596 



KEPT I LI A. 



to one another on each side. The males have a grooved penis attached 

 to the anterior wall of the cloaca. There is a urinary bladder. 



Classification of Chelonia. 



I. ATHEC/E. Vertebree and ribs free from carapace. 

 without descending processes from parietals. 



Skull 



Sphargidae, leathery-skinned turtles, with flexible carapace. Sphargis 

 (Dermatochelys} coriacea, the only living species, the largest modern 



I. dO. 



coel 



d. 



do. 



FIG. 292. Heart and associated vessels of tortoise. After Nuhn. 



;-.., Right auricle; superior venae cavse (s.v.c.) and inferior vena 

 cava (i.v.c.) enter it. r.v., Right half of ventricle ; pulmonary 

 arteries (p. a.) and left aortic arch (Lao.) leave it ; ccel., coeliac ; 

 d.ao., dorsal aorta. La., Left auricle ; p.v., pulmonary veins 

 enter it. 1.7'., Left half of ventricle ; right aortic arch (r.ac.), 

 giving off carotids (c.) and subclavians (s.cL). 



Chelonian, sometimes measuring 6 ft. in length. It is widely, but now 

 sparsely, distributed in intertropical seas, and is said to be herbivorous. 



II. THECOPHORA. Dorsal vertebrae and ribs fused in the carapace. 

 Parietals prolonged downwards. Including the following and other 

 families : 



Chelonidae, marine turtles, with fin-like feet, and partially ossified 

 carapace. They occur in intertropical seas, and bury their soft-shelled 

 eggs on sandy shores. The green turtle (Chelone viridis) is much 



