CHELONIA. 



757 



versely. It has also the anterior margin of the shell slightly reverted and the candal 

 region more produced downwards. The dorsal ridge is also more marked. The 

 interval between the margin of the carapace and the sternum is less than in the 

 female, and instead of being convex, as in the latter, it is irregularly flat and concave, 

 the sternal ridge being much more developed than in the opposite sex, and the 

 sternum slightly contracted at its middle and always more or less concave, with the 

 margins tending to reversion. The anal notch is also deeper than in the female. 

 The plates of the carapace and sternum are much the same as in the female, and 

 they are very thin in both sexes, and are very easily rubbed off. 



In males, measuring as above, the carapace is whoUy ossified, while in females of 

 the same size there is a considerable unossified area between all the costals and mar- 

 ginals, which would appear to be conclusive proof of the smaller size of the male. 



The snout is short and rather pointed, and the nostrils close together, round, 



and directed forwards. The margins of the jaw are finely serrated, and there is 



a notch in the front of the upper jaw, with a tooth on either side of it between 



which the symphysial hook of the lower jaw is received. The upper sm'face of the 



head is flat, and covered by one plate ; and there is a large plate behind the eye. The 



plate of the mandible is backwardly convex on the chin, and there is a small plate 



below its extremities and below the angle of the mouth. A series of very small scales 



behind the angle of the mouth ; the mental glands each open by two orifices in the 



usual position. Skin of tympanum nearly smooth. Neck moderately long ; the 



skin on its upper surface nearly smooth, with scattered minute round blackish 



papill£e ; the skin on the sides and under surface somewhat scaly and papillar. The 



base of the neck is smooth, as is also the skin on the groin. The fore feet are broad 



and powerful ; the toes broad, and the five claws strong. The toes are covered with 



from five to six transverse plates, and the upper surface of the free portion of the 



limb with separate transverse plates. The sole is covered with rounded plates, above 



which there is a transverse naked area, succeeded by a transverse row of three 



large plates. The outer margin is fringed with five to six largish plates. The upper 



surface is nearly free of transverse scales, except on the sides, and there are a few 



scattered minute papillae on the bare portions. The tail is short, but it projects 



one-half of its length beyond the carapace. The latter half of its under sm^face 



has a double row of enlarged scales. Its sides and upper surface are covered with 



sharp conical tubercles, among which some larger ones occur on the sides. 



