30 



NOETH AMERICAN FAUNA. 



[No. 40. 



Type locality. — Cochetopa Pass, Saguache County, Colorado. 



GefograpJiic distribution. — Rocky Mountain region of central and 

 central-southern Colorado and northern New Mexico. North into 

 South Park, Colorado; east to El Paso, Fremont, and Huerfano 

 Counties, Colorado; south into the Sangre de Cristo and Jemez Moun- 

 tains, New Mexico; west to western Gunnison and Hinsdale Coun- 

 ties, Colorado, and to western Eio Arriba County, New Mexico. 

 Chiefly Transition Zone, but also in Upper Sonoran and lower parts 

 of Canadian Zone. 



Characters. — Slightly smaller than Cynomys gunnisoni zuniensisj 

 with smaller hind foot; coloration more buffy and blackish, less pink- 

 ish cinnamon and ochraceous. General coloration much as in C. 

 leucurusj but averaging darker, and with only tip and border of ter- 

 minal half of tail white. 



Color. — Adult in fresJi summer pelage: General coloration, except 

 for tail, very much as in C leucurus, but darker; averaging more 

 drab, less yellowish, and the cheeks less sharply marked by dark 

 patch. Tail for proximal half above concolor with back; distal half 

 dark gray, bordered and tipped with white, and with subterminal 

 band of blackish; underside of tail pale cinnamon, blending into 

 white at tip, and edged with white. The fresh spring coat, which is 

 glossy and much intermixed with blackish, rapidly turns a dull 

 brown, the jet black hair tips having worn away or faded. Winter 

 pelage J except for the tail, much like that of leucurus. 



Molt. — There is a variation of about six weeks in the time of molt, 

 according to altitude, but the average dates in Colorado are about as 

 follows: Spring specimens are in the left-over winter coat or in various 

 degrees of molt up to June 10 or July 1, when the pelage, with the 

 exception of the tail, is entirely renewed. A f ews pecimens have com- 

 pletely renewed the pelage on the tail as early as July 15, but numer- 

 ous examples collected as late as August 10, still have the tail clothed 

 in the old winter hair. The fresh coat rapidly loses its luster, and 

 during the latter half of August the pelage becomes much worn over 

 the anterior half of the body while the posterior half shows consider- 

 able influx of new hair. The molt is usually complete and the animal 

 in full fresh coat again by September 15. Mid-October skins are . 

 in full long coat, with a dense underfur. 



STcuU. — Averaging smaller and of less robust build than skull of 

 C. g, zuniensis. Readily distinguishable from skulls of C. leucurus 

 by its considerably smaller size (see also specific skiill characters, 

 page 29). 



Measurements. — Averages of 12 adult males from Saguache County 

 and Fort Garland, Colorado: Total length, 340 (309-365) ; tail verte- 

 brse, 53 (39-65); hind foot, 56 (52-59). SlcuTl: Condylobasal length, 



