RODENTIA SCIURINAE SPERMOPHILUS RICHARDSONII. 325 



SPERMOPHILUS KICHAKDSONII. 



Richardson's Ground Squirrel. 



Jlrctomys richardsonii, SABINE, Linn. Trans. XIII, 1822, 589; pi. xxviii. IB. Narr. Franklin's Jour. 662. 

 HARLAN, P. Am. 1825, 168. 

 GRIFFITH'S Cuv. V, 1827, 246. 

 GODMAN, Am. N. H. II, 246. 



WAGNER, in Schreb. Sa'ugt. V; pi. ccx, B. (Interpolated; no text.) 

 Jlrctomys (Spermophilus) richardsonii, RICH. F. B. A. I, 1829, 164; pi. xi. 

 Spermophilus richardsonii, F. CUVIER, Suppl. Buffon, I, Mamm. 1831, 321. 

 WAGNER, Suppl. Schreb. Ill, 1843, 243. 

 ACD. & BACH. N. Am. Quad. I, 1849, 377; pi. 1. 



S P . CH. Rather larger than Sciurus hudsonius. Tail about one-third, or a little more, the length of head and body. Ear 

 very short, though with a distinct flap. A distinct thumb claw. Color above, uniform yellowish brown, without spots or lines 

 of any kind. Length, 8 inches; tail, 3|; hind foot, H inch. 



Of this species no specimens were collected by any of the expeditions, and I accordingly make 

 use of one belonging to the Philadelphia Academy of Natural Sciences for the purpose of 

 description. It was collected in the Kocky Mountains by Townsend, but is, unfortunately, not 

 in very perfect condition, the tail appearing somewhat mutilated. 



In size, this animal rather exceeds Wisconsin specimens of Spermophilus tridecemlineatus. 

 The auricle of the ear is thickened and elongated, but low, its greatest height above the base 

 not exceeding two-tenths of an inch. The whiskers are rather short and black. The 

 fore claws are longer than the hinder ones ; the thumb is rudimentary, but its claw is quite 

 long and conspicuous, almost equal to the fifth claw. The tail is short, and in this specimen 

 quite slender, and uniformly cylindrical to the tip, without any flattened appearance whatever. 

 It is, however, probably mutilated. 



The upper parts are of a light yellowish brown, or dull brownish yellow, nearly uniform, but 

 with the faintest possible trace of dusky clouding, where the darker bases of the hairs show 

 themselves. The side of the face is nearly uniformly colored with the top of the head ; the 

 eyelids and an area between the eye and ear are rather lighter colored. The under parts and 

 sides are dull yellowish, lighter than the back, and shading imperceptibly into it. There is a 

 faint wash of stronger yellowish on the sides of the neck in advance of the shoulders. 



Measurements. 



According to Audubon and Bachman, the tail of this animal, when perfect, measures 2^ 

 inches to the end of vertebras, and 3 to end of the hairs ; the hind foot, 1^ inch. 



A very imperfect skin of a spermophile, belonging to the National Institute, and obtained 

 on an island in the Sault Ste. Marie, Michigan, approaches this very closely, but is not in such 



