146 SPECIFIC 



figure represents the interior of the upper valve 

 with the lateral teeth of the hinge. 

 Inhabits the Mediterranean Sea. 



Fig. 2. A. ephippium. 



Shell suborbicular, rough, undulate, the flatter 

 valve perforated. 



Lister Conch tab. 204. fig. 38. 



Specimen white, convex valve purplish, satu- 

 rated towards the apex, silvery within and with- 

 out; translucent, brittle ; rather lamellate. 



Inhabits the Indian and American Ocean, 



Fig. 3. Mytilus Frons, 



Shell plaited ; one lip scabrous. 



Born, Mus. Cces, p. 121. vign, fig. 6. 



Specimen reddish, oval ; the margin on both 

 sides plaited, denticulate ; lower valve smooth, 

 channeled in the middle, upper one rough with ele- 

 vated points upon the margin, and an elevated cen- 

 tral rib. 



Inhabits the American Ocean. 



Fig. 4. M. margaritiferus. 



