XXIII] 



CLASSIFICATION 



605 



Sub-order 2. Ophidia. 



Sauria devoid of pectoral girdle and of urinary bladder ; 

 in which the rami of the lower jaw are united by an elastic 

 ligament. Limbs absent. 



Ex. Crotalus, Vipera, Tropidonotus. 

 Order III. Chelonia. 



Reptilia with one median copulatory organ on the anterior 

 wall of the cloaca and an immovable quadrate. No sternum 

 and the ribs expanded horizontally to form a dorsal shield: 

 a ventral shield of dermal bone. No teeth. 



Ex. Testudo, Chelone. 

 Order IV. Crocodilia. 



Reptilia with one median copulatory organ on the anterior 

 wall of the cloaca and an immovable quadrate. A well-developed 

 sternum, joined by the ribs. With many alveolar teeth. 

 Ex. Crocodilus, Alligator, Gavialis. 



