_Distribution._--Known only from Grand Mound Prairie (type locality), Vail Prairie, near Vail, and Rochester Prairie, near Rochester, all in Thurston County. =Thomomys talpoides couchi= Goldman _Thomomys talpoides couchi_ Goldman, Jour. Mamm., 20:243, May 15, 1939. _Type._--Obtained on Scotts Prairie, 4 miles north of Shelton, Mason County, Washington, by L. K. Couch, on June 27, 1922; type in United States National Museum. _Racial characters._--A small race; rich hazel in color. _Measurements._--Thirteen male and 9 female topotypes average, respectively: total length 196, 191; length of tail 55, 53; hind foot 27, 27; and weight 87, 79 grams. _Distribution._--Known only from the type locality and from Lost Lake Prairie, near Satsop, Mason County. =Thomomys talpoides melanops= Merriam _Thomomys melanops_ Merriam, Proc. Biol. Soc. Washington, 13:21, January 31, 1899. _Thomomys douglasi melanops_ Bailey, N. Amer. Fauna, 39:119, November 15, 1915. _Thomomys talpoides melanops_ Goldman, Jour. Mamm., 20:235, May 15, 1939. _Type._--Obtained at head of Sol Duc River, Clallam County, Washington, by V. Bailey on August 28, 1897; type in United States National Museum. _Racial characters._--Most like _shawi_ but smaller, with larger postauricular patches and dusky areas on side of head. _Measurements._--A male topotype measures: total length 211; length of tail 67; hind foot 28. _Distribution._--Higher Olympic Mountains. =Castor canadensis= Kuhl Beaver _Description._--The beaver is the largest rodent occurring in Washington. Large individuals weight approximately 50 pounds. They are heavily-built, robust animals with large heads and short necks. The large, flat, naked tail immediately separates them from all other mammals occurring in the state. The forelegs are short and the forefeet handlike. The hind legs are long, thick and powerful. The hind feet are large and webbed for swimming. The ears are small and the eyes, although of moderate size, are not prominent. The incisors are large and prominent with a distinct yellow or orange color. The close, dense underfur is overlaid with long, lax, rather stiff overfur or guardhairs. [Illustration: FIG. 99. Beaver (_Castor canadensis_). Silvana, Washington, August 15, 1921. (Fish and Wildlife Service by Leo K. Couch, No. B-21912.)] Beavers are found in Europe, Asia and North America. In America they range from Alaska to Mexico and from the Atlantic to the Pacific. Many American subspecies have been described, all thought to belong to a single species.