126 BULLETIN OF THE MUSEUM OF COMPARATIVE ZOOLOGY. 



Chelonia Agassizii Dumeril & Bocourt, 1870. 



1 Chelonia virgata Schweigger, 1814. 

 Chelonia virgata Agassi z, 1857. 



Carapace subcordiform, considerably arched, narrow posteriorly ; margin 

 with a shallow indentation over neck and each arm, and a deeper one over 

 each leg. Head moderate, about the size and shape of that of C. mydas, more 

 compressed and pointed in front of the eyes than that of C. depressa. Upper 

 jaw not serrate on the edge, with grooves on the inner face corresponding to 

 the teeth on the lower, with a slight notch in front. Lower jaw serrated on 

 the edge, bearing a prominent curved point on the symphysis. Serration of 

 jaw not apparent in very young specimens. Frontal plates one pair, sometimes 

 subdivided. Vertical small, narrow. One supraocular on each side. Inter- 

 parietal moderate, surrounded by seven plates ; supraoculars and vertical in 

 front, and a pair of large plates behind on the occiput. Postoculars four. Cen- 

 tral plates of carapace thirteen, vertebral series five, anterior and posterior 

 wider, posterior costals and vertebrals sometimes divided ; marginals twenty- 

 five, posterior sometimes fused. The anterior and posterior plates of back are 

 rather suddenly bent downward near the margin. The tail of the male is 

 longer ; it appears that the pointed extremity of the carapace is also more 

 elongate in this sex. 



Specimens described from the eastern portion of the tropical Pacific. 



Cambridge, March, 1880. 



