American _Fauna_, as the western Pacific shores belong to the Asiatic _Fauna_. In the Atlantic Ocean there is no purely oceanic _Fauna_ to be distinguished, but in the _Pacific_ we have such a _Fauna_, entirely marine in its main character, though interspread with innumerable islands extending east of the Sunda Islands and New Holland to the western shores of tropical America. The islands west of this continent seem, indeed, to have very slight relations in their zoological character with the western parts of the mainland. South of the tropical zone we have the _South American temperate Fauna_, and that of the _Cape of Good Hope_, as other distinct zoological provinces. Van Diemen's Land, however, does not constitute a zoological province in itself, but belongs to the province of New Holland, by its zoological character. Finally, the antarctic circle encloses a special zoological province, including the _antarctic Fauna_, which, in a great measure, corresponds to the arctic _Fauna_ in its uniformity, though it differs from it in having chiefly a maritime character, while the arctic _Fauna_ has an almost entirely continental aspect. The fact that the principal races of man, in their natural distribution, cover the same extent of ground as the great zoological provinces, would go far to shew that the differences which we notice between them are also primitive; but for the present we shall abstain from further details upon a subject involving so difficult problems as the question of the unity or plurality of origin of the human family, satisfied as we are to have shewn that animals, at least, did not originate from a common centre, nor from single pairs, but according to the laws which at present still regulate their existence. _Additional Illustrations of the Geographical Distribution of Animals._ I.--_Geographical Distribution of Sturgeons._[2] Footnote 2: Agassiz's Lake Superior, p. 264. The sturgeons are generally large fishes, which live at the bottom of the water, feeding with their toothless mouths upon decomposed organized substances. Their movements are rather sluggish, resembling somewhat those of the cod-fish.