Part V., Washington, 1879, 8vo.]

8. C. sapidissima.--The American Shad, abundant, and an important food-fish on the Atlantic coasts of North America. Spawns in fresh water.

9. C. mattowocca.--The “Gaspereau” or “Ale-wife,” common on the Atlantic coasts of North America, ascending into freshwater in early spring, and spawning in ponds and lakes.

10. C. pilchardus.--The “Pilchard” or the “Sardine,” equally abundant in the British Channel, on the coast of Portugal, and in the Mediterranean, and readily recognised by radiating ridges on the operculum, descending towards the sub-operculum.

11. C. sagax.--Representing the Pilchard in the Pacific, and found in equally large shoals on the coasts of California, Chile, New Zealand, and Japan.

12. C. toli.--The subject of a very extensive fishery on the coast of Sumatra for the sake of its roes, which are salted and exported to China, the dried fish themselves being sent into the interior of the island. The fish is called “Trubu” by the Malays, about 18 inches long, and it is said that between fourteen and fifteen millions are caught annually.

13. C. scombrina.--The “Oil-Sardine” of the eastern coast of the Indian Peninsula.

* * * * *

Other, but less important genera of Clupeoids with serrated abdomen, are Clupeoides, Pellonula, Clupeichthys, Pellona, Pristigaster, and Chirocentrodon (these three last with very small or without any ventral fins).

ALBULA.--Body oblong, moderately compressed; abdomen flat. Scales of moderate size, adherent; lateral line distinct. Eyes covered with a broad annular adipose membrane. Snout pointed, the upper jaw projecting beyond the lower. Mouth inferior, of moderate width, with villiform teeth; intermaxillary juxtaposed to the upper anterior edge of the maxillary. Dorsal fin opposite to the ventrals; anal fin shorter than dorsal. Gill-membranes entirely separate, with numerous branchiostegals.

One species only (A. conorhynchus), ranging over all tropical and sub-tropical seas, and very common in many localities near the coasts. It grows to a length of from two to three feet, and is not valued as food.

ELOPS.--Body rather elongate, moderately compressed; abdomen flat. Scales small, adherent; lateral line distinct. A narrow osseous lamella, attached to the mandibulary symphysis, covers the part between the mandibles. Snout pointed; mouth wide, anterior; intermaxillary short, maxillary forming the lateral part of the mouth. Bands of villiform teeth in the jaws, on the vomer, palatine and pterygoid bones, on the tongue, and on the base of the skull. Dorsal fin opposite to ventrals; anal rather shorter than dorsal. Gill-membranes entirely separate, with very numerous branchiostegals.

Two species, of which one, E. saurus, is, like the preceding fish, spread over all tropical and sub-tropical seas; it exceeds a length of three feet, and is not esteemed as food.

MEGALOPS.--Body oblong, compressed, abdomen flat. Scales large, adherent; lateral line distinct. A narrow osseous lamella, attached to the mandibulary symphysis, between the mandibles. Snout obtusely conical; mouth anterior, lower jaw prominent; intermaxillary short; maxillary forming the lateral part of the mouth. Bands of villiform teeth in the jaws, on the vomer, palatine and pterygoid bones, on the tongue and on the base of the skull. Dorsal fin opposite to, or immediately behind, the ventrals; anal rather larger than dorsal. Gill-membranes entirely separate, with numerous branchiostegals. Pseudobranchiæ none.

Two species, one belonging to the Indo-Pacific (M. cyprinoides), the other to the Atlantic (M. thrissoides); they are the largest fishes of this family, exceeding a length of five feet, and excellent eating. Young specimens enter freely fresh waters.

CHANOS.--Body oblong, compressed; abdomen flat. Scales small, striated, adherent; lateral line distinct. Snout depressed; mouth small, anterior, transverse, the lower jaw with a small symphysial tubercle. Intermaxillary in juxtaposition to the upper anterior edge of maxillary. Teeth none. Dorsal fin opposite to the ventrals; anal small, shorter than dorsal; caudal deeply forked. Gill-membranes entirely united below, and free from the isthmus. Branchiostegals four, long. An accessory branchial organ in a cavity behind the gill-cavity proper. Air-bladder divided by a constriction into an anterior and posterior portion. Mucous membrane of the œsophagus raised in a spiral fold. Intestine with many convolutions.

Two species from the Indo-Pacific, of which Ch. salmoneus is extremely common; it enters fresh waters, and exceeds a length of four feet; its flesh is highly esteemed. The accessory branchial organ and the skeleton have been described by Müller, “Bau und Grenzen der Ganoiden,” p. 75; and by Hyrtl, “Denkschr. Ak. Wiss. Wien.” xxi. 1883, p. 1.

* * * * *

The remaining genera belonging to this family are Spratelloides, Dussumieria, and Etrumeus, which together form a small group, distinguished by an anterior and lateral mouth, by the upper jaw not overlapping the lower, by a rounded abdomen, and by lacking the gular plate of some of the preceding genera.

TWENTY-THIRD FAMILY--BATHYTHRISSIDÆ.

Body oblong, with rounded abdomen, covered with cycloid scales; head naked; barbels none. Margin of the upper jaw formed by the intermaxillaries mesially, and by the maxillaries laterally. Opercular apparatus complete. Adipose fin none; dorsal fin much elongate, many rayed; anal fin short. Stomach with a blind sac; pyloric appendages numerous. Gill-apparatus well developed; pseudobranchiæ; gill-openings wide; an air-bladder. Ova very small; ovaries without duct.

One genus and species only (Bathythrissa dorsalis) from deep water (350 fathoms) off the coast of Japan. This remarkable fish has the appearance of a Coregonus, and attains to a length of two feet. Nothing is known of its osteology, but possibly a fossil genus from the Gyps of Montmartre; Notæus, which has also a long dorsal fin, may prove to belong to the same family.

TWENTY-FOURTH FAMILY--CHIROCENTRIDÆ.

Body covered with thin, deciduous scales; barbels none. Margin of the upper jaw formed by the intermaxillaries mesially, and by the maxillaries laterally, both bones being firmly united, in juxtaposition. Opercular apparatus complete. Adipose fin none; the dorsal fin belongs to the caudal portion of the vertebral column. Stomach with a blind sac; intestine short, the mucous membrane forming a spiral fold; pyloric appendages none. Pseudobranchiæ none; air-bladder incompletely divided into cells; gill-opening wide.

One genus and species only (Chirocentrus dorab) is known, which is common in the Indian Ocean, and attains to a length of about three feet; it is not esteemed as food. Remains of fishes similar to Chirocentrus are found in the marl slates of Padang, in Sumatra.

TWENTY-FIFTH FAMILY--ALEPOCEPHALIDÆ.

Body with or without scales; head naked; barbels none. Margin of the upper jaw formed by the intermaxillaries and maxillaries, the former being placed along the upper anterior edge of the latter. Opercular apparatus complete. Adipose fin none; the dorsal fin belongs to the caudal portion of the vertebral column. Stomach curved, without blind sac; pyloric appendages in moderate number. Pseudobranchiæ; air-bladder absent. Gill-openings very wide.

Before the voyage of the “Challenger” one species only of this family was known, Alepocephalus rostratus, a rare fish from the Mediterranean; now, four genera with seven species are known, and there is no doubt that this family is one of the most characteristic, and will prove to be one of the most generally distributed forms, of the deep-sea. Their vertical range varies between 345 (Xenodermichthys) and 2150 (Bathytroctes) fathoms. They approach the Salmonoids, but lack invariably the adipose fin. Their dentition is very feeble; their eye large; bones thin. Coloration black.

ALEPOCEPHALUS has thin cycloid scales; a mouth of moderate width, and no teeth on the maxillary.

BATHYTROCTES has cycloid scales, a wide mouth, and teeth on the maxillary as well as intermaxillary.

PLATYTROCTES has small keeled scales and no ventrals.

XENODERMICHTHYS with fine nodules instead of scales.

TWENTY-SIXTH FAMILY--NOTOPTERIDÆ.

Head and body scaly; barbels none. Margin of the upper jaw formed by the intermaxillaries mesially, and by the maxillaries laterally. Opercular apparatus incomplete. Tail prolonged, tapering. Adipose fin none. Dorsal short, belonging to the caudal portion of the vertebral column; anal very long. Stomach without blind sac; two pyloric appendages. Pseudobranchiae none; air-bladder present, divided in the interior. The ova fall into the cavity of the abdomen before exclusion. On each side a parieto-mastoid cavity leading into the interior of the skull.

One genus only (Notopterus) with five species which inhabit fresh waters of the East Indies and West Africa. Well-preserved remains of this genus occur in the marl slates of Padang, in Sumatra. Their air-bladder is divided into several compartments, and terminates in two horns anteriorly and posteriorly, the anterior horns being in direct connection with the auditory organ.

TWENTY-SEVENTH FAMILY--HALOSAURIDÆ.

Body covered with cycloid scales; head scaly; barbels none. Margin of the upper jaw formed by the intermaxillaries mesially, and by the maxillaries laterally. Opercular apparatus incomplete. Adipose fin none. The short dorsal belongs to the abdominal part of the vertebral column; anal very long. Stomach with a blind sac; intestine short; pyloric appendages in moderate number. Pseudobranchiæ none. Air-bladder large, simple; gill-openings wide. Ovaries closed.

The only genus belonging to this family was discovered by the Madeiran ichthyologist Johnson, in 1863; but since then the naturalists of the “Challenger” expedition have added four other species, showing that this type is a deep-sea form and widely distributed; the specimens were dredged in depths varying from 560 to 2750 fathoms.

TWENTY-EIGHTH FAMILY--HOPLOPLEURIDÆ.

Body generally with four series of subtriangular scutes, and with intermediate scale-like smaller ones. One (?) dorsal only; head long, with the jaws produced.

Extinct; developed in the chalk and extending into tertiary formations: Dercetis (with the upper jaw longest), Leptotrachelus, Pelargorhynchus, Plinthophorus, Saurorhamphus (with the lower jaw longest), Eurypholis; Ischyrocephalus (?). The latter genus, from cretaceous formations of Westphalia, is said to have two dorsal fins.

TWENTY-NINTH FAMILY--GYMNOTIDÆ.

Head scaleless; barbels none. Body elongate, eel-shaped. Margin of the upper jaw formed in the middle by the intermaxillaries, and laterally by the maxillaries. Dorsal fin absent or reduced to an adipose strip; caudal generally absent, the tail terminating in a point. Anal fin exceedingly long. Ventrals none. Extremity of the tapering tail capable of being reproduced. Vent situated at, or at a short distance behind, the throat. Humeral arch attached to the skull. Ribs well developed. Gill-openings rather narrow. Air-bladder present, double. Stomach with a cæcal sac and pyloric appendages. Ovaries with oviducts.

Eel-like freshwater fishes from Tropical America.

STERNARCHUS.--Tail terminating in a distinct small caudal fin. Teeth small. A rudimentary dorsal fin is indicated by an adipose band fitting into a groove on the back of the tail; it is easily detached, so as to appear as a thong-like appendage fixed in front. Branchiostegals four.

Eight species, some have the snout compressed and of moderate length, like St. Bonapartii from the River Amazons; others have it produced into a long tube, as St. oxyrhynchus from the Essequibo.

RHAMPHICHTHYS.--Caudal fin none; teeth none; no trace of a dorsal fin. No free orbital margin.

Six species, of which, again, some have a tubiform snout, whilst in the others it is short.

STERNOPYGUS.--Caudal fin none; no trace of a dorsal fin. Both jaws with small villiform teeth; similar teeth on each side of the palate. Body scaly.

Four species, very common, and growing to a length of 30 inches.

CARAPUS.--Caudal fin none; no trace of a dorsal fin. A series of conical teeth in each jaw. Anterior nostrils, wide in the upper lip. Body scaly.

One species (C. fasciatus) extremely common, and found all over tropical America, east of the Andes, from 18 to 24 inches long.

GYMNOTUS.--Caudal and dorsal fins absent; anal extending to the end of the tail. Scales none. Teeth conical, in a single series. Eyes exceedingly small.

The “Electric Eel” is the most powerful of electric fishes, growing to a length of six feet, and extremely abundant in certain localities of Brazil and the Guyanas. The electric organ consists of two pairs of longitudinal bodies, situated immediately below the skin, above the muscles; one pair on the back of the tail, and the other pair along the anal fin. Each fasciculus is composed of flat partitions or septa, with transverse divisions between them. The outer edge of the septa appear in nearly parallel lines in the direction of the longitudinal axis of the body, and consist of thin membranes, which are easily torn; they serve the same purpose as the columns in the analogous organ of the Torpedo, making the walls or abutments for the perpendicular and transverse dissepiments, which are exceedingly numerous, and so closely aggregated as to seem almost in contact. The minute prismatic cells, intercepted between these two sorts of plates, contain a gelatinous matter; the septa are about one-thirtieth of an inch from each other, and one inch in length contains a series of 240 cells, giving an enormous surface to the electric organs. The whole apparatus is supplied with more than 200 nerves, which are the continuations of the rami anteriores of the spinal nerves. In their course they give out branches to the muscles of the back, and to the skin of the animal. In the Gymnotus, as in the Torpedo, the nerves supplying the electric organs are much larger than those bestowed on any part for the purposes of sensation or movement.

The graphic description by Humboldt of the capture of Electric Eels by horses driven into the water, which would receive the electric discharges and thus exhaust the fishes, seems to rest either on the imagination of some person who told it to the great traveller or on some isolated incident. Recent travellers have not been able to verify it even in the same parts of the country where the practice was said to exist.

THIRTIETH FAMILY--SYMBRANCHIDÆ.

Body elongate, naked or covered with minute scales; barbels none. Margin of the upper jaw formed by the intermaxillaries only, the well developed maxillaries lying behind and parallel to them. Paired fins none. Vertical fins rudimentary, reduced to more or less distinct cutaneous folds. Vent situated at a, great distance behind the head. Ribs present. Gill-openings confluent into one slit situated on the ventral surface. Air-bladder none. Stomach without cæcal sac or pyloric appendages. Ovaries with oviducts.

The fishes of this family consist of freshwater-fishes from tropical America and Asia, which, however, enter also brackish water; and of a truly marine genus from Australia.

AMPHIPNOUS.--Vent in the posterior half of the body, which is covered with minute scales longitudinally arranged.

A common fish (A. cuchia) in Bengal, remarkable for its singular respiratory apparatus. It has only three branchial arches, with rudimentary branchial laminæ, and with very narrow slits between the arches. To supplement this insufficient respiratory apparatus, a lung-like sac is developed on each side of the body behind the head, opening between the hyoid and first branchial arch. The interior of the sac is abundantly provided with blood-vessels, the arterial coming from the branchial arteries, whilst those issuing from it unite to form the aorta. A. cuchia approaches the Eels in having the humeral arch not attached to the skull.

MONOPTERUS.--Vent in the posterior half of the body, which is naked. Three branchial arches with rudimentary gills, but without breathing sac.

One species (M. javanicus), which is extremely common in the East Indian Archipelago and in the eastern parts of the Continent. Upwards of three feet long.

SYMBRANCHUS.--Vent in the posterior half of the body, which is naked. Four branchial arches with well developed gills.

Three species, of which one (S. marmoratus) is extremely common in tropical America, and the other (S. bengalensis) not less so in the East Indies.

CHILOBRANCHUS.--Vent in the anterior half of the length of the body, which is naked. Vertical fins reduced to a simple cutaneous fold, without rays.

A small fish (Ch. dorsalis) from North Western Australia and Tasmania.

THIRTY-FIRST FAMILY--MURÆNIDÆ.

Body elongate, cylindrical or “band-shaped, naked or with rudimentary scales. Vent situated at a great distance from the head. Ventral fins none. Vertical fins, if present, confluent, or separated by the projecting tip of the tail. Sides of the upper jaw formed by the tooth-bearing maxillaries, the fore part by the intermaxillary, which is more or less coalescent with the vomer and ethmoid. Humeral arch not attached to the skull. Stomach with a blind sac; no pyloric appendages. Organs of reproduction without efferent ducts.

