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



The tail is rather short in its proportions, scarely more than half as long as the head and 

 body. It is, however, remarkably dense and bushy, being made up principally of under fur, 

 instead of having its contour determined by the long hairs. It is nearly cylindrical, or slightly 

 depressed, with a truncate and rounded tip, and is slightly contracted at the base. 



There are no strongly marked contrasts of color in this diminutive fox. The entire upper 

 parts and sides extending low down on the thighs and shoulders, are conspicuously grizzled 

 with pale grayish white and brownish yellow, mixed with a little dark brown or black. The 

 under fur in these regions is light plumbeous at base, and light brownish chocolate yellow at 

 tip ; these tints becoming paler towards the sides. The long stiffer hairs are dark brown, 

 (more reddish at the extreme tip,) and broadly annulated near the tip with yellowish grey 

 white ; there is, however, an occasional hair that is entirely black. The under fur on the top 

 of the head has more reddish on the terminal portion. The under parts, generally, for their 

 entire width, as well as the inside of the limbs, are yellowish white. On the sides of the neck 

 and body, extending some distance up behind the shoulders, the hairs are of a pale reddish 

 yellow, without annulation, this color also tinging strongly the fore arm and posterior face of 

 the hind leg ; the rest of the legs, except as described, is of a pale brownish white. There is 

 a dusky tinge around the lips, and a patch of the same between the eye and the nose, above 

 the insertion of the whiskers, which are themselves black. The ears are uniform brownish 

 yellow on their convexity ; anteriorly yellowish white. 



The tail, in general tint, resembles the back, except that there is no distinct annulation, the 

 prevailing hue being a yellowish gray. There is a considerable amount of black on the tips of 

 the hairs, but this is much less conspicuous than in the red and gray foxes. There is most 

 black at the truncate tip. There is nothing corresponding to the white tuft of the red fox. 

 The under surface of the tail is tinged with yellowish red. 



The specimen described above is in very full fur, having probably been taken in the depths 

 of a Fort Union winter. The colors differ slightly from those given by some other authors, 

 owing possibly to season ; and the animal itself appears to have been of unusually large size, 

 and very old, judging by a comparison of its skull with a considerable number of separate 

 skulls sent by Dr. Hammond from Fort Kearny. Its distinctive features are so striking as to 

 render it quite unnecessary to compare it with other American foxes ; according to Richardson, 

 its nearest relative is the Canis corsac of Siberia. It comes nearer in appearance to the gray 

 fox than the red ; it lacks, however, the bright chestnut of the ears and sides of the neck, the 

 black muafcle, the predominant badger gray and black of the back, the well defined black dorsal 

 stripes and tip to the tail, which, in the swift fox, besides, is very much denser, fuller, more 

 truncate, and without the concealed mane of stiff hairs in the upper surface of the tail. The 

 skulls of the two animals are widely different. 



Measurements of No. 59. 



Inches. 



Length from nose to tail 

 Tail to end of vertebrae.. 

 Tail to end of hairs . . 



Width of tail flattened horizontally 

 Height of ear above notch . . 



24 



9 

 10* 



6 



If 



