\Ga*noi"de*i\, n. pl. [NL. See {Ganoid}.] (Zo["o]l.)
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.

Note: 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.