CHAPTER XIX.. The Distribution of Marine Fishes.

THE DISTRIBUTION OF MARINE FISHES.

Marine fishes fall, with regard to their mode of life and distribution, into three distinct categories:--

1. Shore Fishes--That is, fishes which inhabit chiefly parts of the sea in the immediate neighbourhood of land either actually raised above, or at least but little submerged below, the surface of the water. They do not descend to any great depth,--very few to 300 fathoms, and the majority live close to the surface. The distribution of these fishes is determined not only by the temperature of the surface water but also by the nature of the adjacent land, and its animal and vegetable products; some of these fishes being confined to flat coasts with soft or sandy bottoms, others to rocky and fissured coasts, others to living coral formations. If it were not for the frequent mechanical and involuntary removals to which these fishes are exposed, their distribution within certain limits, as it no doubt originally existed, would resemble still more that of freshwater fishes than we find it actually does at the present period.

2. Pelagic Fishes--that is, fishes which inhabit the surface and uppermost strata of the open ocean, which approach the shores only accidentally, or occasionally (in search of prey), or periodically (for the purpose of spawning). The majority spawn in the open sea, their ova and young being always found at great distance from the shore. With regard to their distribution, they are still subject to the influences of light and the temperature of the surface water; but they are independent of the variable local conditions which tie the shore fish to its original home, and therefore roam freely over a space which would take a freshwater or shore fish thousands of years to cover in its gradual dispersal. Such as are devoid of rapidity of motion are dispersed over similarly large areas by the oceanic currents, more slowly than, but as surely as, the strong swimmers. Therefore, an accurate definition of their distribution within certain areas equivalent to the terrestrial regions is much less feasible than in the case of shore fishes.

3. Deep-sea Fishes--that is, fishes which inhabit such depths of the ocean as to be but little or not influenced by light or the surface temperature; and which, by their organisation are prevented from reaching the surface stratum in a healthy condition. Living almost under identical tellurian conditions, the same type, the same species, may inhabit an abyssal depth under the equator as well as one near the arctic or antarctic circle; and all we know of these fishes points to the conclusion that no separate horizontal regions can be distinguished in the abyssal fauna, and that no division into bathymetrical strata can be attempted on the base of generic much less of family characters.

It must not be imagined that these three categories are more sharply defined than Freshwater and Marine Fishes. They gradually pass into each other, and there are numerous fishes about which uncertainty exists whether they should be placed in the Shore or Pelagic series, or in the Pelagic or Deep-sea series; nay, many facts favour the view that changes in the mode of life and distribution of fishes are still in progress.

The change in habitat of numerous fishes is regulated by the distribution of their favourite food. At certain seasons the surface of the sea in the vicinity of land swarms with mollusks, larval Crustaceans, Medusæ, attracting shoals of fishes from the open ocean to the shores; and these are again pursued by fishes of larger size and predacious habits, so that all these fishes might be included, with equal propriety, in the littoral or pelagic series. However, species which are known to normally spawn in the open ocean must be always referred to the latter division.

Chondropterygii, Acanthopterygii, Anacanths, Myxinoids, and Pharyngobranchii furnish the principal contingents to the Marine Fauna; whilst the majority of Malacopterygians, the Ganoids, and Cyclostomes are Freshwater Fishes.

I.--DISTRIBUTION OF SHORE FISHES.

The principal types of Shore-fishes are the following:--

CHONDROPTERYGII-- HOLOCEPHALA 4 species PLAGIOSTOMATA-- Carchariidæ (part.) 12 „ Scylliidæ 30 „ Cestraciontidæ 4 „ Spinacidæ (part.) 8 „ Rhinidæ 1 „ Pristiophoridæ 4 „ Pristidæ 5 „ Rhinobatidæ 14 „ Torpedinidæ 15 „ Rajidæ 34 „ Trygonidæ 47 „

ACANTHOPTERYGII-- Percidæ (part. incl. Pristipomatidæ) 625 „ Mullidæ 35 „ Sparidæ 130 „ Squamipinnes 130 „ Cirrhitidæ 40 „ Heterolepidina 12 „ Scorpænidæ 120 „ Cottiæ (part.) 100 „ Cataphracti (part.) 20 „ Trachinidæ 100 „ Sciænidæ 100 „ Sphyrænidæ 15 „ Trichiuridæ 17 „ Elacate 1 „ Nomeidæ (part.) 5 „ Cyttidæ 8 „ Stromateus 9 „ Mene 1 „ Carangidæ (part.) 130 „ Kurtidæ 7 „ Gobiodon 7 „ Callionymina 30 „ Discoboli 11 „ Batrachidæ 14 „ Pediculati (part.) 11 „ Blenniidæ 90 „ Acanthoclinidæ 1 „ Teuthididæ 30 „ Acronuridæ 60 „ Hoplognathidæ 3 „ Malacanthidæ 3 „ Plesiopina 4 „ Trichonotidæ 2 „ Cepolidæ 7 „ Gobiesocidæ 21 „ Psychrolutidæ 2 „ Centriscidæ 7 „ Fistulariidæ 4 „

ACANTHOPTERYGII PHARYNGOGNATHI--

Pomacentridæ 150 „ Labridæ 400 „ Embiotocidæ 17 „

ANACANTHINI--

Gadopsidæ 1 „ Lycodidæ 15 „ Gadidæ (part.) 50 „ Ophidiidæ (part.) 40 „ Pleuronectidæ 160 „

PHYSOSTOMI--

Saurina (part.) 16 „ Salmonidæ (part.) 7 „ Clupeidæ (part.) 130 „ Chirocentridæ 1 „ Chilobranchus 1 „ Murænidæ (part.) 200 „ Pegasidæ 4 „

LOPHOBRANCHII 120 „

PLECTOGNATHI--

Sclerodermi 95 „ Gymnodontes 83 „

CYCLOSTOMATA--

MYXINIDÆ 5 „

LEPTOCARDII 2 „ ------------- 3587 species. =============

These types of Shore fishes are divided among the following oceanic areæ:--

I. The Arctic Ocean.

II. The Northern Temperate Zone.

A. The Temperate North Atlantic. 1. The British district. 2. The Mediterranean district. 3. The North American district.

B. The Temperate North Pacific. 1. The Kamtschatkan district. 2. The Japanese district. 3. The Californian district.

III. The Equatorial Zone. A. The Tropical Atlantic. B. The Tropical Indo-Pacific. C. The Pacific Coast of Tropical America. 1. The Central American district. 2. The Galapagoes district. 3. The Peruvian district.

IV. The Southern Temperate Zone. 1. The Cape of Good Hope district. 2. The South Australian district. 3. The Chilian district. 4. The Patagonian district.

