947 



Family CASTORID^. 



1821. Castoridie Gray, London Med. Eepos., xv, p. 302, April 1, 1821. 



Geographical distribution. — Forested portions of the Northern 

 Hemisphere, south to the Mediterranean region and the southern 

 United States. 



Characters. — Essentially as in the Sciuridse, but skull without 

 postorbital processes, and cheek-teeth rootless, with re-entrant 

 enamel folds ; premolars { ; .angular portion of mandible short, 

 broadly rounded ; size large ; form heavy ; tail broad, flattened 

 from above downwards, its surface scaly ; habits aquatic. 



Bemarhs. — Though several extinct members of the group are 

 known the family Castoridee is represented by only one living 

 genus, widely distributed in the northern portion of both the 

 Old and New Worlds. 



Genus CASTOR Linnseus. 



1758. Castor Linnaeus, Syst. Nat., i, 10th ed., p. 58 (fiber by tautonymy). 

 1806. Fiber Dumeril, Zoologie Analytique, p. 18, diagnosis on p. 19. 

 (Substitute for Castor.) Not Fiber Cuvier, 1800. 



Type species. — Castor fiber Linnseus. 



Geographical distribution. — As in the family. 



Characters. — General characters as in the family ; upper 

 molars sub-equal, each with one internal and three external 

 enamel folds. 



Bemarhs. — The genus Castor is the only living representative 

 of the family. It contains two closely related species, one 

 peculiar to North America, the other to the northern portions of 

 the Old World. 



CASTOR FIBER Linnseus. 



1758. [Castor] fiber Linnaeus, Syst. Nat., i, 10th ed., p. 58 (Sweden). 



1792. C[astor]f[iber] albus Kerr, Anim. Kingd., p. 222. 



1792. C[astor] f[iber] solitarius Kerr, Anim. Kingd., p. 224. 



1801. C[astor] f[iber] variegatus Beohstein, Gemeinn. Naturgesoh. Deutsch- 



lands, i, 2d ed., p. 913 (Europe). 

 1801. C[astor] f[iber] fulvus Bechstein, Gemeinn. Naturgeseh. Deutsch- 



lands, I, 2d ed., p. 913 (Europe). 

 1803. Castor galliss Geoffroy, Catal. Mamm. du Mus. Nat. d'Hist. Nat., 



Paris, p. 168 (Banks of the Rhone, Prance). 



1822. Castor niger Desmarest, Mammalogie, pt. II, p. 278 (no exact 



locality). 

 1822. Castor varius Desmarest, Mammalogie, pt. n, p. 278 (northern and 



central Europe). 

 1822. Castor flavus Desmarest, Mammalogie, pt. n, p. 278 (no exact 



locality). 

 1829. [Castor fiber] 0. gallicus Fischer, Synops. Mamm., p. 287 (Substitute 



for galUse). 



d p 2 