The “Eels” are spread over almost all fresh waters and seas of the temperate and tropical zones; some descend to the greatest depths of the oceans. The young of some have a limited pelagic existence. (Leptocephali, see p. 179.) At Monte Bolca fossil remains are very numerous, belonging to recent genera, Anguilla, Sphagebranchus, and Ophichthys; even larval Leptocephales have been preserved. Anguilla has been found also in the chalk of Aix and Oeningen.

In the majority of the species the branchial openings in the pharynx are wide slits (Murænidæ platyschistæ); in others, the true Murænæ, (Murænidæ engyschistæ) they are narrow.

NEMICHTHYS.--Exceedingly elongate, band-shaped; tail tapering into a point. Vent approximate to the pectorals, but the abdominal cavity extending far behind the vent. Jaws produced into a long slender bill, the upper part being formed by the vomer and intermaxillaries. The inner surface of the bill covered with small tooth-like asperities. Eye large. The nostrils of each side are close together, in a hollow before the eye. Gill-openings wide, nearly confluent. Pectoral and vertical fins well developed.

This very singular type is a deep-sea form, occurring at depths of from 500 to 2500 fathoms. The two species known have hitherto been found in the Atlantic only.

CYEMA.--This genus combines the form of the snout of Nemichthys, with the soft and shorter body of a Leptocephalus; but the gill-openings are very narrow and close together on the abdominal surface. Vent in about the middle of the length of the body; vertical fins well developed, confined to, and surrounding, the tail. Pectoral fins well developed. Eye very small.

Known from two specimens only, 4½ inches long, dredged in depths of 1500 and 1800 fathoms in the Pacific and Antarctic Oceans.

SACCOPHARYNX.--Deep-sea Congers, with the muscular system very feebly developed, with the bones very thin, soft, and wanting in inorganic matter. Head and gape enormous. Snout very short, pointed, flexible, like an appendage overlapping the gape. Maxillary and mandibulary bones very thin, slender, arched, armed with one or two series of long, slender, curved, widely set teeth, their points being directed inwards; palate toothless. Gill-openings wide, at some distance from the head, at the lower part of the sides; gills very narrow, free, and exposed. Trunk of moderate length. Stomach distensible in an extraordinary degree. Vent at the end of the trunk. Tail band-like, exceedingly long, tapering in a very fine filament. Pectoral small, present. Dorsal and anal fins rudimentary.

This is another extraordinary form of Deep-sea Eels; the muscular system, except on the head, is very feebly developed; the bones are as thin, soft, and wanting in inorganic matter, as in the Trachypteridæ. This fish is known from three specimens only, which have been found floating on the surface of the North Atlantic, with their stomachs much distended, having swallowed some other fish, the weight of which many times exceeded that of their destroyer. It attains to the length of several feet.

SYNAPHOBRANCHUS.--Gill-openings ventral, united into a longitudinal slit between the pectoral fins, separate internally. Pectoral and vertical fins well developed. Nostrils lateral, the anterior subtubular, the posterior round, before the lower half of the eye. Cleft of the mouth very wide; teeth small; body scaly. Stomach very distensible.

Deep-sea Congers, with well-developed muscular system, spread over all oceans, and occurring in depths of from 345 to 2000 fathoms. Four species are known. Probably attaining to the same length as the Conger.

ANGUILLA.--Small scales imbedded in the skin. Upper jaw not projecting beyond the lower. Teeth small, forming bands. Gill-openings narrow, at the base of the pectoral fins. The dorsal fin commences at a considerable distance from the occiput.

Some twenty-five species of “Eels” are known from the freshwaters and coasts of the temperate and tropical zones; none have been found in South America or the west coast of North America and West Africa. The following are the most noteworthy:--The common European species (A. anguilla) is spread over Europe to 64° 30´ lat. N., and all round the Mediterranean area, but is not found either in the Danube or in the Black and Caspian Seas; it extends across the Atlantic to North America. The form of the snout varies much, and some naturalists have believed that specimens with a broad and obtuse snout were specifically distinct from those with pointed snout. However, every degree of breadth of the snout may be observed; and a much safer way of recognizing this species, and distinguishing it from other European Eels, is the forward position of the dorsal fin; the distance between the commencement of the dorsal and anal fins being as long as, or somewhat longer than, the head. Eels grow generally to a length of about three feet, but the capture of much larger examples is on record. Their mode of propagation is still unknown. So much only is certain that they do not spawn in fresh water, that many full-grown individuals, but not all, descend rivers during the winter months, and that some of them at least must spawn in brackish water or in deep water in the sea; for in the course of the summer young individuals from three to five inches long ascend rivers in incredible numbers, overcoming all obstacles, ascending vertical walls or floodgates, entering every larger and smaller tributary, and making their way even over terra firma to waters shut off from all communication with rivers. Such immigrations have been long known by the name of “Eel-fairs.” The majority of the Eels which migrate to the sea appear to return to fresh water, but not in a body, but irregularly, and throughout the warmer part of the year. No naturalist has ever observed these fishes in the act of spawning, or found mature ova; and the organs of reproduction of individuals caught in fresh water are so little developed and so much alike, that the female organ can be distinguished from the male only with the aid of a microscope.

The second species found in Great Britain, on the coasts of Europe generally, in China, New Zealand, and the West Indies, is (A. latirostris) the “Grig” or “Glut,” which prefers the neighbourhood of the sea to distant inland-waters, and in which the dorsal fin begins farther backwards, the distance between the commencement of the dorsal and anal fins being shorter than the head; its snout seems to be always broad. On the American side of the Atlantic other species, beside A. anguilla are found in abundance: A. bostoniensis, A. texana. The largest Eels occur in lakes of the islands of the Indo-Pacific, and they play a conspicuous part in the mythology of the South-Sea Islanders and Maories; individuals of from eight to ten feet in length have been seen, and referred to several species, as A. mauritiana, fidjiensis, obscura, aneitensis, etc.

CONGER.--Scaleless. Cleft of the mouth wide, extending at least to below the middle of the eye. Maxillary and mandibulary teeth arranged in series, one of which contains teeth of equal size, and so closely set as to form a cutting edge. No canine teeth. Vomerine band of teeth short. Pectoral and vertical fins well developed, the dorsal commencing behind the root of the pectoral. Gill-openings large, approximate to the abdomen. The posterior nostril opposite to the upper or middle part of the orbit, the anterior in a tube. Eyes well developed.

The “Congers” are marine Eels; the best known species (C. conger) seems to be almost cosmopolitan, and is plentiful all round Europe, at St. Helena, in Japan, and Tasmania. It attains to a length of eight feet, and thrives and grows rapidly even in confinement, which is not the case with the freshwater Eel. Three other species are known, of which C. marginatus from the Indian Ocean, is the most common. Leptocephalus morrisii is an abnormal larval condition of the Conger.

Genera allied to Conger are Poeciloconger, Congromurcæna, Uroconger, and Heteroconger.

MURÆNESOX.--Scaleless. Snout produced. Jaws with several series of small closely set teeth, anteriorly with canines; vomer with several long series of teeth, the middle of which is formed by large conical or compressed teeth. Gill-openings wide, approximate to the abdomen. Pectoral and vertical fins well developed, the dorsal beginning above the gill-opening. Two pairs of nostrils, the posterior opposite to the upper part or middle of the eye.

Four species from tropical seas, M. cinereus being very common in the Indian Ocean, and attaining to a length of six feet.

NETTASTOMA.--Scaleless. Snout much produced, depressed. Jaws and vomer with bands of card-like teeth, those along the median line of the vomer being somewhat the larger. Vertical fins well developed; pectorals none. Gill-openings of moderate width, open. Nostrils on the upper surface of the head, valvular; the anterior near to the end of the snout, the posterior above the anterior angle of the eye.

This genus lives at some depth, the Japanese species (N. parviceps) having been obtained at 345 fathoms. N. melanurum from the Mediterranean, seems to inhabit a similar depth. Hyoprorus is its Leptocephalid form.

Genera allied to Murcænesox are Saurenchelys, Oxyconger, Hoplunnis, and Neoconger; in all these the nostrils have a superior or lateral position. In other genera the nostrils perforate the upper lip, as in Myrus, Myrophis, Paramyrus, Chilorhinus, Murænichthys, and Ophichthys, the last genus deserving of particular mention on account of its great range and common occurrence.

OPHICHTHYS.--Nostrils labial; extremity of the tail free, not surrounded by a fin.

More than eighty species are known, many of which are abundant on the coasts of the tropical and sub-tropical zones. They do not attain to a large size, but many must be extremely voracious and destructive to other fishes, if we draw an inference from the formidable dentition with which their jaws and palate is armed. Other species have much more feeble, and some even obtuse teeth, better adapted for seizing Crustaceans than vigorous and slippery fishes. Some have rudimentary pectoral fins or lack them altogether. Many are highly ornamented with bands or spots, the coloration being apparently very constant in the several species.

MORINGUA.--Body scaleless, cylindrical, with the trunk much longer than the tail. Pectorals none or small; vertical fins but little developed, limited to the tail. Posterior nostrils in front of the small eye. Cleft of the mouth narrow; teeth uniserial. Heart placed far behind the branchiæ. Gill-openings rather narrow, inferior.

Six species from freshwaters, brackish water, and the coasts of India to the Fiji Islands.

MURÆNA.--Scaleless. Teeth well developed. Gill-openings and clefts between the branchial arches narrow. Pectoral fins none; dorsal and anal fins well developed. Two nostrils on each side of the upper surface of the snout; the posterior a narrow round foramen, with or without tube; the anterior in a tube.

The Murænas are as abundantly represented in the tropical and sub-tropical zones, and have nearly the same range, as Ophichthys. The number of species known exceeds eighty. The majority are armed with formidable pointed teeth, well suited for seizing other fish on which they prey. Large specimens thus armed readily attack persons in and out of the water; and as some species attain a length of some six or eight feet, they are justly feared by fishermen. The minority of species have obtuse and molar-like teeth, their food consisting chiefly of Crustaceans and other hard-shelled animals. Most of the Murænas are beautifully coloured and spotted, some in a regular and constant manner, whilst in others the pattern varies in a most irregular fashion: they have quite the appearance of snakes. The Muræna of the Ancient Romans is Muræna helena, which is not confined to the Mediterranean, but also found in the Indian Ocean and on the coast of Australia. Its skin is of a rich brown, beautifully marked with large yellowish spots, each of which contains smaller brown spots.

Gymnomuræna differs from Muræna in having the fins reduced to a short rudiment near the end of the tail. Six species are known growing to a length of eight feet.

Myroconger and Enchelycore belong to the same sub-family as Muræna, but the former is provided with pectoral fins, and in the latter the posterior nostril is a long slit, and not round as in the other genera.

FIFTH ORDER--LOPHOBRANCHII.

The gills are not laminated, but composed of small rounded lobes attached to the branchial arches. Gill-cover reduced to a large simple plate. Air-bladder simple, without pneumatic duct. A dermal skeleton composed of numerous pieces arranged in segments, replaces more or less soft integuments. Muscular system not much developed. Snout prolonged. Mouth terminal, small, toothless, formed as in Acanthopterygians.

FIRST FAMILY--SOLENOSTOMIDÆ.

Gill-openings wide. Two dorsal fins, the rays of the anterior not articulated. All the other fins well developed.

One living genus only is known, which was preceded in the tertiary epoch by Solenorhynchus (Monte Postale).

SOLENOSTOMA.--Snout produced into a long tube. Body compressed, with very short tail. All parts covered with thin skin, below which there is a dermal skeleton formed by large star-like ossifications. The soft dorsal and anal fins on elevated bases; caudal fin long. Ventral fins inserted opposite to the anterior dorsal, close together, seven-rayed; they are free in the male, but in the female their inner side coalesces with the integuments of the body, a large pouch for the reception of the eggs being formed thereby. Air-bladder and pseudobranchiæ absent. Branchiostegals four, very thin. Intestinal tract very simple, with a stomachic dilatation, without pyloric appendages. Ova very small.

The dermal skeleton of this singular type is formed by star-like ossifications, four in each horizontal and vertical series on the side of the fore part of the trunk; each consists of four or three radiating branches by which it joins the neighbouring bones; on the hind part of the trunk and tail the series are diminished to two. The dorsal and abdominal profiles in front of the fins are protected by similar bones. The vertebral column is composed of eighteen abdominal and fifteen caudal vertebræ, the vertebræ gradually decreasing in length backwards, so that the shortness of the tail is caused not only by the smaller number of vertebræ, but also by their much lesser length. Neural and hæmal spines are developed. The pelvis consists of two pairs of cartilaginous laminæ, the convex margin of the anterior fitting into an angle of a dermal bone which separates the pelvis from the well-ossified humeral arch.

The singular provision for the retention and protection of the eggs has been described above (p. 162, figs. 73 and 74), and we have only to repeat here that it is the female which takes care of the progeny, and not the male as in the following family. Two or three small species are known from the Indian Ocean; they are beautifully marked, especially the male, which also appears to be of smaller size in this genus than the female.

SECOND FAMILY--SYNGNATHIDÆ.

Gill-openings reduced to a very small opening near the upper posterior angle of the gill-cover. One soft dorsal fin; no ventrals, and, sometimes, one or more of the other fins are also absent.

Small marine fishes, which are abundant on such parts of the coasts of the tropical and temperate zones as offer by their vegetation shelter to these defenceless creatures. They are bad swimmers (the dorsal fin being the principal organ of locomotion), and frequently and resistlessly carried by currents into the open ocean or to distant coasts. All enter brackish water, some fresh water. The strata of Monte Bolca and Licata (Sicily) have, yielded evidence of their existence in the tertiary epochs; beside species of Siphonostoma and Syngnathus (Pseudosyngnathus), remains of an extinct genus, Calamostoma, allied to Hippocampus, but with a distinct caudal fin, have been found. On their propagation see p. 163, Fig. 76.

A. SYNGNATHINA.--The tail is not prehensile, and generally provided with a caudal fin.--Pipe-Fishes.

SIPHONOSTOMA.--Body with distinct ridges, the upper caudal ridge continuous with the lateral line, but not with the dorsal ridge of the trunk. Pectoral and caudal fins well developed; dorsal fin of moderate length, opposite to the vent. Humeral bones movable, not united into a “breast-ring.” Males with an egg-pouch on the tail, the eggs being covered by cutaneous folds.

Two species, of which S. typhle is common on the British, and generally distributed on the European coasts.

SYNGNATHUS.--Body with the ridges more or less distinct, the dorsal ridge of the trunk not being continuous with that of the tail. Pectoral fins well developed; caudal present. Dorsal fin opposite or near to the vent. Humeral bones firmly united into the breast-ring. Egg-pouch as in Siphonostoma.

The distribution of this genus nearly coincides with that of the family, some fifty species being known. S. acus, the great Pipe-fish (see Fig. 75, p. 163), is one of the most common European fishes, extending across the Atlantic and southwards to the Cape of Good Hope; it attains a length of 18 inches. Another very common species, frequently met at sea, and spread over nearly all the tropical and sub-tropical seas, is S. pelagicus, agreeably marked with alternate brown and silvery cross-bars.

DORYICHTHYS.--Body with the ridges well developed. Pectoral and caudal fins present. Dorsal fin long or of moderate length, opposite to the vent. Humeral bones firmly united. Males with the lower ridges of the abdomen dilated, the dilated parts forming a broad groove for the reception of the ova.

In these Pipe-fishes the ova are not received in a completely closed pouch, but glued on to the surface of the abdomen. Twenty species from tropical seas.

NEROPHIS.--Body smooth, rounded, with scarcely any of the ridges distinct. Pectoral fin none, caudal absent or rudimentary, the tail tapering into a point. Dorsal fin of moderate length, opposite to the vent. The ova are attached to the soft integument of the abdomen of the male, and are not covered by lateral folds of the skin.

Seven species from the European seas and the Atlantic. N. æquoreus (Ocean Pipe-fish), N. ophidion (Straight-nosed Pipe-fish), and N. lumbriciformis (Little Pipe-fish), are common on the British coasts.

