TAB. VI. 



a X 



50 



b X 



50 



c X 



50 



d X 



50 



e X 



50 



/x 



50 



a X 



50 



b X 



50 



c X 



50 



(/ X 



50 



e X 



50 



e X 



50 



f X 



50 



/ xioo 



Fig. 17. Bairdia Harrisiana. 



Perfect, doi'sal aspect 

 Perfect, anterior aspect 

 Perfect, left valve upwards . 

 Right valve, outside 

 Right valve, inside 

 Left valve, inside 



Fig. 18. Bairdia angmta. 



Perfect, dorsal aspect 



Perfect, anterior aspect 



Perfect, placed obliquely, right valve upwards 



Perfect, left valve upwards . 



Right valve, inside 



Right valve, ventral edge 



Left valve, inside 



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



Fig. 19. Bairdia triquetra. 



Detritus. 



Chalk. 



Gault. 



Detritus. 

 Gault. 



« X 50 Left valve, outside 

 ^ X 50 Left valve, dorsal edge 

 c X 50 Left valve, anterior aspect 



Chalk. 



Ym. 20. Bairdia Silicula. 



a X 50 Left valve, inside 



(5 X 50 Left valve, dorsal edge 



c X 50 Left valve, anterior aspect 



Charinff. 



Charlton. 



Folkstone. 



Charing. 

 Folkstone. 



Gravesend. 



. Detritus. Charing. 



Fig. 21. Cytherella (J) appendicidata. 



a X 50 Right (?) valve, outside . . Gault. Folkstone. 



5 X 50 Perfect, dorsal aspect . . . „ ,, 



Fig. 22. Cytlierella (?) Mantelliana. 



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



5 X 50 Perfect, dorsal aspect . . . „ „ 

 c X 50 Perfect, anterior aspect . . „ „ 



Fig. 23. Cytherella (?) Bosquetiana. 



a X 50 Perfect, right valve upwards . . Detritus. Charing. 



6 X 50 Perfect, dorsal aspect . • „ >, 

 c X 50 Left valve, anterior aspect . . . „ „ 



