MAMMALS MAKTINAE PUTORIUS PUSILLUS. 159 



PUTORIUS, Cuvier. 



Putorius, Cuv. " R. An. I, 1817." 



Teeth, 34; molars, one above, two below; premolars, three above and three below t on eacli side. Lower gectorial tooth 

 without an inner tubercle. Body slender; tail usually long. 



The most tangible difference between this genus and Mustela consists in having one molar 

 less on each side, above and below. The size is generally smaller, and the body more slender 

 in the typical species. 



The genus includes many North American species, none of which are found in Europe. 

 There are three distinct groups, which may be almost considered as generic, or at least as of 

 subgeneric value. They may be characterized as follows: 1 



Putorius. Body stout; darker below than on the sides. Of this particular group America 

 has no immediate representative. 



Gale. Body elongated and very slender. Lighter belo'w than above or on the sides. Naked 

 pads on the feet small, more or less hidden by the hair. 



To this group belong all the American weasels, except the minks, unless the P. nigripes of 

 Aud. and Bach, should prove an additional exception. 



Lutreola. Color nearly uniform all over. Feet much webbed. The naked pads on the feet 

 large, not covered up by the hairy soles ; the intervals between the metacarpal and the metatarsal 

 pads not occupied by hairs. Posterior upper molar longer than in Gale. 



This group includes the well known mink so similar in appearance to a small otter. 



The dental formula of the true weasel is as follows : Incisors, .^; canines, ^ ; premolars, 3 ^ ; 

 molars, jg = ii = 34. 



PUTOKIUS PUSILLUS. 



Least Weasel. 



Putorius vulgaris, RICH. F. B. A. I, 1829, 45. 



Putorius cicognani, RICH. Zool. Beechey's Voyage, 1839, 10.* (By error.) 

 Mustela vulgaris, MAXIM. Reise, II, 1841, 98. 

 Mustela pusilla, DEKAY, N Y. Zool. I, 1842, 34; pi. xiv, f. 1. 

 Putorius pusillus, AUD. & BACH. N. A. Quad. II, 1851, 100; pi. Ixiv. 



Common weasel, FENN. Hist. Quad. 1781, No. 192. IB. Arctic Zool. 1,1784,75. (From N. Am. specimens in 

 Leverian museum.) 



Sp. CH. Smallest of American weasels. Length about six inches to root of tail. Tail vertebrae one-fifth to one-sixth the 

 head and body. The terminal hairs about one-third the vertebrae, which do not exceed two inches. Tail slender, not tufted 

 at the tip. Above, almost liver brown; beneath, white. No distinct black tip to the tail, though this is sometimes darkest. 



This, the smallest species of weasel hitherto described as occurring in North America, is 

 readily distinguishable from the rest, not only by its dimensions, but by the very short tail, 

 which is destitute of the black tip found in all the rest, although the extremity of the tail is 

 sometimes dusky. This member is cylindrical, thin, and, with the hairs, is about one-fifth as 



i Wagner, Suppl. Schreber, II, 1841,229. 



