Sf'LERODERMI. 207 



Order Vi. PLECTOGNATHI. 



Teleosteous fishes with rough scales, or with 

 ossifications of the cutis in the form of scutes or 

 spines ; skin sometimes entirely naked. Skeleton 

 incompletely ossified, with the vertebra; in small 

 number. Gills pectinate ; a narrow gill-opening in 

 front of the pectoral fins. Mouth narrow ; the bones 

 of the upper jaw generally firmly united. A soft 

 dorsal fin, belonging to the caudal portion of the ver- 

 tebral column, opposite to the anal ; sometimes ele- 

 ments of a spinous dorsal besides. Ventral fins none, 

 or reduced to spines. Air-bladder without pneu- 

 matic duct. 



Nearly all are marine fishes. 

 Plectognathi, Cuv. Rlgne Animal. 



Synopsis of the Families. 



Jaws with distinct teeth 1. Sclerodermi, p. 207. 



Jaws modified into a beak 2. Gymnodontes, p. 2G9. 



Fam. 1. SCLERODERMI. 



Sclerodermi, Cuv. Rbgne Animal. 



Snout somewhat produced; jaws armed with di- 

 stinct teeth in small number. Skin with scutes or 

 rough. The elements of a spinous dorsal and ventral 

 fins generally present. 



Marine fishes of the temperate or tropical regions. 



