_Measurements._--Eight males and 7 females, from the area about Puget Sound, average, respectively: total length 343, 338; length of tail 37.5, 33.5; hind foot 57.8, 56; ear 25, 24.5; weight 1342, 1300 grams. _Distribution._--Western Washington, between Puget Sound and the Cascade Mountains and southward. Marginal localities are: Bellingham (U.S.N.M.), Sauk (U.S.N.M.), Forks of Skykomish River (W.W.D.), North Bend (U.S.N.M.), and mouth of Klama River (M.V.Z.). _Remarks._--Individual variation in mountain beavers is considerable. Two weakly defined races are recognized in Washington. =Aplodontia rufa rainieri= Merriam _Aplodontia major rainieri_ Merriam, Proc. Biol. Soc. Washington, 13:21, January 31, 1899. _[Haplodontia rufa] raineri_ Elliot, Field Columb. Mus. Publ. 45, zoöl. ser., 2:112, 1901. _[Aplodontia rufa] raineri_ Trouessart, Catal. Mamm., viv. foss., suppl. p. 348, 1904. _Aplodontia rufa columbiana_ Taylor, Univ. California Publ. Zoöl., 12:499, 1916 (type from Hope, British Columbia). _Type._--Obtained at Paradise Creek, 5, 200 ft., Mount Rainier, Pierce County, Washington, by V. Bailey on August 6, 1897; type in United States National Museum. _Racial characters._--Similar to _rufa_ but larger with larger skull. _Measurements._--Three males and a female from Tye, King County, average and measure respectively: total length 352, 340; length of tail 35, 40; hind foot 60, 59; ear 24, 19. _Distribution._--The higher Cascade Mountains from the Columbia River northward to the Canadian boundary. Marginal localities are: Canyon Creek (U.S.N.M.), Cascade Pass (U.S.N.M.), Tye (W.W.D.), Mt. Rainier (U.S.N.M.), Mt. St. Helens (U.S.N.M.), and Yacolt (M.V.Z.). _Remarks._--Intergradation between _rufa_ and _raineri_ is seen in specimens from the area between Stevens Pass and Skykomish, King County. =Zapus princeps= Allen Big jumping mouse [Illustration: FIG. 123. Big jumping mouse (_Zapus princeps trinotatus_) in hibernation. Puyallup, Washington, January 30, 1939. (Fish and Wildlife Service photo by Victor B. Scheffer, No. 576.)] _Description._--The big jumping mouse is a medium-sized mouse, slightly larger than the house mouse, with an exceptionally long, tapering tail. Head and body measure about 4 inches and the tail about 5 inches. The body is slender with a small head, small eyes and small, naked ears. The forefeet are small and handlike but the hind feet are large with long, powerful legs. The long, naked tail is smoothly tapering to a narrow point. The fur is short, posteriorly directed, stiff and bristlelike. The dorsal area is dusky, the sides are orange or yellow, and the underparts are creamy white. Each upper incisor tooth has a groove on its anterior face.