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:—