CHELONIA CARETTA. 



35 



sub-caudal are triangular, with their outer borders rounded. There are four 

 principal supplemental plates, the anterior of which is small, and does not reach 

 the sternum; the three others are very large; the second is pentagonal, and joins 

 the thoracic; the third is quadrilateral, and unites with the abdominal; the fourth 

 is trapezoid, and is connected both with the abdominal and femoral plates; besides 

 these, there are some smaller plates that border the brachial and thoracic; the two 

 larger of which connect the second supplemental w ith the anterior border of the 

 thoracic plate, but none reach the shell. 



The head is extremely large, broad behind, rather rounded in front, and covered 

 above with about twenty polygonal plates of various sizes. The vertical is 

 small and hexagonal; on each side it has the superior orbital, which are elongated, 

 pentagonal and broadest within; behind these are the posterior superior orbital, 

 one on each side, of similar form but larger without; behind these again, and on the 

 same longitudinal line, are the parietal plates, of irregular pentagonal form; in 

 the midst of all these plates, and united to all, is a large broad occipital, having 

 two or three small plates on its posterior border. There are three posterior 

 orbital plates; the superior of which is pentagonal and large, the middle is 

 hexagonal and nearly of the same size; the inferior is largest of all, oblong, aad 

 makes part of the inferior wall of the orbit; behind these are four longitudinal 

 rows of temporal plates, varying in size and number; the frontal are large and 

 pentagonal, the nasal are small and hexagonal, with a narrow elongated trapezoid 

 inter-nasal plate, which is continued back between the anterior part of the frontal. 

 The upper jaw is protected by a thick horny covering, rounded in front and 

 broad, narrow behind and reaching under the orbit of the eye. 



The nostrils are anterior, near together, and placed in a cartilaginous substance 

 that occupies the space betw^een the nasal plates and the horny covering of the 

 upper jaw. The eyes are large and prominent; the lids are covered with small 

 plates, and open obliquely from behind downward and forward; the pupil is deep 

 sea-blue, with a dusky grey iris. The upper jaw is strong, nearly a straight hue, 

 being but slightly bent downwards in front; the lower jaw is equally firm and 



