_Type._--Obtained at Happy Lake, Clallam County, Washington, by D. G. Elliot on August 18, 1898; type in Field Museum of Natural History. _Racial characters._--Tail long, color dark. _Measurements._--Twelve males and 17 females from southwestern Washington average, respectively: total length 118, 119; length of tail 53, 53; hind foot 13.8, 13.7; weight 6.6, 5.2 grams. _Distribution._--Western Washington, east through the Cascades to Barron (Jackson, 1928: 137), Cascade River (Jackson 1928: 137) and Satus Pass (W. W. D.). =Sorex palustris navigator= (Baird) Mountain water shrew [Illustration: FIG. 31. Distribution of the mountain water shrew. _Sorex palustris navigator_, in Washington.] _Neosorex navigator_ Baird, Rept. Pacific R. R. Survey, 8 (pt. I): 11, 1857. _Sorex (Neosorex) palustris navigator_ Merriam, N. Amer. Fauna, 10:92, December 31, 1895. _Sorex palustris navigator_ Stephens, California Mammals, p. 254, June, 1906. _Type._--Obtained at head of Yakima River, Kittitas County, Washington, by J. G. Cooper on August 31, 1853; type in United States National Museum. _Measurements._--Two males and 4 females from Washington average, respectively: total length 150, 150; length of tail 70, 74; hind foot 18.5, 20; weight?, 11.0 grams. _Distribution._--Mountainous areas of entire state, including the Olympic Mountains, from Elwah (Jackson, 1928: 188) south to Quinault River (Jackson, 1928: 189); the Cascades from Tomyhoi Lake (W. W. D.) south to 15 mi. N. Carson (Jackson, 1928: 189); northeastern Washington from Shovel Creek (W. W. D.) south to Gifford (Jackson, 1928: 189); the Blue Mountains at Godman Springs (M. V. Z.) and Hompeg Falls (M. V. Z.). _Description._--In general form of body the mountain water shrew resembles the cinereous shrew but is perhaps more stocky. It is a large shrew, nearly as large as a house mouse. The head and body measure about 3 inches; the tail also is about 3 inches long. The fur is exceedingly soft. The upper parts are blackish in color, lightly frosted with paler hairs. The underparts, from throat to vent, are whitish tinged with gray or brown. The stiff, curved fringe of bristles on the outer part of the hind foot serves as an aid in swimming. Mountain water shrews range over much of Canada and in mountainous areas of the western United States extend south to Arizona. The subspecies found in Washington ranges over all of the western United States. The mountain water shrew is primarily a mammal of the Hudsonian and Canadian life-zones. It sometimes descends to the Transition Life-zone along clear, cold streams where conditions are similar to those in the Canadian Life-zone.