Chondrostoma.—Scales of moderate size or small. Lateral line terminating in the median line of the depth of the tail. Dorsal fin with not more than nine branched rays, inserted above the root of the ventrals. Anal fin rather elongate, with ten or more rays. Mouth inferior, transverse, lower jaw with a cutting edge, covered with a brown horny layer. Barbels none. Gill-rakers short, fine; pseudobranchiæ. Pharyngeal teeth 5 or 6 or 7.-7 or 6 or 5, knife-shaped, not denticulated. Peritoneum black.
Seven species from the Continent of Europe and Western Asia.
Other Old World genera belonging to the Leuciscina are Myloleucus, Ctenopharyngodon, and Paraphoxinus; from North America: Mylopharodon, Meda, Orthodon, and Acrochilus.
IX. Rhodeina.—Anal fin of moderate length, with from nine to twelve branched rays, extending forwards to below the dorsal. Dorsal fin short, or of moderate length. Lateral line, if complete, running along or nearly in the middle of the tail. Mouth with very small, or without any barbels. Pharyngeal teeth in a single series.
Very small roach-like fishes inhabiting chiefly Eastern Asia and Japan, one species (Rh. amarus) advancing into Central Europe. The thirteen species known have been distributed among four genera, Achilognathus, Acanthorhodeus, Rhodeus, and Pseudoperilampus. In the females a long external urogenital tube is developed annually during the spawning season. The European species is known in Germany by the name of “Bitterling.”
X. Danionina.—Anal fin of moderate length or elongate, with not less, and generally more, than eight branched rays. Lateral line running along the lower half of the tail. Mouth with small, or without any, barbels. Abdomen not trenchant. Pharyngeal teeth in a triple or double series.
Small fishes from the East Indian Continent, Ceylon, the East Asiatic Islands, and a few from East African Rivers, The genera belonging to this group are Danio, Pteropsarion, Aspidoparia, Barilius, Bola, Scharca, Opsariichthys, Squaliobarbus, and Ochetobus: altogether about forty species.
XI. Hypophthalmichthyina.—Anal fin elongate. Lateral line running nearly along the median line of the tail. Mouth without barbels. Abdomen not trenchant. No dorsal spine. Pharyngeal teeth in a single series.
One genus (Hypophthalmichthys) with two species from China.
XII. Abramidina.—Anal fin elongate. Abdomen, or part of the abdomen, compressed.