218 ZOOLOGICAL GEOGRAPHY. [PART III. 
and asses, gazelles, two species of antelopes, flying squirrels 
(Pteromys), ground squirrels (Zamias), marmots, of the genus 
Spermophilus, with camels and dromedaries, probably natives 
of the south-western part of this sub-region. The most 
abundant and conspicuous of the mammalia are the great 
herds of reindeer in the north, the wolves of the steppes, with 
the wild horses, goats, sheep, and antelopes of the plateaus and 
mountains. 
Among the curiosities of this sub-region we must notice the 
seal, found in the inland and freshwater lake Baikal, at an eleva- 
tion of about 2,000 feet above the sea. It is a species of Callo- 
cephalus, closely allied to, if not identical with, one inhabiting 
northern seas as well as the Caspian and Lake Aral. This 
would indicate that almost all northern Asia’ was depressed 
beneath the sea very recently; and Mr. Belt’s view, of the ice 
during the glacial epoch having dammed up the rivers and con- 
verted much of Siberia into a vast freshwater or brackish lake, 
perhaps offers the best solution of the difficulty. 
Plate II.—Characteristic Mammalia of Western Tartary.— 
Several of the most remarkable animals of the Palearctic region 
inhabit Western Tartary, and are common to the European and 
Siberian sub-regions. We therefore choose this district for one 
of our illustrative plates. The large animals in the centre are the 
remarkable saiga antelopes (Saiga Tartarica), distinguished from 
all others by a large and fleshy proboscis-like nose, which gives 
them a singular appearance. They differ so much from all other 
antelopes that they have been formed into a distinct family by 
some naturalists, but are here referred to the great family Bovide. 
They inhabit the open plains from Poland to the Irtish River 
On the left is the mole-rat, or sand-rat (Spalax murinus). This 
animal burrows under ground like a mole, feeding on bulbous 
roots. It inhabits the same country as the saiga, but extends 
farther south in Europe. On the right is a still more curious 
animal, the desman (Myogale Muscovitica), a long-snouted 
water-mole. This creature is fifteen inches long, including the 
tail; it burrows in the banks of streams, feeding on insects, 
1 Quarterly Journal of the Geological Society, 1874, p. 494. 
