92 



with Severai other American Sąuirrels. Tlie fact, that many of them 

 have only *^, he alludesto as indicating the necessity formodifying 

 the dental formula hitherto assigned to the genus Sciurus. 



The incisors are strong and compressed, a little smallerthan those 

 of the Cat Sąuirrel, convex, and of a deep orange colour anteriorly; 

 the upper ones have a sharp cutting edge, and are chisel-shaped ; 

 the lower are much longer and thinner. The anterior grinder, al- 

 though round and small, is as long as the second ; the remaining 

 four grinders are considerably more excavated than those of the Cat 

 Sąuirrel, presenting t\vo transverse ridges of enamel. The lower 

 grinders corresponding to those above have also elevated crowns. 

 The hair is a little softer than that of the Cat Sąuirrel, and is most 

 harsh on the forehead. 



The nose is rather obtuse ; forehead arched ; \vhiskers as long as 

 the head ; ears somewhat rounded, concave ; both sides of the ear co- 

 vered with hair, that which clothes the outside being much the 

 longest. In vvinter the fur projects upvvards, about three lines be- 

 yond the margin. 



Dr. Bachman observes, that although this species exists under 

 many varieties, there appear to be two very permanent ones, These 

 are, 



1. Gray variety. The nose, cheek, around the eyes, extending to 

 the insertion of the neck, the upper surface of the fore and hind feet, 

 and a stripe along the sides, yellowish brown. The ears on their 

 posterior surface are dirty \vhite, edged \vith brown. On the back 

 from the shoulder there is an obscure stripe of brown, broadest at 

 its commencement, and running down to a point at the insertion of 

 the tail. In a few speciraens this stripe is \vanting. On the neck, 

 sides of the body, and hips, the colour is light gray ; the hairs sepa- 

 rately are for one half their length dark cinereous, then light umber, 

 then a narrow mark of black and tipped with white ; a considerable 

 number of black hairs are interspersed, givingit above a gray colour; 

 the hairs in the tail are light yellovvish brown from the roots, ■vvith 

 three stripes of black, the outer one being widest, and broadly tipped 

 with \vhite ; the •whole under surface is white. 



" There are other specimens \vhere the yellowish markings on the 

 sides and feet are altogether wanting. Dr. Godman (vol. ii. p. 133.) 

 asserts that the golden colour on the hind feet is a very permanent 

 mark. The specimens from Pennsylvania in my possession have 

 generally this peculiarity, but many of those from New York and 

 New England have gray feet, without the slightest mizture of yel- 

 low." 



2. Black variety. This variety, on several occasions, Dr. Bachman 

 haa seen taken from the šame nešt with the Gray Sąuirrel. It is of 

 the size and form of the gray variety. It is dark brownish black 

 on the -vvhole of the upper surface, a little lighter beneatli. In sum- 

 mer its colour is less black than in Avinter. The hairs of the back 

 and sides of the body and tail are obscurely grizzled vvith ycl- 

 iovr. 