V. The Antarctic Ocean.

As with freshwater fishes, the main divisions of the Shore-fish faunæ are determined by their distance from the equator, the equatorial zone of the Freshwater series corresponding entirely to that of the Shore-fish series. But as Marine fishes extend farther towards the Poles than Freshwater fishes, and as the polar types are more specialised, a distinct Arctic and Antarctic fauna may be separated from the faunæ of the temperate zones. The two subdivisions of the Northern temperate zone in the Freshwater series are quite analogous to the corresponding divisions in the Coast series. In the Southern Hemisphere the Shore-fishes of the extremity of Africa form a separate district of the temperate zone, whilst the Freshwater fishes of South Africa were found to be tropical types. The Marine series of the Southern temperate zone is also much more diversified than the Freshwater series, and admits of further subdivision, which, although in some degree indicated in the Freshwater series, does not entirely correspond to that proposed for the latter.

I. SHORE FISHES OF THE ARCTIC OCEAN.

The Shore fishes clearly prove a continuity of the Arctic circumpolar fauna, as the southern limit of which we may indicate the southern extremity of Greenland and the Aleutian Archipelago, or 60° of lat. N.

Towards the North, fishes become less in variety of species and fewer in number of individuals, and only very few genera are restricted to this fauna.

The highest latitude at which Shore fishes have been observed is 83° N. lat. The late Arctic Expedition collected at and near that latitude specimens of Cottus quadricornis, Icelus hamatus, Cyclopterus spinosus, Liparis fabricii, Gymnelis viridis, and Gadus fabricii. This number probably would have been larger if the difficulties of collecting fishes in those high latitudes were not almost insuperable for the greater part of the year.

As far as we know, the fishes north and south of Behring’s Straits belong to the same generic or family types as those of the corresponding latitudes of the Eastern Hemisphere, though the majority are specifically distinct. But the information we possess of the fishes of the northernmost extremity of the Pacific is extremely scanty and vague. Farther south, whence now and then a collection reaches Europe, we meet with some European species, as the Herring, Halibut, Hake.

The Chondropterygians are very scarce, and it is doubtful whether another Chondropterygian, beside the pelagic Læmargus or Greenland Shark, crosses the Arctic circle. In the more temperate latitudes of South Greenland, Iceland, and Northern Scandinavia, Acanthias, Centroscyllium, and a species of Raja, also Chimæra, are met with.

Of Acanthopterygians the families of Cottidæ, Cataphracti, Discoboli, and Blenniidæ are well represented, and several of the genera are characteristic of the Arctic fauna: marine species of Cottus; Centridermichthys, Icelus, Triglops; Agonus, Aspidophoroides; Anarrhichas, Centronotus, Stichæus; Cyclopterus and Liparis. Two species of Sebastes are rather common.

Characteristic is also the development of Gadoid fishes, of which some thirteen species, belonging to Gadus, Merluccius, and Molva, form one of the principal articles of food to the inhabitants of the coasts of the Arctic Ocean. The Blennioid Anacanthini or Lycodidæ, are limited to the Arctic and Antarctic coasts. Ammodytes and a few Flat-fishes (Hippoglossoides and Pleuronectes) are common in the more temperate parts.

Labroids only exceptionally penetrate so far towards the north.

Physostomes are very scarce, and represented only by a few species of Clupea and by Mallotus; the latter is an ancient inhabitant of the Greenland coasts, fossil remains, indistinguishable from the species of the present day, being frequently found in nodules of clay of comparatively recent formation.

The Arctic climate is still less favourable to the existence of Lophobranchs, only a few Syngnathus and Nerophis being present in the more southern latitudes, to which they have been carried by oceanic currents from their more congenial home in the south. Scleroderms and Plectognaths are entirely absent.

The Gadoids are accompanied by Myxine, which parasitically thrives in them.

II. THE NORTHERN TEMPERATE ZONE.

A. Shore Fishes of the Temperate North Atlantic.

This part of the fauna may be subdivided into three districts:--

1. The fishes of the north-eastern shores, viz. of the British islands, of Scandinavia so far as it is not included in the Arctic fauna, and of the continent of Europe southwards to about 40° of lat. N.--British district.

2. The fishes of the Mediterranean shores and of the adjoining shores of the Atlantic, including the Azores, Madeira, and the Canary Islands--Mediterranean district.

3. The fishes of the western shores, from 60° lat. N. to about 30° lat. N.--the North American district.

1. The British district shows scarcely any marked distinctive features; the character of its fauna is simply intermediate between that of the Arctic Ocean and the Mediterranean district; truly Arctic forms disappear, while such as are also found in the Mediterranean make their appearance. Also with regard to the abundance of individuals and variety of fishes this district forms a transition from the north towards the south.

Besides the few Arctic Chondropterygians, all of which extend into this district, the small shore Dog-fishes are well represented (Mustelus, Galeus, Scyllium, Pristiurus); the ubiquitous Rhina or Monk-fish is common; of Rays, Raja predominates in a variety of species over Torpedo and Trygon, which are still scarce.

Of Acanthopterygians, Centridermichthys, Icelus, Triglops, and Aspidophoroides, do not extend from the north into this district; and Cottus, Anarrhichas, Centronotus, Stichæus, the Discoboli disappear within its limits. Nearly all the remainder are genera which are also found in the Mediterranean districts. The following are the principal forms, and known to propagate on these shores: Labrax; Serranus, Polyprion, Dentex; Mullus; Cantharus, Pagrus, Pagellus; Sebastes; Cottus, Trigla, Agonus; Trachinus; Sciæna (?); Zeus; Trachurus, Capros; Callionymus; Discoboli; Lophius; Anarrhichas, Centronotus, Stichæus; Blenniops, Zoarces (not in Mediterranean); Cepola; Lepadogaster.

Of the Anacanthini the Gadoids are as numerous as in the Arctic Ocean, most being common to both districts; they are represented by Gadus, Gadiculus, Merluccius, Phycis, Molva, Motella, Raniceps, and Brosmius; but, whilst the majority show their northern origin by not extending into the Mediterranean, Ammodytes and most Pleuronectidæ prove themselves to be the more southern representatives of this order. In the British district we find Hippoglossus, Hippoglossoides, Rhombus, Phrynorhombus, Pleuronectes, Solea, and only the two first are not met with in the Mediterranean.

Labroids are common; with the exception of the North American Tautoga, all the other genera are met with.

Physostomes are not well represented, viz. by one species of Osmerus, one of Engraulis, one of Conger, and about five of Clupea.

Syngnathus and Nerophis become more common as we proceed southwards; but the existence of Scleroderms and Plectognaths is indicated by single individuals only, stragglers from their southern home, and unable to establish themselves in a climate ungenial to them.

The Gadoids are accompanied by Myxine; and Branchiostoma may be found in all suitable localities.

