TIIK ("AROIJNA HKAVKIi. 



487 



in a trap placed on the ground beside a hole in the base of a hol- 

 low tree. 



Economic status. — The food of the flying squirrels consists 

 chiefly of acorns and nuts. I doubt that they ever injure standing 

 grain or crops of any kind, although they may sometimes steal from 

 granaries and corn cribs. They are said to eat some fruit, a few 

 insects, and. occasionally, carrion. 



Family CASTORIDAE. 



BEAVERS. 



Size large for a rodent ; habits aquatic ; tail broad, flat, and 

 almost devoid of hair. 



Genus Castor Linnaeus. 

 Castor Linnaeus, Syst. Nat., ed. 10, Vol. T, ]). 58, 1758. 



Dental Formula.— 1, C, ^Z^; Pm, \z\; M, :-i;;=20. 



Generic characters.— -Size the largest of any North. American 

 rodent ; tail broad and horizontally flattened ; skull very strong and 

 without postorbital processes. 



The genus formerly had a range extending from Mexico to the 

 Arctic zone and throughout Europe and m()r(^ or less of Asia. There 

 were but few species, however, and these are now very generally 

 exterminated except in the thinly settled regions. A single species 

 with several geographic races is found in eastern North America. 



CASTOR CANADENSIS CAROLINENSIS Rhoads. 

 CAROLINA BEAVER. 



Castor canadensis carolinemis Rhoads, Trans. Amer. Philos. 

 Soc, Vol. 19, p. 420, 1898. 

 , Castor fiber Evermann and Butler, Proc. Ind. Acad. Sci. for 

 1893, p. 128. 



Diagnostic characters. — Those of the genus. The southern form, 

 carolinensis is said to be distinguished from the northern beaver 

 by its lighter color, larger size and nuich broader tail. No speci- 

 mens from Indiana are to be had, but it is assumed for geographic 

 reasons that the southern form is the one that formerly occurred 

 in this State. 



Description. — Rhoads saj^s of the color of the two races : ' ' The 

 upper winter fur of canadensis is blackish brown, the haii-s tipped 

 with chestnut, rump and thighs dark chestnut. In carolinensis the 



