REPTILES. 291 



the mouth animals much larger than the ordinary thick- 

 ness of the body. The palatine bones are likewise loosely 

 connected, and armed with recurved pointed teeth. 



A. Destitute of poison-fangs. 



The serpents of this division, like those of the preceding, 

 are not venomous. There are four regular rows of entire 

 teeth above, and two below. 



Shields under the tail simple, like those on the belly. 



42. ERPETON. This genus, instituted by LACEPEDE, is 

 characterized by two soft eminences, covered with scales, 

 seated on the extremity of the snout. The shields under 

 the tail are small. Head with large plates. E. tentacula- 

 tus. 



43. BOA. Snout destitute of soft eminences. V r ent fur- 

 nished with a hook on each side. Boa constrictor. 



Shields under the tail divided, or forming a double 

 row. 



44. COLUBER. (Python of DAUDIN.) Vent furnished 

 with lateral hooks, like the Boa. The ventral shields are 

 narrow. C. Javenensis. 



45. NATRIX. Destitute of anal hooks. Oviparous. T. 

 torquata. Ringed snake. 



B. Furnished with poison-fangs. 



1. Poison-fangs single, followed by a row of common 

 maxillary teeth. These last are not so numerous as. in the 

 harmless kinds of the preceding section. 



Hinder part of the body and tail rounded. 



46. PSEUDOBOA. Shields of the belly and lower side of 

 the tail single. Head covered with large plates. A swel- 

 ling at the occiput. Back carinated, and covered with a 

 row of enlarged scales. P.fasciata, 



47. TRIMERESURA. Shields under the tail, near thje 

 vent, single ; but, toward the extremity, double. Dorsal 

 scales not enlarged. T. viridis. 



T 2 



