94 Bulletin 9 386 



Explanation of Plate 10. 



(16) 



Page. 



Fig. 1-4. Venericardia planicosta Lam 54, 346 



Showing different stages of growth of an 

 upper lyignitic and Lower Claiborne variet}^; 

 ribs few, distin(5t, approximate at beak, be- 

 coming obsolete on the adult shell. All from 

 Woods bluff. 



5. V. planicosta Lam. " " 



A common upper Lignitic and Lower Clai- 

 borne variety from Woods bluff. 



Half-toned by The Albany Engraving Com- 

 pany. 



