILURIDÆ PROTEROPODES.--_The rayed dorsal fin is always present and

rather short; the ventrals are inserted below (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 toothless; 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 “Preñadillas” by the natives,

together with the allied _Arges_, _Brontes_, and _Astroplebus_, 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 volcanoes 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 explanation 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.

Twelve species of this genus are known; they are small, and similarly

distributed as _Doras_, with which they have much in common as regards

their mode of life. They likewise are able to travel over land, and

construct nests for their ova.

[Illustration: Fig. 265.--Callichthys armatus, from the Upper

Amazon. Natural size.]

CHÆTOSTOMUS.--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 longitudinal 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_,

_Pterygoplichthys_, _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 with long bristles round the margin of the snout and

interoperculum.

[Illustration: Fig. 266.--Upper and Lower side of the head of

_Chætostomus heteracanthus_, Upper Amazons.]

_Hypoptopoma._--Differing from _Chætostomus_ in the peculiar

formation of the head, which is depressed, spatulate, the eyes

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 _Chætostomus_, and a second,

larger one, separated from the eye by the narrow sub-orbital

ring, and placed at the lower side of the head.

[Illustration: Fig. 267.--_Hypoptopoma thoracatum_, Upper

Amazons. Natural size.]

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, transverse,

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 series,

sometimes absent. Head and body cuirassed; tail depressed, long;

eye rather small or of moderate size.

[Illustration: Fig. 268.--_Loricaria lanceolate_, 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.