Page:Natural History, Fishes.djvu/201

Rh preceding. They are distinguished, however, by having teeth resembling those of a card, except a range of conical ones in front. The operculum is scaled, the pre-operculum smooth. The pectorals and the ventrals are greatly developed; the former generally, the latter invariably, long and pointed, and sometimes produced into threads: the dorsal also sends forth thread-like filaments. About eighty species constitute this sub-family, which are almost exclusively natives of India. There is, however, a small species in the Mediterranean, and one (Chromis Niloticus, .), which, contrary to the habits of the family, is fluviatile, and reckoned the best fish in the Nile.

3. Scarina. The jaws, (intermaxillaries and premandibles) are convex, rounded, and furnished with scale-like teeth on their margin and anterior surface. The jaws themselves resemble great teeth, and actually perform the office of teeth, being very thick and sharpened at the edges. These rounded bones are divided in the middle by a narrow line, and move vertically, independently of each other, as we have noticed in the living fish. They are nearly covered with fleshy lips, but there are no sub-orbital lips, as in the Labrina. The head and crown are usually elevated, the profile abrupt, sometimes vertical. The body is oblong, covered with coarse, horny scales, which are generally much larger on the tail than elsewhere. The caudal is for, the most part crescent-shaped; the lateral line is interrupted. About one hundred and twenty species belong to this sub-family; scarcely any of which are found beyond the tropics. They are known as Parrot-fishes, chiefly on account of their rounded