PROTOCAMPUS.--The whole dermal skeleton is covered with skin. A broad cutaneous fold runs along the back in front and behind the dorsal; a similar fold along the abdomen. Pectoral fin none; caudal very small.

The single species of this remarkable genus, P. hymenolomus, occurs in the Falkland Islands. It may be regarded as an embryonal form of Nerophis, the median skin-folds being evidently remains of the fringe which surrounds the body of the embryo.

The other genera belonging to this group are, Icthyocampus, Nannocampus, Urocampus, Leptoichthys, Coelonotus, and Stigmatophora.

HIPPOCAMPINA.--The tail is prehensile, and invariably without caudal fin.--Sea-horses.

GASTROTOKEUS.--Body depressed, the lateral line running along the margin of the abdomen. Shields smooth. Tail shorter than the body. Pectoral fins. No pouch is developed for the ova, which are imbedded in the soft integument of the abdomen of the male.

Gastrotokeus biaculeatus, very common in the Indian Ocean to the coasts of Australia.

SOLENOGNATHUS.--Body compressed, deeper than broad. Shields hard, rugose, with round or oval interannular plates; and without elongate processes. Tail shorter than the body. Pectoral fins.

Three species, from the Chinese and Australian Seas; they are the largest of Lophobranchs, S. hardwickii, attaining to a length of nearly two feet.

PHYLLOPTERYX.--Body compressed, or as broad as deep. Shields smooth, but some or all of them are provided with prominent spines or processes on the edges of the body; some of the processes with cutaneous filaments. A pair of spines on the upper side of the snout and above the orbit. Tail about as long as the body. Pectoral fins. The ova are imbedded in soft membrane on the lower side of the tail, without a pouch being developed.

Three species from the coasts of Australia. The protective resemblances with which many Lophobranchs are furnished, attain to the highest degree of development in the fishes of this genus. Not only their colour closely assimilates that of the particular kind of seaweed which they frequent, but the appendages of their spines seem to be merely part of the fucus to which they are attached. They attain a length of 12 inches.

HIPPOCAMPUS.--Trunk compressed, more or less elevated. Shields with more or less prominent tubercles or spines. Occiput compressed into a crest, terminating at its supero-posterior corner in a prominent knob (coronet). Pectoral fins. The males carry the eggs in a sac at the base of the tail, opening near the vent.

A singular resemblance of the head and fore part of the body to that of a horse, has given to these fishes the name of “Sea-horses.” They are abundant between and near the tropics, becoming scarcer in higher latitudes. Some twenty species are known, some of which have a wide geographical range, as they are often carried to great distances with floating objects to which they happen to be attached.--Acentronura is a genus closely allied to Hippocampus.

SIXTH ORDER--PLECTOGNATHI.

Teleosteous fishes with rough scales, or with ossifications of the cutis in the form of scutes or spines; skin sometimes entirely naked. Skeleton incompletely ossified, with the vertebræ in small number. Gills pectinate; a narrow gill-opening in front of the pectoral fins. Mouth narrow; the bones of the upper jaw generally firmly united. A soft dorsal fin, belonging to the caudal portion of the vertebral column, opposite to the anal; sometimes elements of a spinous dorsal besides. Ventral fin none, or reduced to spines. Air-bladder without pneumatic duct.

FIRST FAMILY--SCLERODERMI.

Snout somewhat produced; jaws armed with distinct teeth in small number. Skin with scutes or rough. The elements of a spinous dorsal and ventral fins generally present.

Marine fishes of moderate or small size, very common in the tropical zone, but scarcer in higher latitudes. They have been found in three localities of tertiary strata, viz., at Monte Bolca, where a species of Ostracion occurs, and in the Schists of Glaris, from which two genera have been described, Acanthoderma and Acanthopleurus, closely allied to Balistes and Triacanthus. Glyptocephalus from the Isle of Sheppey has the skull of a Balistes, but its body is covered with tubercles arranged in regular series. The Scleroderms may be divided into three very natural groups:--

A. TRIACANTHINA.--The skin is covered with small, rough, scale-like scutes. A spinous dorsal fin with from four to six spines. A pair of strong, movable ventral spines, joined to the pelvic bone.

To this group belong the genera Triacanthodes, Hollardia, and Triacanthus, represented by five species, of which Triacanthus brevirostris from the Indian Ocean is the most common.

B. BALISTINA.--Body compressed, covered with movable scutes or rough. Spinous dorsal reduced to one, two, or three spines. Ventral fins reduced to a single pelvic prominence, or entirely absent.

To this group belong the genera Balistes, Monacanthus, and Anacanthus, the last genus being distinguished by a barbel at the lower jaw.

Balistes, or the “File-fishes” proper, inhabit the tropical and sub-tropical seas; shoals of young are not rarely met with in mid-ocean. Some thirty species are known, many attaining a length exceeding two feet; but the majority are much smaller, and frequently beautifully and symmetrically marked. Both jaws are armed with eight strong incisor-like and obliquely truncated teeth, by which these fishes are enabled to break off pieces of corals on which they feed, or to chisel a hole into the hard shell of Mollusca, in order to extract the soft parts. They destroy an immense number of Mollusks, thus becoming most injurious to the pearl-fisheries. The first of their three dorsal spines is very strong, roughened in front like a file, and hollowed out behind to receive the second much smaller spine, which, besides, has a projection in front, at its base, fitting into a notch of the first. Thus these two spines can only be raised or depressed simultaneously, and the first cannot be forced down, unless the second has been previously depressed. The latter has been compared to a trigger, hence a second name, “Trigger-fish,” has been given to these fishes. Some species are armed with a series of short spines or tubercles on each side of the tail. Two species (B. maculatus and B. capriscus), common in the Atlantic, sometimes wander to the British coasts.

The Monacanthus are similarly distributed as the Balistes, and still more abundant, some fifty species being known. Their dentition is very similar, but they possess one dorsal spine only, and their rough scales are so small as to give a velvety appearance to the skin (Figs. 17 and 18, p. 48). Adult males of some of the species possess a peculiar armature on each side of the tail, which in females is much less developed or entirely absent. This armature may consist either in simple spines arranged in rows, or in the development of the minute spines of the scales into long stiff bristles, so that the patch on each side of the tail looks like a brush.

C. OSTRACIONTINA.--The integuments of the body form a hard continuous carapace, consisting of hexagonal scutes juxtaposed in mosaic-fashion. A spinous dorsal and ventral fins are absent; but sometimes indicated by protuberances.

The “Coffer-fishes” (Ostracion) are too well known to require a lengthened description. Only the snout, the bases of the fins, and the hind part of the tail are covered with soft skin, so as to admit of free action of the muscles moving these parts. The mouth is small, the maxillary and intermaxillary bones coalescent, each jaw being armed with a single series of small slender teeth. The short dorsal fin is opposite to the equally short anal. The vertebral column consists of fourteen vertebræ only, of which the five last are extremely short, the anterior elongate. Ribs none. The carapaces of some species are three-ridged, of others four- and five-ridged, of some provided with long spines. Twenty-two species from tropical and sub-tropical seas are known.

SECOND FAMILY--GYMNODONTES.

Body more or less shortened. The bones of the upper and lower jaw are confluent, forming a beak with a trenchant edge, without teeth, with or without median suture. A soft dorsal, caudal and anal are developed, approximate. No spinous dorsal. Pectoral fins; no ventrals.

Marine fishes of moderate or small size from tropical and sub-tropical seas. A few species live in fresh water. Fossil remains of Diodon are not scarce at Monte Bolca and Licata; a distinct genus, Enneodon, has been described from Monte Postale. The Gymnodonts may be divided into three groups:

A. TRIODONTINA.--Tail rather long, with a separate caudal fin. Abdomen dilatable into a very large, compressed, pendent sac, the lower part of which is merely a flap of skin, into which the air does not penetrate, the sac being capable of being expanded by the very long pelvic bone. The upper jaw divided by a median suture, the lower simple.

A single genus and species (Triodon bursarius) from the Indian Ocean.

B. TETRODONTINA.--Tail and caudal fin distinct. Part of the œsophagus much distensible, and capable of being filled with air. No pelvic bone.

“Globe-fishes” have a short, thick, cylindrical body, with well developed fins. It is covered with thick scaleless skin, in which, however, spines are imbedded of various sizes. The spines are very small, and but partially distributed over the body in some species, whilst in others they are very large, and occupy equally every part of the body. These fishes have the power of inflating their body by filling their distensible œsophagus with air, and thus assume a more or less globular form. The skin is, then, stretched to its utmost extent, and the spines protrude and form a more or less formidable defensive armour, as in a hedgehog; therefore they are frequently called “Sea-hedgehogs.” A fish thus blown out turns over and floats belly upwards, driving before the wind and waves. However, it is probable that the spines are a protection not only when the fish is on the surface and able to take in air, but also when it is under water. Some Diodonts, at any rate, are able to erect the spines about the head by means of cutaneous muscles; and, perhaps, all fill their stomach with water instead of air, for the same purpose and with the same effect. In some Diodonts the spines are fixed, erect, not movable. The Gymnodonts generally, when taken, produce a sound, doubtless by the expulsion of air from the œsophagus. Their vertebral column consists of a small number of vertebræ, from 20 to 29, and their spinal chord is extremely short. All these fishes have a bad reputation, and they are never eaten; indeed, some of them are highly poisonous, and have caused long continued illness and death. Singularly, the poisonous properties of these fishes vary much as regards intensity, only certain individuals of a species, or individuals from a certain locality, or caught at a certain time of the year, being dangerous. Therefore it is probable that they acquire their poisonous quality from their food, which consists in corals and hard-shelled Mollusks and Crustaceans. Their sharp beaks, with broad masticating posterior surface, are admirably adapted for breaking off branchlets of coral-stocks, and for crushing hard substances.

TETRODON (including Xenopterus).--Both the upper and lower jaws are divided into two by a mesial suture.

Extremely numerous in tropical and sub-tropical zones, more than sixty species being known. In some of the species the dermal spines are extremely small, and may be absent altogether. Many are highly ornamented with spots or bands. A few species live in large rivers--thus T. psittacus from Brazil; T. fahaka, a fish well known to travellers on the Nile, and likewise abundant in West African rivers; T. fluviatilis from brackish water and rivers of the East Indies. The species figured is one of the smallest, about six inches long, and common in the Indo-Pacific.

DIODON.--Jaws without mesial suture, so that there is only one undivided dental plate above and one below.

In these fishes, as well as in some closely allied genera, the dermal spines are much more developed than in the Tetrodonts; in some the spines are erectile, as in Diodon, Atopomycterus, Trichodiodon, and Trichocyclus; in others they are stiff and immovable, as in Chilomycterus and Dicotylichthys. Seventeen species are known, of which Diodon hystrix is the most common as it is the largest, growing to a length of two feet. It is spread over the Tropical Atlantic as well as Indo-Pacific, as is also a smaller, but almost equally common species, Diodon maculatus.

C. MOLINA.--Body compressed, very short; tail extremely short, truncate. Vertical fins confluent. No pelvic bone.

The “Sun-fishes” (Orthagoriscus) are pelagic fishes, found in every part of the oceans within the tropical and temperate zones. The singular shape of their body and the remarkable changes which they undergo with age, have been noticed above (p. 175, Figs. 93, 94). Their jaws are undivided in the middle, comparatively feeble, but well adapted for masticating their food, which consists of small pelagic Crustaceans. Two species are known. The common Sun-fish, O. mola, which attains to a very large size, measuring seven or eight feet, and weighing as many hundredweights. It has a rough, minutely granulated skin. It frequently approaches the southern coasts of England and the coasts of Ireland, and is seen basking in calm weather on the surface. The second species, O. truncatus, is distinguished by its smooth, tessellated skin, and one of the scarcest fishes in collections. The shortness of the vertebral column of the Sun-fishes, in which the number of caudal vertebra is reduced to seven, the total number being seventeen, and the still more reduced length of the spinal chord have been noticed above (p. 96).

THIRD SUB-CLASS--CYCLOSTOMATA.

Skeleton cartilaginous and notochordal, without ribs and without real jaws. Skull not separate from the vertebral column. No limbs. Gills in the form of fixed sacs, without branchial arches, six or seven in number on each side. One nasal aperture only. Heart without bulbus arteriosus. Mouth anterior, surrounded by a circular or subcircular lip, suctorial. Alimentary canal straight, simple, without coecal appendages, pancreas or spleen. Generative outlet peritoneal. Vertical fins rayed.

The Cyclostomes are most probably a very ancient type. Unfortunately the organs of these creatures are too soft to be preserved, with the exception of the horny denticles with which the mouth of some of them is armed. And, indeed, dental plates, which are very similar to those of Myxine, are not uncommon in certain strata of Devonian and Silurian age (see p. 193). The fishes belonging to this sub-class may be divided into two families--

FIRST FAMILY--PETROMYZONTIDÆ.

Body eel-shaped, naked. Subject to a metamorphosis; in the perfect stage with a suctorial mouth armed with teeth, simple or multicuspid, horny, sitting on a soft papilla. Maxillary, mandibulary, lingual, and suctorial teeth may be distinguished. Eyes present (in mature animals). External nasal aperture in the middle of the upper side of the head. The nasal duct terminates without perforating the palate. Seven branchial sacs and apertures on each side behind the head; the inner branchial ducts terminate in a separate common tube. Intestine with a spiral valve. Eggs small. The larvæ without teeth, and with a single continuous vertical fin.

“Lampreys” are found in the rivers and on the coasts of the temperate regions of the northern and southern hemispheres. Their habits are but incompletely known, but so much is certain that at least some of them ascend rivers periodically, for the purpose of spawning, and that the young pass several years in rivers, whilst they undergo a metamorphosis (see p. 170). They feed on other fishes, to which they suck themselves fast, scraping off the flesh with their teeth. Whilst thus engaged they are carried about by their victim; Salmon have been captured in the middle course of the Rhine with the Marine Lamprey attached to them.

PETROMYZON.--Dorsal fins two, the posterior continuous with the caudal. The maxillary dentition consists of two teeth placed close together, or of a transverse bicuspid ridge; lingual teeth serrated.

The Lampreys belonging to this genus are found in the northern hemisphere only; the British species are the Sea-Lamprey (P. marinus), exceeding a length of three feet, and not uncommon on the European and North American coasts; the River-Lamprey or Lampern (P. fluviatilis), ascending in large numbers the rivers of Europe, North America, and Japan, and scarcely attaining a length of two feet; the “Pride” or “Sand-Piper” or Small Lampern (P. branchialis), scarcely twelve inches long, the larva of which has been long known under the name of Ammocoetes.

Ichthyomyzon from the western coasts of North America is said to have a tricuspid maxillary tooth.

MORDACIA.--Dorsal fins two, the posterior continuous with the caudal. The maxillary dentition consists of two triangular groups, each with three conical acute cusps; two pairs of serrated lingual teeth.

A Lamprey (M. mordax) from the coasts of Chile and Tasmania. This fish seems to be provided sometimes with a gular sac, like the following.

GEOTRIA.--Dorsal fins two, the posterior separate from the caudal. Maxillary lamina with four sharp flat lobes; a pair of long pointed lingual teeth.

Two species, one from Chile and one from South Australia. They grow to a length of two feet, and in some specimens the skin of the throat is much expanded, forming a large pouch. Its physiological function is not known. The cavity is in the subcutaneous cellular tissue, and does not communicate with the buccal or branchial cavities. Probably it is developed with age, and absent in young individuals. In all the localities in which these Extra-european Lampreys are found, Ammocoetes forms occur, so that there is little doubt that they undergo a similar metamorphosis as P. branchialis.

SECOND FAMILY--MYXINIDÆ.

Body eel-shaped, naked. The single nasal aperture is above the mouth, quite at the extremity of the head, which is provided with four pairs of barbels. Mouth without lips. Nasal duct without cartilaginous rings, penetrating the palate. One median tooth on the palate, and two comb-like series of teeth on the tongue (see Fig. 101). Branchial apertures at a great distance from the head; the inner branchial ducts lead into the œsophagus. A series of mucous sacs along each side of the abdomen. Intestine without spiral valve. Eggs large, with a horny case provided with threads for adhesion.

