242 ELEMENTS OF ORNITHOLOGY. 
ing of birds in geographical regions. Nevertheless this diffi- 
culty i is obviated by the rule that the breeding-place of a bird 
is always to be considered us its real home. 
The absence of any considerable or significant Ornithological 
group is often as important and as interesting a character as is 
constituted by its presence in some other region, and it may be 
much more interesting and important if the group thus missing 
is otherwise cosmopolitan or nearly so. 
THE PaLwarctic REGION is one in which it is very difficult to 
indicate characteristic forms as present, though it would be easy 
enough to enumerate extensive groups elsewhere to be oe 
which are absent from it. Thus there are no Parrots, 
Humming-birds, no Hornbills, no Toucans, &e., &e. But es 
enumerate such absent forms would be an idle task. Their 
absence will be noted in recording the presence of such bird- 
groups in other regions. On the other hand, the number of 
birds of the Palearctic region which are also found in North 
America is very great, there being at least 128 genera common 
to both these territories, including Thrushes, Crossbills, Mag- 
pies, Goatsuckers, Woodpeckers, Swallows, Snowy Owls, Jer- 
taleons, and a multitude of other kinds. Waxwings, Magpies, 
Snowy Owls, Jer-falcons, Crossbills are just as characteristic of 
the Nearctic region; but the Goatsuckers and Woodpeckers are 
of a different type in the two regions. 
Almost the only group which may be said to characterize the 
Palearctic region positively, is that to which the Bearded Tit- 
mouse (Panur us biarmicus) belongs (but its species are very 
widely diffused through it from East to West). The true Haw- 
finches (Coccothraustes) are also characteristic. Of course it has 
peculiar genera and species. The most conspicuous is the 
Capercailzie, but many Finches and Buntings are confined to it. 
As to the subdivisions of the Palearctic region, the European 
subregion—which consists of Europe north of the Pyrenees, 
Alps, Balkans, to the Caucasus and Asia north of the desert-tract 
of Central Asia, and including the northern island of Japan— 
has an abundance of Grouse, Capercailzie, Hazel-hen, Black- 
game, and plenty of peculiar Buntings, Warblers, and Finches 
—notably Coccothraustes. The genus Eurynorhynchus is peculiar 
to Siberian lands. 
The other division, the Mediterraneo-Persic subregion—which 
extends from Europe south of the Pyrenees, Alps, &c., to 
the Amoor—has many peculiar Chats and Shrikes, and it 
