OBSERVATIONS. 



I obtained a few incomplete specimens on the coast of 

 Newjersey, near Great Egg-Harbour. Since which Dr. 

 T. W. Harris of Milton, Massachusetts, has sent me seve- 

 ral individuals in perfect preservation, from Nahant, where 

 it is therefore probable that they are not uncommon. — 

 When this species was published, the present genus had 

 not been formed, it was of course referred to solen. S. 

 centralis^ Nob., of the same work, is also of the same group. 



REFERENCE TO THE PLATE. 



Upper figure, exterior of'a valve. 

 Middle figure, dorsal view. 

 Lower figure, inside of a valve. 

 PLATE XVIII. 