2. The Mediterranean district is distinguished by a great variety of forms; yet, with the exception of a few genera established for single species, none of the forms can be considered peculiar to it; and even that small number of peculiar genera is more and more diminished as our knowledge of the distribution of fishes advances. Some genera are identical with those found on the western coasts of the Atlantic and in the West Indies; but a most remarkable and unexpected affinity obtains with another very distant fauna, viz. that of Japan. The number of genera common to the Mediterranean district and the Japanese coasts is larger than that of the genera common to the Mediterranean and the opposite American coasts.

The Chondropterygians found in the British district continue in the Mediterranean, their number being increased by Centrina, Spinax, Pteroplatea, and some species of Rhinobatus, a genus more numerously represented in the Tropics. Torpedo and Trygon are common.

The greatest variety belong to the Acanthopterygians, as will be seen from the following list:--Labrax; Anthias, Serranus, Polyprion, Apogon, Pomatomus, Pristipoma, Diagramma (an Indian genus with two Mediterranean species, and otherwise not represented in the Atlantic), Dentex, Mæna, Smaris; Mullus; Cantharus, Box, Scatharxs, Oblata, Sargus, Pagrus, Pagellus, Chrysophrys; Sebastes, Scorpæna; Hoplostethus, Beryx, Polymixia; Trigla, Lepidotrigla, Agonus, Peristethus; Trachinus, Uranoscopus; Umbrina, Sciæna; Sphyræna; Aphanopus, Lepidopus, Nesiarchus, Trichiurus, Thyrsites; Cubiceps; Zeus, Cyttus; Stromateus; Trachurus, Caranx, Capros, Diretmus, Antigonia; Callionymus; Batrachus; Lophius; Cristiceps, Tripterygium; Cepola; Lepadogaster; Centriscus; Notacanthus.

The Labridæ are as common as, or even more so than, in the British district, and represented by the same genera. But, besides, some other Pharyngognaths, properly belonging to the Tropical Atlantic, have fully established themselves, though only by a few species, viz. Glyphidodon and Heliastes; Cossyphus, Novacula, Julis, Coris, and Scarus.

The Gadoids show a marked decrease of development; and the species of Gadus, Gadiculus, Mora, Strinsia, Phycis, and Molva, which are peculiar to the Mediterranean, seem to inhabit rather the colder water of moderate depths, than the surface near the shore. Motella, however, proves to be a true Shore fish also in the Mediterranean, at least in its adult state. Ophidium and Fierasfer appear now besides Ammodytes. As the Gadoids decrease, so the Pleuronectidæ increase, the genera of the Mediterranean district being Rhombus, Phrynorhombus, Arnoglossus, Citharus, Rhomboidichthys, Pleuronectes (a northern genus not extending farther southwards), Solea, Synaptura, and Ammopleurops.

The variety of Physostomes is small; the following only being superadded to those of the British district:--Saurus (a tropical genus), Aulopus; Congromuræna, Heteroconger, Myrus, Ophichthys, Muræna.

The Lophobranchs are more numerous in species and individuals than in the British district; and, besides Syngnathus and Nerophis, several species of Hippocampus are common. Also a few species of Balistes occur.

Myxine is lost in this district; whilst Branchiostoma is abundant.

3. The shore fishes of the North American district consist, as on the eastern coasts of the North Atlantic, of northern and southern elements; but they are still more mixed with each other than on the European coasts, so that a boundary line cannot be drawn between them. The affinity to the fauna of the eastern shores is great, but almost entirely limited to the genera composing the fauna of the British district. British genera not found on the American coasts are--Galeus, Scyllium, Chimæra, Mullus, Pagellus, Trigla, Trachinus, Zeus, Callionymus. The southern elements of North America are rather derived from the West Indies, and have no special affinity to Mediterranean forms; very few of the non-British Mediterranean forms extend across the Atlantic; instead of a Mediterranean we find a West Indian element. Many of the British species range across the Atlantic, and inhabit in an unchanged condition the northern parts of this district; and from the frequent occurrence of isolated specimens of other British species on the North American coast, we may presume that many more occasionally cross the Atlantic, but without being able to obtain a permanent footing.

The genera peculiar to this district are few in number, and composed of very few species, viz. Hemitripterus, Pammelas, Chasmodes, Cryptacanthodes, and Tautoga.

The close resemblance of what must be considered northern forms to those of Europe will be evident from the following list:--

Mustelus, Rhina, Torpedo, Raja, Trygon.

Labrax, Centropristis, Serranus; Pagrus, Chrysophrys; Sebastes, Hemitripterus; Cottus, Aspidophoroides; Uranoscopus; Micropogon, Pogonias, Sciæna; Trachurus, Pammelas; Cyclopterus, Liparis; Lophius; Anarrhichas, Chasmodes, Stichcæus, Centronotus, Cryptacanthodes, Zoarces.

Tautoga, Ctenolabrus.

Gadus, Merluccius, Phycis, Molva, Motella, Brosmius; Ophidium (one species, perhaps identical with a Mediterranean species); Ammodytes; Hippoglossus, Hippoglossoides, Rhombus, Pleuronectes.

Osmerus, Mallotus; Engraulis, Clupea; Conger.

Syngnathus--Myxine--Branchiostoma.

West Indian genera, or at least genera which are more developed within the tropics, and which extend more or less northwards in the North American district, are:--

Pteroplatea (also in the Mediterranean).

Gerres, Dules (auriga), Lobotes, Ephippus; Sargus; Prionotus; Umbrina, Otolithus, Larimus; Sphyræna (Mediterr.); Trichiurus (Mediterr.); Elacate; Cybium, Trachynotus; Stromateus (Mediterr.); Caranx; Batrachus (Mediterr.); Malthe.

Pseudorhombus, Solea (Mediterr.)

Saurus (Mediterr.); Etrumeus, Albula, Elops, Megalops.

Hippocampus (Mediterr.)

Balistes, Monacanthus.

B. SHORE FISHES OF THE TEMPERATE NORTH PACIFIC.

This fauna shows a great affinity to that of the temperate North Atlantic, not only in including a considerable proportion of identical genera, and even of species, but also in having its constituent parts similarly distributed. However, our knowledge of the ichthyology of this fauna is by no means complete. Very few collections have been made in Northern Japan, and on the coasts farther north of it; and, again, the ichthyology of the coasts of Southern California is but little known. Southern Japan has been well searched, but very little attention has been paid to the extent of the northward range of the species. In collections made by Mr. Swinhoe at Chefoo, in lat. 37° N., the proportions of temperate and tropical fishes were found to be about equal. Thus, the details of the distribution of the fishes of these shores have still to be worked out; nevertheless, three divisions may be recognised which, for the present, may be defined as follows:--

1. The fishes of the north-western shores, to about 37° lat. N., including the corresponding northern parts of Japan--Kamtschatkan district; this corresponds to the British district of the Atlantic.

2. The fishes of Southern Japan and the corresponding shores of the continent of Asia, between 37° and 30° lat. N.--Japanese district, which corresponds to the Mediterranean.

