Family II. Balistidæ.
(File-fishes.)
In this Family the muzzle from the eyes onward 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 together, 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,
