Reddish brown above, beneath white; or wholly white: extremity of the tail always black.
M. Erminea, Desm. Mammal, p. 180. Flem. Brit. An. p. 13. Stoat, Penn. Brit. Zool. vol. i. p. 89. pi. 17. no. 18. Shaw, Gen. Zool. vol. i. p. 426. pi. 99.
Length of the head and body ten inches; of the head one inch eleven lines; of the ears six lines; of the tail five inches.
Larger than the last species, to which it is closely allied - (Summer dress). Upper part of the head, neck, and back, as well as a considerable portion of the tail, reddish brown; under parts white tinged with yellow; tail terminating in a tuft of black hair - (Winter dress). Wholly white, or white with a slight tinge of yellow, the extremity of the tail excepted, which remains black - Obs. In spring and autumn these two liveries are found intermixed.
Equally common with the weasel. Habits similar.