78. In the northwestern states to Minn.; often turning white in winter 



Mustela rixosa rixosa (Bangs) Canadian Least Weasel 

 In the northeastern states to Minn., and southward in the mountains; less 

 often turning white in winter 



Mustela rixosa allegheniensis (Rhoads) Allegheny Least Weasel 



79. Total length not over thirteen inches; tail (not including hair) less than 



onc'third total length; usually becoming white in winter; northern 

 states, extending southward along the mountains (Two common sub- 

 species are given here) 80. 

 Total length often exceeding thirteen inches in many subspecies; tail about 

 or over one -third total length; becoming white in winter in most, but 

 not all, subspecies; generally distributed (Several common subspecies 

 are given here) 81. 



80. Usually white in winter; in summer pelage, the color of the upper parts 



does not extend on to the belly; northern states 



Mustela erminea cicognanii Bonaparte Bonaparte's Short-tailed 

 Weasel or Ermine 

 May or may not be white in winter, depending upon locality; in summer 

 pelage, the color of the upper parts often extends well on to the belly; 

 Puget Sound region 



Mustela erminea streatori (Merriam) Puget Sound Short-tailed 

 Weasel or Ermine 



81. With a ver^' short black tip to the tail; turning white in winter; northern 



New England 



Mustela frenata occisor (Bangs) New England Long-tailed 

 Weasel or Ermine 

 Tail usually black for the last quarter or more 82. 



82. Tail usually black for more than the last quarter; turning white in winter 



in the northern part of its range; east of the Mississippi 



Mustela frenata noveboracensis (Emmons) New York Weasel 

 Tail black for about the last quarter; west of the Mississippi 83. 



83. With a conspicuous white band crossing the face between the eyes and the 



ears; not usually turning white in winter; along the Mexican border 

 Mustela frenata frenata Lichtenstein Bridled Weasel 

 No such facial marking; may or may not turn white in winter; usually 

 more northerly in distribution 84. 



84. In the plains states 85. 

 In the mountain and Pacific states 86. 



85. Usually turning white in winter; in summer pelage, upper lip white and 



under parts buff; northern plains 



Mustela frenata long-icauda Bonaparte Plains Long-tailed 

 Weasel 

 Usually turning white in winter; in summer pelage, upper lip not white 

 and under parts yellow; Osark region 



Mustela frenata primulina Jackson Missouri Weasel 



86. With a white spot between the eyes; usually not turning white in winter; 



southern Pacific states 



501 



