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together with many northern birds common to both continents. Yet a few Palæarctic forms, not known in other parts of the sub-region, appear here. These are Budytes flava, Phylloscopus kennicottii, and Pyrrhula coccinea, all belonging to genera not occurring elsewhere in North America. Considering the proximity of the district to North-east Asia, and the high probability that there was an actual land connection at, and south of, Behring's Straits, in late Tertiary times, it is somewhat remarkable that the admixture of Palæarctic and Nearctic groups is not greater than it is. The Palæarctic element, however, forms so small a portion of the whole fauna, that it may be satisfactorily accounted for by the establishment of immigrants since the Glacial period. The great interest felt by ornithologists in the discovery of the three genera above-named, with a wren allied to a European species, is an indication that the faunas even of the northern parts of the Nearctic and Palæarctic regions are, as regards birds, radically distinct. It may be mentioned that the birds of the Aleutian Isles are also, so far as known, almost wholly Nearctic. The number of land-birds known from Alaska is 77; and from the Aleutian Isles 16 species, all of which, except one, are North American.
Reptiles.— These are comparatively few and unimportant. There are however five snakes and three tortoises which are limited to Canada proper; while further north there are only Amphibia, represented by frogs and toads, and a salamander of the genus Plethodon.
Fishes.—Most of the groups of fresh-water fish of the Nearctic region are represented here, especially those of the perch, salmon, and pike families ; but there seem to be few or no peculiar genera.
Insects. These are far less numerous than in the more temperate districts, but are still tolerably abundant. In Canada there are 53 species of butterflies, viz., Papilionidæ, 4; Pieridæ, 2; Nymphalidæ, 21; Satyridæ, 3; Lycænidæ 16; and Hesperidæ 7. Most of these are, no doubt, found chiefly in the southern parts of Canada. That Coleoptera are pretty numerous is shown, by more than 800 species having been collected on the shores of Lake Superior; 177 being Geodephaga and 39 Longicorns.
Greenland. This great arctic island must be considered as belonging to the Nearctic region, since of its six land mammals, three are exclusively American (Myodes torquatus, Lepus glacialis, and Ovibos moschatus), while the other three (Vulpes lagopus, Ursus maritimus, and Rangifer tarundus) are circumpolar. Only fourteen land-birds are either resident in, or regular migrants to the country; and of these two are European (Haliaetus albicilla, and Falco peregrinus), while three are American (Anthus ludovicianus, Zonotrichia leucophrys, and Lagopus rupestris), the rest being arctic species common to both continents. The waders and aquatics (49 in number) are nearly equally divided between both continents; but the land-birds which visit Greenland as stragglers are mostly American. Yet although the Nearctic element somewhat preponderates, Greenland really belongs to that circumpolar debateable land, which is common to the two North Temperate regions.
Concluding remarks. We have already discussed pretty fully, though somewhat incidentally, the status and relations of the Nearctic region ; first in our chapter on Zoological regions, then in our review of extinct faunas, and lastly in the earlier part of this chapter. It will not therefore be necessary to go further into the question here; but we shall, in our next chapter, give a brief summary of the general conclusions we have reached as to the past history and mutual zoological relations of all the great divisions of the earth.
TABLES OF DISTRIBUTION.
In drawing up these tables, showing the distribution of various classes of animals in the Nearctic region, the following sources of information have been chiefly relied on, in addition to. the general treatises, monographs, and catalogues used in the compilation of the 4th Part of this work.
Mammalia.—Professor Baird's Catalogue ; Allen's List of the Bats; Mr. Lord's List for British Columbia ; Brown, for Greenland; Packard for Labrador.
Birds.- Baird, Cassin, and Allen's Lists for United States; Richardson's Fauna Boreali Americana; Jones, for Bermudas; and papers by Brown, Coues, Lord, Packard, Dall, and Professor Newton.
FAMILIES OF ANIMALS INHABITING THE NEARCTIC REGION. ·
EXPLANATION. Names in italics show the families which are peculiar to the region. Names inclosed thus (.....) show families which barely enter the region, and are not
considered properly to belong to it. Numbers correspond to the series of numbers to the families in Part IV.