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° N. lat.
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. The late Arctic Expedition collected at and near that latitude specimens of Cotties quadricornis, Icelus hamat us, Cyclopterus spinosus, Liparis fabricii, Gymnelis viridis, and GaAs j'abricii. The number would probably have been larger were it not that the difficulties of collecting fishes in these high latitudes are almost insuperable for the greater part of the year.
So 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 hemi.
the herring, holibut, and hake.
Chondropterygians are very rare. Of Acanthopteryare characteristic of the arctic fauna. Characteristic also is the development of Gadoid fishes, of which some thirteen species, belonging to Gadus, Merluccius, and Molva, form one of the principal articles of food for the inhabitants of the coasts of the Arctic Ocean. The Bleunoid Anaranthini or Lycodicke 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 rare, and are represented only by a few species of Clupea and by Mallotus. The arctic climate is still less favourable to the existence of Lophobranchs, only a few of Synynathus 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 Myxiue, which thrives in them as a parasite.