CO^GHYLIA—DITHYRA. 36. 141 



Turton, Linn. Syst. iv. p. 219. 



Chemnitz, vi. p. 303, tab. 29, fig. 299, 300. 



Donovan, British Shells, ii. tab. 44. 



Montagu, Test. Brit. p. 112. 



Pennant, iv. p. 201, tab. 57, fig. 1- 



Turton, British Fauna, p. 157. 



Linn. Trans, viii. p. 78 



Dorset Catal. p. 34, tab. 8. fig. 1. 



Dillwyn, Descript. Catal. p. 163. 



Turton, Conch. Diet. p. 231. 

 Pectunculus strigatus. Da Costa, p. 185, tab. 12, fig. I. 

 Pectunculus crassissimus. Ldster, Conch, tab. 284, fig. 122. 

 Mus. nost. English and Irish coasts. 



Shell two inches and a half in diameter, of a brownish-white 

 color, strong and heavy, almost globular like a ball, with transverse 

 undulate plates which break into wart-like protuberances at the 

 sides, esjiecially the anterior part : there are also some longitudinal 

 lines which are chiefly distinguishable about the hinge. 



Venus testa orbiculo-cordatd convexd, laminis transversis subimbrica- Casina. 



tis l(Bvibus, areola cordatd. 

 Shell orbicular heart-shaped convex, with transverse somewhat im- 

 bricated smooth plates, and the areola heart-shaped. 

 Tab. nost. 9, fig. 1. 

 Venus Casina. Linn. Syst. Nat. p. 1130. 

 Gmelin, Syst. p. 3269. 

 Turton, Linn. Syst. iv. p. 220 



