ACHI'RUS, a genus of flatfish, belonging to the sub-branehiate division of Matacopterygii. In external form these fishes resemble the common sole. Like the Pleuronectes in general, they have the body and tail very much compressed, and the eyes both on the same side of the head ; but they are easily distinguished from all other genera of flat-fish by the total want of pectoral fins.
The species of have no air-bladder, and for the most part, at the bottom of the sea ; being, in fact, ungifted with the faculty of increasing or diminishing their specific gravity, which the possession of this important organ bestows upon ordinary fishes. Their power of locomotion in other directions is however considerable ; and, notwithstanding the disadvantages of their form, and the oblique direction in which this necessarily compels them to move, thsir motions are frequently very rapid. Their habits, as far as a present known, are similar to those of the Pleuronectes.
are found in the warmer regions both of the East and West Indies, but not in deep water, or in situations far removed from land ; they abound along the shores, and furnish a plentiful and wholesome food to the inhabitants.
.Various species of Achirus have been enumerated by zoologists, the most remarkable of . which appears to be the Achirus marmoratus of Laedpede. The flesh is of a delicate flavour, and highly esteemed : it inhabits the coasts of the Isle of France. The A chines pavonicus is distinguished by the beauty of the spots, which, like the eyes on the peacock's tail, cover its body ; and the A. fasciculatus and A. bilineatus are easily recognised by the characters from which they respectively derive their names. The former is found on all the coasts of America and the West Indies : the latter inhabits the shores of China, and feeds upon small crustacea and mollusca.