ANAS, very small, being the less necessary, as the food is in a great measure comminuted in the mouth by aid of the grinders.
The body is long, and a little compressed sideways; the skin smooth and slippery: it wants the lateral line. The pectoral fins consist of 18 rays. The dorsal fin extends from the hind-part of the head almost to the tail; the rays in the fresh fish are not visible. The anal fin extends as far as the dorsal fin. The tail is round at its end, and consists of 13 rays. The sides, back, and fins, are of a livid lead colour; the two first marked downwards with irregular obscure dusky lines: these in different fish have different appearances. The young are of a greenish cast, resembling the sea-wrack, amongst which they reside for some time after their birth.