_Type._--Obtained in the Pahsimeroi Mountains, 9,300 ft., Custer County, Idaho, by C. H. Merriam and V. Bailey on September 16, 1890; type in United States National Museum. _Racial characters._--Size medium; color of upper parts brownish gray; sides paler; underparts grayish white. _Measurements._--A large male from Prescott, Walla Walla County, measures: total length 168; length of tail 48; hind foot 20. A female from Prescott, Walla Walla County, and a female from Pullman, Whitman County, average: 133; 31; 18.5. _Distribution._--Southeastern Washington, westward as far as 5 miles east of Wallula (M.V.Z.). =Microtus montanus canescens= Bailey _Microtus nanus canescens_ Bailey, Proc. Biol. Soc. Washington, 12:87, April 30, 1898. _Microtus montanus canescens_ Hall, Proc. Biol. Soc. Washington, 51:133, August 23, 1938. _Type._--Obtained at Conconully, Okanogan County, Washington, by J. A. Loring, on September 12, 1897; type in United States National Museum. _Racial characters._--Size small; color of upper parts pale brownish gray; sides yellowish gray. This race differs from _Microtus m. nanus_ in generally paler, less brownish coloration. It does not differ from _nanus_ in any distinctive cranial features. _Measurements._--Two male and 2 female topotypes average, respectively: total length 151, 143; length of tail 35, 33.5; hind foot, 19.5, 19.5. A series of 8 males and 6 females from Selah, Yakima County, average, respectively: total length 151.7, 150.5; length of tail 41.5, 40.1; hind foot 19.7, 18.8; ear 12.8, 13.0; weight 47.2, 36.8 grams. _Distribution._--The eastern foothills of the Cascade Mountains from the British Columbian boundary south, probably to the Columbia River. Recorded east to Benton City (Taylor and Shaw, 1929: 24). _Remarks._--A large series from Selah, Yakima County, is somewhat intermediate between _nanus_ and _canescens_. These specimens from south of the Wenatchee Mountains are, however, more like _canescens_ in color than they are like _nanus_. Bailey (1900: 32) records a specimen of this race from North Yakima as _Microtus canicaudus_. =Microtus townsendii= (Bachman) Townsend meadow mouse _Description._--The Townsend meadow mouse is a large-bodied, long-furred mouse with a tail of moderate length. Head and body measure about 8 inches, the tail about 2-1/2 inches. The legs are short and the ears scarcely project through the fur on the head. In summer the color is dark reddish-brown. The winter color is dark brownish-black. Underparts are paler, more grayish brown, than are the upper parts. The tail is sparsely haired.