180 



U. S. P. R. R. EXP. AND SURVEYS ZOOLOGY GENERAL REPORT. 



PUTORIUS NIGRESCENS, Aud. & Bach. 



Little Black Mink. 



Putoriiu nigrtscens, AUD. & BACH. N. Am. Quad. Ill, 1853, 104; pi. cxxiv. (Not in first edition.) 



Sr. CM. Smaller than tba common mink. Color, chestnut brown, glossed with black. Tail almost entirely black. End of 

 the chin white. 



It is with very great hesitation that I admit this animal to the rank of a distinct species from 

 the common mink ; at least I have not yet been able to make such examinations and com 

 parisons as satisfy me of the difference. It is true that in the northern States there is a mink 

 of usually small size, and of a considerably darker color and softer fur than others found further 

 south ; whether these are more than climatic differences, yet remains to be proved. Specimens 

 of very large size, from the upper Missouri and westward to the Pacific, are as dark as those 

 in northern New York, although referrible rather to P. vison, on account of their dimensions. 



It is this species or variety that furnishes the most valuable mink skins ; those of best quality 

 readily yielding from three to five dollars each to the hunter. In fact, there is, perhaps, no fur 

 which approaches so near to that of the famed Russian sable as the northern black mink. In 

 nothing is the change of value effected by the caprices of fashion more strikingly illustrated 

 than in the case of this fur. Ten years ago, ten cents would have been considered a good price 

 for the best skin to be found in a latitude such as that of Pennsylvania, and fifty cents for the 

 more northern ones. Since then, the value has increased at least ten-fold, owing to the greater 

 appreciation of the fur as an article of dress. 



List of specimens. 



PUTORIUS NIGRIPES, Aud. & Bach. 



Black-footed Ferret. 



Putorius ni/rripes, AUD. & BACH. N. Am. Quad. II, 1851, 297 ; pi. xctii. 



SP. CH. Size of the pine marten. Tail, with hairs, one-third the length of head and body. Forehead, feet, and end of tail, 

 black. Body yellowish brown above, white beneath. 



I have introduced the diagnosis of this remarkable species from Audubon and Bachman, not 

 having had the opportunity of seeing a specimen. Indeed, the only one known is that figured 

 and described in the North American Quadrupeds of the above mentioned authors, and collected 

 by Mr. Alexander Culbertson, on the lower waters of the Platte. 



The length to root of tail of this specimen is given at 19 inches ; of the vertebras of the tail 

 at 4 ; and of the entire tail at 5| inches. 



It is a little remarkable that so conspicuous and well marked a species should have eluded 

 the notice of all the recent explorers in the Platte region. 



