Descriptions of East Asiatic Mammals 261 
are much less reduced than in Dicrostonyx, and are unprovided 
with valves for opening and closing the ear openings. Lemmings 
are broad-headed, heavy-bodied Voles with very short muscular 
tails, large anterior claws that enlarge in winter, and a large, 
strap-shaped nail on the thumb. The palms are furry to the bases 
of the fingers. A dark dorsal stripe may be present. Lemmus 
lacks the ''collar" of the Collared Lemmings. It too becomes 
white in the winter. The range of the genus is circumpolar; the 
typical species, Lemmus lemmus, is native to the mountains of 
the Scandinavian peninsula. 
In eastern Asia Lemmus is represented by the Yellow-bellied 
Lemming, L. chrysogaster, a close relative of the Alaska Lem- 
ming, by the Little Kolyma Lemming, L. paulus from the 
Kolyma River area, and by L. amurensis from the Amur River 
region. The summer color of L. chrysogaster is yellow-brown 
varied with black, grayer on the head and neck, becoming red- 
dish on the hind back and rump; the undersurface is orange- 
brown, the chin and sides of mouth whitish, the feet gray- 
brown, the tail dark above, its undersurface and tuft of long 
hairs grayish white. The length of head and body reaches 3 
inches, tail % inch, hind foot % inch. 
The summer pelage of L. paulus is buffy, mixed with black- 
ish on the head, becoming clearer posteriorly and on the sides ; 
underparts are ochraceous, chin, throat, and anal region whitish, 
tail pale buff, feet silvery with a dusky tinge. The length of head 
and body is 4% inches, tail % inch, hind foot % inch. The 
measurements of these two forms are as given in their original 
descriptions. 
Lemmus amurensis, colored much as L. chrysogaster, is uni- 
form brown tinged with russet on head and rump, underparts 
cinnamon. The length of its head and body is 4 inches, tail 
% inch, hind foot % inch. 
The east Asiatic Microti, or those Meadow Mouse genera 
which are not closely related to the Lemmings, comprise the 
