The distinctive characters of the Perches proper are two dorsal fins quite separated, of which the fore one possesses only spinous rays, the hinder only flexible or soft ones. The tongue is smooth; the mouth is armed with teeth, situated in both jaws, in front of the vomer or middle

ridge of the palate, and on the bones of the palate itself; the fore gill-flap (preoperculum) is notched below, and has its hind edge cut into small teeth like those of a saw; the gill-cover (operculum) is bony, and terminates in a flattened spiine pointing backwards. The gill-arches are