1895.] Anthropology. 597 
work which was accomplished prior to the Plistocene age with their 
contents, have been removed by atmospheric and other erosion. 
The explorations in American caves conducted by Mr. H. C. Mer- 
cer of the University of Pennsylvania in the last two years, have 
thrown interesting light on the subject.. He examined some twenty 
five caves’ and rock shelters situated in the valleys of the Tennessee, 
Kanawha and Ohio Rivers with great care, digging trenches to bed 
rock, noting the deposits in their bottoms, and saving all the fragments 
met with, carefully classified as to position, ete. In only one of these 
did he find a slight trace of the Megalonyx fauna, and in this case only 
in a stratum at the bottom. In all the others were found the bones of 
the existing wild fauna of the country, the mammalia, birds, reptiles 
and fishes, with bones, pottery, and flints of the American Indian. 
The sole exception mentioned was the Lookout Cave, Tennessee, where 
in a bed of red clay at the bottom, there were found a jaw of a Tapirus 
haysti, and of a small Mylodon. The cave deposits encountered were 
loose and nowhere indurated as in the caves containing the Megalonyx 
fauna explored by myself. It is perfectly clear from these results that 
there exist cave deposits of two ages in eastern North America, the 
one containing the existing fauna and the Indian, and the other con- 
taining the Megalonyx fauna, and which has so far yielded no traces of 
the existence of man. 
What cause exterminated this populous fauna of large and small 
Mammalia from the North American Continent? Some of its features 
are distinctly South American. Such are the genera of sloths, Mylo- 
don, and by relationship Megalonyx, although the genus did not occur 
in the Southern Continent. Such are the genus Smilodon, and the 
species of peccaries and tapirs, and the great rodent Castoroides which © 
probably belongs to the same. The nearest approach to members of 
this fauna in N. America are the peccary of Texas and the tapir of 
Mexico. The appearance of the caves of this period throws some 
light on the question. The Virginian bone breccia which I examined 
was the floor of a cave only, the cave itself had been carried away by 
some powerful agency. The Tennessee cave was a steeply descending 
shaft which had been filled to the mouth. I found it most convenient 
to break from the roof of a hole which pierced the deposit, the frag- 
ments of matrix which contained the bones. The cave at Port Ken- 
nedy on the Schuylkill River, Penna., is a fissure, and it is packed 
from floor to opening with alternating deposits of clay and vegetable 
8 AMERICAN NATURALIST, 1894, pp. 355, 626. 
40 
