162 INDIAN FRESH-WATER FISHES. 



The Tetrodons are most eccentric-looking little 

 creatures with round bodies, which when taken out of 

 the water they inflate suddenly with air, till they 

 have the appearance of a bladder. 



They belong to the 



ORDER PLECTOGKATHI. 



Char. Mouth narrow, the bones of the upper 

 jaw united, ' sometimes produced into the form of a 

 beak. 



FAMILY GYMNODONTES. (Giinth.Cat.vol. viii.) 



Char. Body rounded. One dorsal fin without 

 spines. No ventral fins. Jaw bones forming a beak 

 with a sharp edge. ~No teeth. 



GENUS TETKODON. 



Char. Each jaw divided in the middle, forming 

 an appearance of four teeth. Dorsal and anal fins 

 very short. Body inflatable, sometimes covered with 

 spines. 



1. Tetrodon patoca. 



Hab. Coasts and rivers. 13 inches. 

 Back and abdomen densely covered with very 

 small spines. 



Upper parts brown, with white or yellowish spots. 

 Dorsal 11. Pectoral 16. Anal 10. Caudal 10. 



