127 



Margin of the valves distinctly plaited 



Ostrea comucopiae 



Ostrea plicatula 



cucullata 



glaucina 



doridella 



fusca 



rubella 



turbinata 



limacella 



cristagalli 



erucella 



imbricata 



folium 



hyotis 



labrella 



radiata 



[And thirty-three fossil species.] 



VULSELLA. 

 mya vulsella. — Linn. 



Sowerbys Genera, No. 9» plate 5. 

 The G. Vulsella approximates the G. Ostrea, though 

 the leading characters are very distinct from it; their 

 valves are always nearly of an equal size; the apices 

 equal, though somewhat separated; and beneath them 

 on each valve, a projecting callosity, depressed under- 

 neath, having the impression of a conical cavity, ob- 

 liquely arched for the reception of the ligament. Hinge 

 without teeth. These shells are free, longitudinal, sube- 



