386 MONOGRAPH OF THE GENUS SCIURUS. 



Characters. — Smaller than Sciurus Hudsonius ; tail shorter than the 

 body ; rusty grey above, whitish beneath ; extremity of the tail black. 



This small species was first noticed by Lewis and Clarke, 

 who deposited a specimen in the Philadelphia Museum, where 

 it still exists. I have compared it with the specimen brought 

 by Mr. Townsend, and find them identical. Dr. Richardson, 

 who appears not to have seen it, supposes it to be a mere va- 

 riety of the Sciurus Hudsonicus : on the contrary, Dr. Towns- 

 end says in his notes, — " It is evidently a distinct species ; 

 its habits are very different from those of the Sciurus Hud- 

 sonicus. It frequents the pine trees in the high range of the 

 Rocky Mountains, west of the great chain, feeding upon the 

 seeds contained in the cones. These seeds are large and 

 white, and contain a good deal of nutriment. The Indians 

 eat a great quantity of them, and esteem them good. The 

 note of this squirrel is a loud jarring chatter, very different 

 from the noise of Sci. Hudsonicus. It is not at all shy, fre- 

 quently coming down to the foot of the tree to reconnoitre the 

 passenger, and scolding at him vociferously. It is, I think, 

 a scarce species." 



The difference between these two species can be detected 

 at a glance, by comparing the specimens. The present spe- 

 cies, in addition to its being a fourth smaller, and about the 

 size of the Tamias Lysteri, has less of the reddish brown on 

 the upper surface ; and may always be distinguished from the 

 other by the blackness of its tail at the extremity, as also by 

 the colour of the incisors, which are nearly white, instead of 

 the deep orange colour of those of Sci. Hudsonius. 



Dental formula ; Incisors, § ; Canines, {$ ; Molars, ^ ; — 20. 



The upper incisors are small and of a light yellow colour, 

 the lower are very thin and slender, and nearly white. The 

 first or deciduous grinder, as in all the smaller species of pine 

 squirrel that I have examined, is wanting; the remaining 

 grinders, both in the upper and lower jaws, do not vary ma- 

 terially from those contained in Douglass's squirrel. 



The body of this most diminutive of all the known species 

 of genuine squirrel in North America, is short, and does not 

 present that appearance of lightness and agility which distin- 

 guishes the Sciurus Hudsonius. Head large, less elongated, 

 forehead more arched, and nose a little more blunt, than in 

 that species ; ears short ; feet of moderate size ; the third toe 

 on the fore feet but slightly longer than the second ; claws 

 compressed, hooked, and acute ; tail shorter than the body ; 

 the thumb-nail is broad, flat, and blunt. 



