NO. 1990. MAMMALS FROM THE ALTAI MOUNTAINS— HOLLISTER. 515 



£ 



In color our specimens from the Altai differ conspicuously from a 

 series of E. wosnessensHi, from Kamchatka, in the decidedly darker 

 tone of the red, and the much grayer sides. In all the 16 specimens 

 (except one which has the teeth so worn that the enamel pattern is 

 obliterated) the last upper molar has on the inside four salient angles 

 and three re-entrant angles, the posterior loop being deeply cut by 

 an inner re-entrant angle. Ten adults measure, averages and 

 extremes: Head and body, 101 mm. (95-107); tail vertebrae, 34 

 (30-38); hind foot, without claw, 16.7 (16-17.5). 



EVOTOMYS RUFOCANUS (Sundevall). 



1846. Hypudseus rufocanus Sundevall, Ofversigt af Kongl. Vet. Akad. Forhandl., 



vol. 3, p. 122. 

 1897. Evotomys rufocanus Bailey, Proc. Biol. Soc. Washington, vol. 11, p. 122, 



May 13. 



I can not distinguish the six specimens of this mouse collected in 

 the Tapucha forests, August 6 to 11, from Scandinavian examples. 

 A single immature specimen collected at Tchegan-Burgazi Pass is 

 somewhat paler, and has grayer sides and a restricted dorsal stripe; 

 but with the variation in both rufocanus and latastei m mind is seems 

 best to refer this specimen to the same form as the small series from 

 Tapucha. Thomas has recorded Evotomys rufocanus latastei from a 

 point 100 miles west of Lake Baikal, and remarks that the specimens 

 agree closely with examples from Kamchatka.^ Dr. J. A. Allen has 

 kindly lent me a series of seven specimens of his latastei, from Gichiga, 

 northeast Siberia, but as his specimens are all immature my com- 

 parisons with latastei are of little consequence. My three immature 

 specitnens from Tapucha agree better, however, Avith immature 

 examples from Norway than \Adth the young of latastei. 



The single Tchegan-Burgazi Pass specimen was trapped in open 

 alps at about 9,000 feet elevation. As there are indications of tim- 

 bered draws within comparatively recent times in the immediate 

 vicinity, it is probable that before the almost complete deforestation 

 of such places the species was more abundant in the frontier range 

 than it is at the present time. 



MICROTUS OBSCURUS (Eversmann). 



1841. Hypudaeus ohscurus Eversmann, Y^en. 3aimcKH, KasancKHM-b jhhb., 



(VIII), I, p. 156. [Mem. sav. univ. Kasan.] 

 1899. [Microtus arvalis] var. ohscurus Trouessart, Cat. Mamm., I, p. 558. 



Thirty specimens, from Tchegan-Burgazi Pass and the forests near 

 Tapucha, seem to represent M. ohscurus, described by Eversmann 

 from the Altai. The species is allied to Microtus arvalis, but is 

 larger, with a much larger skull, actually smaller teeth, and is much 

 darker and richer colored. In the 30 specimens the true arvalis 



1 Ann. and Mag. Nat. Hist., ser. 8, vol. 9, p. 39", April, 1912. 



