530 



U. 8. P. R. R. EXP. AND SURVEYS ZOOLOGY GENERAL REPORT. 



The description of A. montana, given by Mr. Peale, is too short to describe fully its characters, 

 and omits to mention some of most importance. As far as it goes, however, it agrees pretty 

 well with the animals collected by Dr. Newberry, and, as both gentlemen gathered their speci 

 mens in much the same region, I have given them the same name. Mr. Peale obtained his near 

 Mount Shasta, as he informs me. Several specimens belonging to Lieut. Bryan's collection, 

 from the upper waters of the Platte, though differing in some slight points, I refer to this 

 species, rather than to make a new one. 



List of specimens. 



1 Measured before skinning. 



ARVICOLA LONGIROSTRIS, Baird. 



Sr. Cu. Size large, (4J inches.) Skull, 1.08 inch. Fur long, .55 of an inch above. Ears rather small, three-fourths 

 the length of hind foot, sparsely coated with short hairs. Feet very short ; hinder ones less than three-quarters of an 

 inch long. Tail the body, the vertebrae twice aa long as the hind foot. 



Above dull yellowish chestnut, or rufous brown, mixed with black, yet without any distinct rusty. Beneath dirty 

 whitish ash. Line separating the colors rather distinct. Feet light brown. Tail nearly unicolor, paler beneath at the 

 base. 



Skull 1.08 X .61, or as 100 to .55. Muzzle of skull very long. Distance between upper molars and incisors more than 

 one-third the whole length of the skull. 



(-- 



-- r - This specimen is indicative of a large and stoutly built animal, nearly equal to the 

 largest eastern species. The whiskers are not as long as the head, and mostly of a light gray 

 color ; a few black ones are interspersed. The hair is rather loose and coarse, with but little 

 lustre ; this may, however, be owicg to immersion in alcohol. The hairs on the back measure 

 about .55 of an inch in length and about half as much on the belly. 



The ears are rather small, almost as broad as long, or nearly orbicular, and about three- 

 fourths the length of the hind foot, or longer than the fore foot ; they are thin and coated on 

 both sides with rather sparse and short hairs. The antitragus is not large. The feet are quite 

 unusually short for members of this group, the hind foot measuring less than 75-100ths of an 



