446 CHORDATA. 
The crocodiles resemble the AZammatvia in the following 
characters :— 
The teeth are thecodont (in sockets) and confined 
to maxilla, premaxilla and dentary. 
2. The maxilla and palatine form a bony palate. 
3. The heart is four-chambered, a septum dividing the 
ventricle into two. 
4. There is an incomplete diaphragm. 
Fig. 316.—VENTRAL VIEW OF CROCODILE’s SKULLx4. (Ad nat.) 
Palatine. 
Transverse. 
Quadrato- 
6) jugal. 
“Quadrate. 
Pterygoid..-- 
Internal Nas. 
Note the thecodont teeth in single row on premaxilla and maxilla, the back- 
ward position of the internal nas, the transverse bone, single 
occipital condyle and quadrate-suspensorium. 
True crocodiles are found in the rivers of tropical Africa 
and in central America. The aé/igators are found in the 
Southern States, West Indies and South America. The 
gavials are small Crocodilia found in the Ganges and its 
tributaries, 
