Page:Natural History, Fishes.djvu/312

298 and silvery-white beneath; the plates are bone-white.

The name Chimæra, that of a monstrous compound being in classic fable, was applied by Linnæus to a cartilaginous fish, on account of its singular and uncouth appearance. One species alone was known to him, a native of the northern seas, but a second, if not a third, has since been added from the southern hemisphere.

The Chimæradæ have much resemblance to the Sharks in external appearance; having the same general form, and nearly the same arrangement of the fins. In the peculiarities of their respiratory organs, they hold an intermediate place between these fishes and the Sturgeons, for while there is only one external gill-aperture on each side, yet the gills are not properly free, but adhere by portions of their edges, so as to leave five openings communicating with the external aperture. Their jaws are merely rudimentary; hard undivided plates supply the place of teeth, four above and two below.

The body is lengthened, terminating in a slender filament; there are two dorsals, the first short, high, and preceded by a stout spine; the second low and very long. The males are distinguished by three pointed bony appendages to