History of British animals - University of Guam Marine Laboratory

Mya. MOLLUSCA. MYAD/E..46aLength about 2 inches, breadth 3 inches ; white, with a thin cuticle oftenof rusty colour ; concentrically striated ;smooth in the middle ;the broadvertical tooth has usually an oblique rib from the beak to its retral angle, andismarginated anteally the ; pit in the opposite valve for the isligament horizontal,with a small tooth or projection on its anteal margin. The animalis frequently used as food, when boiled. In Zetland it is so used, and is calledSmurslin.— 577. M. arenaria.— Shell rounded at both extremities ;theretral one slightly produced and attenuated.Linn. Syst.i. 1112. Penn. Brit. Zool. iv. 79. t. xlii. Mont. Test. Brit.30. Turt. Biv. Brit. 32.— Common near low water-mark, lodged insand or gravel.Length sometimes reaching 3 inches, breadth five and a half; it chiefly differsfrom the last in the production of the posterior extremity, by the presenceof a few obsolete longitudinal ridges, in being more compressed, and the toothrounder, syphon impression more conical—This species, called at SouthamptonOld Maids, and at Cork Sugar Loons, is more frequently found in estuariesunder the influence of fresh water, than the preceding. The M. ovaliso?T)vTurton, Biv. Brit. 33. t. iii. f. 1, 2, seems nothing more than the young of M.arenaria, " with the tooth flattened at the top, and flexuous."-*~578. M. Norwegica.— Dorsal margin nearly straight, wavedand truncated retrally, rounded anteally.Turt. Linn. iv. 178 M. striata, Mont. Linn. Trans, xi. 188. t. xiii. f. 1.— M. pellucida, Brown, Wern. Mem. ii. 505. t. xxiv. f. 1— Lyonsiastriata, Turt. Biv. Brit. 35. t. iii. f. 6, 7— English and Irish coasts.Length half an inch, breadth an inch ; thin, semitransparent, with a browncuticle, rugged retrally ; longitudinally striated ; inequivalve. According toDr Turton (whom I have followed in bringing together the preceding synonims,not, however, without considerable hesitation), the tooth is an independentprocess, moveable with the ligament.579- M. decussata.— Ovate, with irregular concentric ridges,decussated by regular longitudinal striae.Mont. Test. Brit. Sup. 20—Frith of Forth, Mr Laskey.Diameter about half an inch ; white ; margin waved ; umbo-obtuse, recurved,and placed nearest to one end ; a tongue-shaped syphon mark ;in onevalve a broad erect tooth, in the other a projecting plate, with a small indenturefor the reception of the tooth of the opposite valve. Its generic relationsuncertain.EXTINCT SPECIES.1. M. mandibula.— Gibbose, flattish in the middle, transversely undulated ;retral side square, gaping, anteally straightish—Sower. Min. Conch, t. xliii.In Green Sand.2. M. intermedia Depressed, smooth, twice as wide as long ; sides rounded,the anteal one small, the retral one expanded and gaping a little—Sower.Min. Conch, t. lxxvi. f. 1, and t. ccccxix. f. 2.—London Clay.3. M. plana.— Rather depressed, smooth ;wider than long ; ovate ; nearlyequilateral ; retral side rather elongated.—Sower. Min. Conch, t. lxxvi. f. 2.—Plastic Clay.