Type.—Obtained at Osoyoose Lake, British Columbia, on British Columbia-Washington boundary at head of Okanogan River, by J. K. Lord, in 1861 or 1862.
Racial characters.—Color of the upper parts rich, dark brown.
Measurements.—Two males and a female from Seattle, King County, average and measure respectively: total length 565, 555; length of tail 262, 257; hind foot 80.5, 79; weight 2 pounds 13 ounces and 2 pounds 3 ounces.
Distribution.—Eastern Washington generally and all but the southern part of western Washington. Specimens from as far southwest as Tenino (W.W.D.) are typical of osoyoosensis.
Ondatra zibethicus occipitalis ([Elliot])
Fiber occipitalis [Elliot], Field Columb. Mus. Publ. 74, zoöl. ser., 3:162, April, 1903.
Ondatra zibethica occipitalis [Miller], U. S. Nat. Mus. Bull., 79:231, December 31, 1912.
Type.—Obtained at Florence, Lane County, Oregon, by E. Heller, in 1901; type in Chicago Natural History Museum.
Racial characters.—Similar to osoyoosensis but redder; fur shorter and interpterygoid spaces of skull narrower.
Measurements.—A male from Chinook, Pacific County, measures: total length 580; length of tail 248; hind foot 78; ear 21; weight 863 grams.