TAB. III. 



a X 50 

 h X 50 

 c X 50 

 c X 50 

 d X 50 

 d' X 50 

 e X 50 

 /X 50 

 ff X 50 

 // XlOO 



« X 50 



^ X 50 



c X 50 



c X 50 



^ X 50 

 ^' X 

 e X 



50 

 50 

 / X 50 



Fig 9. Ci/thereis triplicata. 

 Left valve, outside 

 Right valve, outside . 

 Right valve, inside 

 Right valve, dorsal edge 

 Left valve, inside 

 Left valve, dorsal edge 

 Perfect, dorsal aspect 

 Perfect, ventral aspect 

 Perfect, anterior aspect 

 Punctations 



Fig. 10. Cytliereis quadrilatera 



Adult, left valve, outside 

 Adult, right valve, outside 

 Adult, right valve, inside 

 Adult, right valve, dorsal edge 

 Adult, left valve, inside 

 Adult, left valve, dorsal edge 

 Adult, perfect, dorsal aspect 

 Adult, perfect, ventral aspect 



Detritus. Charine-, 



Gault. Folkstone. 



Leacon Hill. 



Gault. 



Folkstone. 



