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.

Two species from Ceylon and Southern India.

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.

Ten species, the range of which is co-extensive with that of Chromis. One species, H. sacra, is abundant in the Lake of Galilee.

One species from Madagascar.

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.

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.

Genera allied to Heros, and likewise from Tropical America, are Neetroplus, Mesonauta, Petenia, Uaru, and Hygrogonus.

Four species from Brazil, Guyana, and Peru.

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.

Nine species are known from the Arctic Ocean, four from the southern extremity of the American continent.

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).

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.

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.

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.

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.

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.

Six species from the temperate parts of the North Atlantic and the Mediterranean, one, Ph. blennioides, is occasionally found on the British coast.

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.

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.

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.

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.

The “Trifurcated Hake,” R. trifurcus, not uncommon on the coasts of Northern Europe.

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.

One species (M. marmoratus) from Kerguelen’s Land.

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.

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.

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

Lucifuga are Brotula organised for a subterranean life. The eye is absent, or quite rudimentary, and covered by the skin; the barbels of Brotula are replaced by numerous minute ciliæ or tubercles. They inhabit the subterranean waters of caves in Cuba, and never come to the light.

Deep-sea fishes, inhabiting depths varying from 1000 to 2500 fathoms. Three species are known, the largest specimen obtained being seventeen inches long.

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.

Also of this deep-sea fish two specimens only are known, 10 inches long, from a depth of 2200 fathoms in the Western Pacific.

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.

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).

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.

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 anterior dorsal; the second very long, continued to the end of the tail, and composed of very feeble rays; anal of an extent similar to that of the second dorsal; no caudal. Ventral fins thoracic or jugular, composed of several rays.

This family, known a few years ago from a limited number of examples, representing a few species only, proves to be one which is distributed over all oceans, occurring in considerable variety and great abundance at depths of from 120 to 2600 fathoms. They are, in fact, Deep-sea Gadoids, much 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:—

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.

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.

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.

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.

A tropical genus with a few outlying species, represented chiefly in the Indo-Pacific, and also in the Atlantic. Seventeen species.