668 CASTORID^— CASTOR 



degree of perfection the family specialisations for gnawing, for 

 subsistence upon coarse vegetable foods, and for burrowing. 

 Above all it is peculiarly modified for an aquatic existence. 



Castor is first known from the Pliocene of Europe and from 

 the Pleistocene of Asia ; in North America it apparently dates 

 from the Pleistocene. All the living species are very closely 

 related. The Old World Beavers are at present referred to a 

 single species, C. fiber, because, owing largely to the lack of 

 material, all attempts to work out the geographical variation of 

 this widely distributed animal have failed. In North America 

 C. canadensis is the chief and most widely spread species ; of 

 this, six geographical races or subspecies are now recognized, 

 while one from California (C subauratus, Taylor) and another 

 from Newfoundland (C ccecator. Bangs) have been described as 

 distinct species.^ 



THE BEAVER. 



CASTOR FIBER, Linnaeus. 



1758. Castor fiber, C. Linnaus, Syst Nat., loth ed., i., 58 ; described from 



Sweden. Of most subsequent authors. 

 1792. Castor fiber albus and solitarius, Kerr, Animal Kingdom, 222 and 224. 

 1 801. Castor fiber variegatus and fulvus, Bechstein, Gemein. Naturgesch. 



Deutschlands, ed. 2, i., 913. 

 1803. Castor gallic, Geoffrey, Cat. Mamm. du Mus. Nat. dHist. Nat, Paris, 168 ; 



described from the Rhone, France. 

 1822. Castor NIGER, varius and FLAvus, Desmarest, Mammalogie, part ii., 278. 

 1829. Castor fiber GALLICUS, Fischer, Synops. Mamm., 287 ; a substitute for 



gallice. 



1833. Castor proprius, Billberg, Linn. Samf., 34 in footnote; a substitute 



for fiber. 

 1907. Castor albicus, Matschie, Sitz.-Ber. Gesellsch. nat. Freunde, Berlin, 216 ; 



described from the Elbe, Germany. 

 1907. Castor vistulinus, Matschie, Sitz.-Ber. Gesellsch. nat. Freunde, Berlin, 219 ; 



described from Western Poland. 



Le castor and le biefvre or bievre of the French : der Biber of the 

 Germans. 



As will be seen from the above synonymy numerous names, founded 

 either upon mere individual variations of colour, or upon vain attempts 

 to define local races without sufficient material, have been applied to 

 the European Beaver. 



^ Other subspecies have been described recently by W. P. Taylor in The Status of 

 the Beavers of Western North America, Univ. California Publications, Zool., vol. xii., 

 413-495, March 20, 1916. 



