RODENTIA CASTORINAE CASTOR CANADENSIS. 361 



The American beaver being satisfactorily shown to be distinct from the old world animal, of 

 course, cannot continue to be called Castor fiber. For the proper specific appellation we have two 

 names, canadensis of Kuhl, and americanus of F. Cuvier. The date of the former is 1820 ; the 

 precise place where the latter name is introduced I have not been able to ascertain. The Hist, 

 des Mammiferes du Mus. is usually given as the reference, but here the animal is merely called 

 Le Castor du Canada in the 6th fasciculus (1819.) According to Brandt, F. Cuvier first broached 

 his views of the difference of the species, in the 51st fasciculus of this work, 1825, and there 

 probably gave the name ; but this I am not able to verify at present, not having part 51 at 

 hand. At any rate the point of priority seems to be settled clearly in favor of Kuhl's name. 



The American beaver has a very wide distribution throughout North America, being found 

 from the Polar seas to the Eio Grande, and the Gila on the south, or to, at least, latitude 26 on the 

 east side of the continent, (the mouth of the Rio Grande.) Formerly it extended from the At 

 lantic to the Pacific, but it is at present very rare east of the Missouri. A few are still found in 

 the Adirondac region of New York, as also in the Alleghanies of Pennsylvania, Virginia, North 

 Carolina, and even Alabama, according to some accounts. Their remains in the bone caves of 

 Pennsylvania are very numerous, showing that they were once very abundant there. 



At one time the fur of the beaver was very valuable, and an extensive trade was carried on, 

 so that the animal rapidly diminished in numbers. The substitution of silk, and the introduc 

 tion of the nutria fur, (Myopotamus coypus of South America,) has greatly reduced the demand 

 and the price, so that now beaver fur is not worth more than a few dollars a pound. In conse- 

 sequence, it scarcely pays the expenses of a systematic and laborious pursuit on the part of th e 

 trapper, and the beaver is again multiplying very rapidly, so that the western streams are 

 becoming rapidly stocked again. 



Fossil American Beaver. The bone caves at Carlisle yielded a large number of remains of 

 beaver, both young and old. There are no satisfactory points of difference from the existing 

 species, although in size some of the teeth are larger than any recent specimens I have seen, 

 indicating a length of quite six inches for the skull. There are a good many jaws, with the 

 anterior deciduous first molar still implanted. These are provided with distinct roots. The 

 upper one has three roots, one broad posterior one, and two anterior ? the exterior one longer 

 and a little forward of the other. The lower molar has two roots, one posterior very broad, the 

 anterior smaller. The patterns of the teeth do not differ essentially from their successors, 

 although the crowns are narrower. 



46 L 



