||Ga*noi"de*i (?), n. pl. [NL. See
Ganoid.] (Zoöl.) One of the subclasses of
fishes. They have an arterial cone and bulb, spiral intestinal valve,
and the optic nerves united by a chiasma. Many of the species are
covered with bony plates, or with ganoid scales; others have cycloid
scales.
&fist; They were numerous, and some of them of large size, in
early geological periods; but they are represented by comparatively
few living species, most of which inhabit fresh waters, as the
bowfin, gar pike, bichir, Ceratodus, paddle fish, and sturgeon.