''\^'l4^] ALLEN — MAMMALS 63 



quatus of Pallas, described in 1778 from a specimen from the Obi 

 River, western Siberia. Von Baer's Lemmus ungulatus from Nova 

 Zembia is currently referred to the same species. The total length 

 of an adult iorquatus from Nova Zembia is given by Coues and 

 Allen (Monogr. of the Rodentia, 1877) as 5.75 inches and this ac- 

 cords well with the dimensions from the figures, natural size, given 

 by Middendorff (Reise in den aussersten Norden u. Osten Sibe- 

 riens, 1853) of specimens from the Taim\T River, western Siberia. 

 Pallas's original measurements are evidently from a young animal, 

 unless the head and body length of three inches and one line be a 

 misprint for five inches and one line, as given in Schinz's Synopsis. 

 Middendorff's figures, however, leave no room for doubt that the 

 adult iorquatus is much the same size as the Alaskan species, beside 

 which the Kolyma specimen seems a pygmy indeed, fully adult 

 though it is. I have therefore felt no hesitation in recognizing the 

 latter as distinct. 



Apparently this lemming is uncommon in the region visited by 

 Mr. Koren, or it may be that it is difficult to obtain without special 

 effort. The single specimen was kept a month or more frozen 

 solid, by a friend of Mr. Koren, who chanced to obtain it during 

 his temporary absence. 



Evotomys jochelsoni Allen. Kolyma Red-backed Mouse. 



Evotomys jochelsoni Allen, Bull. Amer. Mus. Nat. Hist., 1903, vol. 19, p. 

 148. 



This species was abundant at Nijni Kolymsk, where INIr. 

 Koren obtained a large series. The type specimens came from 

 higher up the stream at Verklme Kolymsk. The present series 

 in winter pelage is remarkable for the pale coloration, since the red 

 area is greatly diluted with ochraceous. There is much variation 

 in the amount of buffy on the under surface, for while some show a 

 considerable wash of this tint, others lack it altogether. A few 

 specimens taken in October seem still to be in the summer coat, 

 in which the red dorsal area is much more strongly colored and 



