198 CONCHYLIA— I>/ri/r/2J. 44. 



Dillwyn, Descript. Catal. p. 310. 



Turton, Conch. Diet. p. 110. 

 Mytilus edulis. Var. Chemnitz, viii. p. 169, tab. 84, fig. 751. 

 Mus. nost. On the western coasts. 



A very elegant shell both in color and figure, seldom reaching 

 to two inches in length, covered when fresh with a dark olive 

 skin, under which it is blue with wiiite rays ; and is distinguished 

 from the radiated variet>" of the common Mussel in its younger 

 state, by having only two or three tubercular teeth under the beaks. 



44. UOmOLP^— LAMARCK. 



Testa suhtransversa, atquivalvis, latere postico brevissimo ; 



umbonibus subienninalibus, ad latus brevius. Cardo eden- 



iulus. Ligamentum marginale, externum. 

 Shell somewhat transverse, equivalve, with the hinder side very 



short ; the beaks nearly terminal, and placed at the shorter side. 



Hinge witliout teeth. Ligament marginal, external. 



This genus is separated from the Mytilus by sufficiently clear 

 characters ; the want of teeth in the hinge, and the lateral but 

 nearly terminal position of the beaks. The species are sometirof" 



