COmmYLI A— DITHYRA. 9. 



35 



Lyonsia 

 Mya striata. 



Mya pellucida. 

 Mya Norwegica. 



Tab. nost. 3, fig. 6 and 7.. 

 Montagu, Lian Trans, xi. p. 188, tab. 13, fig. 1, A. 

 Turton, Conch. Diet. p. 105, fig. 99. 

 Brown, Wern. Soc. ii. p. 105, tab. 24, fig. 1. 

 Gmelin, Syst. p. 3222. 

 Turton, Linn. Syst. iv. p. 1 78. 

 Chemnitz, x. p. 345, tab. 170, f. 1647, 1648. 

 Wood, Conch, p. 98, tab. 18, fig. 4 and 5. 

 Dillwyn, Descript. Catal. p. 48. 

 Turton, Conch. Diet. p. 100, fig. 100. 

 Mus. nost. Tenby, Ireland and the western coasts. 



Shell more than half an inch long, and an inch broad, oblong, 

 running in a nearly straight direction from the beaks to the ante- 

 rior end, and prominently rounded at the opposite margin, thin, 

 .semitransparent, covered with a pale brown skin, which is wrinkled 

 and very rugged at the anterior end, where it is truncate open and 

 reflected ; the valves finely and closely striate longitudinally : beaks 

 near the rounded end, sometimes decorticated ,• inside perlaceous 

 with a rich metallic lustre. 



The decortication about the hinge seems not to be a fixed, but 

 rather an accidental character : for Chemnitz has observed that they 

 are generally so : natibus plerumque decor ticatis. 



striata. 



f2 



