_Remarks._--Four specimens from Satus Pass, Klickitat County, are somewhat intermediate between this race and _macrurus_, and indicate that _halli_ crossed the Columbia River when an alpine meadow land extended from the Simcoe Anticline to southeastern Washington. One specimen from Selah, Yakima County, is colored somewhat like _halli_, and is smaller than _macrurus_. Possibly the _halli_ type of meadow mouse spread northward to the Yakima Valley. This specimen was taken in the Upper Sonoran Life-zone. A specimen from the Arid Transition Zone at Naches, Yakima County (taken in almost Canadian Life-zone habitat), is like _macrurus-halli_ intergrades from the higher Cascade Mountains. =Microtus longicaudus macrurus= Merriam _Microtus macrurus_ Merriam, Proc. Acad. Nat. Sci. Philadelphia, p. 353, October 4, 1898. _Microtus mordax macrurus_ Dice, Murrelet, 13:49, May, 1932. _Microtus longicaudus macrurus_ Goldman, Jour. Mamm., 19:491, November 14, 1938. _Type._--Obtained at Lake Cushman, Mason County, Washington, by C. P. Streator on June 26, 1894; type in United States National Museum. _Racial characters._--Size large; tail relatively long, almost as long as head and body; color of upper parts dull brown; dorsal stripe obscure; underparts gray. _Measurements._--Two males and 4 females from the Olympic Mountains and the coast of Washington, average, respectively: total length 212.5, 220.5; length of tail 82.5, 86.8; hind foot 25.5, 24.7; ear 15.0, 13.7. _Distribution._--The Olympic Mountains, the coast region of western Washington, and the Cascade Mountains, save in the southeastern part. Marginal occurrences are: Sauk (Taylor and Shaw, 1929: 24), Tye (W.W.D.), Naches River (W.W.D.), and Wind River (W.W.D.). _Remarks._--Specimens from the Cascade Mountains are referred to _macrurus_ but are intermediate between that race and _halli_. =Microtus richardsoni= (De Kay) Water rat _Description._--This is the largest meadow mouse found in Washington. It is too large to be called a mouse and the term water rat, applied to it by Merriam, suits it well. It is the only Washington microtine measuring more than 8 inches in total length. The upper parts are dark, reddish brown in color; the underparts are grayish brown. The tail comprises about one-third of the total length.