RODENTIA SCIURINAE SPERMOPHILUS GRAMMURUS. 



309 



SPERMOPHILUS DOUGLASSII. 



Columbia Ground Squirrel. 



Arctomys Spermophilus douglassii, RICH. F. B. A. I, 1829, 172. 

 Spermophilus douglassii, F. CUVIER, Suppl. Buff. I, Mamm. 1831, 333. 



WAGNER, Suppl. Schreb. Ill, 1843, 247. 



Spermophilus douglassii, AUD. and BACH. N. Am. Quad. I, 1849, 373; pi. xlix. 

 Otospermophilus douglassii, BRANDT, Bull. Phys. Math. Acad. St. Pet. II, 1844, 380. 



SP. CH. Similar in most all respects to S. beecheyi, but with the space on the nape and back, between the light colored 

 more lateral patches, of a uniform dark brown, nearly black. 



A sphermophile from the Columbia river differs from the S. beecheyi, as described from 

 California, in some important points, the comparison being with six specimens from the latter 

 locality. The tail is shorter and much less bushy, the hairs being laid quite close down, as in 

 the small spermophiles, instead of approximating to the bushy form of the squirrels. The 

 under side of the tail is more densely haired. It is more hoary above and below, and the hairs 

 show conspicuously only a distinct ring of black near the base and the hoary tip ; the interme 

 diate dark rings being very faint. The hoary marks on the sides of the neck and shoulders 

 show much more gray than the other species, while the stripe between, instead of being nearly 

 uniform in tint with the posterior portion of the back, is darker than this anteriorly, and in 

 its wider posterior half is uniformly and conspicuously brownish black without any mottling. 

 The hoary patch likewise extends more broadly posteriorly, covering a wide space, instead of 

 being reduced to a narrow line behind the shoulder. The patch on the inner face of the ear is 

 more restricted. The feet and claws appear longer in proportion. 



Additional specimens received from Oregon, since the preceding description was prepared, 

 substantiate the characters assigned as distinguishing a northern species. The tails of these, 

 however, are less compressed, and more like those of S. ~beecheyi, though apparently less ample. 

 The ears do not appear so black. The soles vary from being entirely naked except on the heel 

 in summer, to densely hairy to near the digital tubercles in winter. 



List of specimens. 



1 Measured before skinning. 



