854 MONOGRAPHS OF NOKTII AMERICAN ItOOENTIA. 



Richardson's "Arctomys (Spermopkilus) guttatus?" was based on specimens 

 from the western slope <>t' the Rocky Mountains, obtained by Mr. Douglass. 

 As late as 1839, he had not satisfied himself of its distinctness from the Old 

 World 8. guttatus, at which date lie referred to it as inhabiting the "banks 



of the Col bia and New Caledonia, on the mountains".* In 1839, Bach- 



nian described his SpermophUus toionsendi from specimens obtained "near 

 Walla- Walla" in Oregon, by Mr. Townsend, Bachman at this time regarding 

 it as distinct from both 8. richardsoni and Richardson's guttatus. In 1853, 

 however, he considered it as identical with the guttatus of Richardson, 

 which he had satisfied himself was distinct from the Siberian guttatus 

 of Pallas and Temminck, S. 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 Bridgerj Utah. These Mr. Robert Kennicott later referred in part 

 to S. townsendi and in part to his S. elegans and S. armatus, described by 

 hi in as new species in 18Go. 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. 

 toionsendi to confound S. townsendi with the smaller and entirely distinct 

 S. mollis.^ 



* Zoo!, of Beecbey's Voy. p. 7. 



t That Bachman's S. townsendi is not the S. mollis of Kennicott is evident from its larye size, Hach- 

 inan giving tbe length of bis S. townsendi as 8.75, exclusive of the -tail. I have recently received from 

 Captain Charles Beudire 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 " gntlntusf" are 8.50 and 9.50. These authors both refer to the very small size of the ear in their 



