CROCODILIA. 635 
Examples. — Cobras, Maja tripudians (Indian), Naja haje 
(African); the Hamadryad (Ophzophagus elaps), eating 
other snakes; Coral-snakes (Z/aps, etc.); Sea-snakes 
(Aydrophis, 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 arzetans). 
Order Crocopitia. Crocodiles, Alligators; Gavials 
GENERAL CHARACTERS.— The 
Crocodilians 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 dermis bones or scutes. 
The tail ts laterally compressed, 
and assists in swimming. 
Teeth occur in distinct sockets 
in the premaxille, maxille, and 
dentaries. 
In modern Crocodilians, almost 
all the vertebre are procelous. 
The skull has many charac- 
teristic features, such as the union 
of maxille, palatines, and ptery- 
goids in the middle line on the 
roof of the mouth, and the conse- 
guent shunting of the posterior 
nares tothe very back of the 
mouth. 
- 
C 
Fic. 348.—Lower surface of 
skull of a young crocodile. 
p-mx., Premaxilla; #ex., maxilla; 
pal., palatine; 0.2, os trans- 
versum ; #7., pterygoid ; 7., jugal ; 
Q7.,quadrato-jugal ; Q., quadrate 5 
p.#., posterior nares ; c., 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 pents. 
