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. Coues informs me that he has seldom failed to find Beaver on the 
various streams of the west 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. Owent 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 Hyena. ‘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. Journ. Sci. and Arts, 2d ser., vol. x, 1850, p. 64. 
t Brit. Foss. Mam. and Birds, p. 192. 
