The winter pelage is brown in all specimens at most localities. The only white pelage seen was in each of three specimens from Glacier, Whatcom County, Washington. A fourth specimen from there is in brown winter pelage. At any one locality there is much variation in the degree to which the dark color of the upper parts encroaches on the area that in most other races is light-colored. An extreme degree of encroachment is shown by a specimen taken on December 1, 1935, by R. A. Cummings, at Vancouver, British Columbia, in which the light color occurs only in three restricted areas, the chin, the throat and the lower breast; otherwise the coat is brown. There are other specimens, for instance from the type locality, which differ mainly in having an additional white spot in the inguinal region. The opposite extreme, in a specimen also from the type locality, is where the least width of the light-colored underparts on the abdominal region is a third of the circumference of the body. The two extremes are connected by a dozen intermediate stages. Of 64 specimens in which the color of the lips was carefully examined, one, from Vancouver, has both the upper and lower-lips brown; 9 have both the upper and lower-lips white; and 54 have the upper lips brown and the lower lips white. _Specimens examined._--Total number, 72, arranged by localities from north to south. Unless otherwise indicated, specimens are in the National Museum of Canada. =British Columbia.= Horseshoe Lake, Stillwater, 2; Vancouver, 1[74]; Point Grey, 1[31]; Port Moody, 5[91]; Chilliwack, 8 (2[75], 4[91], 1[60]); Sumas, 19 (18[75], 1[60]); Thurstons Ranch, 2; Cultus Lake, 2; Mt. Baker Range, 5[75]; Lihumption Park, 1; Huntingdon, 14; Tami Hy Creek, 1. =Washington.= _Whatcom County_: Semiahmoo, 1[91]; New Whatcom, 1[68]; Lake Whatcom, 2[91]; 5 mi. W Glacier, 1[51]; Glacier (3 at 900 ft.), 4[91]; E Side Easton Glacier, Mt. Baker, 1[55]; Morovitz Guard Station, 831 ft., 1[55]. =Mustela erminea olympica= Hall Ermine Plates 5, 6, 7, 12, 13 and 14 _Mustela erminea olympica_ Hall, Journ. Mamm., 26:81, February 27, 1945; Hall, Journ. Mamm., 26:181, July 19, 1945. _Mustela rixosa_, Svihla and Svihla, Murrelet, 13:24, January, 1932. _Mustela rixosa rixosa_, Svihla and Svihla, Murrelet, 14:39, May, 1933. _Type._--Male, adult, skull and skin; no. 90738, U. S. Nat. Mus., Biol. Surv. Coll.; near head of Soleduc River, 4500 ft., Olympic Mountains, Clallam County, Washington; April 28, 1897; obtained by Vernon Bailey, original no. 6213. The skin is well prepared and in good condition. The skull (plates 5-7) is unbroken and the teeth all are present and entire. _Range._--Olympic Peninsula, Washington, south to Olympia. See figures 25, 27 on pages 95, 149.