382! PHILOSOPHY OF ZOOLOGY 



are peculiar in being only three in number on each side. 

 Nostrils with double feelers. Body tapering behind. 



26. DIODON. Beak above and below single. D. atmga. 



27. TETRAODON. Beak above and below double, in 

 consequence of a suture. T. stellatus. 



B. Body incapable of being inflated. No tail, the body 

 terminating abruptly, as if part had been cut off. Body 

 smooth. 



28. ORTHAGORISCUS. Beak single. No air bag. The 

 ductus communis choledocus opens into the stomach. O. 

 Mola and truncata. 



2d Tribe. 



Jaws covered, and supporting ordinary teeth. The 

 snout is produced from the eyes, and terminates in a small 

 mouth, armed with a few distinct teeth on each side. Skin 

 rough, or defended by large scales or plates. 



29. BALISTES. Body scaly. The first dorsal fin con- 

 sisting of one or more moveable serrated spines, the mouth 

 has a single row of eight teeth in each jaw. M. CUVIER 

 distributes the species into four subgenera. 1. Balistes 

 (B. ca/priscus). 2. Monacanthis (B. chinensis). 3. Aleu- 

 teres (B. monoceres). 4. Triacanthes (B. biaculeatus). 



80. OSTRACION. Body covered with regular fixed osse- 

 ous plates. The vertebrae are ossified. The jaws have 

 ten or twelve teeth. O. Triqueter, the French-fish. Bloch. 

 tab. 130. 



2d Subdivision. 



Jaws perfect. 



In this group, the maxillary and palatine bones, from 

 their developement and articulation, enjoy separate motion, 

 giving to the mouth a greater or less degree of facility in 

 arranging its form. 