3. The fishes of the eastern shores southwards to the latitude of San Francisco--Californian district; this corresponds to the North American district of the Atlantic.

Too little is known of the shore fishes of the coasts between San Francisco and the tropic to enable us to treat of it as a separate division.

The Shore fishes of the North Pacific generally are composed of the following elements:--

a. Arctic forms which extend into the Arctic Ocean, and the majority of which are also found in the British district.

b. Peculiar forms limited to the North Pacific, like the Heterolepidina, Embiotocidæ, and certain Cottoid and Blennioid genera.

c. Forms identical with fishes of the Mediterranean.

d. Peculiar forms limited to the southern parts of Japan.

e. Tropical forms which have entered the North Pacific from the south.

* * * * *

1. The small list of fishes which we can assign to the Kamtschatkan district is due rather to the imperfect manner in which its fauna has been explored than to its actual poverty of fishes; thus, although we may be sure that sooner or later the small kinds of Dog-fishes of the British district will be found there also, at present we have positive knowledge of the occurrence of only two Chondropterygians, viz. Chimæra and Raja. The species of the latter genus seem to be much less numerous than in the Atlantic.

Of Acanthopterygians the following are known:--Sebastes; Chirus, Agrammus; Podabrus, Blepsias, Cottus, Centridermichthys, Hemilepidotus, Agonus; Trichodon; Callionymus; Liparis; Dictyosoma, Stichæus, Centronotus.

Labroids are absent; they are clearly a type unable to endure great cold; of the Embiotocoids which represent them in the Pacific, one species only (a species of Ditrema) is known from this district.

The Gadoids are, so far as we know at present, sparsely represented, viz. by isolated species of Gadus, Motella, and Lotella, the latter being an inhabitant of moderate depths rather than of the surface. Hippoglossus, Pleuronectes, and Parophrys, seem to occur everywhere at suitable localities.

The Physostomes are nearly the same as in the British district, viz. a Smelt (Hypomesus), probably also the Arctic Mallotus, an Anchovy, several species of Clupea, and the Conger-eel. A very singular Salmonoid fish, Salanx, which is limited to the north-western Pacific, occurs in great abundance.

Also, the Lophobranchs correspond in their development to those of the British district, Nerophis being replaced by Urocampus.

Neither Myxinoids nor Branchiostoma have as yet been found.

2. The Japanese district is, like the Mediterranean, distinguished by a great variety of forms; some of them are peculiar to it (marked J. in the following list); others occur in the Mediterranean, though also in other districts (M.) The resemblance to the Mediterranean is even greater than would appear from the following list of genera, inasmuch as a considerable number of species are identical in both districts. Three of the Berycoid genera have hitherto been found in the Japanese and Mediterranean districts only, and nowhere else. Another very singular fact is that some of the most characteristic genera, like Mullus, Zeus, Callionymus, Centriscus, inhabit the Mediterranean and Japanese districts, but have never reached the opposite American coasts, either in the Atlantic or Pacific; although, at least in the latter, the oceanic currents would rather favour than obstruct their dispersal in the direction towards America. Bold as the hypothesis may appear, we can only account for the singular distribution of these shore fishes by assuming that the Mediterranean and Japanese seas were in direct and open communication with each other within the period of the existence of the present Teleosteous Fauna.

Gadoids have disappeared, or are represented by forms inhabiting moderate depths. Neither Myxine nor Branchiostoma are known to have as yet been found.

List of Japanese Shore Fishes.

Chimæra (M.)

Galeus (M.), Mustelus (M.), Triacis, Scyllium (M.), Crossorhinus, Pristiophorus, Cestracion; Rhina (M.); Rhinobatus (M.), Narcine, Raja (M.), Trygon (M.), Pteroplatea (M.)

Percalabrax (J.), Niphon (J.), Centropristis, Anthias (M.), Serranus (M.), Apogon (M.), Scombrops (J.), Acropoma, Anoplus (J.), Pristipoma (M.), Hapalogenys (J.), Histiopterus, Velifer (J.), Dentex (M.), Erythrichthys--Mullidæ (M.)--Girella, Pagrus (M.), Chrysophrys (M.)--Chilodactylus--Sebastes (M.), Scorpæna (M.), Aploactis, Trichopleura, Pelor--Monocentris (J.), Hoplostethus (M.), Beryx (M.), Polymixia (M.)--Platycephalus, Hoplichthys (J.), Bembras (J.), Prionotus, Lepidotrigla (M.), Trigla (M.), Peristethus (M.)--Uranoscopus (M.), Percis, Sillago, Latilus.--Sciæna (M.), Otolithus--Sphyræna (M.)--Lepidopus (M.), Trichiurus (M.)--Zeus (M.)--Caranx, Trachurus (M.)--Callionymus (M.)--Lophius (M.), Halieuthæa (J.)--Hoplognathus--Cepola (M.)--Centriscus (M.), Fistularia.

Heliastes (M.)--Labrichthys, Duymæria, Platyglossus, Novacula (M.), Julis (M.), Coris (M.)

Sirembo (J.)--Motella (M.)--Ateleopus (J.)

Pseudorhombus, Pleuronectes (M.), Solea (M.), Synaptura (M.)

Saurus (M.), Harpodon.--Salanx (J.)--Engraulis (M.), Clupea (M.), Etrumeus--Conger (M.), Congromuræna (M.), Murænesox (M.), Oxyconger, Myrus (M.), Ophichthys (M.), Muræna (M.)

Syngnathus (M.), Hippocampus (M.), Solenognathus.

Triacanthus, Monacanthus, Ostracion.

3. The Californian district includes a marked northern element, the principal constituents of which are identical with types occurring in the corresponding district of the Atlantic, viz. the North American, as exemplified by Discoboli, Anarrhichas, Centronotus, Cottus, Hippoglossus, Clupea (harengus), etc. But it possesses also, in the greatest degree of development, some types almost peculiar to itself, as the Heterolepidina, some remarkable Cottoid and Blennioid genera, and more especially the Embiotocoids--viviparous Pharyngognaths--which replace the Labroids of the other hemisphere. Gadoids are much less numerous than in the North American district. The southern forms are but little known, but it may be anticipated that, owing to the partial identity of the Faunæ of the two coasts of the Isthmus of Panama, a fair proportion of West Indian forms will be found to have entered this district from the south. The following are the principal genera:--

Chimœra, Galeus, Mustelus, Triacis, Cestracion, Rhina, Raja.

Serranus; Chirus, Ophiodon, Zaniolepis; Sebastes; Nautichthys, Scorpœnichthys, Cottus, Centridermichthys, Hemilepidotus, Artedius, Prionotus, Agonus; Cyclopterus, Liparis; Anarrhichas, Neoclinus, Cebidichthys, Stichœus, Centronotus, Apodichthys; Psychrolutes; Auliscops.

