362 PROCEEDINGS OF THE ACADEMY OF [1898. 



Teeth. — The teeth of Evotomys wosnessenskii (fig. 2 b) present no 

 characters of special importance. 



Ears. — The ears are slightly smaller than in E. alascensis, but 

 not peculiar in form. 



Feet. — The hind feet are slender and much less densely furred 

 than in E. alascensis. The latter character at first sight appears to 

 be due to season, as most of the National Museum specimens of E. 

 wosnessenskii were taken in summer, while the Alaskan series is 

 chiefly composed of October skins. Several of the Kamtschatkan 

 specimens were, however, taken during the last week in September, 

 and one as late as October 8th. In none of these does the hairiness 

 of the hind foot closely approach the condition found in Alaskan 

 specimens taken from three weeks to a month later. 



Tail. — The tail is more slender than in E. alascensis, and less 

 densely haired than in either E. alascensis or E. rutilus. The differ- 

 ence is fully apparent on comparison of specimens in winter pelage. 



Color. — Autumnal specimens have the dorsal stripe a clear, deep, 

 tawny, fiuely and inconspicuously sprinkled with black. Sides 

 ochraceous buff. Belly dull whitish, faintly darkened by the slaty 

 bases of the hairs. Summer adults are essentially similar, but im- 

 mature specimens are much darker and duller. 



Measurements. — For measurements of Evotomys wosnessenskii see 

 table, page 366. 



Specimens examined. — Total number of specimens examined 26, 

 from the following localities : 



Kamtschatka: Bering Island, 17; Kalakhtyrka, 1 ; Petropaul- 

 ski, 6 ; no definite locality, 2. 



General remarks. — Evotomys ivosnessenskii is more distinct from 

 E. rutilus and E. alascensis than either of these is from the other. 

 Aside from its cranial characters it is easily distinguishable from its 

 allies by its slender, thinly haired tail and feet. 



Evotomys rutilus (Pallas). 



1778. Mus rutilus Pallas, Nov. Sp., Quadr. Glir. Ord.,p. 246 (Siberia, east 



of the Obi). 

 1874. Evotomys rutilus Coues, Proc. Acad. Nat. Sci. Philadelphia, p. 187, 



(part). 

 Skull. — In the north European Evotomys to which I have pro- 

 visionally restricted the name rutilus, the skull closely resembles 

 that of E. alascensis, except that the rostral protuberances are placed 

 further forward, as in E. wosnessenskii, and the nasal bones are 

 shorter relatively to the length of the skull. In E. alascensis the 



