166 CO^CHYLIA — DITHYRA. 38. 



The species of this jjeiius are now confined to such as are 

 comprehended in tlje above cliaracter. From the Pectunculus 

 they differ, in having the teeth disposed in a straigiit line. They 

 are inhabitants of rocky coasts, and are generally attached to 

 crevices in the rocks by a filament or byssus which issues from 

 tiie centre of the upper margin. 



^ Margine interno cremtlato. 1-4. 

 With the inner margin toothed. 



No*. A RCA testd oblongd punctato-decussatu, antive anyutatd, 

 margine supero iranscersiin productiori siniiato hianic. 

 Shell oblong decussate in a punctured manner, angular at the 

 anterior side, with the upper margin transversely elongated 

 sinuous and open. 

 Area Noae. Linn. Syst. Nat. p. 1140. 



. Gmelin, Sysf. p. 3-306. 



Turtoti, Linn. Syst. iv. p. 250. 

 Montagu, Test. Brit. p. 139. 

 Pennant, Brit. Zool. iv. p. 215. 

 Linn. Trans, viii. p. 91. 



Donovan, British Shells, v. tab. 158, fig. 1, 2. 

 Turton, British Fauna, p. 161. 

 Dillwyn, Descript. Catal. p. 226. 

 Turton, Conch. Diet. p. 9, fig. 58. 

 Chemnitz, vii. p. 177, tab. 53, fig. 529 to 531. 

 Musculus striatus. Lister, Conch, tab. 368, fig. 208. 

 Mus. nost. Western coasts, and Guernsea. 



