CHELONIA IMBRICATA. 



41 



derived. The lower jaw is also elongated, and furnished in front with a smaller 

 or less developed hook or tooth; and both have their cutting margins entire or 

 without serrae. 



The vertical plate is hexagonal, very large, and is joined before to the frontal, 

 behind to the occipital, and laterally to the superior orbital, which are oblong and 

 of hexagonal form; the frontal plate is large,' hexagonal, with its greatest extent 

 in the antero-posterior direction, and joined before to the anterior frontal plates, 

 and behind to the superior orbital; there are two anterior frontal plates of similar 

 form, but very small, and largest transversely; the nasal are minute and penta- 

 gonal; there are four occipital, the internal are larger and quadrilateral; the 

 external are smaller and of triangular shape; there are two parietal that unite 

 with the superior orbital plates; and three very small posterior orbital plates, the 

 upper quadrilateral and larger; behind these there are several polygonal temporal 

 plates. 



The nostrils are small, anterior, and closely approximated. The eyelids are 

 large, the upper by far the greater, and covered with some large flexible scales; 

 they open obliquely from above, downwards and forwards. The eyes are large 

 and prominent; the pupil deep sea-blue; the iris golden, reticulated with light 

 brown. 



The anterior extremities are very long, though not broad, and are not unhke 

 the wings of an eagle in shape; at the shoulder they are covered with small 

 flexible plates; at the fore-arm, carpus and fingers the plates are much larger and 

 of variable form; a row of large plates, slightly imbricated, ten or twelve in 

 number, are placed on the anterior border; those along the fore-arm are 

 hexagonal; those at the fingers are rather quadrilateral; on the posterior margin 

 is a fold of skin, in which are placed several large, elongated, quadrilateral plates; 

 in front there are two elongated nails. The posterior extremities are half the 

 length of the anterior, rather rounded at the thigh, but flattened like a paddle at 

 the tarsus and toes, and are covered hke the anterior, but with smaller plates, 

 Vol. IL— 6 



