232 NORTH AMERICAN FAUNA. [no. 27. 



of entering storehouses, especially in winter, is common throughout 

 the north and is referred to by Richardson." When they take up 

 their abode in such situations the animals are ruthlessly destroyed by 

 the inhabitants, unmindful of the fact that they prey on mice, which 

 form such a pest in the trading stores and which are doubtless the 

 chief attraction of the weasels, though of course they help themselves 

 to meat and fish. In winter they feed also on the bodies of rabbits 

 which they find in the snares. 



The winter pelage, with the exception of the black terminal portion 

 of the tail, is white, usually tinged with sulphur yellow posteriorly. 

 In perfect specimens the black occupies about two-fifths of the entire 

 length of the tail. A winter skin from Fort Rae is strongly suffused 

 with orange-yellow throughout, except on the head and nape. This 

 color is deepest on the flanks, and is palest, nearly sulphur yellow, on 

 the sides of the neck. 



Mustela riehardsoni b was based on Richardson's Fort Franklin 

 specimen of Mustela ermineaf of which he gives measurements, and 

 on the assumption that the species about Fort Franklin would prove 

 to be identical with that inhabiting the Mackenzie, the name riehard- 

 soni has been generally used for this animal. Fortunately this as- 

 sumption proves to have been well founded, the Mackenzie specimens 

 differing from topotypes from Fort Franklin only in slightly smaller 

 size. The measurements of various adult specimens follow : Two 

 males from Fort Franklin measure, respectively: Total length 340, 

 tail vertebras 111, hind foot 48; and 340, 102, 48; a male from Fort 

 Simpson measures 325, 91, 43; a male from Fort Smith, 320, 9G, 45; 

 a male from Fort Chipewyan, 340, 110, 47; a male from near Crooked 

 Rapid, Athabaska River. 350, 107, 43. Females are considerably 

 smaller. One from Fort Resolution measured 282, 85, 34. Putorius 

 arcticus imperii? recently described by Barrett-Hamilton from a 

 specimen received from B. R. Ross, and said to have been collected at 

 Fort Simpson, ' British Columbia ', undoubtedly came from Fort 

 Simpson on the Mackenzie, where Ross collected extensively, and the 

 name is consequently a synonym of P. riehardsoni. 



Putorius arcticus Merriam. Tundra Weasel. 



. This large weasel occupies portions of the upper part of the Hud- 

 sonian zone and the Barren Grounds. It differs from P. riehardsoni 

 in having darker colored under parts; the white of the toes extends 

 much farther up on the feet, and there are other minor differences of 

 coloration ; it has a much broader skull. I met with this weasel only 



a Fauna Boreali-Ainericana, I, p. 46, 1829. 



P Bonaparte, Cliarlesworth's Mag. Nat. Hist.. II (new ser.), i>. 38, 1S38. 



c Fauna Boreali-Americana. I, p. 47, 1829. 



(J Aun. and Mag. Nat. Hist., ser. 7, XIII, p. 392, 1904. 