Embiotocidœ.

Gadus. Hippoglossus, Psettichthys, Citharichthys, Paralichthys, Pleuronectes, Parophrys.

Osmerus, Thaleichthys, Hypomesus; Engraulis, Clupea.

Syngnathus.

III.--THE EQUATORIAL ZONE.

As we approach the Tropic from the north, the tribes characteristic of the Arctic and Temperate zones become scarcer, and disappear altogether: to be replaced by the greater variety of Tropical types. Of Chondropterygians, the Chimœridœ, Spinacidœ, Mustelus, and Raja, do not pass the Tropic, or appear in single species only; and of Teleosteans, the Berycidæ, Pagrus, the Heterolepidina, Cottus and allied genera, Lophius, Anarrhichas, Stichæus, Lepadogaster, Psychrolutes, Centriscus, Notacanthus, the Labridæ and Embiotocidæ, the Lycodidæ, Gadidæ, and marine Salmonidæ disappear either entirely, or retire from the shores and surface into the depths of the ocean.

With regard to variety of forms, as well as to number of individuals, this zone far surpasses either of the temperate zones; in this respect, the life in the sea is as that on the land. Coast fishes are not confined to the actual coast-line, but abound on the coral reefs, with which some parts of the Atlantic and Pacific are studded, and many of which are submerged below the water. The abundance of animal and vegetable life which flourishes on them renders them the favourite pasture-grounds for the endless variety of coral-fishes (Squamipinnes, Acronuridæ, Pomacentridæ, Julidæ, Plectognathi, etc.), and for the larger predatory kinds. The colours and grotesque forms of the Fishes of the Tropics have justly excited the admiration of the earliest observers. Scarlet, black, blue, pink, red, yellow, etc., are arranged in patterns of the most bizarre fashion, mingling in spots, lines, bands; and reminding us of the words of Captain Cook when describing the coral-reefs of Palmerston Island: “The glowing appearance of the Mollusks was still inferior to that of the multitude of fishes that glided gently along, seemingly with the most perfect security. The colours of the different sorts were the most beautiful that can be imagined--the yellow, blue, red, black, etc., far exceeding anything that art can produce. Their various forms, also, contributed to increase the richness of this sub-marine grotto, which could not be surveyed without a pleasing transport.”

Of Chondropterygians the Scylliidæ, Pristis (Saw-fishes), Rhinobatidæ, and Trygonidæ attain to the greatest development. Of Acanthopterygians Centropristis, Serranus, Plectropoma, Mesoprion, Priacanthus, Apogon, Pristipoma, Hæmulon, Diagramma, Gerres, Scolopsis, Synagris, Cæsio, Mullidæ, Lethrinus, Squamipinnes, Cirrhites, some genera of Scorpænidæ, Platycephalus, Sciænidæ, Sphyræna, Caranx Equula, Callionymus, Teuthis, Acanthurus, Naseus, are represented by numerous species; and the majority of these genera and families are limited to this zone. Of Pharyngognaths the Pomacentridæ, Julidina, and Scarina, are met with near every coral formation in a living condition. Of Gadoids, a singular minute form, Bregmaceros, is almost the only representative, the other forms belonging to deep water, and rarely ascending to the surface. Flat-fishes (Pleuronectidæ) are common on sandy coasts, and the majority of the genera are peculiar to the Tropics. Of Physostomi only the Saurina, Clupeidæ, and Murænidæ are represented, the Clupeidæ being exceedingly numerous in individuals, whilst the Murænidæ live more isolated, but show a still greater variety of species. Lophobranchii and Sclerodermi are generally distributed. Branchiostoma has been found on several coasts.

Geographically it is convenient to describe the Coast fauna of the tropical Atlantic separately from that of the Indo-Pacific ocean. The differences between them, however, are far less numerous and important than between the freshwater or terrestrial faunæ of continental regions. The majority of the principal types are found in both, many of the species being even identical; but the species are far more abundant in the Indo-Pacific than in the Atlantic, owing to the greater extent of the archipelagoes in the former. But for the broken and varied character of the coasts of the West Indies, the shores of the tropical Atlantic would, by their general uniformity, afford but a limited variety of conditions to the development of specific and generic forms, whilst the deep inlets of the Indian ocean, with the varying configuration of their coasts, and the different nature of their bottom, its long peninsulas, and its archipelagoes, and the scattered islands of the tropical Pacific, render this part of the globe the most perfect for the development of fish-life. The fishes of the Indian and Pacific oceans (between the Tropics) are almost identical, and the number of species ranging from the Red Sea and east coast of Africa to Polynesia, even to its westernmost islands, is very great indeed. However, this Indo-Pacific fauna does not reach the Pacific coast of South America. The wide space devoid of islands, east of the Sandwich Islands and the Marquesas group, together with the current of cold water which sweeps northwards along the South American coast, has proved to be a very effectual barrier to the eastward extension of the Indo-Pacific fauna of coast fishes; and, consequently, we find an assemblage of fishes on the American coast and at the Galapagoes Islands, sufficiently distinct to constitute a distinct zoological division.

The following list, which contains only the principal genera and groups of coast fishes, will give an idea of the affinity of the tropical Atlantic and Indo-Pacific:--

Trop.-Atl. Indo-Pac.

Scylliidæ -- 13 Pristis 3 4 Rhinobatidæ 4 8 Torpedinidæ 1 8 Trygonidæ 14 24 Etelis 1 1 Aprion -- 1 Apsilus 1 -- Centropristis 15 -- Anthias 4 5 Serranus 30 85 Plectropoma 11 5 Grammistes -- 2 Rhypticus 3 -- Diploprion -- 1 Myriodon -- 1 Mesoprion 15 50 Priacanthus 4 12 Apogon and Chilodipterus 2 75 Pristipoma 12 14 Hæmulon 15 -- Diagramma -- 30 Gerres 12 16 Scolopsis -- 20 Dentex and Symphorus -- 7 Synagris and Pentapus -- 24 Cæsio -- 12 Mullidæ 5 22 Sargus 7 2 Lethrinus 1 18 Chrysophrys 1 7 Pimelepterus 1 5 Squamipinnes 13 110 Toxotes -- 2 Cirrhites -- 20 Scorpænidæ 2 65 Myripristis 3 15 Holocentrum 6 25 Platycephalus -- 25 Prionotus 1 -- Trigla -- 4 Peristethus 2 6 Uranoscopina 2 8 Champsodon -- 1 Percis -- 10 Sillago -- 5 Latilus 1 2 Opisthognathus 2 5 Pseudochromis -- 8 Cichlops and Pseudoplesiops -- 2 Sciænidæ 44 43 Sphyræna 1 10 Trichiuridæ 6 5 Caranx 20 60 Chorinemus 4 7 Trachynotus 6 4 Psettus 1 2 Platax -- 7 Zanclus -- 1 Equula and Gazza -- 20 Teuthis -- 30 Acanthurus 3 42 Naseus -- 12 Kurtidæ 1 6 Gobiodon -- 7 Callionymus -- 17 Batrachidæ 5 4 Tetrabrachium -- 1 Malthe 1 -- Petroscirtes -- 30 Clinus 6 -- Dactyloscopus 1 -- Malacanthus 1 2 Cepola -- 1 Gobiesocidæ 5 1 Amphisile -- 3 Fistulariidæ 3 3 Pomacentridæ 17 120 Lachnolæmus 1 -- Julidina 36 190 Pseudodax -- 1 Scarina 21 65 Pseudophycis -- 1 Bregmaceros -- 1 Ophidiidæ 3 7 Fierasfer -- 6 Pleuronectidæ 21 56 Saurina 5 9 Clupeidæ. 33 84 Chirocentrus -- 1 Murænidæ 47 130 Pegasus -- 3 Solenostoma -- 2 Syngnathidæ 7 41 Sclerodermi 16 67 Gymnodontes 23 40

