TOWNSEND'S GROUND-SQUIRREL. 161 



usually answered by another at some distance, for a considerable time. 

 Their note so much resembles that of the dusky grouse, (Tetrao ohscurus,) 

 that I have more than once been deceived by it." 



GEOGRAPHICAL DISTRIBUTION. 



We have heard of this species as existing from the 37th to the 45th 

 degree of latitude, on the Rocky Mountains. It probably does not extend 

 to the eastward of that chain, as we saw nothing of it on our late expe- 

 dition up the Missouri river, to the mouth of the Yellow-Stone, &c. 



GENERAL REMARKS. 



The markings of this Ground-Squirrel differ widely from those of any 

 other known species. From Tamias Lysteri it differs considerably, 

 being larger and having a much longer tail ; it has a white patch 

 behind the ear, and cinereous markings on the neck, of which the latter 

 is destitute ; the ears are a third longer than in T. Lysteri. The stripes 

 on the back are also very differently arranged. In Tamias Lysteri there 

 is first a black dorsal stripe, then a space of grayish-brown, half an inch 

 wide, then two shorter stripes, within two lines of each other ; which 

 narrow intervening portion is yellowish-white. The stripes in the pre- 

 sent species are at a uniform distance from each other, the dorsal one 

 running to the tail ; whereas, in the other it does not reach within an 

 inch of it, and the intervening spaces are filled up by a uniform colour. 

 This species has not the whitish stripes on the sides, nor the rufous colour 

 on the hips, which are so conspicuous in T. Lysteri. 



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