6 INTEODUCTOEY. 



III. THEKIOilOEPHA. 



Aglossa . . . Pipa or Surinam Toads. 



Hani dee . . . Frogs. 



Hylid(E . . . Tree Progs. 



Bti/onidts . . Toads. 



Chelonia, or Turtles. 

 Distinguislied by the double shield in which their bodies are 

 enclosed, whether thej^ are terrestrial, fresh- water, or marine. 



The Turtles, C'hdoma, have the limbs natatory. 



Mud Turtles, Tn'oHJVx, 1 ,. , -,-,■ 



' I limbs ampmbious. 



Terrapens, Erays, j 



Tortoises, Testudo, limbs terrestrial. 



Lacertilia. 

 Having a single transverse process on each side, single-headed 

 ribs, two external nostrils, ej^es with movable lids ; body covered 

 with horny, sometimes bony, scales. 



Lacerta — the Monitors, Crocodiles, Lizards; having ambulatory limbs. 

 Anguis — Ophisaurus, Bimanus, Chalcides, Seps ; limbs abortive ; no sacrum. 



Opiudia. 

 Having numerous vertebra; with single-headed hollow ribs, no 

 visible limbs, ej^elids covered by an immovable transparent lid ; 

 bod}' covered hy horny scales. It includes : — 



Viperince — the Vipers and Crotalidtc. 

 Coluhrina — the Colubers, Hydiidw, and Boidie. 



Crocodilia. 

 Teeth in a single row, implanted in distinct sockets ; bodj- de- 

 pressed, elongated, protected on the back by solid shield ; tail 

 longer than the trunk, compressed laterallj', and furnished with 

 crests above. The several families are : — • 



Grocodilidte — the Gravials, Mecistops, Crocodiles. 



AlUgatorida — Jacares, Alligators, Caim.au. * 



* By some naturalists the Amphibia are consirlcred as a distinct class, by other 

 as a sub-class either of RrptUia or of Pisces. Of the reptiles proper (at' present 

 existing), the arrangement into the orders Tcstiidinata (or Tortoises), Saiiria (or 

 Lizards), and Ophidia (or Snakes), is the one most generally adopted; hut De Blain- 

 ville elevates the Zorieata (or Crocodiles) to the rank of an order, and others have 

 adopted a division of corresponding rank, Saiiropliidia, for the Anr/iiis series above 

 referred to ; but the latter are merely limbless Lizards (or with ahortivo limhs) akin 

 to the Scinques. — Ed. 



