162 



flattened, has lost the fore part and right border of the carapace. The, plas- 

 tron, less injured, has lost its anterior extremity. 



The outline of the carapace appears to have been broadly oval; and the 

 shell was apparently not more elevated than in our common snapper. 



All the bones of the carapace and plastron are so intimately co-ossified that 

 the position of the former sutures cannot be detected. The grooved bound- 

 aries of the scutal areas are, on the other hand, well marked. 



The carapace corresponding with the position of the intermediate vertebral 

 scutes is flattened and slightly depressed at the middle. It is most prominent 

 along the lateral boundaries of the vertebral scutes. In the position of the 

 last of the latter it is most prominent at the middle. No distinct carination 

 exists, but a feeble and widely interrupted ridge occupies the median line of 

 the carapace, scarcely noticeable were it not better developed in other speci- 

 mens. The sides of the carapace slope evenly outward to the rounded flex- 

 ure of the lateral marginal plates. 



The posterior marginal plates are notched as in the snapper, and are slightly 

 recurved at the prominent ends. Between the last pair of marginal bones a 

 wide concave emargination exists, as in Chelydra, but of less depth. 



The intermediate vertebral scute tracts are nearly square, and are as broad 

 as, or a little broader than, long. The lateral grooves have the usual brace 

 form. The groove between the second and third tracts is convex forward ; 

 the succeeding one much lessee!?; and that between the fourth and fifth tracts 

 is much produced forward with a mammiform outline. 



The costal scute. tracts arejnearly like those of Emys and Chelydra. Their 

 grooves are directed nearly parallel outwardly, except the extreme back and 

 front ones. 



The plastron appears quite flat and nearly on the same level with its pedi- 

 cles, but this condition is evidently in some degree the result of accidental 

 pressure from above. The posterior extremity is broad, linguiform, with the 

 ^W end slightly and concavely emarginate. 



The pectoral scute impressions, as in the Chelydra, are larger than any 

 others of the plastron. They extend outwardly on half the breadth of the 

 sternal bridges. The anterior groove is directed outwardly on a level with 

 the bottom of the axillary fossae, and near its end turns abruptly and obliquely 

 forward to the edge of the latter. 



The abdominal scute impressions, shorter than those next in front and 



