EVOTOMYS 239 



Colour briglit; mantle well defined, though not strikingly 

 contrasted with the flanks, extending backwards from crown to 

 root of tail, bright rufous chestnut scarcely darkened by the dusky 

 tips of the longer hairs. Sides and cheeks pale, grey tinged with 

 ochraceous buff merging below in the creamy or dull whitish under 

 surface, which is irregularly darkened by the slaty bases of the 

 hairs. Ears concolorous with the mantle. Feet whitish, with 

 the soles hairier than usual, the posterior pads sometimes hidden. 

 Tail sharply bicoloured, reddish-brown above, dirty white or 

 cream below. 



Skull distinguished from that of E. glarcolus by its shorter 

 and more nearly square braincase, its upper surface and that of 

 the rather broad interorbital region somewhat flattened. Post- 

 orbital (squamosal) processes very weak or not developed. Palate 

 and choanse narrower than in E. glareolus ; the postero-lateral 

 bridges of palate often incomplete. Auditory bullse large. 



Cheek-teeth smaller and lighter than in E. glareolus ; enamel 

 pattern normal, but re-entrant folds deeper and salient angles 

 more acute, with the dentinal spaces rather tightly closed; 

 m^ with deep first outer infold, so that its anterior loop does not 

 present the AUicola-Mka appearance often seen in E. glareolus, etc., 

 and with its inner infolds always well developed ; outer infolds of 

 Hig and ))i^ relatively deep ; m^ with four substantially closed 

 triangles in front of the jjosterior loop ; m^ tending to assume 

 a similar form. 



Geographical differeiUiafioii.- — Owing to the scantiness of 

 material and to the very poor character of the descriptive literature, 

 it is impossible to say how many geographical races of E. rutilus 

 should be recognized or what status should be accorded to the 

 many nominal species of Evotomys which in recent years have 

 been described from Northern and Central Asia. E. haikalensis, 

 E. laticeps, E. farvidens and E. otas, dealt with above, if 

 distinct, are probably no more than subspecies of E. rutilus. 



17a. Evotomys rutilus rutilus Pallas. 



1779. Mus rutilus Pallas, Nov. Spec. Quadr. Glir. Ord., p. 246. 



1811. Myodes rutilus Pallas, Zoogr. Rosso-Asiatica, 1, p. 177. 



1819. Lemmus rutilus Desmarest, Nouv. Diet. d'Hiat. Nat., ed. 2, 5, 



p. 84; Fisher, Synops. Mamm., 1829, p. 295. 

 1822. Arvicola rutilus Desmarest, Mammalogie, p. 284; Poljakow, 



Mem. Imp. Acad. Sci. St. Petersburg, 39, 1881, Supplement, p. 51. 

 1827. Hypudceus rutilus Brants, Muizen, p. 70. 

 1874. Evotomys rutilus Coues, Proc. Acad. Nat. Sci. Philadelphia, p. 



187 (in part); Miller, Proc. Washington Acad. Sci., 2, 1900, p. 91 ; 



Trouessart, Faune Mamm. d'Europe, 1910, p. 169; Miller, Catal. 



Mamm. W. Europe, 1912, p. 646. 

 1840. Arvicola rutila Eversmann, Hist. Nat. gouv. Orenbourg, 2, 167. 

 1887. Mirrolus {Myodes) rutilus Lataste, Ann. Mus. Civ. Storia Nat. 



Geneva, (2), 4, p. 261. 

 1898. Microtus rutilus CoUett, Nyt. Mag. f. Naturw., 36, p. 282. 



