146 Bulletin American Museum of Natural History. [Vol. XIX, 



[The name kamtschaticus (Arvicola rufocanus var. kamtscha- 

 ticus Lataste, 1884) cannot be used in this connection, owing 

 to the previous Arvicola kamtschaticus of Polyakoff (1881). 

 It may therefore be called Evotomys latastei, after the author 

 who first recognized the form. 



13. Evotomys wosnessenskii (Polyakoff). 



WOSNESSENSKI RED-BACKED MOUSE. 



Arvicola wosnessenskii POLYAKOFF, Zapiski Imp. Acad. Sci. St. 

 PStersb. XXXIX., No. 2, 1881, 56. 



Evotomys wosnessenskii .MILLER, Proc. Acad. Nat. Sci. Phila. 1898, 

 361. Description, synonymy, etc.; Bering Island and Petropaulski, 

 Kam. 



This species is represented by 83 specimens (including six 

 in alcohol), all taken at Gichiga, as follows: April 10-13, 2; 

 June 29, i (juv.); July 26-29, 4 (2 juv.); Sept. 24 and 30, 2; 

 Oct. 2-27, 49; Nov. i-n, 15; Dec. 15 and 20, 2. All but 

 twelve are adult and are exceedingly uniform in coloration. 

 The two April specimens and the two December specimens 

 have the red of the back a little lighter or paler than the Sep- 

 tember-October series, with the pelage longer and fuller, and 

 the tail more heavily clothed. The young specimens (half to 

 three fourths grown) are duller colored, with the soft woolly 

 pelage of immaturity, and the red of the back not fully devel- 

 oped. Two nursing young, in very short close pelage, have 

 the dorsal area orange rufous, the sides orange, and the ven- 

 tral surface yellow in one specimen and white in the other, in 

 which latter also the sides are somewhat paler. This colora- 

 tion cannot be considered as due to the effect of formalin or 

 alcohol, as the adults preserved with them, when removed 

 from the preserving fluid and dried, do not differ from the 

 skins. 



In adult autumn specimens the back is rich chestnut rufous 

 varied with black-tipped hairs ; sides yellowish buff ; ventral 

 surface clear dull white, the plumbeous underfur imparting a 

 grayish cast. About one specimen in ten has the ventral 

 surface faintly washed with buff, strongest posteriorly. 



This series does not differ appreciably in coloration or 

 cranial characters from specimens in the U. S. National 



