CASTORIDA—CASTOR—CASTOR FIBER. 437 
RELATION OF THE AMERICAN AND OLD WORLD BEAVERS. 
The earlier, and by far the greater part of naturalists have regarded the 
Beavers of the Old World and the New as specifically identical. According to 
Brandt,* Oken,t in 1816, first suggested that they were different; he regarding 
the American animal as being more reddish and much the larger. G. Cuvier, t 
in 1817, affirmed, that, after the most scrupulous comparison of the Old 
World Beaver, from different localities, with the New World Beaver, he was 
unable to satisfy himself whether or not they were specifically distinct. In 
1820, Kuhl§ described a young specimen of the American Beaver from Hud- 
son’s Bay, under the name Castor canadensis, without, however, giving any 
special reasons therefor. In 1825, F. Cuvier, || in describing specimens of 
the European Beaver, claimed that there were very decided differences in the 
structure of the skull as well as in size, he stating the European Beaver to be 
“Pun sixiéme plus grand qu’un Castor du Canada”. His detailed account of 
the cranial differences, however, show that his American skull was that of a 
quite immature animal, and that the differences mentioned were mainly such 
as would result from differences of age. He calls attention, however, to one 
point of some importance, and one which all subsequent comparisons have 
confirmed, namely, the greater posterior extension of the nasal bones in the 
European animal. G. Cuvier,{ the same year, also dwells upon the impor- 
tance of the same character as distinctive of the two forms, as well as also 
upon the general form of the nasal bones. ~ In 1827, Brandt and Ratzeburg** 
pointed out numerous minor Cifferences in the shape of the head, tail, feet, 
incisors, etc., as existing between the single individuals compared. Richard- 
son,tt in 1829, called the American Beaver Castor fiber, americanus, but 
cited no differences characterizing the two forms. Keyserling and Blasius ft 
treated the European Beaver as specifically distinct from the American, and 
Wagner, §§ in 1844, as varietally distinct. Audubon and Bachman, || || in 1846, 
also formally adopted the same view, but stated that the only difference per- 
Mém. Acad. St. Pétersb., 6th ser., vol. vii, p. 44. 
t Lehrb. d. Zoologie, 2te Abth., p. 880. 
$ Regne Anim., Ist ed., tome i, p. 191. 
§ Beitriige zur Zoologie, p. 64. 
|| Hist. Nat. des Mam., liv. 51. 
4] Ossem. Foss., 3d ed., tome v, p. 57. 
** Medizinische Zoologie, vol. i, pp. 13-30. 
tt Faun. Bor.-Amer., vol. i, p. 105. 
tt Wirbelthiere des Europas, p. 7. 
§§ Abhandl. d. Miinchener Akad., math.-pliys. Classe, 1844, p. 36; Suppl. Schreber’s Siinget., iv, 7. 
Ill Quad. N. Amer., vol. i, p. 347. 
