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



claw of the fourth. The under part of the foot, from the heel nearly to the base of the toes, or 

 to the callosities, is densely coated with short grayish hairs ; and the sides of the toes being 

 similarly coated, the ends of the hairs here project beyond so as almost to cover the inferior 

 surfaces, which, in fact, are actually provided with scattered hairs. 



The tail with its hairs is rather shorter than the body. It is much flattened, as in Pteromys, 

 but narrow, scarcely exceeding an inch and a half in a natural expansion. 



The prevailing color of the upper parts and sides and the under surface of the tail is a yel 

 lowish rusty, mixed with black by the fine annulations on the distal third of the hairs, their 

 basal portion being dark lead color. The dorsal surface, however, for about the width of the 

 tail, as well as the upper surface of the tail itself, are washed with dark ferruginous. This 

 color is seen, likewise, on the top of the head. The sides of the head are mixed gray, a ring 

 around the eye, and the whole under parts dull silvery white. In some specimens the hairs on 

 the latter surface are unicolored to the roots, which, in others, are lead colored. The colors of 

 the belly and sides are separated by a dusky stripe. The tail, as stated, is ferruginous above, 

 grayer beneath. It is margined all around by pale yellowish red, darker at the tip. Within 

 this is a narrow border of black, of greatest extent at the tip. The single hairs at the end of 

 the tail are brown at base, then ferruginous, then black and tipped with ferruginous ; on the 

 sides they are similar, but the tints lighter ; beneath, they are mixed brown and pale yellowish 

 brown ; above, they are nearly uniform ferruginous, with little, if any, annulation a character 

 seldom seen in squirrels. 



Measurements of a dried skin, No. 184. 



Measurements of specimens in alcohol. 



Specimens vary from this description in the less intensity of ferruginous above ; in a greater 

 amount of grayish on the sides; in the ferruginous of the dorsal region being narrower and 

 more concentrated. I have occasionally seen specimens in which the upper parts were nearly 

 uniform gray and black, the former with the slightest possible mixture of rusty. 



