GEOGRAPHICAL DISTRIBUTION 337 
the shores of the Atlantic, for throughout that immense tract species 
of Passeres are found that wear the Desert uniform and scarcely differ 
from one end to the other. 
Having already indicated the component parts of the Subregion, 
it is time to say somewhat of its ornithic characters. - Like the 
Nearctic, it seems to produce but a single peculiar Family of Birds 
—the Panuridz, the type of which is the beautiful species known 
to most Englishmen as the Bearded Titmouse, Panurus biarmicus? ; 
but this fact need excite no surprise when we remember that along 
almost the whole of its southern frontier, extending from long. 120° 
E. to 10° W., it is conterminous with the Indian or the Ethiopian 
Region, whereas the Nearctic Subregion presents not more than 20° 
of latitude to the Neotropical Region.?_ Indeed, the wonder rather is 
that the Palearctic Subregion should have even a single peculiar 
Family, for we ought to bear in mind that all the Families of the 
Holarctic Region consist of stronger forms than those inhabiting 
the Regions which abut upon it, so that the faculty of extending 
their range is possessed in a greater degree by the former. The 
whole number of Palearctic Families may be taken to be 67, and of 
the genera 323, about which there can be little doubt, or if any 
exist, it is that the number is understated. Of these, as before 
stated, 128 are common to the Nearctic Subregion. Species of 51 
more seem to occur as true natives within the Ethiopian and Indian 
Regions, and besides these, 18 appear to be common to the Ethiopian, 
without being found in the Indian, and no fewer than 71 to the 
Indian without occurring in the Ethiopian—a result that might be 
expected from geographical considerations, since the latter Region 
is cut off by a wide desert, constituting (as above stated) a barrier 
as hard to pass as a sea, while the former Region, though in fact 
separated by one of the highest mountain-ranges in the world, is 
in almost its whole length conterminous. 
Taking the Provinces separately, we find that the Siberian has 
but one genus peculiar to it—Hurynorhynchus, the Spoon-billed 
Sandpiper, a bird of wide wanderings, whose home was finally dis- 
covered by the companions of Baron Nordenskjéld on the mainland 
opposite to Burney Island (long. 174° W.) during the memorable 
voyage of the ‘Vega.’ The Mongolian seems to have the largest 
number of peculiar genera of any Palearctic Province, there being 
no fewer than 13, which may be assigned as follows—Fringillidz, 
1 This bird is most unhappy in its names. It has nothing whatever to do 
with the Tirmoust-Family, Paridz, and its specific title, signifying of or belong- 
ing to Biarmia, the district of Perm in Russia, is just as inapt. 
2 As the southern boundary of both Subregions lies in much the same latitude 
(say roughly 30° N.), the degrees of longitude are practically equal in either case. 
3 Paimén, Bidrag till Kannedomen om Sibiriska Ishafskustens Fogelfauna. 
Vega-Expeditionens vetenskapliga Iakttagelser, v. pp. 326, 327. 
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