BIVALVES. 



No. 4. MYA. 

 Gaper. Inhabitant an Jlscidia. 



The ocean rolling, and the 6helly shore; 

 Beautiful objects. 



Shell bivalve, generally gaping at one end, hinge has a solid thick patulous 

 tooth, but seldom two, and not inserted in the opposite valve. The name or 

 term Mya is also derived from the Greek iavm, which is from uvu, to com- 

 press. It was formerly applied to the mytilus. 



The greater part of these animals are inhabitants of the ocean, but some 

 of them are found in fresh water. They perforate the sand or mud at the bot- 

 tom. Many of the species are caught for food, and others for the pearl, which 

 are formed within their shells ; some few of the species perforate and live in 

 limestone, in the same manner as the Pholades. 



The pearl bearing Mya, (Margaritifera) is found chiefly in the large rivers 

 of northern latitudes. The British islands, especially Ireland, have been 

 considered famous for their fisheries of the Mya, and a few pearls of great 

 value have at times been obtained from these sources; but the quality of 

 British specimens is not held in the highest estimation. Some fine pearls, 

 however, were procured from the Shannon, in the year 1821. The river 

 Irt, in Cumberland, the Canway, in Wales, and the Fay, in Scotland, were 

 once noted for their pearl fisheries. Suetonius reports, that Caesar was in- 

 duced to undertake his British expedition for the sake of the pearls, and, 

 according to Pliny and Tacitus, he brought home a buckler made with 



