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 Nordenskiold {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, Bull. Amer. Mus. Nat. 

 /^w/., 31st March 1903, 152). For the ease with which lemmings may be dug out 

 and killed by man or carnivora, see Buxton {pp. cit.) ; Preble, North Amer. Fauna, 

 No. 22, 1902, 56; and Goldwaite (in Bangs), Proc. Biol. Soc, Washington, 17th 

 September 1897, 237).] 



[Genus LEMMUS.i 



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. 

 The short rostrum is thick and 

 heavy. The auditory bullse are 

 large, and of spongy texture. 

 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 



' Extinct in Britain. Lemmus, Link, 1795, antedating Myodes, Pallas, 1811, is 

 based on Mus lemmus of Linnaeus. 



Fig. 56.— Skull of Lemmus lemmus (life 

 size). From Miller's Catalogue of the 

 Mammals of Western Europe. (By kind 

 permission of the Trustees of the British 

 Museum.) 



