OCT., 1900.] MAMMALS OF THE YUKON REGION. . 29 



Skull. — Similar to that of ]^. h<rre<(lis, ])ut Avith a slightly fuller brain- 

 case -and larger audital l)ulltB. 



MeanuremenU. — Typ^^ (f rom dry skin): Total length i!23; tail verte- 

 brae 103; hind foot 32. 



Hemarks. — The typc^ of E. harealis from Fort Liard, British Colum- 

 bia, is missing, but specimens from Fort Simpson, which is not far 

 from Fort Liard, and other points east of the Rock}^ Mountains, are 

 available for comparison. These are all much suffused with fulvous, 

 and are very easily distinguished from those of the Upper Yukon. 

 E. canicejjs is characterized not only ])y gray head and cheeks, but by 

 gray feet, gray edging to tail, and pure white imdcrparts. 



This species is found from the headwaters of the Yukon about Lake 

 Lindeman to the vicinity of Fort Selkirk, where it was last seen by 

 our party. I found it most common in the dry and open rocky 

 country about Lake Bennett and Lake Leljargc, and a few were taken 

 in the thickets of Lepanjyriea about Lake Marsh and Fifty-Mile River. 

 It is not abundant anywhere in the region, but is remarkably tame 

 and unsuspicious. I seldom saw more than two or three in a half 

 daj'^s tramp, l>ut these would often frisk about within a few feet of 

 me as if entirely oblivious of ni}^ presence. 



Spermophilus empetra plesius subsp. nov. Bennett Ground Squirrel. 



Type from Bennett City, head of Lake Bennett, British Cohimbia. No. 98931, U. S. 

 Nat. Mus., Biological Survey Collection, 9 ad. Collected June 19, 1899, by 

 W. H. Osgood. Original No., 465. 



Characters. — Similar to S. emjpetra and S. kadlacenHia., but smaller; 

 general color less fulvous; under side of tail always clear bright cinna- 

 mon rufous; molar teeth relatively much larger than in kadtacensis,' 

 skull small and light and otherwise slightly peculiar. 



Color. — Postbreeding j)elage: Above, mottled as in S. emjpetra^ but 

 general colorless fulvous; upperparts, mixed black, white and yellow- 

 ish gray extending forward to top of head, becoming narrower and 

 slightly grayer between shoulders; top of head chestnut mixed with 

 black; nose and forehead clear hazel; under side of bod}' cinnamon 

 rufous paling to nearly white around chin and extending to sides of 

 body, neck and cheeks, and botR sides of legs; under side of tail some- 

 what deeper cinnamon rufous margined by yellowish white; subterminal 

 black in tail less extensive than in empet7'a and kadlacensis; median 

 part of upper side of tail grizzled black and yellowish, narrow sub- 

 margin and subterminal zone black, the whole edged and overlaid with 

 yellowish white. The hairs of the back in ,6'. j^^&si-us are of two kinds, 

 some being of several colors arranged in zones and some pure black 

 for their entire length. The former, which are most abundant, are 

 dark sooty plumbeous at the base followed by a zone of light gray, 



1 See Allen, Bull. Am. Mus. Nat. Hist., N. Y., Ill, 109, 1890. 



