316 U. S. P. R. R. EXP. AND SURVEYS—ZOOLOGY GENERAL REPORT. 
States, (Tamias striatus,) 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. 
| Catalogue number. 
Number of skull. 
Sex and age. 
Locality. 
Whence and how obtained. 
Nature of specimen. 
Measurements. 
Nose to eye. 
Nose to ear. 
Nose to occiput. 
Nose to tail. 
Tail to end of verteb. 
Tail to end of hairs. 
Fore foot, length. 
Hind foot, length. 
1584 
*2419 
$ 
Fort Yuma, Cal. 
Major G. H. Thomas. 
Skin. 
1.60 
5.25 
4.42 
4.84 
1.36 
1585 
Body in alcohol.... 
.68 
1 28 
1.58 
3.60 
.90 
1.30 
2190 
O 
.do. 
Entire in alcohol... 
.55 
1.14 
1.30 
3.84 
2.80 
3.27 
.75 
1.20 
» Skull 1.42 + .85. 
SPERMOPHILUS TRIDECEM-LINEATUS. 
Striped Prairie Squirrel. 
Sdurus trideem-lineatm, Mitchell, Medical Repository, XXI, Jan. to June 1821, 248. (Brought from the sources 
of the Mississippi by Prof. Douglass, U. S. A.) 
Desmarest, Mammif. II, 1822, 339. 
Ardomys tridecem-lineatus, Harlan, F. Am. 1825, 164. 
Spermophilus tridecem-lineatus, Aud. & Bach. N. Am. Quad. I, 1849, 294; pi. xxxix. 
Hot, Rep. U. S. Patent Office, 1854? Agricultural, p. 
Kennicott, Rep. U. S. Patent Office, Agricultural, for 1856, (1857,) 74 ; plate viii. 
Arclomys hoodii, Sabine, Linn. Transactions, Xni, 1822, 590 ; pi. xxix.— Ib. in Franklin’s Journal, 663. 
