When near the ground they swim slowly and horizontally, but if suddenly disturbed they change the horizontal to the vertical position, darting along with meteor-like rapidity, and then again quickly resuming their inactive habits at the bottom of the water. Plaice feed on small fish and young crustacea, and have sometimes been taken on our coasts weighing fifteen pounds, but a fish half that weight is considered very large. The finest kind, called Diamond Plaice, are caught on the Sussex coast. These fish are in considerable demand as food, though by no means equal to the turbot and sole. Those of a moderate size are reckoned the best eating. [Illustration: THE FLOUNDER. (_Platessa flesus._)] THE principal distinction between the plaice and the Flounder consists in the former having a row of six tubercles behind the left eye, of which this fish is entirely destitute; it is also a little longer in the body, and, when full-grown, somewhat thicker. The back is of a dark olive colour, spotted. In taste, they are reckoned more delicate than the plaice. They live long after being taken out of their element, and are often cried in the streets of London, but they seldom appear on the tables of the rich and dainty. They are common in the British rivers, and in all large rivers which obey the impression of the tide, and they feed upon worms bred in the mud at the bottom of the water. [Illustration: THE SOLE, (_Solea vulgaris_,)] IS well known as a very excellent fish, whose flesh is firm, delicate, and of a pleasing flavour. Soles grow to the length of eighteen inches, and even more, in some of our seas. They are often found of this size and superiority in Torbay, whence they are sent to market at Exeter and several other towns in Devonshire and the adjacent counties. They are found also in the Mediterranean and several other seas, and, when in season, are in great requisition for the most luxurious tables. The upper part of the body is brown; the under part white; one of the pectoral fins is tipped with black, the sides are yellow, and the tail rounded at the extremity. It is said that the small Soles, caught in the northern seas, are of a much superior taste to the large ones, which the southern and western coasts afford. This fish has also the quality of keeping sweet and good for several days, even in hot weather, and is thought to acquire a more delicate flavour by being thus kept. On this account it is that Soles in the London markets are frequently more esteemed than those which are cooked immediately after they are taken out of the sea. In the economy of flat fish we have an account of one circumstance which is very remarkable: among various other marine productions, they have been known to feed on shell-fish, although they are furnished with no apparatus whatever in their mouth which would seem to be adapted for reducing these to a state calculated for digestion. [Illustration: THE SALMON-PINK, BRANDLING, PAR, OR SKEGGER.]