76 Merriam — Kew Mammals from the United States, 



Cranial measurements of Island Foxes. 



Putorius streatoi 5 leptus snbsp. nov. 



Type from Silverton, Colorado. No. 56,800 $ yg. ad., U. S. National 

 Museum, Biological Survey Collection. October 20, 1893. J. Alden 

 Loring. Original No. 1185. 



Characters. — Similar to strfatori but smaller; Mac k tip of tail very much 

 shorter (projecting only 15 mm. beyond white hairs): Teeth about same 

 size as in streatori, but skull disproportionally smaller; frontals and 

 rostrum more depressed; bulke smaller and narrower. 



Winter pelage. — White all over except short black tip of tail. White 

 without yellowish tinge. (Two males from Colorado — the type from 

 Silverton, and another from Crested Butte collected February 17, 1902 

 by E. R. Warren). 



Summer pelage. — Upperparts uniform drab brown (or between drab 

 brown and hazel, but lacking the reddish of hazel); end of tail black; 

 underparts white throughout with straight line of demarcation along 

 sides, the white reaching down on underside of legs to Wrists and ankles; 

 rest of legs and feet brown like back; toes of forefeet white on upper 

 side; toes of hind feet mixed brown and white. (Young female from 

 Rocky Mountains of Alberta, Canada, near Henry House, July 21, 1896, 

 J. Alden Loring). 



Remarks. — The animal is nearly as small as rixosus, from which it is 

 easily distinguished by the longer tail and black tip, and slightly larger 

 skull and teeth. 



