SAURIANS. 39 



any other preparation, and is known as rough tortoise shell, which 

 is afterwards manufactured in the same manner as horn. By 

 softening it by the action of hot water, and afterwards pressing, 

 it can be spread out, soldered or moulded into any required shape. 

 What is termed rww, or cast shelly is obtained by agglutinating, 

 by a similar process, the scrapings and powder, detached from the 

 ordinary shell, in fashioning, or giving it the desired dimensions. 

 36. The marine Tortoises, designated under the name of 

 SPHARGIS, have no covering composed of horny plates, but one 

 of a coriaceous skin, similar to leather. Only one species is 

 known, the Luth, which is found in the Mediterranean, and the 

 Atlantic ; it attains seven or eight feet in length. 



LESSON III. 



ORDER OP SAUEIA. Organization. Classification. 

 FAMILY OP CROCODILIDA. Circulation. Habits. Crocodile* 



properly so called. Alligators. 



FAMILY OF LACERTINIDA. Characters. Monitors. Lizards. 

 FAMILY OP IGUANIDA. Characters. Dragons. Iguanas. 



Basilisks. 



FAMILY OP GECKOTIDA. Characters. Habits. 

 FAMILY OF CHAMJELEONIDA. Characters. Common Chameleon. 

 FAMILY OF SCINCOIDEA Characters Scinques Fossil Saurian*. 



ORDER OP OPHIDIA, or Serpents. Characters. 



FAMILY OF ANGUINA. Characters. 



FAMILY OF SERPENTIA, or True Serpents. Coluber. Boa. 



Venomous Serpents. Rattle Snake. Trigonocephalus 



Vipers. Naia, or rfsps. Effects and treatment of the bites 

 of Vipers, #c. 



FAMILY OF NUDA. Characters. 



ORDER OF SAURIANS. 



1. The order of Sauria comprises all reptiles that resemble 

 lizards in their general conformation. Animals of this order 

 always have an elongated body, terminated by a tail of greater 

 or less length, and provided with extremities, which, with some 

 exceptions, are four in number. 



36. How are the Tortoises of the genus Sphargis characterised? 

 1. What is the general character of animals included in the order of 

 Sauria ? 



