4 



38 

 GASTROCHiENA. 



MYA DUBIA. 



Pennant, 4, pi. 44, f. 19- 



A shell nearly allied to the G. Pholas, being like it 

 a Borer; it is generally found in madrepore; but, not 

 having the accessory valves, it necessarily constitutes a 

 new genus. Shell bivalve, equivalve, almost wedge- 

 shaped, widely gaping, the anterior aperture very large, 

 oval, and oblique, the posterior extremity nearly closed ; 

 hinge linear, marginal, and without teeth. 



Gastrochaena cuneiformis Gastrochaena mytiloides 

 Gastrochaena modiolina, 



SOLEN. 



SOLEN VAGINA. LinnCBUS. 



Chem.6, *.4,/86. 

 With a few shells separated which were confounded 

 with this genus by other authors, it now stands de- 

 fined by La Marck as a bivalve transversely oblong, 

 extremely wide; while thai part, which would by ma- 



