82 The Mammals of Colorado 
forms the southern boundary of the dispersion of this species." It 
probably ranges up to about 7,000 feet elevation. 
FIG. 29. FACE OF MOUNTAIN POCKET GOPHER, Thomomys foSSOV 
Showing openings of cheek pouches. E. R. Warren, Photo. 
Habits. — Half-grown young were taken at Craig about the 
thirteenth of June. 
Thomomys fossor (Lsit fossus, pp. of fodere, to dig). 
Mountain Pocket Gopher. 
Thomomys fossor Allen, Bull. Am. Mus. N . H ., v., p. 51 (1893). 
Type locality.— Florida, La Plata County, Colo., 7,200 ft. (C. P. 
Rowley). 
Measurements. — Total length, 8.25 ;tail vert., 2.25 ;hind foot, 1.15. 
Description. — (From a specimen taken near McCoy, Eagle 
