Vol. 32, pp. 169-172 September 30, 1919 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



A NEW POCKET GOPHER FROM WESTERN 

 WASHINGTON. 



BY WALTER P. TAYLOR. 



Specimens of pocket gophers collected for the Biological Sur- 

 ve 3 r by George G. Cantwell during the winter of 1918, six miles 

 south of Tacoma, Pierce County, Washington, prove to repre- 

 sent a new subspecies of the douglasii group. 



Thomomys douglasii tacomensis, new subspecies. 



TACOMA POCKET GOPHER. 



Type. — From six miles south of Tacoma, Pierce County, Washington; 

 No. 231,096, U. S. National Museum (Biological Survey collection); 9 

 young adult; collected by George G. Cantwell, December 24, 1918; original 

 no. 857. 



General characters. — Darker than any others of the pocket gophers occu- 

 pying the lowlands of western Washington. Similar to Thomomys douglasii 

 yelmensis, to which it appears to be most closely related, but upperparts 

 and face darker; postauricular black area more extensive; nasals narrower 

 anteriorly. Similar to T. d. melanops, but with interparietal larger. 



Geographic distribution. — The typical form occurs on a prairie six miles 

 south of Tacoma, Pierce County, Washington. Specimens from Olympia, 

 Thurston County, and Steilacoom, Pierce County, are tentatively referred 

 to this subspecies. 



Color. — Upperparts (winter pelage) in general, cinnamon-buff or clay 

 color, grizzled with blackish; face blackish; black postauricular area one 

 centimeter square nearly continuous with blackish of sides of face; nose 

 usually with white spots; whiskers, white or gray; underparts rather pale, 

 ochraceous-buff or light buff, a trifle darker in some examples, lacking the 

 irregular white areas observable in certain specimens of yelmensis. 



Skull. — As in Thomomys douglasii yelmensis, but nasals averaging nar- 

 rower anteriorly; anterior nasal openings apparently smaller; rostrum ap- 

 parently more slender; cranium a little more rounded; interparietal averag- 

 ing shorter and narrower. 



34— Proc. Biol. Soc. Wash., Vol. 32, 1919. (169) 



