193'] Allen, Mammals from Northeast Siberia. 149 



15. Microtus kamtschaticus (Polyakofj). 1 

 KAMCHATKA VOLE. 



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

 P6tersb. XXXIX., No. 2, 1881, 43,%. 4, dentition. Kamchatka. 



Microtus kamtschaticus MILLER, Proc. Biol. Soc. Wash. XIII., 1899, 

 1 1 (in text) . 



Represented by 33 specimens, of which 12 were collected at 

 Marcova, March 7-20, and 21 at Gichiga, the latter as follows: 

 Jan. 12, i; July 28, i; Aug. 1-3 and 29-31, 5; Sept. i and 24, 

 2; Oct. 1-4, 12. One of the specimens is very old, 9 are fully 

 adult, and 8 are young adults, the rest being immature, of 

 various ages, from nurslings to specimens one half to two 

 thirds grown. The January specimen is only about half 

 grown, the March series contains two less than half grown, 

 some of the July specimens are quite young, and the October 

 series includes nursing young, half grown, and adults; hence, 

 apparently, young are reared at all seasons of the year. 



The March series of adults are in full soft winter pelage, 

 with heavily furred tails, and the dorsal pelage about 20 mm. 

 long. They differ greatly in respect to pelage from the July, 

 September, and October adults, in which the coat is quite 

 short and the tail thinly haired. They are also darker and 

 browner. There is, however, much individual variation in 

 color, and in the length of the tail, in specimens taken prac- 

 tically at the same date, there being a tendency to a yellowish 

 brown phase and to a reddish brown phase, with many inter- 

 mediates. The March adults are strong buffy brown above 

 varied strongly with black-tipped hairs, the general color 

 ranging in tone from yellowish brown to slightly rufescent 

 brown; lower parts clear grayish white, the plumbeous under- 

 fur tinging the otherwise nearly clear white superficial tint. 

 The tail is sharply bicolor, the lower surface being white and 

 the upper surface blackish mixed slightly with gray-tipped 

 hairs; feet dull grayish white. 



In September specimens the dorsal pelage is only about 



1 Poliakoff appears to attribute the name kamtschatica to Pallas, citing a "Mus aco- 

 nomictis, var. kamtschatica Pallas, Novae spec. Quadrp. e Gliri Ord. p. 233." But Pallas 

 did not use the name in a nomenclatorial sense, but in a descriptive or geographical 

 sense. He says: " Varietas Kamtschatica muris ceconomi, cujus exuvias habeo," etc. 

 The name should therefore date from Polyakoff, 1881. 



