906 MONOGRAPHS OF NORTH AMERICAN RODENTIA. 
thumb. Lewis and Clarke’s account of their mode of living in communities, 
of the character of their burrows, and of their habits, is truthful in all its 
details, as I can affirm from personal observation. On the other hand, there 
is nothing in the account of the external characters of these animals that very 
strongly recalls Spermophilus townsendi, while the size and the relative length 
of the tail at once show the impossibility of referring the “Burrowing 
Squirrel” of Lewis and Clarke ‘0 the Spermophilus townsendi of Audubon and 
Bachman. 
In 1855, Professor Baird gave to this species the name gunnisoni, based 
on a single specimen collected by Mr. Kreutzfeldt, in the Cooachitope Pass, 
Rocky Mountains. In 1857, in redescribing the species in his Mammals of 
North America, he very doubtfully referred the Burrowing Squirrel of Lewis 
and Clarke, together with the systematic names based thereon by Ord and 
Ratinesque, to his C. gunnisoni, but noted some discrepancies between Lewis 
and Clarke’s description and his specimens, of which he had at this time 
three,—the original one from Cooachitope Pass and one each from Pole 
Creek and Medicine Bow Creek. As the two latter differ from the first, he 
thought it possible that they represented two species, while the Arctomys 
lewist of Audubon and Bachman he deemed might form a third, all different 
from C. ludovicianus. Later, he thought it quite possible that the Arctomys 
lewist might prove to be the same as Lewis and Clarke’s animal, explaining 
how some of the discrepancies between the accounts given by Lewis and 
Clarke and by Audubon and Bachman might be presumably explained. On 
the whole, he was inclined to consider “the Arctomys /ewisi rather as a 
Cynomys [than an Arctomys], and quite possibly the same with the Burrowing 
Squirrel of Lewis and Clarke, called Arctomys columbianus by Ord, and 
Anisonyx brachyura by Rafinesque”. 
The large number of specimens since received renders unquestionable 
the reference of all these names to the Burrowing Squirrel of Lewis and 
Clarke, for which the name codumbianus of Ord becomes the only tenable 
specific designation. 
This species, as already stated, was first met with on the Plains of the 
Columbia by Lewis and Clarke, in 1806. As shown by the subjoined list 
of specimens, it has beea since met with on the Ogden River and about Fort 
Bridger in Northern Utah, and as far eastward as the Medicine Bow and 
Wind River Mountains. Further southward, it ranges throughout the Parks 
