SCIUELDiE— SrEKMOrniLUS TEIDECEMLINEATCTS. 875 



the eastern edge of the plains are intermediate in color and size between the 

 two varieties ; those from Eastern Kansas and Eastern Nebraska, from as 

 far west as Topeka and Fort Riley, are still referable to the eastern rather 

 than the western race, but those from Western Nebraska, Western Kansas, 

 and Colorado are distinctly referable to var. pallidus. In Fort Riley and 

 Topeka specimens, the dark ground-color is more rufous, especially on the 

 sides, and the light markings are of a clearer grayish-white. 



Synonymy and nomenclature. — The present species was first described 

 by Dr. Mitchill in June, 1821, as Sclurus tridecemlineatus, from specimens 

 collected during the summer of 1820, on the Upper Mississippi, by Professor 

 Douglass of the United States Military Academy. It was redescribed by 

 Sabine,* about eight months later, under the name of Arctomys hoodi, from 

 specimens collected near Carlton House in May, 1820. While tridecemli- 

 neatus has been almost universally adopted by American writers as the name 

 of t his species of Spermophile, Sabine's later name of hoodi has been as 

 uniformly adopted by English and European writers. The species has 

 thus far escaped other synonyms. It has, however, been burdened with a great 

 number of vernacular names, scarcely two authors having adopted the same 

 vernacular appellation. In 1874, I briefly characterized the pale desert race 

 as var. pallidus. 



Nuttall was probably the first naturalist who observed this animal, who, 

 some years prior to its discovery at other localities, met with it at the Mandan 

 village on the Upper Missouri, and, according to Say,f sent specimens of it 

 to "several of his scientific friends in London" as early as 1814. It appears, 

 however, to have been first described, as above stated, by Dr. Mitchill in 1821. 

 Dr. Hoy and Mr. Kcnnicott have made interesting contributions to its biog- 

 raphy, I he former noting especially its carnivorous, Weasel-like propensities. 



Geographical distribution. — The most northerly point at which this 

 species has been observed seems to be the vicinity of Carlton House on the 

 Saskatchewan, where Richardson states he found it quite common. It is 

 abundant at the Red River Settlements and in the neighborhood of Pembina, 

 and is doubtless common at all favorable localities between these points and 

 the Saskatchewan River. In the United States, it has been met with at fre- 



* Dr. Sabine's paper was read before the Royal Society of London "Jan. 15, 1822", and was not 

 published till some months later. Dr. Mitchill's description appeared in June, 1821. 



t Long's Expedition to the Rocky Mountains, vol. ii, p. 174 (apparently quoted by Ilarlau without 

 credit to the original authority). 



