^lo-p ' INTRODUCTION ^^^^^^ 



' Herpetology (from a Greek word meaning *to 



creep') is a science which deals with two classes of 

 cold-blooded vertebrates, the Amphibians and the 

 Reptiles. The first class contains the frcgs,. toads, 

 , salamanders, and certain worm-like forms constitu- 

 ting a group called the Caecilians. The second, 

 Reptiles, contains the turtles, snakes, lizards, croc- 

 idilians, and Rhynchocephalians. The key does 

 not take the Caecilians into consideration. 



KEY to CLASSES and ORDERS 

 A. Skin without scales; young usually under- 

 going a metamorphosis. 

 Amphibia. 



a. A tail present in adult stage. 



Order Caudata- the Salamanders, 

 aa. 1 ail absent in adult; hind legs modified for 

 jumping. 



Order Salentia- the Frogs and Toads. 

 AA. Skin with scales; young similar to parents 

 wiien born. 

 Reptilia. 



a. Anal opening transverse. 



b. Copulatory organs absent. 

 Order Rhynchocephalia. 



bb. Copulatory organs present. 



Order Squamafc-Snakes and Lizards. (These 

 may be told apart by the absence of external 

 ear-opening and eyelids in the former and 

 presence of them in latter) . 