A. Shore Fishes of the Tropical Atlantic.

The boundaries of the tropical Atlantic extend zoologically a few degrees beyond the Northern and Southern Tropics, but as the mixture with the types of the temperate zone is very gradual, no distinct boundary line can be drawn between the tropical and temperate faunæ.

Types, almost exclusively limited to it, and not found in the Indo-Pacific, are few in number, as Centropristis, Rhypticus, Hæmulon, Malthe. A few others preponderate with regard to the number of species, as Plectropoma, Sargus, Trachynotus, Batrachidæ, and Gobiesocidæ. The Sciænoids are equally represented in both oceans. All the remainder are found in both; but in the minority in the Atlantic, where they are sometimes represented by one or two species only (for instance, Lethrinus).

B. Shore Fishes of the Tropical Indo-Pacific Ocean.

The ichthyological boundaries of this part of the tropical zone may be approximately given as 30° of lat. N. and S.; on the Australian coasts it should probably be placed still farther south, viz., to 34°; it includes, as mentioned above, the Sandwich Islands, and all the islands of the South Sea, but not the American coasts.

Some eighty genera of Shore fishes are peculiar to the Indo-Pacific, but the majority consists of one or a few species only; comparatively few have a plurality of species, as Diagramma, Lethrinus, Equula, Teuthis, Amphiprion, Dascyllus, Choerops, Chilinus, Anampses, Stethojulis, Coris, Coilia.

The Sea-perches, large and small, which feed on Crustaceans and other small fishes, and the coral-feeding Pharyngognaths are the types which show the greatest generic and specific variety in the Indo-Pacific. Then follow the Squamipinnes and Murænidæ, the Clupeidæ and Carangidæ families in which the variety is more that of species than of genus. The Scorpænidæ, Pleuronectidæ, Acronuridæ, Sciænidæ, Syngnathidæ, and Teuthyes, are those which contribute the next largest contingents. Of shore-loving Chondropterygians the Scylliidæ and Trygonidæ only are represented in moderate numbers, though they are more numerous in this ocean than in any other.

C. Shore Fishes of the Pacific Coasts of Tropical America.

As boundaries within which this fauna is comprised, may be indicated 30° lat. N. and S., as in the Indo-Pacific. Its distinction from the Indo-Pacific lies in the almost entire absence of coral-feeding fishes. There are scarcely any Squamipinnes, Pharyngognaths or Acronuridæ, and the Teuthyes are entirely absent. The genera that remain are such as are found in the tropical zone generally, but the species are entirely different from those of the Indo-Pacific. They are mixed with a sprinkling of peculiar genera, consisting of one or two species, like Discopyge, Hoplopagrus, Doydixodon, but they are too few in number to give a strikingly peculiar character to this fauna.

The Three districts are distinguishable:--

a. Central American district, in which we include, for the present, Lower California, shows so near an affinity to the tropical Atlantic that, if it were not separated from it by the neck of land uniting the two American Continents, it would most assuredly be regarded as a portion of the Fauna of the tropical Atlantic. With scarcely any exceptions the genera are identical, and of the species found on the Pacific side nearly one-half have proved to be the same as those of the Atlantic. The explanation of this fact has been found in the existence of communications between the two oceans by channels and straits which must have been open till within a recent period. The isthmus of Central America was then partially submerged, and appeared as a chain of islands similar to that of the Antilles; but as the reef-building corals flourished chiefly north and east of those islands, and were absent south and west of them, reef-fishes were excluded from the Pacific shores when the communications were destroyed by the upheaval of the land.

b. The Galapagoes district received its coast fauna principally from the Central American district, a part of the species being absolutely the same as on the coast of the Isthmus of Panama, or as in the West Indies. Yet the isolation of this group has continued a sufficiently long period to allow of the development of a number of distinct species of either peculiarly Atlantic genera (such as Centropristis, Rhypticus, Gobiesox, Prionotus), or at least tropical genera (such as Chrysophrys, Pristipoma, Holacanthus, Caranx, Balistes). A few other types from the Peruvian coast (Doydixodon), or even from Japan (Prionurus), have established themselves in this group of islands. A species of Cestracion has also reached the Galapagoes, but whether from the south, north, or west, cannot be determined.

The presence of the Atlantic fauna on the Pacific side is felt still farther west than the Galapagoes, some Atlantic species having reached the Sandwich Islands, as Chætodon humeralis and Blennius brevipinnis.

c. The Peruvian district possesses a very limited variety of shore fishes, which belong, with few exceptions, like Discopyge, Hoplognathus, Doydixodon, to genera distributed throughout the tropical zone, or even beyond it. But the species, so far as they are known at present, are distinct from those of the Indo-Pacific, as well as of the tropical Atlantic; and therefore this district cannot be joined either to the Central American or the Galapagoes.

IV.--THE SOUTHERN TEMPERATE ZONE.

This zone includes the coasts of the southern extremity of Africa, from about 30° lat. S., of the south of Australia with Tasmania, of New Zealand, and the Pacific and Atlantic coasts of South America between 30° and 50° lat. S.

The most striking character of this fauna is the reappearance of types inhabiting the corresponding latitudes of the Northern Hemisphere, and not found in the intervening tropical zone. This interruption of the continuity in the geographical distribution of Shore-fishes is exemplified by species as well as genera, for instance--Chimæra monstrosa, Galeus canis, Acanthias vulgaris, Acanthias blainvillii, Rhina squatina, Zeus faber, Lophius piscatorius, Centriscus scolopax, Engraulis encrasicholus, Clupea sprattus, Conger vulgaris. Instances of genera are still more numerous--Cestracion, Spinax, Pristiophorus, Raja; Callanthias, Polyprion, Histiopterus, Cantharus, Box, Girella, Pagellus, Chilodactylus, Sebastes, Aploactis, Agonus, Lepidopus, Cyttus, Psychrolutidæ, Notacanthus; Lycodes, Merluccius, Lotella, Phycis, Motella; Aulopus; Urocampus, Solenognathus; Myxine.

