450 



CHELONIA. 



gonal. The first and fourth costal shields are subtrapezoid ; the second 

 and third pentagono-pyramidal. The marginal shields are twenty-five 

 in number, subequal, somewhat longer than broad posteriorly than 

 anteriorly ; the anterior odd one is the largest of all. 



The ridges over the plastron are more conspicuous than those of the 

 carapax, without, however, being too prominent ; they are more deve- 

 loped along the middle region, than towards the extremities. The 

 vitelline split is yet distinctly seen between the fourth and fifth pair 

 of shields. As usual, the shields constitute six middle pairs, and an 

 anterior odd one, small and triangular in the specimens now before us. 

 The three anterior pairs are narrower than the fourth and fifth. There 

 are four lateral pairs of angular, subequal shields, and from six to eight 

 quite small, postaxillar plates, and a few still smaller preinguinal ones. 

 The skin about the axillae and groins is covered with very small, 

 irregular, and unequal plates, or scales, or derinic indurations, which- 

 ever called. 



The anterior flippers are very large ; when stretched backwards 

 along the periphery of the carapax, they will -reach the edge of the 

 last pair of marginal shields. Both their upper and lower surfaces are 

 plated, the plates over the middle region being much smaller than 

 towards the edge. The first and second fingers exhibit each an acute 

 nail, more conspicuous on the first than on the second, which is pro- 

 tected by three plates, the one bearing the nail being larger than the 

 two remaining ones combined. 



The hind flippers are very broad and thin, and when extended for- 

 wards, along the sides of the plastron, they do not quite reach the 

 axillae. Their upper and lower surfaces are likewise plated, and the 

 plates over their middle regions are much smaller than towards their 

 margin. The first and second toes exhibit also an acute nail, stouter 

 on the first (or thumb) than on the second. 



The tail is very small, subconical, and plated ; the series of plates 

 along its upper aspect being larger than the rest, and transversely 

 elongated. 



The upper surface of the head and carapax is blackish -brown ; the 

 temporal plates are blackish in the centre, and yellowish at their 

 margins ; the edge of the upper jaw, beneath the eye, is black also ; 

 the eyelids and rest of the snout are yellowish-brown. The chin and 

 neck are greyish. The edge of the carapax and the entire plastron 

 are yellowish. The upper surface of the flippers is blackish in the 



