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U. S. P. R. R. EXP. AND SURVEYS-ZOOLOGY-GENERAL REPORT. 
specimens has, however, since convinced me that the differences are perfectly consistent with 
one and the same species. This view Dr. Cooper himself has all along insisted upon. 
The typical condition of the species will then he that of five broad black stripes, with the 
interspaces of about the same width or a little wider, and colored exactly like the sides and 
shoulders. There is no margin to the black lines different from the rest of the. interspaces. 
The color of the body, exclusive of the stripes, varies slightly, being sometimes dull reddish 
brown, grizzled with black, sometimes a bright rusty brownish. 
In the other extreme, the interspaces are lighter than the sides and shoulders, and more or 
less ashy gray ; sometimes it is only the external interspace thus colored, and at others the 
whole four. When not grayish, the rusty brown shade is sometimes lighter than on the sides. 
These lighter specimens are apparently smaller than the dark ones, which seem confined to the 
coast, especially the mouth of the Columbia, the others occurring more in the interior. 
The gray striped varieties run sometimes very closely into the characters of Tamias quadri- 
vittatus, from which, indeed, they are hardly distinguishable, except by the size. They never, 
perhaps, have the external stripe of as pure white as in this last mentioned species ; and the 
size is considerably larger—the hind foot measuring over 1.30 inches from the heel, while in the 
quadrivittatus this measurement is less than 1.20. 
Dr. Cooper suggests that there may he some connexion between the coloration of different 
specimens of this species, and the localities they inhabit; the dark ones from the mouth of the 
Columbia living in the dense dark forests, while the grayer ones occupy more open regions 
more in the interior. 
There is still another variety of the western striped squirrel, recently obtained by Mr. Samuels 
in the redwoods of California, north of Petaluma, in which, owing to the much darker color of 
the intervals between the stripes, and of the body generally, the stripes themselves are scarcely 
distinguishable. This obscuration is owing partly to the greater admixture of black hairs 
among the brown. There is a strong tinge of rusty brown over the whole under parts, which I 
have not observed in more northern specimens. This variety by the measurements, appears 
even larger than Astoria specimens, and may possibly prove to be distinct. 
There is little necessity of comparing this species with T. striatus. From T. pallasii it differs 
in larger body, thinner tail, less approximation and distinctness of the dark lines, the light 
intervals being larger than the dark lines, instead of narrower, &c. 
species ; the broad dark stripes extending to the tail, separated by uniform grayish intervals. From T. quadrivittaius by the 
gray (not ferruginous) tips to the hairs on the tail, as well as absence of clear ferruginous generally. The dorsal stripes are 
broader and darker ; the intervals are grayish, not whitish, the anterior three-fourths of the ear is brown, or more than in 
the other. 
The species is stouter than T. striatus, the skull broader and the teeth much larger. The small anterior molar (making 
five) is present. * 
Compared with a specimen of T. townsendii from the Columbia River, brought- by Mr. Townsend, many differences are 
observable. Thus, in T. townsendii the ground color of the upper parts and sides is of a nearly uniform dusky yellowish brown, 
with five well defined black or dark brown stripes on the back ; the intervals between these lines are uniform with the rest of 
the back ; the under parts are ash gray, shading gradually into the color of the sides through dusky. The claws of the 
outer toe on fore foot does not reach to the base of that on the next, as in T. cooperi; the chestnut at the base of the caudal 
hairs is darker. The size is considerably larger and the tail longer in proportion. In T. cooperi the light intervals between 
the lines are grayer than the ground color and the exterior pale ash. The under surfaces are nearly white, and the 
line of demarcation from the sides very distinct. There is none of the general dusky yellowish brown tint of T. townsendii. 
Two specimens of this species were procured on the west side of the Cascade range of mountains, in Washington Territory, 
hv Dr. J. G. Cooper. 
