1 32 Bulletin American Museum of Natural History. [Vol. XIX, 



American forms, although these are, of course, its nearest 

 affines. 



"Russian name, Dee-ke Bar-an, meaning wild sheep. 

 Mountain Sheep probably occur all over Northeastern Siberia 

 wherever the mountains are rugged enough to attract them, 

 although I have only a few reliable records of their presence 

 at widely separated places in that vast territory. They are 

 found in the Stanovoi Mountains, at Ayan, Okhotsk, Ola, 

 Yamsk, Mickina or Niakinsk, and on as far north at least as 

 the Arctic Circle, and perhaps further, although the range 

 becomes much less rugged towards the north. They are also 

 found along the Kolyma River to the westward of that range. 

 A few are taken in the mountains in the Anadyr Territory 

 about Marcova. They are common on the Taiganose Penin- 

 sula, and are said to be abundant all over Kamchatka from 

 Petropavlovsk northward. Kamchatka, from the nature of 

 its mountains and vegetation, offers the most suitable place 

 for them. The wandering reindeer Koryaks inhabiting the 

 Taiganose Peninsula kill a few every winter. Three of those 

 in the collection are from that locality, while the fourth is 

 from Baronesskorf Gulf." N. G. B. 



6. Sciuropterus russicus (Tiedemann). 

 SIBERIAN FLYING SQUIRREL. 



Mus volans LINNAEUS, Syst. Nat. ed. 10, I, 1758, 64 (in part; based 

 primarily on Sciurus volans Seba, exclusively American) . 



Sciurus volans LINNAEUS, Syst. Nat. ed. 12, I, 1766, 88 (in part). 



"Pteromys russicus TIEDEMANN, Zool. I, 1808, 451." 



Pteromys sibiricus DESMAREST, Mamm. II, 1822, 342 (= Sciurus 

 volans Pallas, non Linnaeus). 



This species is represented by four hunters' skins, without 

 skulls or feet, obtained by Mr. Buxton at Marcova, obviously 

 winter skins. Three of them have the upper parts nearly 

 uniform pale whitish gray, while the fourth has a barely per- 

 ceptible tinge of pale buff; the lower parts are white with a 

 very faint buffy tinge, and a slight mixture of black-tipped 

 hairs overtopping the general pelage. The tail is grayish 



