FILE-FISHES. 



263 



inflation, and their tall is so short and so high vertically, that they look like 

 fishes with the hinder part cut off. One species, which sometimes attains 

 more than four feet in length, weighing about three hundred pounds, is occa- 

 sionally taken off our own coasts. 



FIG. 281. SUN-FISH. 



FIG. 282. FILE-FISH. 



The File-Pishes (Sderoderms}* are easily distinguished by their conical 

 or pyramidal snout, prolonged from the eyes, and terminated by a small mouth 

 armed with a few teeth that are distinct from each other. Their skin is gene- 

 rally rough or covered with hard scales ; some of them, named 



Balistes, have a compressed body covered by a scaly or granular skin (not 

 bony) ; they have eight teeth, generally trenchant* arranged in a single row in 

 each jaw, and two dorsal fins. They are found in great numbers in the torrid 

 zone. Others, called 



Trunk-Fishes (Ostracion)^ have, instead of scales, an inflexible coat of 

 mail made up of bony plates, which covers the head and body, so that they 

 can only move their tails, their fins, and their mouth, all of which protrude 

 through apertures in their remarkable armour. Each jaw is armed with ten 

 or twelve conical teeth. They are common on the coast of America. 



DIVISION II. CARTILAGINOUS FISHES. 

 ORDER CHONDROPTERYGII.J 



The Chondropterygii differ from all the fishes we have as yet 

 spoken of in the following particulars. Their skeleton is carti- 

 laginous, and always more simple in > its conformation than that 



* ovcAT/pos, skleros, hard ; dep/j-a, derma, skin. ^ ocrrpaKov, ostracon, a shdl. 



s, chondros, cartilage ; irrepi.'yLov, pterygion, a Jin. 



