42 



NORTH AMEEICAN FAUNA. 



[NO. 39. 



highly probable that the unusually weak front claws of this gopher 

 result from their disuse in heavier kinds of digging. 



The subgeneric characters ascribed to this species consist of little 

 more than the convex wings of the pterygoids. While this character 

 is unique in the genus it involves only the form of a weak and variable 

 bone and seems too superficial for more than specific value. As there 

 are no other divisions of subgeneric rank in the genus this one seems 

 of doubtful value. 



The largo mounds of these gophers have been observed in Oregon 

 at Albany, Cottage Grove, Harris, Lyons, and almost continuously 

 along the roads from Salem to a little south and 12 miles east of 

 Eugene. 



Specimens examined, — Total number, 62, as follows: 



Oregon: Beaverton, 12; Corvallis, 1; Eugene, 8; Gaston, 2; Grand Ronde, 3; 

 McCoy, 6; Mulino, 6; Portland, 5; Salem, 20; Sheridan, 2. 



Thomomys towns endi Group. 



THOMOMYS TOWNSENDI TOWNSENDI (Bachman). 

 TowNSEND Pocket Gopher. 

 (PI. II, fig. 2; PL III, fig. 2.) 



Geomys townsendii Bachman (from Richardson's MS,.), Jom^n. Acad. Nat. Sci. Phila- 



delpliia, VIII, pt. 1, 105, 1839. 

 Thomomys nevadensis atrogriseus Bailey, Proc. Biol. Soc. Washington, XXVII, 118, 



July 10, 1914. Type locality, Nampa, Idaho. 



Type. — ^Type locality erroneously given as Columbia River," but 

 probably southern Idaho and very probably near Nampa, where 

 Townsend's party camped to trade with Indians, August 22, 1834. 

 Type specimen in Acad. Nat. Sci. Philadelphia. 



Distribution. — Valley of Snake River in southern Idaho, from 

 American Falls to Weiser (fig. 5). 



CJiaracters. — Size very large; ears small but pointed; claws medium; 

 mammae 4 pairs, inguinal, 2-2, pectoral 2-2; color dichromatic, a 

 dark gray phase and a black phase; skull relatively wide and angular. 



Color. — In gray phase: Upperparts dark buffy gray or sooty gray; 

 nose and face blackish; ear patch black; feet and tail soiled gray; 

 underparts washed with rich buff; cheek pouches lined with black 

 and white; chin white. In black phase: DuU, slaty black all over 

 except white patch on chin and toes and usually on lower part of 

 feet. There seems to be little seasonal variation except for a general 

 darkening with wear as the buff tips disappear from the hairs. Two 

 specimens from Caldwell, Idaho, collected May 30 and June 3, are 

 clearer, richer buff than any others and much darker and richer 

 even than any specimens of the subspecies nevadensis. This may be a 

 normal but rare pelage. 



