In observing the activities and habits of mammals in their natural habitat, I have often relied on tracking in fresh snow. Strangely enough, tracks of ermines were seldom found, and the few that were seen came from beneath a log, bush or wind-fall and disappeared beneath similar cover, rarely extending 20 feet on the surface of the snow. The larger, long-tailed weasels often traveled for miles on the surface of the snow. Possibly the ermines were following the burrows of mice through the snow, or perhaps they kept beneath the surface from fear of owls. This suggests a reason why ermines are so seldom seen abroad. They may be following burrows and runways of mice and seldom come to the surface of the ground. On November 18, 1936, we saw three ermines and two long-tailed weasels taken by a trapper on Deception Creek near Stevens Pass, King County. All were in the white winter coat. In December, 1938, we obtained two ermines at Skykomish, King County, 18 miles west of Stevens Pass. These were in the brown winter coat. In that area the break between the brown and white winter coat seems to come just west of the main Cascade Summit, or at the same point that the break occurs between the brown and white winter coats of the long-tailed weasel. Ermine skins have little value and usually bring from 10 to 35 cents. They are saved incidentally by trappers, for it takes but a few moments to skin and prepare them. They possess the strong, musk odor so typical of the long-tailed weasel. =Mustela erminea invicta= Hall _Mustela erminea invicta_ Hall, Jour. Mamm., 26:75, February 27, 1945. _Type._--Obtained at Benewah, Benewah County, Idaho, by W. T. Shaw on October 24, 1926; type in Museum of Vertebrate Zoölogy. _Racial characters._--Largest of the Washington ermines; winter coat entirely white; upper lips white; black of tail more than half length of tail vertebrae. _Measurements._--Ten males and 5 females from central Idaho average, respectively (Hall, 1945): total length 291, 255; length of tail 86, 71; hind foot 40, 32. 3. _Distribution._--Northeastern Washington and the northeastern Cascades, west to Chilliwack River and Hannegan Pass (Hall, 1945: 78). =Mustela erminea fallenda= Hall _Mustela erminea fallenda_ Hall, Jour. Mamm., 26:79, February 27, 1945. _Type._--Obtained at Huntingdon, British Columbia, by C. H. Young on May 21, 1927; type in National Museum of Canada. _Racial characters._-Size large; winter coat usually brown; pale color of underparts much restricted; color of upper parts dark; color of lips variable; tail with more than distal half black. _Measurements._--Seven males and 2 females average, respectively (Hall, 1945: 79): total length 278, 232; length of tail 77, 60; hind foot 36.5, 27.