1908.] MAMMALS. 237 



Simpson, November 15, 1903. In the latter the tinge of the underfill* 

 of the back is a trifle more ochraceous than in the type of M. boria; 

 the hind feet and legs agree precisely ; the fore feet and legs are less 

 black; the general color beneath differs only in being slightly more 

 ochraceous than the type, but agrees exactly with a topotype (No. 

 13-187) . On the head and face the Fort Simpson specimen and the 

 type of M. boria agree precisely; the throat patch is less extensive in 

 the former but agrees in color. A young animal taken near Fort 

 Simpson early in the summer of 1904, and examined late in July, was 

 of a nearly uniform umber brown throughout. It was then about 

 half grown and had become quite tame. It was very playful, but 

 was inclined to use its teeth, which were too sharp for comfort. 



The average measurements of a number of skulls from various 

 localities follow. These were taken from specimens which had 

 attained full size. They were mainly old, were selected on account of 

 their large size, and probably are all males. Five from the Jasper 

 House region average: Basal length (measured from inferior lip of 

 foramen magnum to posterior base of middle incisors) 76; zygomatic 

 breadth 18; breadth across post orbital processes 22.6. Five from the 

 Athabaska below Grand Rapid average : Basal length 79 ; zygomatic 

 breadth 49.6; postorbital breadth 23.8. Five from Slave River aver- 

 age: 78.8, 46.4, 23.2; five from Fort Rae, 77, 48, 23.6; five from Fort 

 BicPherson, 80, 48.2, 23.2; an adult from Fort Simpson measures 79, 

 HO, 23: the skull of the Fort Franklin specimen measures 75, 45, 21; 

 the adult male from near Leith Point, Great Bear Lake, measures 69, 

 1 1. 22 ; the immature male measures (\S, 40, 20. These latter specimens, 

 in conjunction with their small size, have very small teeth and may 

 represent a dwarfed race occupying the extreme edge of the timbered 

 belt. 



The flesh measurements of a number of specimens are as follows: 

 An adult male from Fort Simpson, total length 585, tail vertebra* 188, 

 hind foot 90; the male from Fort Franklin, 615, 180, 100; the adult 

 male from near Leith Point, 570, 160, 90; the immature male from 

 same place, 545, 150, 85. 



A male taken by J. Alden Loring near Henry House, Alberta, Sep- 

 tember 26, 1895, agrees almost precisely in color with the specimen 

 from Fort Franklin, described above, with the exception of the feet 

 and legs, which are a much lighter brown. It measured : Total length 

 589, tail vertebrae 155, hind foot (measured dry) 82. It is referred 

 only provisionally to .1/. a. actuosa. Cranially it agrees essentially 

 with this form and differs widely in characters from the Mustela 

 caurina type, to which the animal occupying the Rocky Mountains 

 to the southward belongs. 



A skin of an almost perfect albino was sent to the National Museum 

 from Fort Chipewyan some years ago by MacFarlane. The head 

 and neck are pure white; general color of rest of fur white, tinged 