The fishes of this family are known by the names of “Hag-Fish,” “Glutinous Hag,” or “Borer;” they are marine fishes with a similar distribution as the Gadidæ, being most plentiful in the higher latitudes of the temperate zones of the northern and southern hemispheres. They are frequently found buried in the abdominal cavity of other fishes, especially Gadoids, into which they penetrate to feed on their flesh. They secrete a thick glutinous slime in incredible quantities, and are therefore considered by fishermen a great nuisance, seriously damaging the fisheries and interfering with the fishing in localities where they abound. Myxine descends to a depth of 345 fathoms, and is generally met with in the Norwegian Fjords at 70 fathoms, sometimes in great abundance.

MYXINE.--One external branchial aperture only on each side of the abdomen, leading by six ducts to six branchial sacs.

Three species from the North Atlantic, Japan, and Magelhæn’s Straits.

BDELLOSTOMA.--Six or more external branchial apertures on each side, each leading by a separate duct to a branchial sac.

Two species from the South Pacific.

FOURTH SUB-CLASS--LEPTOCARDII.

Skeleton membrano-cartilaginous and notochordal, ribless. No brain. Pulsating sinuses in place of a heart. Blood colourless. Respiratory cavity confluent with the abdominal cavity; branchial clefts in great number, the water being expelled by an opening in front of the vent. Jaws none.

This sub-class is represented by a single family (Cirrostomi) and by a single genus (Branchiostoma); it is the lowest in the scale of fishes, and lacks so many characteristics, not only of this class, but of the vertebrata generally, that Hæckel, with good reason, separates it into a separate class, that of Acrania. The various parts of its organisation have been duly noticed in the first part of this work.

The “Lancelet” (Branchiostoma lanceolatum, see Fig. 28, p. 63), seems to be almost cosmopolitan within the temperate and tropical zones. Its small size, its transparency, and the rapidity with which it is able to bury itself in the sand, are the causes why it escapes so readily observation, even at localities where it is known to be common. Shallow, sandy parts of the coasts seem to be the places on which it may be looked for. It has been found on many localities of the British, and generally European coasts, in North America, the West Indies, Brazil, Peru, Tasmania, Australia, and Borneo. It rarely exceeds a length of three inches. A smaller species, in which the dorsal fringe is distinctly higher and rayed, and in which the caudal fringe is absent, has been described under the name of Epigionichthys pulchellus; it was found in Moreton Bay.

APPENDIX.

DIRECTIONS FOR COLLECTING AND PRESERVING FISHES.

Whenever practicable fishes ought to be preserved in spirits.

To insure success in preserving specimens the best and strongest spirits should be procured, which, if necessary, can be reduced to the strength required during the journey with water or weaker spirit. Travellers frequently have great difficulties in procuring spirits during their journey, and therefore it is advisable, especially during sea voyages, that the traveller should take a sufficient quantity with him. Pure spirits of wine is best. Methylated spirits may be recommended on account of their cheapness; however, specimens do not keep equally well in this fluid, and very valuable objects, or such as are destined for minute anatomical examination, should always be kept in pure spirits of wine. If the collector has exhausted his supply of spirits he may use arrack, cognac, or rum, provided that the fluids contain a sufficient quantity of alcohol. Generally speaking, spirits which, without being previously heated, can be ignited by a match or taper, may be used for the purposes of conservation. The best method to test the strength of the spirits is the use of a hydrometer. It is immersed in the fluid to be measured, and the deeper it sinks the stronger is the spirit. On its scale the number 0 signifies what is called proof spirit, the lowest degree of strength which can be used for the conservation of fish for any length of time. Spirits, in which specimens are packed permanently, should be from 40 to 60 above proof. If the hydrometers are made of glass they are easily broken, and therefore the traveller had better provide himself with three or four of them, their cost being very trifling. Further, the collector will find a small distilling apparatus very useful. By its means he is able not only to distil weak and deteriorated spirits or any other fluid containing alcohol, but also, in case of necessity, to prepare a small quantity of drinkable spirits.

Of collecting vessels we mention first those which the collector requires for daily use. Most convenient are four-sided boxes made of zinc, 18 in. high, 12 in. broad, and 5 in. wide. They have a round opening at the top of 4 in. diameter, which can be closed by a strong cover of zinc of 5 in. diameter, the cover being screwed into a raised rim round the opening. In order to render the cover air-tight, an indiarubber ring is fixed below its margin. Each of these zinc boxes fits into a wooden case, the lid of which is provided with hinges and fastenings, and which on each side has a handle of leather or rope, so that the box can be easily shifted from one place to another. These boxes are in fact made from the pattern of the ammunition cases used in the British army, and extremely convenient, because a pair can be easily carried strapped over the shoulders of a man or across the back of a mule. The collector requires at least two, still better four or six, of these boxes. All those specimens which are received during the day are deposited in them, in order to allow them to be thoroughly penetrated by the spirit, which must be renewed from time to time. They remain there for some time under the supervision of the collector, and are left in these boxes until they are hardened and fit for final packing. Of course, other more simple vessels can be used and substituted for the collecting boxes. For instance, common earthenware vessels, closed by a cork or an indiarubber covering, provided they have a wide mouth at the top, which can be closed so that the spirit does not evaporate, and which permits of the specimens being inspected at any moment without trouble. Vessels in which the objects are permanently packed for the home journey are zinc boxes of various sizes, closely fitting into wooden cases. Too large a size should be avoided, because the objects themselves may suffer from the superimposed weight, and the risk of injury to the case increases with its size. It should hold no more than 18 cubic feet at most, and what, in accordance with the size of the specimens, has to be added in length should be deducted in depth or breadth. The most convenient cases, but not sufficient for all specimens, are boxes 2 feet in length, 1½ foot broad, and 1 foot deep. The traveller may provide himself with such cases ready made, packing in them other articles which he wants during his journey; or he may find it more convenient to take with him only the zinc plates cut to the several sizes, and join them into boxes when they are actually required. The requisite wooden cases can be procured without much difficulty almost everywhere. No collector should be without the apparatus and materials for soldering, and he should be well acquainted with their use. Also a pair of scissors to cut the zinc plates are useful.

Wooden casks are not suitable for the packing of specimens preserved in spirits, at least not in tropical climates. They should be used in cases of necessity only, or for packing of the largest examples, or for objects preserved in salt or brine.

Very small and delicate specimens should never be packed together with larger ones, but separately, in small bottles.

Mode of preserving.--All fishes, with the exception of very large ones (broad kinds exceeding 3–4 feet in length; eel-like kinds more than 6 feet long), should be preserved in spirits. A deep cut should be made in the abdomen between the pectoral fins, another in front of the vent, and one or two more, according to the length of the fish, along the middle line of the abdomen. These cuts are made partly to remove the fluid and easily decomposing contents of the intestinal tract, partly to allow the spirit quickly to penetrate into the interior. In large fleshy fishes several deep incisions should be made with the scalpel into the thickest parts of the dorsal and caudal muscles, to give ready entrance to the spirits. The specimens are then placed in one of the provisional boxes, in order to extract, by means of the spirit, the water of which fishes contain a large quantity. After a few days (in hot climates after 24 or 48 hours) the specimens are transferred into a second box with stronger spirits, and left therein for several days. A similar third and, in hot climates sometimes a fourth, transfer is necessary. This depends entirely on the condition of the specimens. If, after ten or fourteen days of such treatment the specimens are firm and in good condition, they may be left in the spirits last used until they are finally packed. But if they should be soft, very flexible, and discharge a discoloured bloody mucus, they must be put back in spirits at least 20° over proof. Specimens showing distinct signs of decomposition should be thrown away, as they imperil all other specimens in the same vessel. Neither should any specimen in which decomposition has commenced when found, be received for the collecting boxes, unless it be of a very rare species, when the attempt may be made to preserve it separately in the strongest spirits available. The fresher the specimens to be preserved are, the better is the chance of keeping them in a perfect condition. Specimens which have lost their scales, or are otherwise much injured, should not be kept. Herring-like fishes, and others with deciduous scales, are better wrapped in thin paper or linen before being placed in spirits.

The spirits used during this all-important process of preservation loses, of course, gradually in strength. As long as it keeps 10° under proof it may still be used for the first stage of preservation, but weaker spirits should be re-distilled; or, if the collector cannot do this, it should be at least filtered through powdered charcoal before it is mixed with stronger spirits. Many collectors are satisfied with removing the thick sediment collected at the bottom of the vessel, and use their spirits over and over again without removing from it by filtration the decomposing matter with which it has been impregnated, and which entirely neutralises the preserving property of the spirits. The result is generally the loss of the collection on its journey home. The collector can easily detect the vitiated character of his spirits by its bad smell. He must frequently examine his specimens; and attention to the rules given, with a little practice and perseverance, after the possible failure of the first trial, will soon insure to him the safety of his collected treasures. The trouble of collecting specimens in spirits is infinitely less than that of preserving skins or dry specimens of any kind.

When a sufficient number of well-preserved examples have been brought together, they should be sent home by the earliest opportunity. Each specimen should be wrapped separately in a piece of linen, or at least soft paper; the specimens are then packed as close as herrings in the zinc case, so that no free space is left either at the top or on the sides. When the case is full, the lid is soldered on, with a round hole about half an inch in diameter near one of the corners. This hole is left in order to pour the spirit through it into the case. Care is taken to drive out the air which may remain between the specimens, and to surround them completely with spirits, until the case is quite full. Finally, the hole is closed by a small square lid of tin being soldered over it. In order to see whether the case keeps in the spirit perfectly, it is turned upside down and left over night. When all is found to be securely fastened, the zinc case is placed into the wooden box and ready for transport.

Now and then it happens in tropical climates that collectors are unable to keep fishes from decomposition even in the strongest spirits without being able to detect the cause. In such cases a remedy will be found in mixing a small quantity of arsenic or sublimate with the spirits; but the collector ought to inform his correspondent, or the recipient of the collection, of this admixture having been made.

In former times fishes of every kind, even those of small size, were preserved dry as flat skins or stuffed. Specimens thus prepared admit of a very superficial examination only, and therefore this method of conservation has been abandoned in all larger museums, and should be employed exceptionally only, for instance on long voyages overland, during which, owing to the difficulty of transport, neither spirits nor vessels can be carried. To make up as much as possible for the imperfection of such specimens, the collector ought to sketch the fish before it is skinned, and to colour the sketch if the species is ornamented with colours likely to disappear in the dry example. Collectors who have the requisite time and skill, ought to accompany their collections with drawings coloured from the living fishes; but at the same time it must be remembered that, valuable as such drawings are if accompanied by the originals from which they were made, they can never replace the latter, and possess a subordinate scientific value only.

Very large fishes can be preserved as skins only; and collectors are strongly recommended to prepare in this manner the largest examples obtainable, although it will entail some trouble and expense. So very few large examples are exhibited in museums, the majority of the species being known from the young stage only, that the collector will find himself amply recompensed by attending to these desiderata.

Scaly fishes are skinned thus: with a strong pair of scissors an incision is made along the median line of the abdomen from the foremost part of the throat, passing on one side of the base of the ventral and anal fins, to the root of the caudal fin, the cut being continued upwards to the back of the tail close to the base of the caudal. The skin of one side of the fish is then severed with the scalpel from the underlying muscles to the median line of the back; the bones which support the dorsal and caudal are cut through, so that these fins remain attached to the skin. The removal of the skin of the opposite side is easy. More difficult is the preparation of the head and scapulary region; the two halves of the scapular arch which have been severed from each other by the first incision are pressed towards the right and left, and the spine is severed behind the head, so that now only the head and shoulder bones remain attached to the skin. These parts have to be cleaned from the inside, all soft parts, the branchial and hyoid apparatus, and all smaller bones, being cut away with the scissors or scraped off with the scalpel. In many fishes, which are provided with a characteristic dental apparatus in the pharynx (Labroids, Cyprinoids), the pharyngeal bones ought to be preserved, and tied with a thread to the specimen. The skin being now prepared so far, its entire inner surface as well as the inner side of the head are rubbed with arsenical soap; cotton-wool, or some other soft material is inserted into any cavities or hollows, and finally a thin layer of the same material is placed between the two flaps of the skin. The specimen is then dried under a slight weight to keep it from shrinking.

The scales of some fishes, as for instance of many kinds of herrings, are so delicate and deciduous that the mere handling causes them to rub off easily. Such fishes may be covered with thin paper (tissue-paper is the best), which is allowed to dry on them before skinning. There is no need for removing the paper before the specimen has reached its destination.

Scaleless Fishes, as Siluroids and Sturgeons, are skinned in the same manner, but the skin can be rolled up over the head; such skins can also be preserved in spirits, in which case the traveller may save to himself the trouble of cleaning the head.

Some Sharks are known to attain to a length of 30 feet, and some Rays to a width of 20 feet. The preservation of such gigantic specimens is much to be recommended, and although the difficulties of preserving fishes increase with their size, the operation is facilitated, because the skins of all Sharks and Rays can easily be preserved in salt and strong brine. Sharks are skinned much in the same way as ordinary fishes. In Rays an incision is made not only from the snout to the end of the fleshy part of the tail, but also a second across the widest part of the body. When the skin is removed from the fish, it is placed into a cask with strong brine mixed with alum, the head occupying the upper part of the cask; this is necessary, because this part is most likely to show signs of decomposition, and therefore most requires supervision. When the preserving fluid has become decidedly weaker from the extracted blood and water, it is thrown away and replaced by fresh brine. After a week’s or fortnight’s soaking the skin is taken out of the cask to allow the fluid to drain off; its inner side is covered with a thin layer of salt, and after being rolled up (the head being inside) it is packed in a cask, the bottom of which is covered with salt; all the interstices and the top are likewise filled with salt. The cask must be perfectly water-tight.

Of all larger examples of which the skin is prepared, the measurements should be taken before skinning so as to guide the taxidermist in stuffing and mounting the specimens.

Skeletons of large osseous fishes are as valuable as their skins. To preserve them it is only necessary to remove the soft parts of the abdominal cavity and the larger masses of muscle, the bones being left in their natural continuity. The remaining flesh is allowed to dry on the bones, and can be removed by proper maceration at home. The fins ought to be as carefully attended to as in a skin, and of scaly fishes so much of the external skin ought to be preserved as is necessary for the determination of the species, as otherwise it is generally impossible to determine more than the genus.

A few remarks may be added as regards those Faunæ, which promise most results to the explorer, with some hints as to desirable information on the life and economic value of fishes.

It is surprising to find how small the number is of the freshwater faunæ which may be regarded as well explored; the rivers of Central Europe, the Lower Nile, the lower and middle course of the Ganges, and the lower part of the Amazons are almost the only fresh waters in which collections made without discrimination would not reward the naturalist. The oceanic areas are much better known; yet almost everywhere novel forms can be discovered and new observations made. Most promising and partly quite unknown are the following districts:--the Arctic Ocean, all coasts south of 38° lat. S., the Cape of Good Hope, the Persian Gulf, the coasts of Australia (with the exception of Tasmania, New South Wales, and New Zealand), many of the little-visited groups of Pacific islands, the coasts of north-eastern Asia north of 35° lat. N., and the western coasts of North and South America.

No opportunity should be lost to obtain pelagic forms, especially the young larva-like stages of development abounding on the surface of the open ocean. They can be obtained without difficulty by means of a small narrow meshed net dragged behind the ship. The sac of the net is about 3 feet deep, and fastened to a strong brass-ring 2 or 2½ feet in diameter. The net is suspended by three lines passing into the strong main line. It can only be used when the vessel moves very slowly, its speed not exceeding three knots an hour, or when a current passes the ship whilst at anchor. To keep the net in a vertical position the ring can be weighted at one point of its circumference; and by using heavier weights two or three drag-nets can be used simultaneously at different depths. This kind of fishing should be tried at night as well as day, as many fishes come to the surface only after sunset. The net must not be left long in the water, from 5 to 20 minutes only, as delicate objects would be sure to be destroyed by the force of the water passing through the meshes.

Objects found floating on the surface, as wood, baskets, seaweed, etc., deserve the attention of the travellers, as they are generally surrounded by small fishes or other marine animals.

