Holland : Pleistocene Fauna at Frankstown, Pa. 233 



of Ursus haplodon, which, as has been pointed out by Cope, shows 

 affinities to the fossil Ursidse of South America, rather than to existing 

 North American species, shows that at the time when these deposits 

 were made there was a commingling on the soil of Pennsylvania of 

 nearctic and neotropical genera, though the nearctic forms predomi- 

 nated. The deposits in the Frankstown cave were probably a little 

 later in their origin than those at Port Kennedy. 



Probably the most interesting of all the numerous specimens ob- 

 tained in the cave at Frankstown is the mandible of a very young mas- 

 todon, sufficiently well preserved to enable a study to be made of the 

 early stages of the dentition. It is, I think, the most perfect speci- 

 men of its kind in existence in any collection. It recalls at once the 

 publication by Dr. Godman in 1830 of his genus Tetracanlodon for the 

 reception of certain specimens which Dr. Isaac Hays in 1834 figured 

 in the Transactions of the American Philosophical Society for that 

 year. Dr. Hays with great chivalry defended the position of Dr. 

 Godman, which had been assailed, and maintained the valid character 

 of the genus Tetracaulodon, which was based principally upon the exist- 

 ence of four incisors, or tusks, in the lower jaw. No better evidence of 

 the correctness of the position of Dr. Godman' s critics could be found 

 than that given by the remains discovered in the Frankstown cave. 



The presence of the remains of numerous infant mastodons and of 

 various species of artiodactyles in the cave, associated with the remains 

 of the huge Arctodus haplodon, suggests that the latter, at a time when 

 what later became a sealed cavern was still an open cleft in the rocks, 

 preyed upon young mastodons, which they may have separated from 

 their mothers and chased over the edge of the cliff-like wall. Falling 

 to the bottom they became an easy prey to the great bears, just as 

 calves to-day fall a prey both to the black bear and to the grizzly. In 

 like manner these bears dragged into this place, which was their lair, 

 in order to feed their young, the carcasses of deer and other hoofed 

 animals. Or they may have driven them over the rocks, as it is pos- 

 sible to imagine that the young mastodons were driven. Arctodus 

 haplodon was a bear somewhat larger than the grizzly and in weight 

 might well have been quite equal, if not superior, to a young mas- 

 todon, judging from the size of the jaws of the latter which we 

 possess. A young mastodon could not have been larger than a baby 

 elephant and probably was not more than three and a half feet in 

 height. It is an interesting picture of the life of the Pleistocene 

 period in Pennsylvania which these fragments suggest. 



