i94 xjO^CHYLlX—niTHYRA. 41. 



liinn. Trans, viii. p. 9l. 



Turton, British Fauna, p. 160. 



Dillwyn, Descript. Cata!. p. 212. 



Turton, Conch. Diet. p. 32, fig. ] 7. 



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



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

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



Mus. nost. From Dublin bay : found also at Bantry bay, Bel- 

 fast; and St. Abbs' Head in -Scotland. 



Shell four inches long, and three and a half wide, of a blacivisii 

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

 some fine irregular striai : the beaks twisted into a single fiat 

 volution, both fronting the hinder side. 



43. MYTILUS— i./iV^iVJS. 



Testa longitudinalis, fsquivalvis, medio plerumque hysso Jixa ; 

 iimbonibus acutis, rectiHsculis, terminalibus. Cardo denfi- 

 culis obtusis, numero Vt^'fiis, 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 