It is of the greatest importance to note the longitude and latitude at which the objects were collected in the open ocean.

Fishing in great depths by means of the dredge, can be practised only from vessels specially fitted out for the purpose; and the success which attended the “Challenger,” and North American Deep-sea explorations, has developed Deep-sea fishing into such a speciality that the requisite information can be gathered better by consulting the reports of those expeditions than from a general account, such as could be given in the present work.

Fishes offer an extraordinary variety with regard to their habits, growth, etc., so that it is impossible to enumerate in detail the points of interest to which the travellers should pay particular attention. However, the following hints may be useful.

Above all, detailed accounts are desirable of all fishes forming important articles of trade, or capable of becoming more generally useful than they are at present. Therefore, deserving of special attention are the Sturgeons, Gadoids, Thyrsites and Chilodactylus, Salmonoids, Clupeoids. Wherever these fishes are found in sufficient abundance, new sources may be opened to trade.

Exact observations should be made on the fishes the flesh of which is poisonous either constantly or at certain times and certain localities; the cause of the poisonous qualities as well as the nature of the poison should be ascertained. Likewise the poison of fishes provided with special poison-organs requires to be experimentally examined, especially with regard to its effects on other fishes and animals generally.

All observations directed to sex, mode of propagation, and development, will have special interest: thus those relating to secondary sexual characters, hermaphroditism, numeric proportion of the sexes, time of spawning and migration, mode of spawning, construction of nests, care of progeny, change of form during growth, etc.

If the collector is unable to preserve the largest individuals of a species that may come under his observation he should note at least their measurements. There are but few species of fishes of which the limit of growth is known.

The history of Parasitic Fishes is almost unknown, and any observations with regard to their relation to their host as well as to their early life will prove to be valuable; nothing is known of the propagation of fishes even so common as Echeneis and Fierasfer, much less of the parasitic Freshwater Siluroids.

The temperature of the blood of the larger freshwater and marine species should be exactly measured.

Many pelagic and deep-sea fishes are provided with peculiar small round organs of a mother-of-pearl colour, distributed in series along the side of the body, especially along the abdomen. Some zoologists consider these organs as accessory eyes, others (and it appears to us with better reason) as luminous organs. They deserve an accurate microscopic examination made on fresh specimens; and their function should be ascertained from observation of the living fishes, especially also with regard to the question, whether or not the luminosity (if such be their function) is subject to the will of the fish.

INDEX.

