1936] MAMMALS OF OREGON 293 



General habits. Little is known of the habits of these little 

 weasels, but it is fair to infer that they do not differ greatly from 

 those of streatori or dcognanii. Because of their small size it is 

 probable that their prey is chiefly mice, as was assumed by the au- 

 thor of the name mwrww a mouser. At present it is not known 

 that they turn white in winter, but from the high altitude of their 

 habitat this seems probable. 



MUSTELA CICOGNANII LEPTUS (MERKIAM) 



ROCKY MOUNTAIN LEAST WEASEL 

 Putorius streatori leptus Merriam, Biol. Soc. Wash. Proc. 16: 76, 1903. 



Type. Collected at Silver-ton, San Juan County, Colo., by J. Alden Loring in 

 1893. 



General cJtaracters. Very small; tail short with well-developed pencil; skull 

 light and smooth, relatively shorter and wider than in muricus or streatori, 

 with inflated bullae and mastoids. Summer pelage, upper parts drab brown, 

 lacking the reddish or hazel ; tip of tail black ; toes and whole lower parts 

 white, or yellowish white posteriorly. Winter pelage pure white or greenish 

 white all over except black tip of tail. 



Measurements. Type, male: Total length, 243 mm; tail, 64; foot, 31. Fe- 

 male: 195; 50; 26. 



Distribution and habitat. Ranging the Rocky Mountain region 

 of the United States, south to northern New Mexico and west to the 

 Blue Mountains of southeastern Washington, these weasels usually 

 are found in Canadian Zone (fig. 68). There seems to be no definite 

 record for Oregon; but a specimen taken by L. R. Dice on Butte 

 Creek, Walla Walla County, Wash., was within a few miles of the 

 Oregon line, and undoubtedly the species occurs throughout the 

 Blue Mountain section, where tracks of a tiny weasel are reported. 



LUTREOLA VISON ENERGUMENOS (BANGS)" 



WESTERN MINK; PAHUNA-AH of the Burns Piute; ADETE of the Wasco; KLA-PA 

 of the Klamath (C. H. M.) 



Putorius vison energumenos Bangs, Boston Soc. Nat. Hist. Proc. 27 : 5, 1896. 



Type. Collected at Sumas, British Columbia, by Allan C. Brooks, September 

 23, 1895. 



General characters. Form long and low, somewhat weasellike but heavier 

 bodied ; feet fully webbed for swimming ; ears low and wide ; eyes small ; nose 

 pointed ; outer hairs coarse and lax ; underfur dense, soft, and fine ; tail about 

 one-third of total length, heavily furred and without long terminal pencil or 

 brush as in the weasels ; anal glands secreting unmistakable mink odor. Nearly 

 uniform dark brown all over. Adults in summer pelage, dull chestnut brown, 

 fading to almost rusty brown, sometimes with white streaks on chin, breast, or 

 belly; tail blackish toward tip. Young dark chocolate brown or blackish. 

 Winter pelage full and soft, bright chestnut brown with blackish tail and the 

 same white markings as in summer. 



Measurements. A large male near Mount Jefferson: Total length, 615 mm; 

 tail, 211 ; foot, 72 ; ear from basal notch to tip of upper rim, measured dry, 20. 

 Adult female from Beaverton : 503 ; 157 ; 61 ; 18. Weight of males about 2 to 

 4 pounds, females considerably less. 



11 In retaining the genus Lutreola Wagner, 1841, rejected by recent authors on the 

 ground that the minks are not generically separable from the weasels of the older genus 

 Mustela, the writer is not passing final judgment on the value of generic characters 

 beyond our North American species of the two genera. Such a decision must wait a 

 final thorough revision of the Mustelidae of the world, which may show radical changes 

 necessary in the nomenclature of the group. Such studies may even reveal intermediate 

 characters in some remote part of the earth, between the two genera. In "our own 

 species, however, the differences between the minks and weasels are certainly as great as 

 those separating many other of our recognized genera. 



