MAMMALS—MARTINAE-PUTORIUS PUSILLUS. 
159 
PUTORIUS, Cuvier. 
Putorius, Cuv. “ R. An. I, 1817.’’ 
Teeth, 34; molars, one above, two below; premolars, three above and three below, on each side. Lower sectorial tooth 
without an inner tubercle. Body slender; tail usually long. 
The most tangible difference between this genus and Mastela 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 below 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. 
Lulreola .—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, ~ ; 
molars, ^ ^ — 34 . 
PUTORIUS 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, Acd. & 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.—S mallest 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 
! Wagner, Suppl. Schreber, II, 1841, 229. 
