316 



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



States, (Tamias atriatus,) and in everything but the long round tail it is a minature of the 

 prairie dog. 



The head is short and broad, the whiskers black, and reaching to the occiput. The nose is 

 entirely hairy, the narrow septum of the nostrils being alone naked. The external ears in the 

 dried specimen appear entirely wanting ; in those preserved in alcohol they appear like a very 

 low thickened margin to the ear opening. The feet appear disproportionately large and stout, 

 and very similar to those of the prairie dog. 



The anterior claws are larger than the posterior, strong and considerably curved. The 

 thumb is rudimentary and armed with a short thickened nail not a claw. The third claw is 

 longest, then the fourth, the second a little shorter. The hind feet are very broad, the soles 

 densely coated with long stiff hairs, except on and between the tubercles at the bases of the 

 toes. 



The tail is long, the vertebral portion alone nearly equal to the body, exclusive of head and 

 neck ; it is nearly cylindrical, not appreciably flattened or distichous, the hairs close pressed ; 

 it ends in a slight brush. 



The color is very similar to that of a light colored prairie dog ; it is of a dull yellowish 

 brown, very finely grizzled with lighter tips ; beneath, it is dirty brownish white. The tail 

 agrees in color with the corresponding regions of the body ; the hairs above are faintly annu- 

 lated ; it is dark at the end, with a yellowish tip. 



This animal is so entirely different from any other known North American species as to 

 render any special comparisons unnecessary. It was first discovered by Major Thomas at Fort 

 Yuma. 



List of specimens. 



Skull 1.42 + .85. 



SPERMOPHILUS TRIDECEM-LINEATUS. 



Striped Prairie Sqnirrel. 



Sciunu tridecem-lineotus, MITCHELL, Medical Repository, XXI, Jan. to June 1821, 248. (Brought from the sources 



of the Mississippi by Prof. Douglass, U. S. A.) 

 DESMAEKST, Mammif. II, 1822, 339. 

 Arctomyi tridecem-lineoius, HAELAN, F. Am. 1825, 164. 



Spermophaus Iridecem-Knealiu, ACD. & BACH. N. Am. Quad. I, 1849, 294 ; pi. xxxix. 

 HOT, Rep. U. S. Patent Office, 1854? Agricultural, p. 



KKNNICOTT, Rep. U. S. Patent Office, Agricultural, for 1856, (1857,) 74 ; plate viii. 

 Arctomyt hoodti, SABINK, Linn. Transactions, XIII, 1822, 590 ; pi. xxix. IB. in Franklin's Journal, 663. 



