SYNOPSIS OF THE ARRANGEMENT OF FISHES. 193 



4. Sub-family Squatin^. — Body shark-like ; head obtuse, 



detached ; mouth terminal. 



Squatika. Head furnished with cirri. 



5. Sub-family Rhinobatin^. — Body shark-like ; head 



pointed, mouth beneath. 



Rhinobates. Head pointed. 

 Rhina. Head obtuse. 



Family 3. PRION ID^. 



Branchial aperture as in osseous fishes. 



Prioxodon. Muzzle forming a long lanceolate plate. 



Family 4. STURIONID^. 

 Body covered with osseous plates and tubercles. 



AciPENSER. Jaws performing the office of teeth ; mouth 

 cirrated. 



Family 5. CHIM^RIDiE. 

 Head with appendages ; tail ending in a point. 



Chimera. Tail ending in a long filament. 



Callorhynchus. Caudal fin narrow, placed on the sides of 

 the pointed tail. 



Order IV. PLECTOGNATHES. 



Skeleton semi-cartilaginous ; branchial spiracle single. 



Family 1. BALISTID^. 

 Body hard, mailed, tuberculated, or spined ; mouth very small. 



1. Sub-femily OsTRAciN-^.-^Body mailed with angular 

 plates. 



Ostracion. Body quadrangular, destitute of spines. 

 VOL. II. O 



