186 MICROTIN^ 



Genus : 4. LEMMUS Link. 



1758. 3Ius Linnseus, Syst. Nat., ed. 10, 1, p. 59 (in part). 



1777. Glis Erxleben, Syst. Reg. Anim., 1, p. 371 (in part). Not of 



Brisson, 1762. 

 1795. Lemmus Link, Zool. Beytr., 1, pt. 2, p. 75. 

 1811. HyfudcBUs lUiger, Prod. Syst. Mamm., p. 87 (in part). 

 1811. Myodes Pallas, Zoogr. Rosso-Asiatica, 1, p. 172 (in part). 

 1821. Marmotta Blumenbach, Handbuch d. Naturgesch., 10th Aufl., 



p. 86. Not of Frisch, 1775. 

 1827. Hifudceus Lesson, Man. Mamm., p. 276 (in part). 

 1898. Lemmus Miller, N. Amer. Fauna, No. 12, p. 36. 



Genotype. — Mus lemmus Linnaeus. 



Range. — Circumpolar. Northern Europe and Asia, from 

 Scandinavia to Kamtschatka, northwards to Novaya Zemlya and 

 the New Siberian Islands. In the late Pleistocene period south- 

 wards and westwards in Europe to Ireland, Great Britain, and 

 to the Pyrenees and Alps. In North America from the Pribilof 

 Islands and Alaska eastwards to Baffin Land. 



Characters. — External form, skull, and dentition highly 

 modified for fossorial habits and for subsistence upon a coarse 

 and but slightly nutritious vegetable diet. Fur dense and long; 

 coloration usually much more brilliant than in Synaptomys and 

 Myopus. 



General form much heavier and stouter than usual in voles, 

 the head relatively large very broad and somewhat flattened, 

 the neck, limbs and tail very short and muscular, the hands 

 and feet very broad. Eyes small. Ears small, though larger 

 than in Dicrostonyx, completely hidden in the fur and destitute 

 of meatal valves. Hands large and broad with short stout 

 fingers; thumb very short, provided with a large flattened 

 strap-shaped and distally truncate nail ; other digits armed 

 with large simple claws, sharper or blunter according to the 

 degree of use, but considerably longer than those of the hind- 

 foot; in the two longest fingers (III and IV, of which III is 

 slightly the longer) the metacarpals are much shorter than the 

 phalanges measured together, and in all the fingers the ungual 

 phalanges are somewhat longer than the combined length of the 

 first and second phalanges. Palms, to the bases of the digits, 

 densely clad with stiff hairs, about 3 mm. in length. Palmar 

 tubercles reduced usually to a single functionless vestige placed 

 at the bases of digits III and IV.^ Feet short and broad with five 

 digits, of which II, III, and IV are longer and subequal (III being 

 the longest), and I and V considerably shorter, provided with 



1 Occasionally the reduction of the palmar pads does not proceed so 

 far. In one specimen of L. lemmns before me there are four vestigial pads 

 on each palm arranged as in Synajitomyn and Myopvs, three alternating 

 with the bases of digits II to V, the fourth being a minute postero-external 

 or carpal pad. 



