14 



35. Spermophilus tridecem-lineatus Aud. and Bach. (Striped 

 Prairie Squirrel. Striped Gopher.) 



Abundant, and to the fanners a destructive pest. Seen almost 

 daily, both on the wild prairie and in the cultivated fields. They 

 are active throughout the summer, and quite destructive to the young 

 corn in the spring, the kernel of which they dig up, and thus destroy 

 the crop. It is said, however, to be less frequently noticed during the 

 summer, when the grass is high, than earlier. Their burrows run 

 usually but a few inches below the surface, but sometimes extend 

 horizontally for the distance of ten feet, though usually much less. 1 



36. Spermophilus Franklini Richardson. (Gray Prairie 

 Squirrel. Gray Gopher.) 



Abundant, and, in proportion to its numbers, far more destructive 

 than the preceding (. tridecem-lineatus). When very numerous 

 they sometimes destroy acres of newly planted corn by eating the 

 seed. During the spring months it is generally numerous, but after 

 about the first of June is rarely observed, and all my efforts to obtain 

 specimens, both in this State and in Illinois, where it is equally com- 

 mon, were ineffectual. The burrows of this species run to the depth 

 of three or four feet, and extend to a considerable distance. 



The Prairie Dog (Cynomys ludovicianus) , so characteristic of the 

 more western prairies, is not met with to the eastward of the Mis- 

 souri river. Dr. Hayden says the first village he met with in as- 

 cending the Missouri was about ten miles below the mouth of the 

 Niobrara. 2 Mr. Cyrus Thomas erroneously includes this animal in 

 his catalogue of the " Mammals of Illinois," published in Vol. iv of 

 the Transactions of the Illinois State Agricultural Society. 



37. Arctomys monax Gmelin. (Woodchuck. Marmot.) 

 This animal appears also to be absent from western Iowa, I met 



with but a single individual who had seen it in the State. He had 

 formerly lived in Davis county, in the southeastern part, where he 

 informs me it occurs, as also in the adjoining counties of Missouri. 

 On this authority it is included in the present list. 



38. Castor fiber Linn. (Beaver.) 



Reported to still exist on the South Raccoon river, but nearly or 

 quite exterminated in most of the eastern and southern portions of 

 the State. A gentleman residing in the southern part of Dallas 



1 For a very, complete account of the habits of this species, see the late Robert 

 Kennicott's excellent papers on the Mammals of Illinois, in the Patent Office Re- 

 ports (Agriculture) for 1856 and 1857 (1856, p. 74). 



> Transact. Amer. Phil. Soc., Vol. xit, 2d series, p. 145. 