Naturally, where the coasts of the tropical zone are continuous with those of the temperate, a number of tropical genera enter the latter, and genera which we have found between the tropics as well as in the temperate zone of the Northern Hemisphere, extend in a similar manner towards the south. But the truly tropical forms are absent; there are no Squamipinnes, scarcely any Mullidæ, no Acronuri, no Teuthyes, no Pomacentridæ (with a single exception on the coast of Chili), only one genus of Julidina, no Scarina, which are replaced by another group of Pharyngognaths, the Odacina. The Labrina, so characteristic of the temperate zone of the Northern Hemisphere, reappear in a distinct genus (Malacopterus) on the coast of Juan Fernandez.

The family of Berycidæ, equally interesting with regard to their distribution in time and in space, consists of temperate and tropical genera. The genus by which this family is represented in the southern temperate zone (Trachichthys) is much more nearly allied to the northern than to the tropical genera.

The true Cottina and Heterolepidina (forms with a bony stay of the præoperculum, which is generally armed) have not crossed the tropical zone; they are replaced by fishes extremely similar in general form, and having the same habits, but lacking that osteological peculiarity. Their southern analogues belong chiefly to the family Trachinidæ, and are types of genera peculiar to the Southern Hemisphere.

The Discoboli of the Northern Hemisphere have likewise not penetrated to the south, where they are represented by Gobiesocidæ. These two families replace each other in their distribution over the globe.

Nearly all the Pleuronectidæ (but they are not numerous) belong to distinct genera, some, however, being remarkably similar in general form to the northern Pleuronectes.

With Gadoids Myxinidæ reappear, one species being extremely similar to the European Myxine. Bdellostoma is a genus peculiar to the southern temperate zone.

As in the northern temperate zone, so in the southern, the number of individuals and the variety of forms is much less than between the tropics. This is especially apparent on comparing the numbers of species constituting a genus. In this zone genera composed of more than ten species are the exception, the majority having only from one to five.

The proportion of genera limited to this zone is rather high; they will be indicated under the several districts, which we distinguish on geographical rather than zoological grounds.

1. The Cape of Good Hope district.

The principal genera found in this district are the following (those limited to the entire zone being marked with a single (*) and those peculiar to this district with a double (**) asterisk):--

Chimæra, *Callorhynchus, Galeus, **Leptocarcharias, Scyllium, Acanthias, Rhinobatus, Torpedo, Narcine, Astrape, Raja.

Serranus, Dentex, Pristipoma; Cantharus, Box, **Dipterodon, Sagrus, Pagrus, Pagellus, Chrysophrys; *Chilodactylus; Sebastes, *Agriopus; Trigla; Sphyræna; Lepidopus, Thyrsites; Zeus; Caranx; Lophius; Clinus (10 species), Cristiceps; **Chorisochismus.

*Halidesmus, *Genypterus, Motella.

Syngnathus.--*Bdellostoma.

This list contains many northern forms, which in conjunction with the peculiarly southern types (Callorhynchus, Chilodactylus, Agriopus, Clinus, Genypterus, Bdellostoma) leave no doubt that this district belongs to the southern temperate zone, whilst the Freshwater fishes of South Africa are members of the tropical fauna. Only a few (Rhinobatus, Narcine, Astrape, and Sphyræna) have entered from the neighbouring tropical coasts. The development of Sparoids is greater than in any of the other districts of this zone, and may be regarded as one of its distinguishing features.

2. The South Australian district comprises the southern coasts of Australia (northwards, about to the latitude of Sydney), Tasmania, and New Zealand. It is the richest in the southern temperate zone, partly in consequence of a considerable influx of tropical forms on the eastern coast of Australia, where they penetrate farther southwards than should have been expected from merely geographical considerations; partly in consequence of the thorough manner in which the ichthyology of New South Wales and New Zealand has been explored. On the other hand, the western half of the south coast of Australia is still almost a terra incognita.

The shore-fishes of New Zealand are not so distinct from those of south-eastern Australia as to deserve to be placed in a separate district. Beside the genera which enter this zone from the Tropics, and which are more numerous on the Australian coast than on that of New Zealand, and beside a few very local genera, the remainder are identical. Many of the South Australian species, besides, are found also on the coasts of New Zealand. The principal points of difference are the extraordinary development of Monacanthus on the coast of South Australia, and the apparently total absence in Australia of Gadoids, which in the New Zealand Fauna are represented by six genera.

Shore-fishes of the South Australian district.

South Australia and Tasmania. New Zealand. *Callorhynchus (antarcticus). 1 1 Galeus (canis) 1 1 Scyllium ... 2 1 **Parascyllium 1 -- Crossorhinus 1 -- Cestracion ... 2 1 Mustelus (antarcticus) 1 1 Acanthias (vulgaris and blainvillii) 2 1 Rhina 1 -- Pristiophorus 1 -- **Trygonorhina (fasciata) 1 1 Rhinobatus 1 1 Torpedo -- 1 Narcine 1 -- Raja 3 1 Trygon (Urolophus) 3 2 **Enoplosus 1 -- Anthias (richardsonii) 1 1 Callanthias 1 -- Serranus x -- Plectropoma 4 -- **Lanioperca 1 -- **Arripis 3 1 Histiopterus 1 -- Erythrichthys -- 1 *Haplodactylus 2 2 Girella 4 -- **Tephræops 1 -- Pagrus 1 1 *Scorpis 2 1 **Atypichthys 1 -- **Trachichthys -- 1 **Chironemus 1 1 **Holoxenus 1 -- Chilodactylus 9 4 **Nemadactylus 1 -- **Latris 2 2 Scorpæna 4 2 **Glyptauchen 1 -- Centropogon 2 -- *Agriopus 1 1 *Aploactis 1 -- **Pentaroge 1 -- Platycephalus 5 -- Lepidotrigla 3 1 Trigla 3 1 Anema -- 1 **Crapatalus -- 1 **Kathetostoma 1 2 **Leptoscopus 1 3 Percis 2 1 *Aphritis 1 -- Sillago 2 -- *Bovichthys 1 1 *Notothenia -- 1 Sphyræna 1 -- Lepidopus -- 1 Trichiurus 1 -- Thyrsites 1 1 **Platystethus -- 2 Zeus (faber) 1 1 Cyttus 1 1 Trachurus (trachurus) 1 1 Caranx x 2 *Seriolella -- 1 Pempheris 1 -- Callionymus 3 -- Batrachus 1 -- **Brachionichthys 2 -- **Saccarius -- 1 Clinus 1 1 **Lepidoblennius 1 -- Cristiceps and Tripterygium 4 5 **Patæcus 3 -- **Acanthoclinus -- 1 **Diplocrepis -- 1 **Crepidogaster 3 1 **Trachelochismus -- 1 **Neophrynichthys -- 1 Centriscus 2 1 Notacanthus (sexspinis) 1 1 **Labrichthys 8 2 **Odax 5 1 Coridodax -- 1 **Olistherops 1 -- **Siphonognathus 1 -- Gadus -- 1 Merluccius -- 1 Lotella -- 1 **Pseudophycis -- 1 Motella -- 1 Bregmaceros -- 1 *Genypterus 1 1 **Lophonectes 1 -- **Brachypleura -- 1 Pseudorhombus -- 1 **Ammotretis 1 1 **Rhombosolea 3 3 **Peltorhamphus -- 1 Solea 1 -- Aulopus 1 -- Gonorhynchus (greyi) 1 1 Engraulis (encrasicholus) 1 1 Clupea 1 1 **Chilobranchus 1 -- Conger (vulgaris) 1 1 Ophichthys 1 1 Murænichthys 1 -- Congromuræna -- 1 Syngnathus 5 2 Ichthyocampus -- 1 **Nannocampus 1 -- Urocampus 1 -- **Stigmatophora 2 1 Solenognathus 2 1 **Phyllopteryx 2 -- Monacanthus 15 1 Ostracion 3 1 *Bdellostoma -- 1 Branchiostoma 1 1

