Pinna

Nacre. In zoology, agenus of the cla vermes, order testacea. Animal a ‘Himax; shell bivalve, fragile, upright, gaping at one end, and furnished with a by us or béard; hinge without teeth, the valves united into one. ‘The inhabitants of these shells produce a large quantity of fine strong by us, which by the Italians is woven into a sort of silk; the shells are generally found standing erect in the smoother waters of bays, with the Jarger end a little open; the animals or fishes of many are aceounted a rich food. Eighteen species, scattered through the seas of the globe, ‘of which only one is found on our own coast, P. muricata, a striate shell with concave, ovate, acute scales: from three to nine inches long, and from one to three broad; thin, brittle, pellucid, horny; the outside with longitudinal ribs, rough, with rows of small prickles. See Nat. Hist. Pl. CLXEV.