■:!; ' M 



854 



»IONOGRAPH8 OF NORTH AMERICAN RODENTIA. 



Richardson's "Arciomys (Spermophilus) gutfatus?" was based on specimens 

 from tlie western slope of the Rocky Mountains, ol)taineH by Mr. Douglass. 

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

 World S. guttatus, at which date he referred to it its inhabiting the " banks 

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

 man described his Spcrynophilus toionsendi 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 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. 8. toicmendi was redescribed by Baird in 

 1857, from one of Bachman's specimens, under the same name. In 1868, 

 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 !iis S. elegans and S. armatus, descrilied by 

 him as new species in 18G3. Since this date, a large number of specimens 

 have been brought in by diflerent collectors from various localities in Wyo- 

 ming, Montana, and Diikota, 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 l)y 

 Sabine and Richardson. 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 ra,nge of individual vari- 

 ation, and that the S. ^^elegam", 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. 

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

 8. moUis.f 



* Zool. of IJtechcy'ii Voy. p. 7. 



I Tbat Baclinian'H S. toicnuendi in not tliu 5. molUn of Kennicott iH ovident from its large Bizo, Uucb- 

 niuu givinj; the length of kis S. towntendi as H.T5, oxuluHive of the tail. I have recently received from 

 Captain Cburles Beudiro a specimen of u SpcruiopUile, from nenr Camp Harney, that agrees in size and 

 coloration with Uacbman's S. toinitrndi. The corresponding ineasurenienls of two specimens of Rich- 

 ardson's " gMlttttm t " are 8.!i0 and i>M. These antboni hot h refer to the very small size of the ear in their 



