Polymixia.—Snout short, with the cleft of the mouth nearly horizontal; eye large. Two barbels at the throat. Opercles without armature. Scales of moderate size. One dorsal. Anal with three or four spines; caudal forked; ventrals with six or seven soft rays.
Three species are known: P. nobilis from Madeira and St. Helena, P. lowei from Cuba, and P. japonica from Japan; the latter species from a depth of 345 fathoms. Average size eighteen inches.
Myripristis.—Snout short, with oblique cleft of the mouth and prominent chin; eye large or very large. Villiform teeth on the vomer and palatine bones. Opercular bones serrated; præoperculum without spine. Scales large, ctenoid. Two dorsals, the first with ten or eleven spines; anal with four spines; caudal forked; ventrals with seven soft rays. Air-bladder divided by a contraction in two parts, the anterior of which is connected with the organ of hearing.
Eighteen species from the tropical seas of both hemispheres, the majority living near the coast at the surface. The coloration is (principally) red or pink on the back and silvery on the sides. They attain a length of about 15 inches, and are esteemed as food.
Holocentrum.—Snout somewhat projecting, with the cleft of the mouth nearly horizontal; eye large. Villiform teeth on the vomer and palatine bones. Opercular bones and præorbital serrated; operculum with two spines behind; a large spine at the angle of the præoperculum. Scales ctenoid, of moderate size. Two dorsals, the first with twelve spines; anal with four spines, the third being very long and strong; caudal forked. Ventrals with seven soft rays.
Fig. 185.—Holocentrum unipunctatum, from the South Sea.
About thirty species are known from the tropical seas of both hemispheres; all are surface fishes, and very common. The young have the upper part of the snout pointed and elongate, and were described as a distinct genus (Rhynchichthys). The coloration of the adult is uniform; red, pink, and silvery prevailing. They attain to a length of about 15 inches, and are esteemed as food.
Third Division—Acanthopterygii Kurtiformes.
One dorsal fin only, much shorter than the anal, which is long and many-rayed. No superbranchial organ.