FAMILY SCIURID^. 65 



S. capisiratus. (Fox Squirrel of Bachman, p. 117.) Usually grey ; ears and nose white ; fur coarse. 



Tail longer than head and body. Length 29 • 5. Largest of the genus. Southern States, New- 

 Jersey. 

 S. lanuguwsus. (Bachman, p. 387.) Yellowish grey above, silver-grey on sides, beneath white. 



Tail shorter than the body. Palms and inner surface of toes thickly clothed with silky hairs. Fur 



soft and downy. Length 14 "0. Columbia River. 

 S. nigrescens. (Bachman, p. 334.) Black above, slightly varied with grey; sides of the neck, upper 



part of thigh and rump pale yellow, beneath soiled grey ; feet black. Tail longer than body. 



Length 27 -5. California. 

 S. collei.' (Richardson, App. Beechy.) Above varied with black and yellow, beneath white ; feet 



white; cheeks greyish. Tail less than length of head and body. Length 20* 1. 



GENUS PTEROMYS. Illiger. 



Teeth as in the preceding genus. Ears round. Upper lip divided. ' Toes elongated, deeply 

 divided. The skin dilated on the sides from the fore to the hind legs, forming a sort of 

 parachute in the air. 



Obs. This genus at present embraces nine species, of which two are found in America, one 

 in northern Eiurope, and the remainder in Java. Some of the species are nocturnal. 



THE SMALL AMERICAN FLYING SQUIRREL. 



Pteromys volucella. 

 plate xvi. fig. s — (state collection.) 



Scivrus ammcanus rolans. RiY, Synop. Quad. p. 215. 



Flying SipUrrel. Pekn. Hist. Quad. Vol.2, p. 153, No. 351. 



Sciuna volucella. Gmelin. 



Flying Squirrel. Pesn. Arct. Zool. Vol. 1, p. 120. 



Pteromys voluceUa. Harlan, Fauna, p. 187. 



Common Flying Squirrel. GOD.MAN, Am. Nat. Hist, Vol. 2, p. 147, figure. Emmohs, Mass. Report, 1840, p. 69. 



Characteristics. Brownish ash, tinged with cream color on the body, above ; darker on the 

 membrane, which is bordered with white. Length 9"0 - 10" 0. 



Description. Head short and rounded ; muzzle rather obtuse. Ears large, broad, membra- 

 nous, nearly naked, and 0*5 high. Eyes large, brilliant and prominent. Whiskers numerous, 

 some of them three inches in length. Claws feeble, compressed, convex and acute, nearly 

 covered by hairs ; the two middle claws of the fore feet subequal, longest on the hind feet, 

 the inner toe shortest. Tail flat, distichous, linear, rounded at the tip, I ' 2 broad. The fur 

 particularly fine and soft ; on the extremities beyond the membrane, it is very short. 



Color. Head mouse-grey. Orbits of the eyes margined with black. Sides of the nose, 

 cheeks, and all beneath pure white, with occasionally a slight tinge of reddish on the under 

 Facna. 9 



