850 MONOGRAPHS OF NORTH AMERICAN RODENTIA. 
between Pembina and the Rocky Mountains, shows a considerable range of 
color variation. It is, however, mainly individual, the variation occurring at 
the same locality, covering nearly the whole range of variation presented by 
the whole series. The differences consist mainly in the distinctness of the 
mottling above and in the amount of fulvous ‘pervading the general colora- 
tion. In No. 11956, from Frenchman’s River, the general color above is gray, 
the light spots being almost white; the sides, especially posteriorly, incline 
to brownish; the lower surface is grayish-white, with a very slight but dis- 
tinct tinge of fulvous. Another (No. 11963), from the same locality, is still 
whiter below, with a rather browner cast above, wholly unvaried by spotting. 
Still another (No. 11954), also from the same locality as the others, is decidedly 
reddish-brown, more varied with dusky above, while otherwise not different 
from the last. Others differ from these in being strongly fulvous beneath, 
with a more yellowish cast above. “These can all be nearly matched by others 
from the Milk River series, collected some two hundred miles further west. 
The specimens most strongly suffused with tawny are from the Two Forks of 
Milk River and the Three Buttes, these averaging more fulvous than speci- 
mens from further eastward. Nos. 11975 (Three Buttes), 11953 (Two Forks: 
of Milk River), and 11945 (Milk River at 49°) present a strong contrast with 
the pale phase already described, the lower surface being quite bright rusty- 
yellow. Between these extremes there is, however, almost every conceivable 
intermediate stage. 
Var. TOWNSENDI. 
Townsend's Spermophile. 
VARIETAL CHARS.—Smaller than var. richardsoni, with larger ears and 
much darker coloration. Length of head and body 6 75 to 8.50; of tail to 
end of vertebre 2.10 to 3.50; to end of hairs 3.35 to 4.60. Above, finely 
varied with yellowish-gray and black, with generally a slight wash of dark 
reddish-brown along the middle of the back and very indistinctly mottled ; 
below, grayish-white, tinged more or Jess with brownish-yellow. Top of the 
nose, ears, outer side of the fore and hind limbs, and buttocks reddish-brown, 
often in striking contrast with the general coloration ; tail mostly black above, 
edged with yellowish-white. The hairs individually, especially the lateral 
ones, are barred successively with black, the outer bar being very broad and 
edged with yellowish-white. 
This variety is also represented by a large suife of specimens from a con- 
