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U. S. P. R. R. EXP. AND SURVEYS ZOOLOGY GENERAL REPORT. 



of this line is tinged with rusty. There is a light ring around the eye, and the sides of the 

 nose are of a pale rusty. 



The hairs of the tail are long and coarse, scarcely distichous. At the extremity of the tail 

 they are glossy black throughout, or with a slight base of chestnut ; on the rest of the tail 

 above they are dark plumbeous at the base, then dark chestnut to beyond the middle ; then 

 glossy black to near the tip, which is pale rusty, the latter increasing in extent towards the 

 base of the tail. Beneath, the hairs are several times annulated with black and pale rusty for 

 more than half their length ; then glossy black to near the tip. 



According to Dr. Bachman it would appear that S. richardsonii is about the size of the striped 

 squirrel, (Tamias striatusj) has less of reddish brown than in S. hudsonius, being even rusty 

 gray. These specimens, on the contrary, are larger than S. Jmdsonius, and the upper parts are 

 deeper reddish brown than in this species. They agree in the colors of the under parts and 

 the dark line on the sides, as well as in the peculiar color of the tail. The feet appear smaller 

 too. The description of the ' ' small brown squirrel ' ' of Lewis'and Clark, referred to as belonging 

 to this species, suits better S. douglassii, especially in respect to the ferruginous belly. 1 



This squirrel appears to be confined to the region between the main chain of the Kocky Moun 

 tains and the Cascade range. Its northern and southern limits are not ascertained. 



The Sciurus lanuginosus of Bachman, as far as I can judge from examining the original 

 specimen brought by Townsend, is a partly albino and boreal variety of Sciurus richardsonii. 

 It is of the same size, and the tail presents the same peculiarly cylindrical tail. The fur is 

 very soft and full, the sole, from heel to bases of toes, densely hairy. The muzzle, sides of face, 

 and under parts are white ; the sides mottled silver gray ; the back with a wash of rufous. 

 There is no distinct annulation on the tail, though the hairs generally are light gray at the 

 roots, then broadly pale rufous, then dark brown, and finally tipped with lighter brown or gray. 



There is nothing in the color to militate against the supposition that this is the same with S. 

 richardsonii, and the white head and lighter colors generally furnish strong confirmation of the 

 idea that the color has been influenced by temperature, latitude, or other causes. As is well 

 known, North America has no species in which a head lighter than the body is a permanent 

 characteristic. The peculiarly cylindrical tail is a strong point in the resemblance. It is 

 barely possible that it may more properly be referrible to S. douglassii. 



The specimen is described by Bachman as coming from Sitka ; it is, however, labelled 

 " Columbia river, November 13, 1834," most probably erroneously. 



List of specimens. 



1 Since writing this description I have. examined the original specimen collected by Townsend and described by Dr. Bachman, 

 now in the collection of the Philadelphia Academy. It is undoubtedly a quite immature animal, of the same species with the 

 subject of the present article. 



2 Length, 9.00; tail, vertebra, 6.00; hairs, 8.00; ear, 0.50; hind foot, 1.83. 



