TAB. VI. 



Fig. 17. Bairdia Harrisiana. 



a X 



50 



b X 



50 



c X 



50 



d X 



50 



e X 



50 



/x 



50 



a X 



50 



3 X 



50 



c X 



50 



^ X 



50 



e X 



50 



Perfect, dorsal aspect 

 Perfect, anterior aspect 

 Perfect, left valve upwards 

 Right valve, outside 

 Right valve, inside 

 Left valve, inside 



Detritus. Charing. 



Chalk. 



e X 50 

 / X 50 

 / XlOO 



Fig. 18. Bairdia angmta. 



Perfect, dorsal aspect . . . Gault. 



Perfect, anterior aspect . . „ 



Perfect, placed obliquely, right valve upwards Detritus. 



Perfect, left valve upwards . . . Gault. 



Right valve, inside . . . „ 



Right valve, ventral edge . . . „ 



Left valve, inside . . . „ 



Left valve, hinge-margin (of fig. 18/) . „ 



Fig. 19. Bairdia triquetra. 



a X 50 Left valve, outside 

 3 X 50 Left valve, dorsal edge 

 c X 50 Left valve, anterior aspect 



Fig. 20. Bairdia Silicula. 



a X 50 Left valve, inside 



^ X 50 Left valve, dorsal edge 



c X 50 Left valve, anterior aspect . 



Fig. 2 1 . Cytlierella (?) appendiculata. 



« X 50 Right (?) valve, outside 

 3 X 50 Perfect, dorsal aspect 



Chalk. 



Gault. 



Fig. 22. Cytherella (?) Mantelliana. 



a X 50 Perfect, left valve upwards . . Detritus. 



5 X 50 Perfect, dorsal aspect . . . „ 



c X 50 Perfect, anterior aspect . . „ 



Fig. 23. Cytherella (?) Bosquetiana. 



« X 50 Perfect, right valve upwards . . Detritus. 



^ X 50 Perfect, dorsal aspect . . „ 



c X 50 Left valve, anterior aspect . • ■ » 



Charlton. 



Folkstone. 



Charing. 

 Folkstone. 



Gravesend. 



Detritus. Charing. 



Folkstone. 



Charing. 



Charing. 