3. The coast-line of the Chilian district extends over 20 degrees of latitude only, and is nearly straight. In its northern and warmer parts it is of a very uniform character, and exposed to high and irregular tides, and to remarkable and sudden changes of the levels of land and water, which must seriously interfere with fishes living and propagating near the shore. No river of considerable size interrupts the monotony of the physical conditions, to offer an additional element in favour of the development of littoral animals. In the southern parts, where the coast is lined with archipelagoes, the climate is too severe for the majority of fishes. All these conditions combine to render this district comparatively poor as regards variety of Shore fishes, as will be seen from the following list:--

*Callorhynchus; Scyllium, Acanthias, Spinax; Urolophus.

Serranus, Plectropoma, Polyprion, Pristipoma, Erythrichthys; *Haplodactylus; *Scorpis; Chilodactylus, **Mendosoma; Sebastes, *Agriopus; Trigla, Agonus; *Aphritis, *Eleginus, Pinguipes, Latilus, Notothenia (1 sp.) Umbrina; Thyrsites; Trachurus, Caranx, *Seriolella; Porichthys; **Myxodes, Clinus; Sicyases, Gobiesox.

Heliastes; **Malacopterus; *Labrichthys.

Merluccius; *Genypterus; Pseudorhombus.

Engraulis, Clupea; Ophichthys, Muræna.

Syngnathus.--*Bdellostoma.

Of these genera six only are not found in other districts of this zone. Three are peculiar to the Chilian district; Porichthys and Agonus have penetrated so far southwards from the Peruvian and Californian districts; and Polyprion is one of those extraordinary instances in which a very specialised form occurs at almost opposite points of the globe, without having left a trace of its previous existence in, or of its passage through, the intermediate space.

4. The Patagonian district is, with the exception of the neighbourhood of the mouth of the Rio de la Plata, almost unknown. In that estuary occur Mustelus vulgaris, two Raja, two Trygon, several Sciænoids, Paropsis signata and Percophis brasilianus (two fishes peculiar to this coast), Prionotus punctatus, Læmonema longifilis (a Gadoid), a Pseudorhombus, two Soles, Engraulis olidus, a Syngnathus, Conger vulgaris, and Ophichthys ocellatus; and if we notice the occurrence of a Serranus and Caranx, of Aphritis and Pinguipes, and of two or three Clupea, we shall have enumerated all that is known of this fauna. The fishes of the southern part, viz. the coast of Patagonia proper, southwards to Magelhæn’s Straits, are unknown; which is the more to be regretted, as it is most probably the part in which the characteristic types of this district are most developed.

V.--SHORE FISHES OF THE ANTARCTIC OCEAN.

To this fauna we refer the shore fishes of the southernmost extremity of South America, from 50° lat. S., with Tierra del Fuego and the Falkland Islands, and those of Kerguelen’s Land, with Prince Edward’s Island. No fishes are known from the other oceanic islands of these latitudes.

In the Southern Hemisphere surface fishes do not extend so far towards the Pole as in the Northern; none are known from beyond 60° lat. S., and the Antarctic Fauna, which is analogous to the Arctic Fauna, inhabits coasts more than ten degrees nearer to the equator. It is very probable that the shores between 60° and the Antarctic circle are inhabited by fishes sufficiently numerous to supply part of the means of subsistence for the large Seals which pass there at least some season of the year, but hitherto none have been obtained by naturalists; all that the present state of our knowledge justifies us in saying is, that the general character of the Fauna of Magelhæn’s Straits and Kerguelen’s Land is extremely similar to that of Iceland and Greenland.

As in the arctic Fauna, Chondropterygians are scarce, and represented by Acanthias vulgaris and species of Raja. Holocephali have not yet been found so far south, but Callorhynchus, which is not uncommon near the northern boundary of this fauna, will prove to extend into it.

As to Acanthopterygians, Cataphracti and Scorpænidæ are represented as in the arctic Fauna, two of the genera (Sebastes and Agonus) being identical. The Cottidæ are replaced by six genera of Trachinidæ, remarkably similar in form to arctic types; but Discoboli and the characteristic Arctic Blennioids are absent.

Gadoid Fishes reappear, but are less developed; as usual they are accompanied by Myxine. The reappearance of so specialised a genus as Lycodes is most remarkable. Flat-fishes are scarce as in the North, and belong to peculiar genera.

Physostomes are probably not entirely absent, but hitherto none have been met with so far south. Lophobranchs are scarce, as in the Arctic zone; however, it is noteworthy that a peculiar genus, with persistent embryonic characters (Protocampus), is rather common on the shores of the Falkland Islands.

The following are the genera known from this zone. Those with a single asterisk (*) are known to extend into the Temperate zone, but not beyond it; those with a double asterisk (**) are limited to the Antarctic shores:--

Magelhæn’s and Falkland. Kerguelen.

Acanthias vulgaris 1 -- Raja 1 2 Psammobatis 1 -- Sebastes 1 -- **Zanclorhynchus -- 1 *Agriopus 1 -- Agonus 1 -- *Aphritis 1 -- *Eleginus 1 -- **Chænichthys 1 1 *Bovichthys 2 -- *Notothenia 8 7 **Harpagifer 1 1 Lycodes 4 -- **Magnea 1 -- Lotella 1 -- Merluccius 1 -- **Lepidopsetta -- 1 **Thysanopsetta 1 -- Syngnathus 1 -- **Protocampus 1 -- Myxine 1 -- --- --- 31 13 === ===