Abdominal Cavity, 123

Abdominal fins, 42

Abramis, 602

Abrostomus, 596

Acanthaphritis, 466

Acanthias, 331

Acanthicus, 576

Acanthobrama, 604

Acanthoclinus, 498

Acanthodes, 355

Acanthodini, 355

Acantholabrus, 528

Acanthonus, 547

Acanthophthalmus, 606

Acanthopsis, 606

Acanthopterygiau, 41

Acanthopterygii, 374

Acanthorhodeus, 601

Acanthurus, 438, 439

Acanus, 421

Acara, 536

Acclimatisation, 185

Acentronura, 683

Acerina, 378

Acestra, 579

Achilognathus, 601

Acipenser, 361

Acipenseridæ, 360

Acrochilus, 601

Acrochordonichthys, 567

Acrodus, 330

Acrogaster, 421

Acrognathus, 631

Acrolepis, 370

Acronuridæ, 438

Acronurus, 439

Acropoma, 395

Acyprinoid division, 218

Adipose eyelid, 113

Adipose fin, 42

Aegæonichthys, 476

Aellopos, 325

Aelurichthys, 569

Aesopia, 558

Aëtobatis, 345

African region, 227

Agassiz, 20, 31, 32

Ageniosus, 572

Agnus, 463

Agoniates, 610

Agonostoma, 504

Agonus, 480

Agrammus, 491

Agriopus, 416

Ailia, 566

Aipichthys, 441

Air-bladder, 142

Akysis, 567

Albacore, 458

Albinism, 183

Alborella, 604

Albula, 660

Albulichthys, 596

Alburnus, 603

Alepocephalus, 664

Alestes, 608

Ale-wife, 659

Alisphenoid, 56, 88

Allice Shad, 659

Alopecias, 322

Ambassis, 393

Amblyopsis, 618

Amblyopus, 489

Amblypharyngodon, 598

Amblypterus, 370

Amblyrhynchichthys, 596

Amia, 372

Amioidei, 370

Amiurus, 567

Ammocoetes, 693

Ammodytes, 550

Ammopleurops, 559

Ammotretis, 557

Amphioxus, 696

Amphipnous, 668

Amphiprion, 525

Amphisile, 509

Amphistium, 442

Anabas, 516

Anableps, 617

Anacanthini, 537

Anacanthus, 684

Anacyrtus, 611

Anal fin, 40, 42

Anampses, 529

Anapterus, 582

Anarrhichas, 492

Anastomus, 608

Anchovy, 656

Ancistrodon, 319

Ancylodon, 430

Anema, 463

Anenchelum, 433

Angel-fish, 334

Angler, 470

Anguilla, 671

Angular bone, 54, 91

Anomalops, 449

Anoplogaster, 422

Antarctic ocean, 289

Antennarius, 473

Anthias, 380

Anticitharus, 556

Antigonia, 449

Aphanopus, 434

Aphareus, 390

Aphoristia, 559

Aphredoderus, 396

Aphritis, 466

Aphyocharax, 610

Aphyocypris, 598

Aphyonus, 548

Apionichthys, 559

Apistus, 415

Aploactis, 417

Apocryptes, 487

Apodichthys, 496

Apogon, 394

Apophyses, 51

Appendices pyloricæ, 131

Aprion, 397

Apsilus, 397

Apua, 606

Arapaima, 654

Archæus, 442

Archipterygium, 74

Arctic ocean, 261

Arctic zone, 241

Argentina, 650

Arges, 575

Argyropelecus, 628

Argyriosus, 443

Aristotle, 1

Arius, 569

Arnoglossus, 556

Arrhamphus, 621

Arripis, 393

Artedi, 9

Artedius, 480

Arthropterus, 342

Articulary bone, 54, 90

Articulated rays, 40

Asima, 405

Aspidoparia, 602

Aspidophoroides, 480

Aspidorhynchidæ, 369

Aspius, 603

Aspredo, 580

Aspro, 379

Astracanthus, 314

Astrape, 340

Astrolepis, 354

Astronesthes, 629

Astrophysus, 572

Astroplebus, 575

Astroptychius, 314

Ateleopus, 553

Atherina, 500

Atherinichthys, 501

Atlantic, tropical, 278

Atlantic, northern, 262

Atopochilus, 570

Atopomycterus, 689

Atypichthys, 402

Auchenaspis, 354

Auchenipterus, 572

Auchenoglanis, 569

Aulacocephalus, 383

Aulolepis, 631

Aulichthys, 508

Auliscops, 507, 508

Aulopus, 587

Aulopyge, 596

Aulorhynchus, 508

Aulostoma, 507, 508

Ausonia, 455

Ausonius, 3

Autochthont, 214

Autostylic skull, 71

Auxis, 459

Avola, 604

Badis, 418

Baer, 32

Bagarius, 570

Bagrichthys, 567

Bagroides, 567

Bagropsis, 568

Bagrus, 567

Baird, 29

Bakker, 32

Balfour, 32, 33

Balistes, 684

Ballan Wrasse, 527

Band-fish, 490

Barbel, 594

Barbels, 37

Barbichthys, 596

Barbus, 594

Barilius, 602

Barracuda, 437, 499

Barramunda, 357

Barynotus, 596

Basibranchial, 58

Basihyal, 58

Basioccipital, 56, 87

Basisphenoid, 56, 57, 89

Basking shark, 322

Bass, 376

Bastard Dorey, 388

Bathydraco, 465

Bathygadus, 552

Bathylagus, 650

Bathynectes, 547

Bathyophis, 629

Bathypterois, 583

Bathysaurus, 582

Bathythrissa, 668

Bathytroctes, 664

Batoidei, 335

Batrachocephalus, 570

Batrachus, 467

Bayad, 567

Bdellostoma, 695

Becker, 408

Bellows-fish, 509

Belodontichthys, 566

Belon, 3

Belone, 620

Belonesox, 617

Belonostomus, 369

Bembras, 480

Benedenius, 370

Benthophilus, 489

Berycidæ, 420

Berycopsis, 421

Beryx, 422

Betta, 518

Bib, 541

Bichir, 364

Bitterling, 601

Black Bass, 393

Black-fish, 452, 527

Black Head, 596

Black Horses, 589

Black Sea-bream, 406

Blanchard, 28

Bleak, 604

Bleeker, 30

Bleekeria, 550

Blenniidæ, 492

Blenniops, 496

Blennius, 493

Blennodesmus, 538

Blennophis, 498

Blenny, 492

Blepsias, 480

Blind fish, 618

Bloch, 13

Blood-corpuscles, 150

Blue-fish, 447

Boar-fish, 388, 449

Bocage, 28

Bocourt, 31

Bola, 602

Boleophthalmus, 487

Boleosoma, 379

Bolty, 535

Bombay-duck, 584

Bonaparte, 28

Bonelli, 7

Bonito, 458

Bony Pike, 367

Borer, 694

Botia, 605

Bovichthys, 465

Bow-fin, 372

Box, 406

Brachionichthys, 474

Brachymystax, 646

Brachypleura, 556

Brackish water fishes, 250

Brain, 97

Brama, 454

Branched rays, 40

Branchiæ, 136

Branchial arches, 58

Branchiostegals, 39, 58, 91

Branchiostoma, 696

Bream, 602

Bregmaceros, 545

Brill, 555

British district, 263

Brontes, 575

Brook-trout, 646

Brosmius, 546

Brotula, 546

Brotulophis, 549

Brünnich, 13

Brycon, 610

Bryconæthiops, 610

Bryconops, 610

Bryttus, 396

Buccal cavity, 123

Bulbus aortæ, 152

Bull-head, 476

Bull-trout, 644

Bulti, 535

Buffaloe, 589

Bummaloh, 584

Bungia, 596

Bunocephalichthys, 580

Bunocephalus, 580

Bunocottus, 480

Burbot, 544

Bursa entiana, 128

Burton Skate, 341

Butter-fish, 496, 533

Bynni, 594

Bythites, 549

Cachius, 604

Cænotropus, 607

Cæsio, 390

Calamoichthys, 364

Californian district, 271

Calamostoma, 680

Callanthias, 381

Callichrous, 566

Callichthys, 575

Callionymus, 489

Callipteryx, 462

Callomystax, 573

Callophysus, 569

Callorhynchus, 350

Callyodon, 532

Camper, 16

Campostoma, 596

Cantharina, 405

Cantharus, 405

Cantor, 30

Capelin, 647

Capello, 28

Cape of Good Hope, 283

Capitodus, 405

Capoëta, 593

Capros, 449

Carangidæ, 440

Carangopsis, 442

Caranx, 442

Carapus, 667

Carassius, 591

Carboniferous fishes, 196

Carcharias, 316

Carchariidæ, 316

Carcharodon, 320

Carcharopsis, 319

Cardlike teeth, 126

Caribe, 613

Carmoot, 563

Carp, 589

Carpals, 59

Carpiodes, 589

Cartilage-bones, 87

Castelnau, 31

Cataphracti, 480

Cat-fishes, 568

Catla, 592

Catopra, 418

Catoprion, 613

Catostomus, 589

Caturidæ, 371

Caudal fin, 40

Cebidichthys, 498

Central American district, 279

Centrarchus, 396

Centridermichthys, 477

Centrina, 331

Centriscus, 509

Centrolabrus, 528

Ceutrolepis, 370

Centrolophus, 452

Centromochlus, 572

Centronotus, 496

Centrophorus, 331

Centropogon, 417

Centropomus, 379

Ceutropristis, 380

Centroscyllium, 332

Centrum, 51

Cephalacanthus, 482

Cephalaspis, 353

Cephaloptera, 347

Cephenoplosus, 368

Cepola, 490

Ceratias, 472

Ceratichthys, 596

Ceratobranchial, 58

Ceratodus, 357

Ceratohyal, 58

Ceratoptera, 347

Cerebellum, 97

Cestracion, 330

Cestraciontidæ, 328

Cetengraulis, 656

Cetopsis, 572

Chaca, 564

Chad, 408

Chænichthys, 466

Chætobranchus, 537

Chætodon, 398

Chætopterus, 390

Chætostomus, 576

Chalceus, 610

Chalcinopsis, 610

Chalcinus, 610

Champsodon, 464

Channa, 513

Chanodichthys, 604

Chanos, 662

Characinidæ, 606

Characodon, 615

Charr, 645

Chasmodes, 494

Chatoëssus, 657

Chauliodus, 628

Chaunax, 474

Cheilio, 530

Chela, 604

Chelmo, 399

Chiasmodus, 546

Chilian district, 288

Chilinus, 528

Chilobranchus, 669

Chilodactylus, 411

Chilodipterus, 395

Chilomycterus, 689

Chilorhinus, 674

Chiloscyllium, 326, 327

Chimæra, 349

Chimæridæ, 348

Chimarrhichthys, 466

Chiracanthus, 355

Chirocentrites, 656

Chirocentrodon, 660

Chirocentrus, 663

Chirodon, 609

Chirodus, 370

Chirolepis, 370

Chironemus, 411

Chirus, 491

Chlorophthalmus, 587

Chœrops, 530

Chologaster, 618

Chomatodus, 329

Chondropterygii, 313

Chondrostei, 360

Chondrosteus, 363

Chondrostoma, 600

Chorda dorsalis, 63

Chorinemus, 446

Chorismodactylus, 417

Chorisochismus, 512

Chromatophors, 183

Chromides, 534

Chromis, 535

Chrysichthys, 567

Chrysophrys, 409

Chub, 596, 599, 600

Cichla, 536

Cichlops, 466

Circulation, organs of, 150

Cirrhilabrus, 530

Cirrhina, 596

Cirrhites, 411

Cirrhitidæ, 410

Cirrostomi, 696

Citharichthys, 556

Citharinus, 607

Citharus, 556

Cladacanthus, 314

Cladodus, 328

Clarias, 563

Clarotes, 567

Claspers, 167

Clavicula, 59, 92

Clepticus, 530

Climbing Perch, 516

Clinus, 495

Cloudy Bay cod, 549

Clupea, 658

Clupeichthys, 660

Clupeoides, 660

Cnidoglanis, 564

Coal-fish, 541

Cobitis, 605

Coccia, 628

Coccosteus, 351

Cochlognathus, 596

Cochliodus, 329

Cock-and-hen Paddle, 484

Cod-fishes, 539

Cœcal stomach, 130

Coelacanthidæ, 365

Coelodus, 367

Coelogaster, 656

Coelonotus, 681

Coelorhynchus, 433

Coffer-fish, 686

Coilia, 657

Collichthys, 430

Commerson, 13

Conger, 673

Congrogadina, 550

Congromuræna, 674

Conodon, 386

Conodonts, 193

Conodus, 368

Conorhynchus, 569

Conus arteriosus, 151

Cook, 527

Copidoglanis, 564

Coracoid, 59, 92

Coral-fishes, 397, 525

Corax, 317

Coregonus, 647

Coridodax, 533

Coris, 530

Cork-wing, 527

Cornide, 13

Corpora quadrigemina, 103

Corpora restiformia, 99

Corpora striata, 100

Corvina, 430

Corvo, 429

Corynopoma, 607

Coryphæna, 452

Coryphænoides, 552

Cosmolepis, 370

Cosmoptychius, 370

Cossyphus, 528

Costa, 28

Cottoperca, 466

Cottus, 476

Cotylis, 512

Couch, 27

Couchia, 544

Craig-fluke, 557

Creagrutus, 610

Cremnobates, 495

Crenicichla, 537

Crenidens, 406

Crenilabrus, 527

Crenuchus, 612

Crepidogaster, 513

Cretaceous fishes, 199

Cricacanthus, 314

Cristiceps, 495

Crossochilus, 596

Crossognathus, 656

Crossorhinus, 328

Crossostoma, 604

Crucian carp, 591

Crura cerebri, 98

Cryptacanthodes, 496

Cryptopterus, 566

Ctenododipteridæ, 359

Ctenodus, 359

Ctenoid scales, 46

Ctenolabrus, 527

Ctenopharyngodon, 601

Ctenopoma, 516

Ctenoptychius, 329

Cubiceps, 456

Culter, 604

Curimatus, 607

Cut-lips, 596

Cuvier, 17

Cyathaspis, 354

Cybium, 459

Cyclobatis, 340

Cycloid scales, 46

Cyclopoma, 375

Cyclopterus, 484

Cycloptychius, 370

Cyclostomata, 691

Cyclurus, 588

Cyema, 670

Cymolutes, 530

Cynodon, 611

Cynoglossus, 558

Cynolebias, 615

Cyprinidæ, 587

Cyprinion, 598

Cyprinodon, 614

Cyprinoid division, 217

Cyprinus, 589

Cyttidæ, 450

Cyttus, 451

Dab, 557

Dace, 599, 600

Dactylopterus, 481

Dactyloscopus, 498

Dangila, 596

Danio, 602

Dascyllus, 525

Datnioides, 397

Daurade, 409

Day, 30

Deal-fish, 522

Decodon, 530

Deep-sea fishes, 296

Dekay, 29

Dendrodus, 365

Dentary, 54, 91

Dentex, 389

Dercetis, 666

Dermal spines, 53

Dermoskeleton, 85

Devil-fishes, 344

Devonian fishes, 193, 194

Diagramma, 386

Diana, 455

Dibranchus, 475

Dicerobatis, 347

Dicotylichthys, 689

Dicrotus, 437

Dictyosoma, 498

Didymaspis, 354

Digestion, organs of, 121

Dimeracanthus, 314

Dinematichthys, 549

Dinichthys, 352

Diodon, 689

Dioecious, 157

Diplocrepis, 513

Diplomystax, 569

Diplophos, 629

Diploprion, 383

Diplopterus, 365

Dipnoi, 355

Dipterodon, 406

Dipterus, 359

Diptychus, 595

Diretmus, 449

Discoboli, 483

Discognathus, 593

Discopyge, 340

Distichodus, 612

Ditrema, 534

Dog-fishes, 325, 619

Doliichthys, 487

Dolphins, 453

Domesticated fishes, 185

Domine, 436

Donovan, 17

Doras, 572

Doratonotus, 530

Dorsal fin, 40

Dorsch, 540

Dory, 450

Doryichthys, 681

Doydixodon, 406

Dragonet, 489

Drepane, 402

Drepanephorus, 331

Drum, 427

Ductor, 442

Ductus choledochus, 133

Ductus cysticus, 133

Duhamel, 13

Dules, 384

Duméril, 33

Dussumieria, 662

Duverney, 7

Duymæria, 530

Eagle-Rays, 344

Ear, 116

Echeneis, 460

Echinorhinus, 333

Echiostoma, 629

Ectopterygoid, 90

Edaphodon, 349

Eel, 671

Eel-pout, 544

Egertonia, 526

Elacate, 460

Elasmodus, 349

Elasmognathus, 349

Electric Eel, 667

Electric organs, 94

Electric Rays, 339

Electric Sheath-fish, 574

Eleotris, 488

Elonichthys, 370

Elopichthys, 604

Elops, 661

Embiotocidæ, 533

Encheliophis, 549

Enchelycore, 677

Enchodus, 433

Endoskeleton, 85

Engraulis, 656

Enneodon, 687

Enoplosus, 380

Entopterygoid, 55, 90

Epalzeorhynchus, 596

Ephippus, 402

Epibranchial, 59

Epibulus, 528

Epicoracoid, 59

Epididymis, 167

Epigionichthys, 696

Epihyal, 58

Epinnula, 436

Epioticum, 88

Epiphysis, 98

Epitympanic, 55

Equatorial zone, 218, 272

Eques, 431

Equula, 449

Eremophilus, 581

Erethistes, 580

Ericymba, 596

Erythrichthys, 391

Erythrinus, 607

Escholar, 437

Esox, 624

Etelis, 397

Etheostomatidæ, 379

Ethmoid, 57, 89

Etroplus, 534

Etrumeus, 662

Euanemus, 572

Euctenogobius, 487

Euglyptosternum, 571

Eugnathus, 368

Eulachon, 647

Eulepidotus, 368

Euoxymetopon, 434

Euprotomicrus, 334

Europo-Asiatic region, 243

Eurynotus, 370

Eurypholis, 666

Eurysomus, 370

Eustira, 604

Eutropiichthys, 566

Eutropius, 566

Evorthodus, 487

Exoccipital, 56, 87

Exocoetus, 621

Exoglossum, 596

Exostoma, 580

Eye, 36, 111

Fabricius, 13

Fall-fish, 600

Fierasfer, 549

Fighting-fish, 519

File-fishes, 684

Fins, 40

Fishing-Frog, 470

Fistularia, 507, 508

Fitzroyia, 615

Flat-fishes, 553

Flounder, 557

Flute-mouth, 507

Flying-fish, 621

Flying Gurnard, 482

Forskal, 13

Forster, 13

Freshwater-fishes, 208

Freshwater-Herring, 645

Fries and Ekström, 27

Frog-fish, 470

Frontal bone, 57, 89

Frost-fish, 436

Fuegian sub-region, 248

Fundulus, 615

Gadiculus, 541

Gadidæ, 539

Gadopsis, 537

Gadus, 539

Galapagoes district, 280

Galaxias, 624

Galeichthys, 569

Galeocerdo, 317

Galeoides, 425

Galeus, 318

Gallo, 451

Gambusia, 616

Ganodus, 349

Ganoidei, 350

Ganoid scales, 47

Gar-pike, 367, 620

Gaspereau, 659

Gastrochisma, 455

Gastrocnemus, 452

Gastromyzon, 604

Gastropelecus, 610

Gastrosteus, 505

Gastrotokeus, 682

Gazza, 450

Gegenbaur, 32

Gempylus, 437

Genidens, 569

Genyoroge, 384

Genypterus, 549

Geoffroy, 33

Geophagus, 537

Geotria, 693

Gerres, 388

Gillaroo, 645

Gill-cover, 38

Gill-opening, 38

Gill-rakers, 59, 139

Gills, 136

Gilthead, 409

Ginglymostoma, 326

Girardinus, 618

Girella, 406

Glanidium, 572

Glanis, 566

Glaucosoma, 384

Globe-fish, 687

Glossohyal, 58

Glottis, 149

Glut, 673

Glutinous hag, 694

Glyphidodon, 525

Glyptauchen, 415

Glyptolæmus, 365

Glyptolepis, 365

Glyptopomus, 365

Glyptosternum, 572

Gmelin, 13

Gobiesocidæ, 510

Gobiesox, 513

Gobio, 595

Gobiodon, 487

Gobiosoma, 487

Gobius, 486

Goby, 486

Gold-fish, 591

Gold-Sinny, 527

Gomphodus, 319

Gomphosus, 530

Gonatodus, 370

Goniognathus, 452

Gonorhynchus, 652

Gonostoma, 629

Gourami, 517

Grammistes, 382

Granular teeth, 126

Graphiurus, 365

Grayling, 649

Greenland Shark, 333

Grey Mullet, 501

Grig, 673

Gronow, 12

Growler, 393

Growth of Fishes, 170

Grystes, 392

Gudgeon, 596

Gular plates, 80

Güldenstedt, 13

Gunellichthys, 498

Gunnel-fish, 496

Günther, 27, 30

Gurnard, 479

Gwyniad, 649

Gymnachirus, 558

Gymnarchus, 626

Gymnelis, 538

Gymnocrotaphus, 406

Gymnocypris, 595

Gymnomuræna, 677

Gynmoscopelus, 585

Gymnotus, 667

Gyracanthus, 314

Gyrodus, 367

Gyropristis, 314

Gyroptychius, 365

Haddock, 540

Hadot, 540

Hæmal arches, 86

Hæmal spine, 52

Hæmapophyses, 51

Hæmulon, 386

Hag-fish, 694

Hair-tail, 436

Hake, 542

Halargyreus, 541

Halec, 656

Halecidæ, 656

Half-beak, 621

Halidesmus, 549

Halieutæa, 475

Halieutichthys, 475

Haliophis, 550

Haller, 16

Haloporphyrus, 543

Halosauridæ, 665

Hamilton, 17

Hammerhead, 318

Hapalogenys, 386

Haplochilus, 615

Haplochiton, 651

Haplodactylina, 406

Hapuku, 392

Harpagifer, 467

Harpodon, 583

Harttia, 580

Hasse, 32

Hasselquist, 13

Hausen, 361

Head, 36

Heart, 150

Heckel, 28

Hector, 32

Heliastes, 525

Helicophagus, 566

Heliodus, 359

Helmichthys, 180

Helogenes, 567

Helotes, 385

Hemerocœtes, 491

Hemichromis, 535

Hemiculter, 604

Hemigaleus, 319

Hemigymnus, 530

Hemilepidotus, 480

Hemiodus, 607

Hemipimelodus, 569

Hemipristis, 317

Hemirhamphus, 621

Hemirhombus, 556

Hemirhynchus, 437

Hemisaurida, 582

Hemisilurus, 566

Hemisorubim, 568

Hemithyrsites, 434

Hemitrichas, 656

Hemitripterus, 417

Heniochus, 399

Heptanchus, 325

Heptapterus, 581

Hermaphroditism, 157

Heros, 536

Herring, 658

Heteracanth, 41

Heterobranchus, 563

Heterocercy, 80

Heteroconger, 674

Heterognathodon, 389

Heterolepidotidæ, 491

Heteropygii, 618

Heterostichus, 498

Heterotis, 655

Hexanchus, 325

Hexapsephus, 588

Himantolophus, 472

Hippocampus, 683

Hippoglossoides, 555

Hippoglossus, 555

Histiophorus, 431

Histiopterus, 387

Holacanthus, 400

Holibut, 555

Hollardia, 684

Holocentrum, 423

Holocephala, 348

Holophagus, 365

Holoptychidæ, 365

Holosteus, 619

Homacanth, 41

Homaloptera, 604

Hombron et Jacquinot, 27

Homelyn Ray, 341

Homocanthus, 314

Homocercy, 83

Homoeolepis, 366

Homonotus, 421

Hopladelus, 568

