66 BIRDS AND MAMMALS OF EAST SIBERIA [^VoLV^ 



(skull length 50, instead of 57, but upper cheek teeth 9.6 in both). 

 The tail, ears and feet are black, the rest of the body, a beautiful 

 dark blue-gray, except the throat, chest, inner side of the upper 

 arms and a narrowing mid-ventral area, which are pure white. 

 The collector's measurements are: total length, 401 mm.; tail, 

 151. Mr. Koren tells me that these squirrels occur in the growth 

 of larches back from the coast along the sheltered stream beds. 

 They are much hunted for their fur. 



Ochotona kolymensis Allen. Kolyma Mouse Hare. 

 Ochotona kolymensis Allen, Bull. Amer. Mus. Nat. Hist., 1903, vol. 19, p. 154. 



The collection contains six specimens of this very northerly 

 species. It belongs to the ladacensis group, in which the incisive 

 and palatal foramina, though separated, are conjoined by a narrow 

 isthmus. It seems to be very different in color from the other 

 members of the group hitherto discovered. According to Mr. 

 Koren it is found in rocky places. 



Lepus tschuktschorum Nordquist. Tchuktchi Hare. 



Lepus timidus tschuktschorum Nordquist, Vega Exped., 1883, vol. 2, p. 84. 



Two polar hares, one in winter and one in summer pelage, appear 

 to be this species. The external measurements, as indicated by 

 the collector, are: total length, 680, 585 mm.; tail, 67, 51; hind 

 foot, 171, 158. The ear in the dried skins measures 102, 92. The 

 larger specimen, collected July 15 at Cape Bolshaja Baranov, has 

 a few long white hairs of the winter pelage along the sides and in 

 the forehead. 



