144 Notice of tioo New Fossil Mammals. 



Total length of the fragment, - - - - 9| inches. 

 " height of do. at alveoles and base, - - 3| " 

 " breadth of same, - - - - - If " 

 .Length of last molar, - - -'. - - - IJ " 



Breadth of do. O-J " 



..Length of alveolar processes, - - - - 6 " 

 WhQ drawing (Plate III, Fig. 1) representing the exterior or 

 dermal aspect, reduced size, obviates the necessity of more mi- 

 nute detail. 



The crowns of the molars are so worn by detrition as to have 

 destroyed their specific characters — the animal appears to have 

 died at a very advanced age. In size, the animal probably sur- 

 passed the largest of our common hogs. In form of the jaw, 

 general appearance, and number of the teeth, this fragment bears 

 a close analogy with the same part in the Sus babirussa, BufF., 

 or babyroussa, — which species of hog does not exist in the 

 American continent. The structure and composition of the mo- 

 lars are similar, but the Babyroussa was a much smaller animal. 

 Vide Plate III, Fig. L 



Chelonia Coiiperi.* 



The right os femoris of a Chelonian or marine tortoise, pretty 

 well preserved, and well characterized as a nondescript spe- 

 cies, came to my hands, along with the others, but without a 

 number or label attached, as in most of the others. It is com- 

 pletely petrified, heavy, and impregnated with iron. It bears 

 comparison with figures 33 and 34, plate 12, of a recent Chelonia, 

 Cuvier, Ossem. Foss., edit. 1824; and with figures 11 and 19, 

 plate 15, for a fossil specimen. In one remarkable respect, this 

 thigh bone differs from the same part of all recent or fossil spe- 

 cimens, viz. on the exterior and anterior aspect of the shaft, pre- 

 cisely where in other species the bone is smallest, it is here enlarg- 

 ed by a strongly marked scabrous protuberance or exostosis, for 

 the attachments of powerful muscles, vide Plate III, Fig. 2, (a) : 

 so that if this species was not larger than those at present exist- 

 ing, it was probably proportionally stronger. The trochanter has 

 been broken off. Total length, 13 inches. Circumference at the 

 middle of the shaft, 9 inches. A portion of the shield of a Che- 

 lonian occurred along with this bone. 



Philadelphia, May 15,- 1842. . 



