92 



with several other American Squirrels. 1'he fact, that many of them 

 have only J^, he alludes to as indicating the necessity for modifying 

 the dental formula hitherto assigned to the genus Sciurus. 



The incisors are strong and compressed, a little smaller than those 

 of the Cat Squirrel, 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 

 Squirrel, presenting two 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 Squirrel, and is most 

 harsh on the forehead. 



The nose is rather obtuse ; forehead arched ; whiskers 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 winter the fur projects upwards, about three lines be- 

 yond the margin. 



Dr. Bachman observes, that although this species exists under 

 many varieties, there appear to be two veiy 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 white, edged with 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 specimens this stripe is wanting. 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, giving it above a gray colour; 

 the hairs in the tail are light yellowish brown from the roots, with 

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

 with white ; the whole under surface is white. 



" There are other specimens where 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 mixture of yel- 

 low." 



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

 has seen taken from the same nest with the Gray Squirrel. It is of 

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

 on the whole of the upper surface, a little lighter beneath. In sum- 

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

 and sides of the body and tail are obscurely grizzled with yel- 

 low. 



