CROCODILIA. 



635 



Examples. Cobras, Naja tripudians (Indian), Naja haje 

 (African); the Hamadryad (Ophiophagus daps), eating 

 other snakes; Coral -snakes (Elaps, etc.); Sea-snakes 

 (Hydropkis, etc.), with paddle-shaped tails. The British 

 adder (Pelias berus); the rattlesnake (Crotalus\ with a rattle 

 formed chiefly from epidermic remnants of successive slough- 

 ings ; the African Puff-adder ( Clotho artetans). 



mx. 



Order CROCODILIA. Crocodiles, Alligators, Gavials 



GENERAL CHARACTERS. The 

 Crocodilian* are carnivorous 

 fresh-water reptiles of large size, 

 now represented by a few genera, 

 e.g. Crocodilus, Alligator, and 

 Gavialis. 



The skin bears epidermic scales, 

 underneath some of which there 

 are dermic bones or scutes. 



The tail is laterally compressed, 

 and assists in swimming. 



Teeth occur in distinct sockets 

 in the premaxilla, maxilla, and 

 dentaries. 



In modern Crocodilians, almost 

 all the vertebra are proccelous. 



The skull has many charac- 

 teristic features, such as the union 

 of maxilla, palatines, and ptery- FlG> 34 g.1.Lo WCr surface' of 

 grids in the middle line on the skull of a young crocodile. 

 roof of the mouth, and the COnse- p.mx., Premaxilla; mx., maxilla; 



quent shunting of the posterior > a gg% a gb , & 



nares to the Very back Of the (?/,quadrato-jugal;0., quadrate; 

 ,7 /**> posterior nares ; c. t condyle. 



Some of the ribs have double articulating heads, and bear 

 small uncinate processes ; transverse ossifications form so- 

 called abdominal ribs. 



The heart is four - chambered ; a muscular diaphragm 

 partially separates the thoracic from the abdominal cavity. 



The cloaca has a longitudinal opening. The males have 

 a grooved penis. 



