CO^CBYLIA—DITHYRA. 40. 177 



Dillwyn, Descript. Catal. p. 244. 



Turton, Conch Diet. p. 8. 



Chemnitz, vii. p. 241. tab. 58, fig. 574. 

 Glycymeris argentea. Da Costa, p. 170, tab. 15, fig. 6. r. hand. 

 Mus. nost. On most coasts. 



Shell half an inch long, and not quite so broad, produced on one 

 side, covered with a smooth blackish or dark olive-green skin, with 

 often some yellowish rays and very minute striae, beaks near one end, 

 inclining to the shorter side, with an oval impression under them ; 

 inside silvery white ; teeth about twenty on the elongated side, and 

 half the number on the other. 



** Margine interna integerrimo. 2-4. 

 The inner margin very entire. 



NucuLA testa obliqud cordatd rotundatd Iceviusculd. 2. 



Shell obliquely heart-shaped roundish and nearly smooth. 



Montagu, Sujjpl. p. 56, tab. 29, fig. I. 



Pennant, Brit Zool. iv. p. 218. 



Dillwyn, Descript. Catal. p. 246. 



Turton, Conch. Diet. p. 11. 

 On the Scotch coasts. 



Shell a quarter of an inch long, and rather more in breadth, white 

 or covered with a thin olive skin, produced and rounded at one end ; 

 inside white, a little perlaceous, with the margin plain. 



2a 