Hoplichthys, 478

Hoplognathus, 410

Hoplopleuridæ, 665

Hoplopteryx, 421

Hoplopygus, 365

Hoplostethus, 421

Hoplunnis, 674

Horse-mackerel, 442

Hounds, 319

Huchen, 645

Humeral arch, 59

Hunds-fish, 619

Hunter, 16

Huro, 393

Hutton, 32

Huxley, 33

Hybernation, 188

Hybodontidæ, 328

Hybognathus, 596

Hyborhynchus, 596

Hybridism, 178

Hydrocyon, 611

Hygrogonus, 536

Hyodon, 653

Hyoid arch, 58

Hyomandibular, 55, 89

Hyoprorus, 674

Hyoptopoma, 578

Hyostylic skull, 74

Hypamia, 372

Hyperoglyphe, 387

Hyperopisus, 625

Hypnos, 340

Hypobranchial, 58

Hypomessus, 647

Hypophthalmichthys, 602

Hypophthalmus, 566

Hypophysis, 98

Hypotympanic, 55

Hypsinotus, 402

Hypsodon, 500

Hypural, 53, 84

Hyrtl, 32

Hysterocarpus, 534

Hystricodon, 611

Icelus, 477

Ichthyborus, 612

Ichthyocampus, 681

Ichthyodorulites, 194

Ichthyomyzon, 693

Id, 599

Ikan sumpit, 403

Impregnation, artificial, 186

Indian region, 220

Indo-Pacific ocean, 278

Infraorbital, 54

Infundibulum, 98

Interhæmals, 53

Intermaxillary, 53

Interneurals, 53

Interoperculum, 38, 55, 91

Intestine, 127

Ipnops, 585

Ischyodus, 349

Ischyrocephalus, 666

Isistius, 334

Isthmus, 39, 58

Isurus, 457

Japanese District, 270

Jenyns, 27

Jenynsia, 616

John Dory, 451

Jugular fins, 42

Julis, 529

Kabeljau, 540

Kalm, 13

Kamtschatkan district, 269

Karausche, 591

Karpfen, 589

Kathetostoma, 463

Kaup, 33

Kelb el bahr, 611

Kelb el moyeh, 611

Kelp-fish, 533

Keris, 440

Ketengus, 569

Kidney, 155

King of the herrings, 522

Klein, 12

Klipvisch, 549

Klunzinger, 30

Kner, 27, 28

Kneria, 606

Kokopu, 625

Kölliker, 32

Kovalevsky, 33

Kröyer, 27

Kurtus, 425

Labberdan, 540

Labeo, 593

Labials, 64, 69

Labrax, 376

Labrichthys, 530

Labridæ, 525

Labroides, 530

Labrus, 526

Labyrinthici, 514

Lachnolæmus, 528

Lachs, 644

Lacépède, 15

Lactarius, 450

Ladislavia, 596

Læmargus, 333

Læmonema, 543

Læops, 557

Lais, 566

Laminæ branchiales, 136

Lamna, 320

Lamnidæ, 319

Lampern, 692

Lampris, 454

Lamprey, 692

Lancelet, 696

Lanioperca, 397

Larimus, 431

Lateral line, 48

Lates, 377

Latilus, 466

Latris, 412

Latrunculus, 486

Launce, 550

Leather-carp, 591

Lebiasina, 607

Lemon-sole, 558

Lentipes, 487

Lepadogaster, 513

Lepidoblennius, 498

Lepidocephalichthys, 606

Lepidocephalus, 606

Lepidocottus, 476

Lepidopsetta, 556

Lepidopus, 435

Lepidosiren, 355

Lepidosteidæ, 367

Lepidotrigla, 479

Lepidotus, 368

Lepidozygus, 525

Leporinus, 608

Lepracanthus, 314

Leptacanthus, 314

Leptobarbus, 597

Leptocarcharias, 319

Leptocardii, 696

Leptocephali, 179

Leptoichthys, 681

Leptojulis, 529

Leptolepidæ, 371

Leptopterygius, 513

Leptoscopus, 463

Leptosomus, 656

Leptotrachelus, 666

Lesson, 26

Lethrinus, 407

Leucaspius, 604

Leuciscus, 598

Leucosomus, 600

Liacanthus, 314

Liachirus, 558

Liassic fishes, 198

Lichia, 446

Ligamentum longitudinale, 72

Limnurgus, 615

Ling, 544, 549

Linnæus, 10

Liocassis, 567

Liopsetta, 556

Lioscorpius, 415

Liparis, 485

Liposarcus, 576

Liver, 132

Loach, 604

Lobotes, 387

Lonchurus, 431

Lophiogobius, 487

Lophiosilurus, 569

Lophiostomus, 368

Lophius, 470

Lophobranchii, 678

Lophonectes, 556

Loricaria, 578

Lota, 544

Lotella, 543

Loxodon, 319

Lucania, 615

Lucifuga, 547

Luciocephalidæ, 519

Luciogobius, 489

Lucioperca, 378

Luciosoma, 598

Luciotrutta, 646

Lump-sucker, 484

Lütken, 32

Lycodes, 537

Mackerel, 456, 457

Mackerel Midge, 544

Macrodon, 607

Macrolepis, 421

Macrones, 567

Macropoma, 365

Macropus, 517

Macrosemius, 368

Macruridæ, 557

Macruronus, 552

Macrurus, 552

Mæna, 390

Mahaseer, 594

Malacanthus, 467

Malacocephalus, 552

Malacopterus, 528

Malacopterygian, 41

Malacosteus, 629

Malapterurus, 574

Mallotus, 647

Malpighi, 7

Malpighian corpuscle, 155

Malthe, 475

Mandible, 54

Margrav, 7

Marine fishes, 254

Mary sole, 555

Maskinonge, 624

Mastacembelus, 498

Mastoid, 57, 88

Maurolicus, 628

Maynea, 538

Maxillary, 53, 90

Meagre, 427

Meckel’s cartilage, 54

Meda, 601

Mediterranean district, 264

Medulla oblongata, 98

Megalichthys, 365

Megalobrycon, 610

Megalops, 661

Meidinger, 13

Melamphaes, 423

Melanocetus, 473

Melanonus, 541

Membrane-bones, 75, 84

Mendosoma, 412

Mene, 455

Menhaden, 659

Merluccius, 542

Mesencephalon, 97

Mesoarium, 158

Mesodon, 367

Mesogaster, 500

Mesolepis, 370

Mesonauta, 536

Mesoprion, 384

Mesops, 537

Mesopterygium, 70

Mesotympanic, 55

Mesturus, 367

Metacarpals, 59

Metamorphosis, 170

Metapterygium, 70

Metapterygoid, 55, 90

Metencephalon, 97

Micracanthus, 519

Microconodus, 370

Microdesmus, 538

Microdon, 367

Micropogon, 428

Micropteryx, 443

Micropus, 416

Microstoma, 650

Miller’s-thumb, 476

Minnow, 596, 599

Minous, 417

Misgurnus, 604

Mishcup, 408

Mitchell, 17

Mixogamous, 177

Mollienesia, 617

Molva, 544

Monacanthus, 684

Monk-fish, 334

Monocentris, 421

Monocirrhus, 418

Monopterus, 669

Moon-eye, 653

Mora, 541

Mordacia, 693

Moringua, 675

Mormyrops, 626

Mormyrus, 625

Mossbanker, 659

Motella, 544

Mouth, 37, 123

Moxostoma, 589

Mud-fish, 372, 619

Mugil, 501

Müller, H., 33

Müller, J., 22, 32, 33

Müller, O. F., 13

Müller, W., 33

Mullidæ, 403

Mulloides, 404

Mullus, 404

Munro, 16

Muræna, 675

Murænesox, 674

Murænichthys, 674

Murænolepis, 545

Murray-Cod, 392

Muscles, 93

Muskellunge, 624

Mustelus, 318

Mylesinus, 613

Myletes, 613

Myliobatis, 344

Mylocyprinus, 588

Myloleucus, 601

Mylopharodon, 601

Myology, 93

Myriacanthus, 314

Myriodon, 383

Myriolepis, 370

Myripristis, 423

Myroconger, 677

Myrophis, 674

Myrus, 674

Mystacoleucus, 598

Myxine, 695

Myxodes, 498

Myxus, 504

Nandus, 418

Nannœthiops, 610

Nannobrachium, 587

Nannocampus, 681

Nannocharax, 608

Nannostomus, 607

Narcine, 340

Naseus, 438, 440

Nauclerus, 446

Naucrates, 444

Nautichthys, 480

Nealotus, 434

Nearctic region, 246

Nebris, 431

Nebrius, 326

Neetroplus, 536

Nefasch, 612

Nemacanthus, 314

Nemachilus, 605

Nemadactylus, 412

Nematogenys, 581

Nematops, 557

Nematoptychius, 370

Nemichthys, 670

Nemophis, 498

Nemopteryx, 434, 539

Neochanna, 624

Neoclinus, 498

Neoconger, 674

Neophrynichthys, 469

Neotropical region, 233

Nerfling, 599

Nerophis, 681

Nerves, 103

Nesiarchus, 434

Nettastoma, 674

Neural arches, 85

Neural spine, 52

Neurapophyses, 51

Neurology, 96

Neuroskeleton, 85

New Zealand sub-region, 248

Nictitating membrane, 113

Nilsson, 27

Niphon, 397

Nomeidæ, 455

Nomeus, 456

Nonnat, 501

Nordmann, 28

North American district, 266

North American region, 246

North Atlantic, 262

Northern temperate zone, 262

Northern zone, 240

North Pacific, 268

Nostrils, 37, 109

Notacanthus, 523

Notidanus, 325

Notochord, 63

Notoglanis, 569

Notograptus, 498

Notopterus, 665

Notothenia, 466

Noturus, 568

Novacula, 529

Nummopalatus, 526

Nuria, 598

Nutrition, organs of, 121

Oar-Fish, 522

Oblata, 406

Occipital, 56

Ochetobius, 602

Odax, 532

Odontaspis, 321

Odonteus, 525

Odontostomus, 587

Oil-sardine, 660

Old Red Sandstone, 194

Old wife, 406

Olfactory lobes, 97

Olfactory organ, 109

Oligorus, 392

Oligosarcus, 611

Olistherops, 533

Ombre, 429

Ombre chevalier, 645

Omentum, 132

Onchus, 314

Oncorhynchus, 646

Oneirodes, 473

Oolithic fishes, 199

Opercular gill, 138

Operculum, 38, 54, 91

Ophichthys, 674

Ophidiidæ, 546

Ophidium, 549

Ophiocephalidæ, 513

Ophiodon, 491

Ophiopsis, 368

Opisthognathus, 466

Opisthopteryx, 656

Opisthoticum, 88

Opsariichthys, 602

Optic lobes, 97

Oracanthus, 314

Orbitosphenoid, 57, 88

Oreinus, 595

Oreonectes, 606

Orestias, 615

Orfe, 599

Orthacanthus, 334

Orthagoriscus, 690

Orthodon, 601

Orthostomus, 489

Osbeck, 13

Osmeroides, 582, 631

Osmerus, 646

Os operculare, 91

Osphromenus, 517

Osteobrama, 604

Osteochilus, 596

Osteogeniosus, 569

Osteoglossum, 654

Osteolepis, 365

Ostracion, 686

Os transversum, 56

Otolith, 116

Otolithus, 430

Oulachon, 647

Ovaries, 158, 166

Ovum, 158, 159, 167

Owen, 33

Oxuderces, 489

Oxyconger, 674

Oxydoras, 572

Oxygnathus, 370

Oxymetopon, 489

Oxyrhina, 320

Oxytes, 319

Pachycormus, 368

Pachymetopon, 406

Pachyurus, 430

Pagellus, 408

Pagrus, 408

Paired fins, 42

Palæarctic region, 243

Palæichthyes, 312

Palæogadus, 539

Palæoniscidæ, 369

Palæorhynchus, 437

Palæeoscyllium, 326

Palæospinax, 330

Palatine, 56, 90

Palatine arch, 55

Palimphyes, 457

Pallas, 13

Pammelas, 447

Pancreas, 133

Pangasius, 566

Pantodon, 653

Papilla urogenitalis, 156

Paracanthobrama, 598

Paradiplomystax, 569

Paradise-fish, 517

Paragoniates, 610

Paralepis, 585

Paralichthys, 556

Paramisgurnus, 606

Paramyrus, 674

Paraperca, 375

Paraphoxinus, 601

Parapophyses, 51

Parascopelus, 582

Parascyllium, 326

Parasphenoid, 56, 89

Pardachirus, 558

Paretroplus, 535

Parietals, 57, 89

Pariodon, 581

Parker, 32

Parma, 525

Parnell, 27

Paroccipital, 56, 88

Parodon, 607

Parophrys, 557

Paropsis, 450

Parra, 13

Parr-marks, 631

Parrot-wrasses, 530

Patæcus, 497

Patagonian district, 289

Peal, 644

Pectoral arch, 92

Pectoral fins, 42

Pediculati, 469

Pegasus, 482

Pelagic fishes, 292

Pelamys, 459

Pelargorhynchus, 666

Pelecus, 604

Pelerin, 322

Pellona, 660

Pellonula, 660

Pelor, 417

Pelotrophus, 604

Peltorhamphus, 557

Pempheris, 425

Pennant, 13

Pentaceros, 397

Pentanemus, 425

Pentapus, 390

Pentaroge, 417

Perca, 375

Percalabrax, 378

Perch, 375

Percichthys, 376

Percidæ, 375

Percilia, 397

Percis, 464

Percophis, 466

Percopsis, 651

Periophthalmus, 487

Peristethus, 481

Permian fishes, 197

Peruvian district, 280

Pesce Rey, 501

Petalopteryx, 480

Petenia, 536

Peters, 31

Petrodus, 329

Petromyzon, 692

Petrosal, 56

Petroscirtes, 494

Phaneropleuridæ, 360

Pharyngeal bones, 58

Pharyngognathi, 523

Pholidichthys, 498

Pholidophorus, 368

Photichthys, 629

Phractocephalus, 568

Phrynorhombus, 555

Phycis, 543

Phyllodus, 526

Phyllopteryx, 682

Physiculus, 543

Physostomi, 559

Piabuca, 610

Piabucina, 610

Pickerell, 624

Pike, 624

Pike-perch, 378

Pilchard, 660

Pileoma, 379

Pilot-fish, 444

Pimelepterus, 410

Pimelodus, 568

Pimephales, 596

Pinguipes, 466

Pipe-fishes, 680

Piramutana, 568

Piratinga, 568

Pirinampus, 569

Piso, 7

Pituitary gland, 98

Placodermi, 351

Placoid scales, 48

Plagiostomata, 313

Plagiotremus, 498

Plagusia, 559

Plagyodus, 586

Plaice, 557

Pla-kat, 519

Platax, 448

Platinx, 656

Platycephalus, 477

Platycornus, 421

Platyglossus, 529

Platynematichthys, 566

Platypoecilus, 618

Platyptera, 489

Platyrhina, 342

Platysomidæ, 370

Platystethus, 450

Platystoma, 568

Platystomatichthys, 568

Platytroctes, 664

Playfair, 29

Plecoglossus, 646

Plecostomus, 576

Plectropoma, 382

Plesiops, 418

Pleurapophyses, 52

Pleurolepidæ, 366

Pleuronectes, 557

Pleuronectidæ, 553

Pleuropholis, 368

Plinthophorus, 666

Plionemus, 442

Plotosus, 563

Podabrus, 480

Podocys, 421

Poecilia, 617

Poeciloconger, 674

Poecilopsetta, 557

Poey, F., 31

Pogonias, 427

Poisonous fishes, 189

Poisson bleu, 650

Pollack, 541

Pollan, 649

Polyacanthus, 516

Polycaulus, 480

Polycentrus, 418

Polyipnus, 628

Polymixia, 423

Polynemus, 425

Polyodontidæ, 362

Polyprion, 382

Polypteroidei, 363

Polypterus, 364

Polyrhizodus, 330

Pomacanthus, 401

Pomacentrus, 525

Pomatomus, 395

Pomotis, 396

Pompilus, 444

Pope, 378

Porbeagle, 320

Porgy, 408

Porichthys, 468

Portheus, 500

Porthmeus, 446

Port Jackson Shark, 330

Porus abdominalis, 123

Porus genitalis, 123, 158

Postclavicula, 59, 92

Postfrontal bone, 57, 89

Post-pliocene fishes, 201

Post-temporal, 59, 92

Pout, 541

Powen, 649

Præoperculum, 38, 54, 90

Præorbital, 54

Prefrontal, 57, 89

Premaxillary, 53, 90

Premnas, 525

Preñadillas, 575

Pretympanic, 55

Priacanthus, 395

Pride, 693

Prionotus, 479

Prionurus, 440

Pristacanthus, 314

Pristidæ, 336

Pristigaster, 660

Pristiophorus, 335

Pristipoma, 385

Pristis, 337

Pristiurus, 326

Prochilodus, 607

Prooticum, 88

Propterus, 368

Propterygium, 70

Prosencephalon, 97

Prosopodasys, 417

Protamia, 372

Protocampus, 681

Protopterus, 356

Protosphyræna, 500

Prototroctes, 652

Prussian carp, 591

Psaliodus, 349

Psammobatis, 342

Psammodiscus, 557

Psammodus, 329

Psammoperca, 378

Psenes, 456

Psephurus, 363

Psettichthys, 556

Psettodes, 554

Psettus, 447

Pseudecheneis, 580

Pseudeutropius, 566

Pseudobagrus, 567

Pseudoberyx, 421

Pseudoblennius, 498

Pseudobranchiæ, 140

Pseudochalceus, 610

Pseudochilinus, 530

Pseudochromis, 466

Pseudodax, 530

Pseudoeleginus, 462

Pseudogobio, 596

Pseudojulis, 529

Pseudolabuca, 604

Pseudoperilampus, 601

Pseudophycis, 542

Pseudoplesiops, 466

Pseudorasbora, 596

Pseudorhombus, 556

Pseudoscarus, 532

Pseudosyngnathus, 680

Pseudovomer, 442

Pseudoxiphophorus, 617

Psilorhynchus, 604

Psychrolutes, 469

Pteraclis, 455

Pteragogus, 530

Pteraspis, 354

Pterichthys, 351

Pteroplatea, 344

Pteridium, 549

Pterois, 415

Pterophyllum, 537

Pteropsarion, 602

Pterygocephalus, 492

Pterygoid, 56

Pterygoplichthys, 576

Ptychacanthus, 314

Ptychobarbus, 595

Ptychodus, 330

Ptycholepis, 368

Ptyonotus, 480

Pycnodontidæ, 366

Pygopterus, 370

Pyloric appendages, 131

Pyrrhulina, 607

Quadrate Bone, 55, 89

Quoy et Gaimard, 26

Radius, 59

Raja, 340

Raniceps, 544

Rasbora, 597

Rasborichthys, 604

Rathke, 32

Ray, 8

Rays of fins, 40

Rays, 335, 341

Red bodies, 147

Red-dace, 599

Red-eye, 599

Red-fin, 599

Red-horse, 589

Red mullet, 404

Regalecus, 522

Reproduction of lost parts, 188

Reproduction, organs of, 157

Respiration, organs of, 135

Rete mirabile, 147

Retropinna, 647

Retzius, 32

Rhabdolepis, 370

Rhacolepis, 421

Rhadinichthys, 370

Rhamphichthys, 666

Rhamphocottus, 480

Rhamphosus, 507

Rhina, 334

Rhinelepis, 576

Rhinellus, 656

Rhinichthys, 596

Rhinobatus, 338

Rhinodon, 323

Rhinodoras, 572

Rhinoglanis, 573

Rhinonus, 549

Rhinoptera, 346

Rhizodus, 365

Rhodeus, 601

Rhomboidichthys, 556

Rhombosolea, 557

Rhombus, 555

Rhynchichthys, 424

Rhynchobatus, 337

Rhynchobdella, 498

Rhynchodus, 349

Rhypticus, 383

Rhytiodus, 608

Rib, 52

Ribbon-fishes, 520

Richardson, 27, 28

Risso, 17

Rita, 567

Rivulus, 615

Roach, 599, 600

Rock-cook, 528

Rockling, 544

Rohteichthys, 597

Rondelet, 5

Rosenthal, 32

Rough Dab, 555

Rudd, 599

Rüppell, 29

Russel, 16

Saccarius, 474

Saccobranchus, 565

Saccodon, 607

Saccopharynx, 670

Sælbling, 645

Sail-fish, 589

Sail-fluke, 555

Salanx, 650

Salarias, 494

Salivary glands, 124

Salminus, 611

Salmo, 631

Salmon, 644

Salmon-trout, 644

Salvelini, 645

Salviani, 5

Samaris, 556

Sand-eel, 550

Sand-piper, 693

Sandy Ray, 341

Sar, 406

Saragu, 406

Sarcodaces, 611

Sardine, 660

Sargina, 406

Sargo, 406

Sargodon, 405

Sargus, 406

Satanoperca, 537

Saurenchelys, 674

Saurichthys, 365

Saurida, 582

Sauridæ, 368

Saurocephalus, 500

Saurodipteridæ, 355

Saurodontidæ, 500

Saurorhamphus, 666

Saurus, 582

Saury, 620

Saw-fishes, 337

Scabbard-fish, 435

Scald-fish, 556

Scales, 45

Scaphaspis, 354

Scaphirhynchus, 362

Scapula, 59, 92

Scapular arch, 59

Scarichthys, 531

Scarus, 526, 530

Scatharus, 406

Scatophagus, 401

Schacra, 602

Schal, 573

Schedophilus, 455

Schell-fisch, 540

Schelly, 649

Schilbe, 566

Schilbichthys, 566

Schizopygopsis, 595

Schizothorax, 595

Schlegel, 29

Schneider, 15

Schultze, 33

Sciades, 568

Sciæna, 429

Sciænidæ, 426

Scissor, 610

Sclerodermi, 684

Sclerognathus, 589

Scolopsis, 389

Scomber, 457

Scombresox, 620

Scombridæ, 456

Scombroclupea, 656

Scombrops, 395

Scopelidæ, 582

Scopelosaurus, 587

Scopelus, 584

Scorpæna, 444

Scorpænichthys, 480

Scorpænidæ, 412

Scorpis, 402

Scup, 408

Scylliodus, 326

Scyllium, 325

Scymnus, 332

Sea-bat, 448

Sea-bream, 405, 408

Sea-cat, 493

Sea-devil, 344, 470

Sea-hedgehog, 687

Sea-horses, 682

Sea-perch, 381

Sea-serpents, 521

Sea-trout, 644

Sea-wolf, 493

Seba, 9

Sebastes, 413

Secondary sexual characters, 176

Seingo, 378

Selache, 322

Selachoidei, 314

Semicossyphus, 530

Semionotus, 368

Semiophorus, 441, 442

Semiplotus, 598

Seriola, 444

Seriolella, 444, 450

Seriolichthys, 444

Serranus, 381

Serrasalmo, 613

Setiform teeth, 126

Sewin, 644

Sexual characters, 176

Shad, 659

Shagreen, 315

Shagreen Skate, 341

Sharks, 314

Shark’s fins, 315

Sheep’s head, 406

Shiner, 599, 603

Shore-fishes, 257

Sicyases, 513

Sicydium, 487

Siebold, 28

Sillago, 464

Silondia, 566

Siluranodon, 566

Silurian fishes, 193

Silurichthys, 566

Siluridæ, 559

Siluris, 565

Siniperca, 376

Sinus rhomboidalis, 99

Siphagonus, 481

Siphonal stomach, 130

Siphonognathus, 533

Siphonostoma, 680

Sirembo, 549

Sirenidæ, 355

Sisor, 580

Skate, 341

Skeleton of-- Amia, 82 Amphioxus, 63 Chondropterygians, 66 Chondrostei, 74 Cyclostomes, 64 Dipnoi, 71 Ganoids, 71 Lepidosteus, 80 Polypterus, 77 Teleostei, 83

