288 PLECTOGNATHl. — BALISTID^. 



Family II. Balistid^e. 



{File-Jishes.) 



In this Family the muzzle from the eyes on- 

 ward is conical, or pyramidal in form, terminating 

 in a small mouth, with distinct teeth in both 

 jaws. The skin is either rough and marked with 

 lines or scorings crossing each other at definite 

 angles, or else covered with angular bony plates. 

 The air-bladder is large, strong and oval. There 

 are one hundred and ten species known, all 

 natives of the warmer seas ; and they form two 

 Sub-families. 



1. Balistina, The File-fishes. In these the 

 body is compressed, more or less oval, and covered 

 with a granulated, hard, leathery skin, marked 

 all over with a scored pattern of lozenges, the 

 crossing lines being perfectly smooth, while the 

 rest of the skin is rough. They have eight teeth 

 in one row in each jaw. 



2, Ostracionina. The Trunk-fishes. These have 

 the body angular, four or three-sided, covered 

 with angular plates of solid bone soldered to- 

 gether, and forming a sort of inflexible box, with 

 openings for the mouth, the fins, the tail, and 

 the gill-aperture. They have ten or twelve 

 conical teeth in each jaw. 



Genus Balistes, (Linn.) 



The body, which generally assumes an oval 

 form, more or less pointed at each end, and often 

 Compressed, is invested with a leathery skin, 



