CONCHYLI A— D/THFi?^. 23. 75 



Shell an inch and a quarter long, and nearly two broad, pale 

 yellowish-white, transparent, smooth except a few irregular ob- 

 scure transverse ridges, angular at the more produced side by a 

 rib which runs obliquely from the hinge to the margin : beaks 

 pointed not quite central, with a depression under them on the 

 shorter side : teeth as in this division. 



The discovery of this species, of which we have as yet found only 

 a few single valves, will we trust set at rest all doubts concerning 

 the two species of Chemnitz, the Mactra pellucida, and the Mactre 

 fragilis. 



Our specimens correspond exactly with his figure and description. 

 testa ovuli-oblongd, subcompressd, alba, diaphand, IcBvi, cum Jlexurd 

 notabili et manifestd in parte untied. "Shell oval-oblong, flattish, 

 white, transijarent, smooth, with a singular and evident flexure at 

 the anterior side." He remarks also, that it has the figure of a 

 Telliua, but the hinge of a Mactra. 



Mactra testd subtrigond, striiss transversis longitudinalibiisque minutis. ^^j; 

 Shell somewhat triangular, with transverse striae and minute Ion- ^'^^ 



gitudinal ones. 

 Mactra radiata. Donovan, British Shells, v. tab. 161. 



Linn. Trans, viii. p. 61. 



Turton, British Fauna, p. 154. 



Dillwyn, Descript. Catal. p. 1.38. 



Turton, Conch. Diet p. 80. 

 Cardium edentulum. Montagu, Test. Brit. Suppl. p. 29. 

 Found by Captain Laskey, at Portsmouth. 



l2 



