_Second Group--Haplodactylina._--In both jaws flat and generally tricuspid teeth; no molars; vomerine teeth. The lower pectoral rays simple, not branched. Vegetable feeders. Only one genus is known, _Haplodactylus_, from the temperate zone of the Southern Pacific. _Third Group--Sargina._--Jaws with a single series of incisors in front, and with several series of rounded molars on the side. One genus is known, _Sargus_, which comprises twenty species; several of them occur in the Mediterranean and the neighbouring parts of the Atlantic, and are popularly called “Sargo,” “Sar,” “Saragu:” names derived from the word Sargus, by which name these fishes were well known to the ancient Greeks and Romans. One of the largest species is the “Sheep’s-head” (_Sargus ovis_), from the coasts of the United States, which attains to a weight of 15 lbs., and is highly esteemed on account of the excellency of its flesh. Singularly enough, this genus occurs also on the east coast of Africa, one of these East-African species being identical with _S. noct_ from the Mediterranean. These fishes evidently feed on hard-shelled animals, which they crush with their molar teeth. [Illustration: Fig. 174.--The Sheep’s-head, _Sargus ovis_, of North America.] [Illustration: Fig. 175.--Scale of Lethrinus.] _Fourth Group--Pagrina._--Jaws with conical teeth in front and molar teeth on the sides. Feeding, as the preceding, on hard-shelled animals, like Mollusks and Crustaceans. This group is composed of several genera:-- LETHRINUS.--Cheeks scaleless. Body oblong, covered with scales of moderate size (L. lat. 45–50). Canine teeth in front; lateral teeth in a single series, broadly conical or molar-like. Formula of the fins: D. 10/9, A. 3/8. More than twenty species are known, all of which, with one exception, occur in the tropical Indo-Pacific. The species, forming this exception, occurs, singularly enough, on the west coast of Africa, where more than one Indian genus reappears in isolated representative species. Some Lethrini attain to a length of three feet. _Sphærodon_ is closely allied to _Lethrinus_, but has scales on the cheek. One species from the Indo-Pacific. PAGRUS.--Body oblong, compressed, with scales of moderate size. Several pairs of strong canine-like teeth in both jaws; molars arranged in two series. Cheeks scaly. The spines of the dorsal fin, eleven or twelve in number, are sometimes elongate, and can be received in a groove; anal spines three.