130 BUI.I<ETIN 4 «44 



Explanation gf Plate 2. 



.(12) 



Page. 



Fig. I. Ostrea crenulimarginata Gabb 45, 159. 



Kxterior, right valve.* 

 a. Interior, right valve.* 



2. Plicatulaf 47, 161. 



Exterior, 

 a. Interior. 



3. Peden alabamensis Aldrich 48, 163. 



Interior view, x 3. 



4. Avicula sp 48, 162. 



Cast of left valve, 

 a. Cast of right valve. 



I 



