ACULEATED ODONTOGNATHUS. ^5 



larger at their origin than at their tips, denticulated 

 on their anterior margin, and attached, one on one 

 side, and the other on the opposite, to the most 

 prominent part of the upper jaw: when the mouth 

 is closed again, these pieces apply themselves on 

 each side to one of the opercula, of which they re- 

 present the exterior denticulated border: in the 

 middle of these jaws is placed the tongue, which is 

 pointed and free in its movements : the gill-covers, 

 which are composed of several pieces, are very 

 transparent at the hind part, but scaly and of a 

 bright silver-colour in front : the gill membrane is 

 also silvery, and has five rays : the breast is ter- 

 minated below by a sharp carina furnished with 

 eight crooked spines : the carina of the belly is also 

 furnished with twenty-eight spines, disposed in two 

 longitudinal ranges : the anal fin is very long, and 

 extends almost as far as the base of the tail-fin, 

 which is of a forked shape : the dorsal fin is placed 

 on the tail, properly speaking, at about three quar- 

 ters of the whole length of the animal, but it is ex- 

 tremely small. The general length of this fish is 

 three decimetres, and its colour, so far as may be 

 conjectured from specimens preserved for some 

 time in spirits, is a bright silver. It is a native 

 of the American seas, and is common about the 

 coasts of Cayenne, where it ranks in the number 

 of edible fishes. 



