668 CASTORID/E—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. swbaurxatus, Taylor) and another 
from Newfoundland (C. ce@cator, Bangs) have been described as 
distinct species.’ 
THE BEAVER. 
CASTOR FIBER, Linneus. 
1758. CASTOR FIBER, C. Linnzeus, Sys¢. (az., 1oth ed., i, 58; described from 
Sweden. Of most subsequent authors. 
1792. CASTOR FIBER ALBUS and SOLITARIUS, Kerr, Animal Kingdom, 222 and 224. 
1801. CASTOR FIBER VARIEGATUS and FULVUS, Bechstein, Gemezn. Naturgesch. 
Deutschlands, ed. 2, 1., 913. 
1803. CASTOR GALLIA, Geoffroy, Cat. Mamm. du Mus. Nat. @ Hist. Nat., Paris, 168 ; 
described from the Rhone, France. 
1822. CASTOR NIGER, VARIUS and FLAVUS, Desmarest, Mammalogie, part ii., 278. 
1829. CASTOR FIBER GALLICUS, Fischer, Syvofs. Mamm., 287; a substitute for 
gallie. 
1833. CASTOR PROPRIUS, Billberg, Zzun. Samf., 34 in footnote; a substitute 
for fiber. 
1907. CASTOR ALBICUS, Matschie, S7z¢z.-Ber. Gesellsch. nat. Freunde, Berlin, 216; 
described from the Elbe, Germany. 
1907. CASTOR VISTULINUS, Matschie, Sz¢z.-Ber. Geselisch. nat. Freunde, Berlin, 219 ; 
described from Western Poland. 
Le castor and le biefure or biévre of the French: der Biber of the 
Germans. 
As willbe 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. 
1 Other subspecies have been described recently by W. P. Taylorin The Status of 
the Beavers of Western North America, Univ. California Publications, Zool., vol. xii., 
413-495, March 20, 1916. 
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