947 



Family CASTORID^. 



1821. Casioridn: Gray, London Med. Repos., xv, p. 302, April 1, 1821. 



Geoijraijhical distribution. — Forested portions of the Northern 

 Hemisphere, south to the Mediterranean region and tlie southern 

 United States. 



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

 postorbital processes, and cheek-teeth rootless, with I'e-entrant 

 enamel folds ; premolars j ; angular portion of mandible short, 

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

 from above downwards, its surface scaly ; habits aquatic. 



BemarJcs. — Though several extinct members of the group are 

 known the family Cadoridse is represented by only one living 

 genus, widely distributed in the northern portion of both the 

 Old and New AVorkls. 



Genus CASTOR Linnreus. 



1758. Castor Linn^us, Syst. Nat., i, 10th ed., p. 58 (flher by tautonymy). 

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

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



Ti/pc species. — Castor fiber Linnaeus. 



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. 



EcntarJiS. — 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 Linnjeus. 



1758. [Castor] fiber Linnseus, 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, Auim. Kingd., p. 221. 



1801. Clast07-1 /[iber] variegatus Bechstein, Gemeiun. Naturgesch. Dcutsch- 



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

 1801. C[astor] f\ibcr] fulviis Bechstein, Gemeinn. Naturgesch. Deutsch- 



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

 1803. Castor galluv Geoffroy, Gatal. ]\Iamm. du Mus. Nat. d'Hist. Nat., 



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



1822. Castor niger Desmarest, Jilammalogie, pt. ii, p. 278 (no exact 



locality). 

 1822. Castor varitis Desmarest, Mammalogie, pt. ii, p. 278 (northern and 



central Europe). 

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



locality). 

 1829. [Castor fiber] /3. gallicus Fischer, Synops. Mamm., p. 287 (Substitute 



for gallisv). 



