194 CONCHYLIA— i)JTHrK^. 43- 



Linn. Trans, viii. p. 91. 



Turton, British Fauna, p. 160. 



Dillwyn, Descript. Catal. p. 212. 



Turton, Conch. Diet. p. 32, fig. 17. 



Laskey, Wern. Soc. i. p. 385, tab. 8. fig. 7. 



Chemnitz, vii. p. 101, tab. 48, fig. 483. 

 Bucardia. Lister, Conch, tab. 275, fig. iii. lower fig. 



Mus. nost. From Dublin bay : found also at Bantry bay, Belfast ; 

 and St. Abbs' Head in Scotland. 



Shell four inches long, and three and a half wide, of a blackish or 

 tawny color, whitish about the beaks, nearly smooth, or with some 

 fine irregular striae : the beaks twisted into a single flat volution, 

 both fronting the hinder side. 



43. MYTILUS—LINNE, 



Testa longitudinalis, cequivalvis, medio plerumqui hysso fixa ; umboni- 

 bus acutis, rectiusculis, terminalibus, Cardo denticulis obtusis, nu- 

 mero variis, alternatim insertis : lateralibus nullis. Ligamentum 

 marginale, externum. 



Shell longitudinal, equivalve, generally fixed by a byssus issuing 

 from the middle ; with the beaks acute, nearly straight, and 

 terminal. Hinge with small teeth, varying in number, and alter- 



