58 BIRDS AND MAMMALS OF EAST SIBERIA [^VoLV*^' 



Mustela kanei (Baird). Kane's Weasel. 



Putorius kaneii Baird, Mammals of No. Amer., 1857, p. 172. 



Two small weasels of the erminea group were taken by Mr. 

 Koren at Nijni Kolymsk, both males, the one adult, the other 

 a smaller and younger animal. The former is in summer, the latter 

 in winter, pelage. They seem to represent Baird's Putorius kanei, 

 described from two specimens, the one from Semipalatinsk, Siberia,, 

 (possibly a different race), the other from Arikatutchitchi Island, a 

 small islet in Bering Strait. This, says Baird, is the form of the 

 Tchuktchi country, and differs from P. erminea of northern Europe 

 in having a much shorter tail, of which the black pencil forms about 

 one half or more. These differences are apparent in the two speci- 

 mens taken by Mr. Koren ; and in addition the summer specimen 

 differs very noticeably in being an olive brown, rather than the 

 chocolate brown of erminea in summer. The belly is washed with 

 yellow, shading into an ochraceous buff on the throat and chest. 

 Compared with specimens of about the same age from Norway, 

 the skulls are not noticeably different, except that the audital 

 bullae are markedly longer in the Siberian form — 15 mm. against 

 13.7. The tail measurement (80 and 66 mm. respectively) is 

 shorter than in most of the specimens recorded by Dr. J. A. Allen 

 (1903, p. 175) from Gichiga, though he did not recognize the Kamt- 

 chatkan weasel as distinct from P. erminea. 



Myopus thayeri sp. nov. Thayer's Slaty Lemming. 



Type, skin and skull, no. 15,264, M. C. Z., adult male, from Nijni Kolymsk, 

 near the mouth of the Kolyma River, northeastern Siberia, collected March 

 28, 1912, by Johan Koren. 



General characters. — Like M. schisticolor, but lacking the dorsal chestnut 

 area; skull shghtly larger. 



Description. — Entire pelage 'deep neutral gray,' lined with white hairs, 

 which predominate ventrally; hairs of the mid-dorsum with a faint sub- 

 terminal band of 'russet' giving a faint tinge to that region, but imper- 



