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882 



MONOGRAPHS OP NORTH AMERICAN RODENTIA. 



Different specimens vary in respect to the purity and darkness of the 

 gray on the head and buttocks and in tiie depth of the yellowish-brown of 

 the upper surface, wliicli latter ranges from pale yellowish-brown to ochry- 

 brown. The Pembina specimens average considerably larger and paler than 

 tliose from lUino" and Wisconsin and Southern Minnesota. While the 

 southern speci' do not exceed 9.00 in length, the Pembina specimens 



range generally above 10.00. 



This species is one of the most strongly marked of the genus, and can- 

 not, by any possibility, be confounded with any other. It was first described 

 by Sabine in 1822, and subsequently by Richardson, Kennicott, and Baird. 

 Though a common animal of the prairies of Northern Illinois and Wisconsin, 

 it was unknown even to Audubon and Bachman, as late as 1851, except from 

 Sabine's and Richardson's descriptions, and a specimen brought in by Town- 

 send and supposed to have been taken "near the Columbia River". All 

 the earlier descriptions were based wholly on the accounts given by Sabine 

 and Richardson. It has hence fortunately escaped synonyms. It is confined 

 to a narrow belt of country, and specimens are .still of rather rare occurrence 

 in collections. Mr. Kennicott, in the Agricultural Report of the Patent 

 Office, has given an excellent and very detailed account of its habits. 



It was first described from specimens collected at Fort Enterprise, in 

 about latitude 64°. Sabine also gives it as occurring at Cumberland House. 

 Richardson states that he met with it only in the neighborhood of Carlton 

 House, "where it lives in burrows dug in the sandy soil, amongst the little 

 thickets of brushwood tiiat skirt the plains". He states that it awakens from 

 its winter's sleep about three weeks later than does S. richardsoni, which he 

 thinks may be due to the snow lying longer on the shady places it frequents 

 than on the open plains inhabited by the latter. 



Mr. Donald Gunn, in notes transmitted with specimens to the Smith- 

 sonian Institution, states that its range does not extend much to the eastward 

 of Lake Winnipeg, but that it is numerous to the westward of the lake, 

 where it does considerable injury in the wheat-fields, hoarding up the grain 

 in its burrows for winter use. He says it begins to hibernate about tlie 

 first of November, and does not reappear till the snow is off in the spring. Dr. 

 Coues found it abundant in the vicinity of Pembina; it also occurs in Minne- 

 sota and over tlie prairie regions of Wisconsin, Illinois, Missouri, and lown. 

 Mr. Kennicott also states that Dr. Hoy met with it in Eastern Kansas, and 

 tiiat it is found much further south in Illinois and Missouri tlian 8. tridecem- 



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