246 PEOCEEDINGS OP THE MALACOLOGICAL SOCIETY. 



Meecimonia, Dall, 1902 (= Mercenaria, Cossmann, 1886). 



Subgenus. Type, V. Bernayi, Cossm. Eocene of France. 



Shell small, oval, tumid. Lunule superficial and feebly circum- 

 scribed. Teeth in right valve like those of Samarangia, but the 

 median is stouter and semi-triangular ; in left valve the teeth are all 

 entire, the median being thick and having a narrow shelf on the 

 anterior side. Pallial sinus rather short, angular ; sometimes obsolete. 



Species. — M. Bernayi, Cossm. ; M. cytheremformis, Desh. ; M. in- 

 opinata, Desh. ; M. delicatula, Desh. ; and possibly some other species. 



In conclusion, I desire to thank many friends and correspondents for 

 their kind assistance in various ways, especially Dr. "W. E. Hoyle, 

 Dr. J. C. Verco, Mr. E. A. Smith, Mr. J. J. MacAndrew, Dr. J. C. 

 Melvill, and Mr. R. H. Burne. 



EXPLANATION OF PLATE X. 



Fig. 



1. Goniphina donacina (Chem.). 



2. G. {Liocyma) Jluctuosa (Gould). 



3. Marcia pinguis {Ghem.). 



4. M. (Hemitapes) rimularis (Lam.). 



5. M. [Katelysia) corrugata (Lam.). 



6. Samarangia lenticularis (Sow.). 



All the figures are reduced to about four-fifths of the natural size. 