Skin, 45

Skip-jack, 447

Skipper, 620

Skull, 51, 85

Skulpin, 489

Smaris, 390

Smear-dab, 557

Smelt, 647

Smerdis, 375

Smiliogaster, 604

Snapper, 408

Snock, 437

Snout, 37

Solander, 13

Sole, 557

Solea, 557

Solenognathus, 682

Solenorhynchus, 678

Solenostoma, 678

Soleotalpa, 559

Sonnerat, 13

Soricidens, 405

Sorubim, 568

South Australian district, 283

Southern temperate zone, 281

Southern zone, 248

Spaniodon, 656

Sparidæ, 405

Sparnodus, 405

Sparoid scales, 46

Spathobatis, 338

Spathodactylus, 656

Spatularia, 362

Spawn-eater, 599

Spear-fish, 589

Sphærodon, 408

Sphærodontidæ, 368

Sphenacanthus, 314

Sphenocephalus, 421

Sphenodus, 319

Sphenoid, 57

Sphenoideum anterius, 89

Sphyræna, 499

Sphyrænodus, 500

Spiegel-Karpfen, 591

Spinacidæ, 330

Spinal chord, 96

Spinal column, 51

Spinax, 332

Spines of fins, 40

Spiracles, 138

Spiral valve, 128

Spirobranchus, 516

Splanchnoskeleton, 85

Spleen, 133

Splenial, 54, 91

Sprat, 659

Spratelloides, 662

Squaliobarbus, 602

Squaloraja, 335

Squamipinnes, 397

Squamosal, 88, 89

Stannius, 32, 33

Stare-gazer, 462

Starry Ray, 341

Stegophilus, 581

Stegostoma, 326

Steindachner, 28

Steller, 13

Stenostoma, 421

Sterlet, 361

Sternarchus, 666

Sternoptyx, 627

Sternopygus, 667

Stethojulis, 529

Stichæopsis, 498

Stichæus, 495

Sticharium, 498

Stickleback, 505

Stigmatophora, 681

Sting Rays, 342

Stock-fish, 540, 542

Stomach, 127

Stomias, 629

Stone-bass, 382

Stone-lugger, 596

Stone-roller, 589

Stone Toter, 596

Storer, 29

Strepsodus, 365

Strinsia, 541

Stromateus, 452

Strophodus, 330

Sturgeons, 361

Stygogenes, 575

Stylodontidæ, 368

Stylohyal, 58

Stylophorus, 522

Suboperculum, 38, 55, 91

Suborbital, 91

Sucker, 588

Sucking-fish, 460

Sudis, 586

Sun-fishes, 396, 454, 690

Supraclavicula, 59, 92

Supraoccipital, 56, 87

Supraorbital, 89

Suprascapula, 59

Supratemporal, 91

Surgeon, 439

Suspensorium of mandible, 55

Swammerdam, 7

Sword-fish, 431

Symbranchus, 669

Sympathic nerves, 108

Symphorus, 390

Symphysis, 54

Symphysodon, 537

Symplectic, 55, 89

Sympterygia, 342

Synagris, 390

Synanceia, 416

Synaphobranchus, 671

Synaptura, 558

Syngnathus, 680

Synodontis, 573

Taenianotus, 417

Taeniura, 343

Taractes, 454

Tasmanian sub-region, 248

Taste, organ of, 119

Taurinichthys, 526

Tautoga, 527

Teeth, 121, 124

Teleostei, 373

Telescope-fish, 592

Tellia, 615

Temera, 340

Temnodon, 446

Tenacity of life, 186

Tench, 600

Tephraeops, 406

Tephritis, 555

Tertiary fishes, 200

Testicles, 162, 167

Tetragonolepis, 368

Tetragonopterus, 609

Tetragonurus, 501

Tetranematichthys, 572

Tetraroge, 417

Tetrodon, 688

Teuthididæ, 418

Teuthis, 419

Thalassophryne, 468

Thalassorhinus, 319

Thaleichthys, 647

Thaumas, 334

Thectodus, 330

Therapon, 385

Tholichthys, 172

Thoracic fins, 42

Thornback, 341

Thrissonotus, 370

Thrissopater, 656

Thrissops, 371

Thunberg, 13

Thymallus, 649

Thynnichthys, 595

Thynnus, 457

Thyrsites, 436

Thysanopsetta, 556

Tiger-shark, 327

Tilurus, 180

Tinca, 599

Tongue, 124

Tope, 318

Top-knot, 555

Torgoch, 645

Torpedinidæ, 338

Torpedo, 339

Torsk, 546

Touch, organ of, 120

Toxabramis, 604

Toxotes, 403

Trachelochismus, 513

Trachelyopterus, 572

Trachichthys, 422

Trachinidæ, 462

Trachinops, 418

Trachinopsis, 462

Trachinus, 463

Trachurus, 442

Trachynotus, 447

Trachypterus, 522

Transverse line, 50

Triacanthodes, 684

Triacanthus, 684

Triacis, 319

Triænodon, 319

Triænophorichthys, 487

Triassic fishes, 197

Trichiurichthys, 434

Trichiuridæ, 433

Trichiurus, 436

Trichocyclus, 689

Trichodiodon, 689

Trichodon, 466

Trichogaster, 518

Trichomycterus, 581

Trichonotus, 490

Trichopleura, 417

Trifurcated Hake, 545

Trigla, 478

Triglops, 480

Trigorhina, 338

Triodon, 687

Tripterodon, 406

Tripterygium, 495

Tristichopterus, 365

Tristychius, 314

Trochocopus, 530

Tropical American region, 233

Trout, 644

Trubu, 660

Trumpeter, 412

Trumpet-fish, 509

Trunk, 39

Trygon, 343

Trygonidæ, 342

Trygonorhina, 338

Trypauchen, 489

Tunny, 458

Turbinal, 57, 91

Turbot, 555

Twaite Shad, 659

Tyellina, 326

Tylognathus, 596

Typhlichthys, 618

Typhlonus, 548

Uaru, 536

Ulna, 59

Umbra, 429, 619

Umbrina, 428

Umbrine, 429

Undina, 365

Upeneichthys, 404

Upeneoides, 404

Upeneus, 404

Upokororo, 652

Uraleptus, 543

Uranoscopus, 462

Urinary organs, 155

Urocampus, 681

Urocentrus, 498

Uroconger, 674

Urogymnus, 343

Urohyal, 58, 91

Urolophus, 343

Uronectes, 538

Uronemus, 360

Urosphen, 507

Urosthenes, 370

Useful fishes, 189

Vaillant, 31

Valenciennes, 18

Vandellia, 581

Velifer, 397

Vendace, 649

Ventral fins, 42

Vertebral column, 51

Vertical fins, 40

Villiform teeth, 126

Viviparous Blenny, 497

Vogt, 32

Vomer (bone), 56, 89

Vomer (gen.), 441

Vulsus, 489

Wallago, 566

Wardichthys, 370

Weever, 464

Wels, 565

Whiff, 555

White-bait, 658

White-fish, 599, 648

Whiting, 541

Whiting-pout, 541

Willughby, 8

Wrasses, 525

Xenocephalus, 553

Xenocharax, 612

Xenocypris, 598

Xenodermichthys, 664

Xenomystus, 576

Xenopterus, 688

Xiphias, 431

Xiphidion, 496

Xiphiidæ, 431

Xiphochilus, 530

Xiphopterus, 434

Xiphorhampus, 611

Xiphostoma, 611

Yarrell, 27

Yellow-tail, 444

Zanchus, 449

Zaniolepis, 491

Zärthe, 603

Zebra-Shark, 327

Zeus, 451

Zoarces, 497

Zope, 603

Zuzuki, 378

Zygaena, 318

Zygapophyses, 52

Zygobatis, 346

THE END.

Printed by R. & R. CLARK, Edinburgh.

FOOTNOTES:

From ιχθυς, fish, and λογος, doctrine or treatise.

Down to this period the history of Ichthyology is fully treated in the first volume of Cuvier and Valenciennes “Hist. nat. d. Poiss.”

Description of Ceratodus. “Phil. Trans.,” 1871, ii.

In the formula generally preceding the description of a fish, “L. lat. 40,” would express that the scales between the head and caudal fin are arranged in 40 transverse series; and probably, that the lateral line is composed of the same number of scales. “L. transv. 8/5” would express that there are eight longitudinal series of scales between the median line of the back and the lateral line, and five between the lateral line and the middle of the abdomen.

Pterotic of Parker.

C. Hasse has studied the modifications of the texture of the vertebræ and the structure of the Chondropterygian skeleton generally, and shown that they correspond in the main to the natural groups of the system, and, consequently, that they offer a valuable guide in the determination of fossil remains.

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

As first proposed by Huxley.

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

Parker’s nomenclature is adopted here.

According to Langerhans “Untersuchungen über Petromyzon planeri” (Freiburg, 1873) an optic chiasma exists in that species.

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

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

On the development and structure of the dentition of Scarina, see Boas, “Die Zähne der Scaroiden,” in Zeitschr. f. Wiss. Zoolog. xxxii. (1878).

This applies to individuals only growing up under normal conditions. Dr. H. A. Meyer has made observations on young Herrings. Individuals living in the sea had attained at the end of the third month a length of 45 to 50 millimetres, whilst those reared from artificially-impregnated ova were only from 30 to 35 millimetres long. When the latter had been supplied with more abundant food, they grew proportionally more rapidly in the following months, so that at the end of the fifth month they had reached the same length as their brethren in the sea, viz. a length of 65 to 70 millimetres.

Ray Lankester considers it to be a portion of the long denticulated cornua of a genus Eukeraspis allied to Cephalaspis.

Ekström, Fische in den Scheeren von Mörkö.

Will probably be found.

We distinguish these sub-regions, because their distinction is justified by other classes of animals; as regards freshwater fishes their distinctness is even less than that between Europe and Northern Asia.

Martens (Preuss. Exped. Ostas. Zool. i. p. 356), has already drawn attention that a Barbel, said to have been obtained by Ida Pfeiffer in Amboyna (Günth. Fish. vii. p. 123), cannot have come from that locality.

In the following and succeeding lists, those forms which are peculiar to and exclusively characteristic of, the region, are printed in italics; the other regions, in which the non-peculiar forms occur, are mentioned within brackets [].

Lates calcarifer in India as well as Australia.

One species (Arius thalassinus) found in Indian and African rivers.

This species extends from India into East Africa.

We have left out from these considerations the Ariina and Cyprinodonts, which can pass with impunity through salt water, and are spread over much larger areas.

Cope has discovered in a tertiary freshwater-deposit at Idaho an extinct genus of this group, Diastichus. He considers this interesting fact to be strongly suggestive of continuity of territory of Asia and North America.--“Proc. Am. Phil. Soc. 1873,” p. 55.

Leidy describes a Siluroid (Pimelodus) from tertiary deposits of Wyoming Territory. “Contrib. to the Extinct Vert. Fauna of the Western Territ. 1873,” p. 193.

The genera peculiar to the Equatorial zone are printed in italics.

Number of species uncertain.

See p. 151, Fig. 67.

See p. 128, Fig. 55.

See p. 104.

See p. 167, Figs. 79, 81.

See p. 136, Fig. 58.

See p. 167, Fig. 78.

The cartilaginous jaws of Sharks shrink at least a third in drying, and, therefore, cannot be kept at full stretch without tearing.

This exception is a Ray obtained during the “Challenger” expedition, and said to have been dredged in 565 fathoms.

See pp. 73 and 74, Figs. 35 and 36.

For other illustrations see p. 73, Fig. 35 (palatal view of head); p. 74, Fig. 36 (pectoral skeleton); p. 141, Fig. 60 (gills); p. 148, Fig. 65 (lung); p. 151, Fig. 67 (heart); p. 134, Fig. 57 (intestine); p. 165, Fig. 77 (ovary).

See p. 97, Fig. 41; and p. 152, Fig. 68.

The Acanthopterygians do not form a perfectly natural group, some heterogeneous elements being mixed up with it. Neither are the characters, by which it is circumscribed, absolutely distinctive. In some forms (certain Blennioids) the structure of the fins is almost the same as in Anacanths; there are some Acanthopterygians, as Gerres, Pogonias, which possess coalesced pharyngeals; and, finally, the presence or absence of a pneumatic duct loses much of its value as a taxonomic character when we consider that probably in all fishes a communication between pharynx and air-bladder exists at an early stage of development.

In this instance, one may entertain reasonable doubts as to the usefulness of the Pilot to the Shark.

Mackerel, like other marine fishes, birds, and mammals of prey, follow the shoals of young and adult Clupeoids in their periodical migrations; on the British coasts it is principally the fry of the Pilchard and Sprat which wanders from the open sea towards the coast, and guides the movements of the Mackerel.

The systematic affinities of these extinct genera are very obscure. Cope places them, with others (for instance Protosphyræna, which has a sword-like prolongation of the ethmoid), in a distinct family, Saurodontidæ: see “Vertebrata of the Cretaceous Formations of the West,” 1875.

For specific characters and detailed descriptions we refer to Günther, “Catal. of Fishes,” vol. vi.

The names “Bull-trout” and “Peal” are not attributable to definite species. We have examined specimens of S. salar, S. trutta, and S. cambricus and S. fario, to which the name “Bull-trout” had been given; and that of “Peal” is given indiscriminately to Salmon-grilse and to S. cambricus.

Fig. 317 is taken from a specimen in which the horny covers of the dentition were lost, hence it does not represent accurately the shape of the teeth.

This name is two years older than Amphioxus.

Transcriber’s Notes:

1. Obvious printers’, punctuation and spelling errors have been corrected silently.

2. Where hyphenation is in doubt, it has been retained as in the original.

3. Some hyphenated and non-hyphenated versions of the same words have been retained as in the original.

4. Superscripts are represented using the caret character, e.g. D^r. or X^{xx}.

5. Italics are shown as xxx.

6. Bold print is shown as =xxx=.