CONCHYLW—DITHYRA. 2H. 



Dorset Catal. p , 30, tab. 5, fig. 8. 



Wood, Concli. p. 187, 



Dillwyn, Descriof. Catal. p. 99. 



Turton, Coiicli. i)ict. p. 176. 

 Pectunculus tenuis. Lister, Concli. tab. 297j fig. 134. 

 Mus. nost. Western coasts, and Ireland. 



Shell an incii or rather more in diameter, convex, very ob- 

 scurely striate transversely in an irregular manner, a little oblique 

 and irregular round the circumference, yellowisii-white or pale 

 horn-color and transparent : beaks not quite central, rather pro- 

 minent; inside white but not glossy, except the area round the 

 marg^in which is faintly striate longitudinally : hinge with two 

 teeth in each valve, one cloven, the other diverging; the lateral 

 cavity narrow and nearly straight. 



LuciNA testd eonvevu transversim striolatd, margine undato, 



valvd altera iridentatd, altera bidentatd. 

 Shell convex slightly striate transversely, undulate in the circum- 

 ference, with three teeth in one valve and two in the other. 

 Venus undata. Pennant, Brit. Zool. p. 209, tab. 58, fig. 3. 



Turton, Linn. Syst. iv. 233. 



Linn. Trans, vi. p. 169, tab. 17, fig. 17 and 18. 



Montagu, Test. Brit, p 117. 



Donovan, British Shells, iv. tab. 121. 



Linn. Trans, viii. p. 86. 



Turton, British Fauna, p. 157. 



Dillwyn, Descript. Catal. p. 197. 



Turton, Conch. Diet. p. 241, fig. 54. 

 3fus. nost. Common on most sandy shores. 



Q 2 



115 



undata. 

 .5. 



