'72 LLOVDS NATURAL HISTORY. 



tlie trade has gradually declined, and is now mainly carried on 

 in Germany. The backs are used for several purposes, the 

 whitish under-parts are employed for the hnings of cloaks, 

 while the tails are used in the manufacture of boas, and also as 

 trimmings. The so-called "Camels'-hair" paint-brushes are like- 

 wise made from Squirrel's hair. 



THE BEAVERS. FAMILY CASTORID^. 



The members of this Family are aquatic Rodents, differing from 

 the Sciuridce in having but a single pair of pre-molars in each 

 jaw, and in all the cheek-teeth being rootless and having re- 

 entering foldings of enamel on their crowns, which become 

 perfectly flat by wear ; while, in the one existing genus, at 

 least, the tail is broad, depressed, and naked, and the hind- 

 feet are webbed. Moreover, the skull is devoid of projecting 

 processes on its upper surface defining the hinder border of 

 the socket of the eye. 



GENUS CASTOR. 

 Castor, Linn., Syst. Nat. ed. 12, vol. i. p. 78 (1766). 



Upper molar teeth sub-equal in size, with one fold of enamel 

 on the inner, and three on the outer side. Form massive ; 

 fur soft and thick ; tail as above ; hind-feet with an additional 

 rudimentary claw on the second toe. 



THE EUROPEAN BEAVER. CASTOR FIBER. 



Castor fiber, Linn., Syst. Nat. ed. 12, vol. i. p. 78 (1766). 

 Castor fossilis, Goldfuss, Nova Acta. Ac. Cses. Leop.-Car. vol. 



xi. p. 488 (1S23). 

 Castor europceus, Owen, Brit. Foss. Mamm. p. 190 (1846). 



Characters. — Since the Beaver is no longer an inhabitant of 

 the British Isles, it will be unnecessary to describe it, and it 



