GO^GBYLIA—DITHYRA. 43. ' 195 



nately closing together : lateral teeth none. Ligament marginal, 

 external. 



All the species of the Mussel, properly so called, are confined to 

 the above generic character, and as far as we know them, are fur- 

 nished with small obtuse teeth under the points of the beaks; a 

 circumstance sufficient to distinguish them from the Modiola, which 

 is always destitute of them. 



Mytilus testa semiovatd transversim rugosd, antici curvatd, umbonibus ungulatus. 



subquadridentatis. 

 Shell semioval with transverse plaits, curved on the anterior side 



with four or five teeth in the hinge. 

 Mytilus ungulatus. Linn. Syst. Nat. p. 1157. 



Gmelin, Syst. p. 3354. 



Turton, Linn. Syst. iv. p. 592. 



Chemnitz, viii. p. 176, tab. 85, fig. 756. 



Donovan, British Shells, iv. tab. 128, fig-. 2. 



Linn. Trans, viii. p. 107. 



Pennant, Brit. Zool. iv. p. 238. 



Dilhvyn, Descript. Catal. p. 310. 



Turton, Conch. Diet. p. 111. 

 Mytilus ungulinus. Montagu, Test. Brit. p. 582. 



Turton, British Fauna, p. 164. 

 Musculus major. Lister, Conch, tab. 360, fig. 199. 

 Mus. nost. From Cornwall, but probably French. 



Shell four or five inches long, and nearly two broad, covered with 

 a purplish or blackish skin, and resembles the common Mussel, 



2c 2 



