446 MONOGRAPHS OF NORTH AMERICAN RODENTIA. 



existence in great abundance throughout the Atlantic States, and thence west- 

 ward to the Pacific, is thoroughly attested. They having been less persistently 

 hunted during recent years than formerly, they are reported to be slowly on 

 the increase at most localities where they still remain. 



Dr. Cones informs me that he has seldom tailed to find Beaver on the 

 various streams of the wes* he has explored, from the British to the Mexican 

 boundary. In some of the more secluded waters, where the animals have 

 been little hunted, he has watched them disporting in broad daylight with 

 little sense of danger. He has nowhere found them more abundant than 

 on the various mountain-streams which unite to form the heads of the North 

 Platte River, in North Park. Colorado, where some of the rivulets are choked 

 for miles with successive dams. 



The Berlandier MSS. attest the presence of the animal in various por- 

 tions of Mexico. 



FOSSIL REMAINS. 



Fossil remains of the American Beaver have been discovered in New 

 York and New Jersey, at Memphis, Tennessee, associated with the remains 

 of Castoroides* in the Post-pliocene deposits of the Ashley River, South 

 Carolina, and in the bone-caverns of Pennsylvania and Virginia. The bones 

 of the European Beaver have been found also in deposits of Post-pliocene 

 age, and even in those of the Tertiary. Ovvenf reports the occurrence of the 

 remains of the European Beaver with those of the Trogontherium, Megaceros, 

 and Mastodon, under circumstances indicative of their contemporaneous 

 existence, carrying the antiquity of the European Beaver "far back into the 

 Tertiary period". In the Val d'Arno, according to the same authority, they 

 have been found associated with the remains of the Mammoth, Hippopotamus, 

 and Hyaena. They have also been found in Europe in bone-caves, but most 

 commonly occur in peat bogs and other superficial deposits. Some of these 

 remains indicate an animal rather larger than the largest specimens of the 

 existing Beaver. The Castor issiodorensis from Issoire is closely related to, 

 if not identical with, Castor fiber. 



* Wyman, Amer. Jouru. Ssi. and Arts, 2d ser., vol. x, 1850, p. 64. 

 tBrit. Foss. Mam. and Birds, p. 192. 



