Page:Natural History, Fishes.djvu/93

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Cuvier formed these Fishes into the second Family of the Acanthopterygii in his system, giving to the group, however, thus constituted, no other appellation than the descriptive one of "Fishes with hard cheeks." In these words their most obvious character is indicated, the head and face being encased in a solid buckler of bone, or in hard plates soldered together. In general, the plates as well as the gill-covers, are more or less armed with projecting spines. The technical distinction between the Gurnards and the Perches, to which Family they are very closely allied, consists in the bone beneath the eyes (the sub-orbital bone)—which is greatly dilated, so as to cover the cheeks,—being jointed to the gill-cover. Those curious fishes of the Perch family, the Stargazers (Uranoscopus), have the head mailed and angled much in the same way as the Gurnards, and have their eyes directed even still more vertically; but, in that genus, the sub-orbital bone, though very broad, is united with the temporal bones, and not with the gill-cover.

The fins are well developed; especially the pectorals, which often assume gay colours, and dimensions so great, that, like the true Flying fishes of another Order (Exocœtus), these fishes are capable of projecting their bodies into the air, and of taking long leaps. Some genera have several finger-like rays, unconnected by membrane, in front of the pectorals; which probably