854 MONOGRAPHS OF NORTH AMERICAN RODENTIA. 
Richardson’s “Arctomys (Spermophilus) guttatus?” was based on specimens 
from the western slope of the Rocky Mountains, obtained by Mr. Douglass. 
As late as 1839, he had not satisfied himself of its distinctness from the Old 
World S. guétatus, at which date he referred to it as inhabiting the “ banks 
of the Columbia and New Caledonia, on the mountains”.* In 1839, Bach- 
man described his Spermophilus townsendi from specimens obtained “near 
Walla-Walla” in Oregon, by Mr. Townsend, Bachman at this time regarding 
it as distinct from both S. richardsoni and Richardson’s guttatus. In 1858, . 
however, he considered it as identical with the guttatus of Richardson, 
which he had satisfied himself was distinct from the Siberian gwttatus 
of Pallas and Temminck. 8. townsendi was redescribed by Baird in 
1857, from one of Bachman’s specimens, under the same name. In 1858, 
Mr. Drexler collected a suite of some thirty specimens in the vicinity of 
Fort Bridger, Utah. These Mr. Robert Kennicott later referred in part 
to S. townsendi and in part to his S. elegans and S. armatus, described by 
him as new species in 1863. Since this date, a large number of specimens 
have been brought in by different collectors from various localities in Wyo- 
ming, Montana, and Dakota, which serve to throw much light upon the rela- 
tionship of these several supposed species, and show beyond question that 
all are specifically referable to S. richardsoni, though differing, as already 
shown, quite widely from the northern type of this animal, as described by 
Sabine and Richardscn. As already detailed, S. richardsoni, as represented 
in the United States, within and to the westward of the Rocky Mountains, 
is smaller, much darker colored, and otherwise different from the S. richard- 
soni of Sabine. The abundant material now at command (embracing nearly 
one hundred and fifty specimens) shows also a wide range of individual vari- 
ation, and that the S. “elegans”, S. “armatus”, and S. “‘townsendi” refer 
respectively merely to the light, dark, and mottled phases of one and the 
same animal, all of which occur at the same locality. Three years since, I 
was myself led by immature specimens from near the original locality of S. 
townsend: to confound S. townsendi with the smaller and entirely distinct 
S. mollis.t ; 
* Zool. of Beechey’s Voy. p. 7. 
+ That Bachman’s S. townsendi is not the S. mollis of Kennicott is evident from its large size, Bach- 
man giving the length of his S. townsendi as 8.75, exclusive of the tail. I have recently received from 
Captain Charles Bendire a specimen of a Spermophile, from near Camp Harney, that agrees in size and 
coloration with Bachman’s S. townsendi. The corresponding measurements of two specimens of Rich- 
ardson’s “ guttatus?” ave 8.50 and 9.50. These authors both refer to the very small size of the ear in their 
