328 U. 8. P, R. R. EXP. AND SURVEYS—ZOOLOGY—GENERAL REPORT. 
“Size of the cat squirrel, (Sciwrus cinereus ;) fur rather coarse; body mottled with black and 
ashy white, forming irregular narrow transverse bars on the back and sides; tail as long as 
the body, (exclusive of head?) and moderately bushy. Top of head pure black ; muzzle rufous 
brown above, whitish on the sides. Back of the ears blackish brown. Hairs of the tail long, 
(some of them two inches ;) brownish white, annulated by three broad black rings, the sub- 
terminal one broadest. Length to root of tail, 13 inches; of tail vertebrae, 7$ inches; of tail, 
with hairs, 10 inches ; height of ear, halfan inch; hind foot, 2;°; inches.’’ (Aud. and Bach.) 
This species was described by Bennett from a specimen collected in western Mexico, and has 
not yet been fairly established as an inhabitant of the United States. It has a very close 
resemblance to S. grammurus, and may possibly prove the same, though I have seen none of 
this last mentioned species with the black crown, nor is any mention made by Bennett or 
Audubon and Bachman of the purer gray of the anterior part of the body. I have already 
suggested the possibility that the specimen from Los Nogales (No. 1046) may be different from 
S. grammurus, and belong to this species, but, as its colors have been altered by immersion in 
alcohol, it is impossible now to decide. 
? SPERMOPHILUS CLARKII. Western America. 
This supposed species has already been discussed under the head of Sciwrus clarkii, page 279. 
Its reference, by some authors, to the genus Spermophilus rather than to Sciurus, is scarcely 
warranted by the vague description of Hamilton Smith. 
