_Distribution._--The Olympic Peninsula of Washington. Marginal localities on the south are: Potlatch (M.V.Z.) and Lake Quinault (Jackson, 1928: 199). =Microsorex hoyi washingtoni= Jackson Pigmy shrew _Microsorex hoyi washingtoni_ Jackson, Proc. Biol. Soc. Washington, 38:125, November 13, 1925. _Type._--Obtained at Loon Lake, Stevens County, Washington, by V. Bailey on September 26, 1897; type in United States National Museum. _Measurements._--Of type: total length 89; length of tail 27; hind foot 9. _Distribution._--In Washington, known only from the type specimen which was "found dead in a trail in dry pine woods" (Jackson, 1928: 4). _Description._--The pigmy shrew is similar in form of body to the cinereous shrew but smaller. The head and body are about 1-3/4 inches in length; the tail is about 1 inch long. The upper parts are reddish brown and the underparts are gray. These tiny mammals range widely across central Canada and northern United States from the Atlantic nearly to the Pacific, and north to central Alaska. A single species is known, one race of which occurs in Washington. The subspecies is known from but two specimens: the type and an individual from Montana (Koford, 1938: 372.) Genus =Myotis= Kaup Mouse-eared bats _Description._--The genus _Myotis_ may be separated from all other bats that occur in Washington by the presence of 38 teeth (dental formula i. 2-2/3-3, c. 1-1/1-1, p. 3-3/3-3, m. 3-3/3-3 = 38). Their small size separates them from all other genera save _Pipistrellus_, from which _Myotis_ may be distinguished by the straight, rather than hooked, anterior border of the tragus. Species of _Myotis_ found in Washington vary considerably in size, but all are less than 100 mm. in total length. The upper parts are various shades of brown in color. The ears, when laid forward, always extend to the nostrils or beyond. This genus is one of the most widely ranging groups of Recent mammals. It occurs on all continents, including Australia and many of the larger islands. Of the 19 American species recognized by Miller and Allen (1928), eight occur in the state of Washington. They are low-flying forms and as a rule appear relatively late in the evening. Their flight is rapid and erratic. They often hunt over the surfaces of streams, pools, and lakes. Some kinds hunt in the shade of forest trees and these are especially difficult to collect. Others hunt the brushy canyons and coulees of the desert areas of eastern Washington.