The croaker was described by Linnæus, in 1766, from South Carolina. He named it _undulatus_, "undulating or wavy," owing to the undulating character of the markings on the body and fins. Its range extends along the Atlantic coast and Gulf of Mexico from the Middle states to Texas, though it is more abundant from the Chesapeake Bay to Florida. The outline of the body is somewhat elliptical and compressed, not much elevated on the back, but with rather a regular curve from the snout to the tail; its depth is less than a third of its length. The head is about as long as the depth of the body, with a prominent, somewhat blunt snout, and a rather large mouth, with small barbels beneath the lower jaw. [Illustration THE WEAKFISH] [_Cynoscion regalis_] [Illustration THE KINGFISH] [_Menticirrhus saxatilis_] [Illustration THE GERMAN CARP] [_Cyprinus carpio_] The border of the cheek-bones is strongly toothed. The teeth of the jaws are in brushlike bands, with somewhat longer ones in the upper jaw. There are two dorsal fins, slightly connected; the caudal fin is double concave or trifurcate. The back is dusky gray with silvery lustre, sides silvery or brassy, belly white and iridescent. There are a number of dusky or cloudy vertical or oblique bands, and the upper part of the body is profusely sprinkled with numerous dark spots, irregularly placed, in undulating lines. A dusky spot is at the base of the pectoral fin; the dorsal fins are marked with dark spots, which form lines along the soft dorsal fin. The croaker frequents grassy situations in the brackish water of bays and bayous, feeding on crabs, shrimps, and other crustaceans, and small fishes. It grows to a length of ten or twelve inches, and is a good pan-fish when perfectly fresh. It spawns in the autumn. On the grassy flats of the Patapsco and other tributaries of the Chesapeake Bay I have caught countless numbers of the "crocus," as we boys called it. Just under the gill-cover, nearly always, we found a parasitic crustacean or sea-louse, a half inch in length, resembling the land crustacean known as the wood-louse, or sow-bug,--probably an isopod.