142 SPECIFIC 



crenate ; hinge furnished with an anterior tooth 

 besides the usual callus. 

 Inhabits the Indian Ocean. 



Fig. 3. Hinge of Arca ^rawo5fl. 



Fig, 4. Arca tortuosa, 



Shell parallelopiped, striate; larger valve ob- 

 liquely carinate. 



U Argenville Conch, tab. 19. fig. 1. 



Specimen white; striated longitudinally and 

 transversely; valves dissimilar, much twisted; mar- 

 gin subcrenate. 



Inhabits the Indian Ocean. 



Fig. 5. A. NocB, 



Shell oblong, striated, emarginate at the apex, 

 beaks remote, margin gaping. 



Lister Conch, tab. 368. fig. 208. 



Specimen white and brown, rhomboidal ; exter- 

 nal margin crenate, internal one entire ; area witli 

 angular brown lines and impressed marks. 



Inhabits the Mediterranean, Red, Atlantic, and 

 Indian seas. 



