LEMMUS 391 
northern naturalists, e.g. Manniche for Greenland, agree about the helplessness of 
lemmings in the absence of moderately deep snow. In Novaya Zemlya their snow- 
tunnels are very remarkable, as described by Nordenskiéld (Voyage Vega, 1881, i., 
146-7); in Alaska, in the absence of snow, their runs may be in moss, and they 
may have young in every month of the year (Buxton in Allen, Bu//. Amer. Mus. Nat. 
Hist., 31st March 1903, 152). For the ease with which lemmings may be dug out 
and killed by man or carnivora, see Buxton (of. cz¢.); Preble, North Amer. Fauna, 
No. 22, 1902, 56; and Goldwaite (in Bangs), Proc. Biol. Soc., Washington, 17th 
September 1897, 237).] 
[Genus LEMMUS1 
The true lemmings are stout, short-legged, thickly furred 
animals, with disproportionately large heads, short but well- 
developed valveless external ears, and rudimentary tails. Both 
hands and feet are highly specialised for a fossorial existence, 
the palms and soles being large, broad, strong, and densely 
furred, and the pads absent 
or rudimentary; the digits, ex- 
cept the thumbs, are provided 
with long, sharp, but simple 
claws, not subject to periodic 
changes, and borne on greatly 
enlarged, unequal phalanges ; the 
thumbs carry remarkably power- 
ful nails. 
The skull is particularly 
heavy and massive, with low, 
broad brain-case. The temporal 
ridges unite to form a knife- 
like ridge between the orbits. Reel Ph te - , a 
The short rostrum is thick and Sat per amen ee oa 
heavy. The auditory bullae are Mammals of Western Europe. (By kind 
large, and of spongy texture. ea of the Trustees of the British 
The powerful zygomatic arches 
are expanded centrally into wide, strongly oblique plates ; 
the anterior edges of the squamosals form narrow but 
distinct shelf-like post-orbital processes. The pterygoids are 
short, with the lateral pits of the bony palate deep, and the 

1 Extinct in Britain. Zemmus, Link, 1795, antedating Myodes, Pallas, 1811, is 
based on Mus demmus of Linnzus. 
