TAB. IV. 



y X 50 



h X 50 



^■ X 50 



I X 50 



J X 



.;'x 



50 

 50 



« X 50 



^ X 50 



c X 50 



^ X 50 



e X 50 



/ X 50 



y X 50 



/ X 50 



/i X 50 



// X 50 



Fig. 10. Cy titer eis quadrilatera, continued. 

 Adult, perfect, anterior aspect . . Gault. 



Immature, left valve, outside 

 Immature, left valve, outside 

 Immature, perfect, dorsal aspect . 

 Young, right valve, outside 

 Young, perfect, dorsal aspect . . Detritus. 



Fig. 1 1 . Cythereis ciliata. 



Adult, left valve, outside 



Adult, perfect, placed obliquely, left valve 



upwards 

 Adult, perfect, dorsal aspect 

 Adult, perfect, ventral aspect 

 Adult, perfect, anterior aspect 

 Immature, left valve, outside 

 Young, left valve, outside . 

 Young, perfect, dorsal aspect 

 Young, left valve, outside . 

 Young, perfect, dorsal aspect 



Detritus. 



Gault. 



Folkstone. 



Charing. 



Charing. 



Folkstone. 



Detritus. Charing. 



