The American Voles of the Genus Evotomys. 127 



Geographic distribution. Boreal zone of mountains of Colorado and 

 northward along eastern ranges of Rocky Mountains to northern Mon 

 tana. 



General characters. Similar to E. gapperi, with slightly longer tail and 

 lighter coloration, skull developing prominent superciliary ridges with 

 age. 



Color. Winter pelage : dorsal stripe sharply defined, reddish chestnut, 

 with a few black hairs ; sides and face buffy gray ; belly and feet whitish 

 or yellowish gray ; tail bicolor, whitish below, blackish or buffy gray 

 above, except the black upper part of pencil ; ears faintly tinged with 

 color of back. In spring and early summer pelage the dorsal stripe 

 darkens to warm hazel and the sides to rich buffy gray. Full summer 

 pelage: dorsal stripe chestnut, slightly darkened with black hairs; sides 

 and face clearer gray than in winter; feet gray. Young, in August: 

 darker than the adults, with ears strongly tipped with chestnut ; feet 

 dusky and tail not sharply bicolor ; spots covering side glands in old 

 males whitish or gray. 



Cranial characters. Skull of adult narrower than that of gapperi, sharply 

 concave interorbitally, with prominent superciliary ridges ; zygomatic 

 arches not abruptly spreading ; audital bullse small and globose ; palate 

 straight-edged or rarely with a slight central projection. 



Measurements. Average of 6 adults from Longs Peak, measured in the 

 flesh by Edward A. Preble : total length, 145; tail vertebrae, 43.6; hind 

 foot, 18.2; tail, 30 per cent, of total length. One adult tf topotype, No. 

 74076: 146; 40; 18. Skutt of adult topotype, No. 74076: basal length, 

 22.2; nasals, 6.5; zygomatic breadth, 13; mastoid breadth, 11; alveolar 

 length of upper molar series, 5. 



General remarks. Apparently galei branches off from gapperi along the 

 east base of the Canadian Rockies and extends southward in a frequently 

 interrupted line, following the eastern ranges of the Rocky Mountains to 

 Colorado. Specimens from St. Marys Lake, Summit, and Java, in north 

 western Montana, except for slightly smaller size, are identical with galei. 

 Specimens from Silverton and Crystal Lake, Colorado, are not typical, 

 but the difference is not uniform and may be in part due to age and sea 

 son. A badly mutilated skin in the National Museum from the Uinta 

 Mountains, Wyoming, ought on geographic grounds to belong to this 

 species. Four not fully adult specimens from the Bighorn Mountains, 

 Wyoming, agree better with galei than with any other species. A good 

 series from the Big Snowy Mountains, Montana, does not agree with 

 gapperi, galei, or saturatus, but, as the degree of difference is too slight to 

 warrant a new name, they are referred to galei. 



Specimens examined. Total number, 81, from 12 localities: 



Colorado: Ward, 8; Gold Hill, 2; Longs Peak, 6; Silverton, 8; Crys 

 tal Lake, 1. 



Wyoming: Bighorn Mountains, 4. 



Montana : St. Marys Lake, 15 ; Java, 2 ; Summit, 4 ; Big Snowy Moun 

 tains, 25 ; Red Lodge, 2 ; Beartooth Mountains, 4. 



