PLATE 4 



Fig. i. Hystrichosphaera buccina sp. nov. Holotype, ¥.51761(1). X400. 



Fig. 2. Diphyes colligerum (Defiandre & Cookson). ¥.51754(1). X500. 



Fig. 3. Diphyes colligerum (Deflandre & Cookson). London Clay; (85 feet above base 

 of London Clay) Sheppey. Sh.3/i(i). Apical archaeopyle to the north-west. X500. 



Fig. 4. Hystrichosphaera ramosa var. granomembranacea nov. Holotype, ¥.51759(1). 

 X500. 



Fig. 5. Hystrichosphaera cornuta var. laevimura nov. Holotype, ¥.51752(3). X500. 



Fig. 6. Hystrichosphaera ramosa var. multibreva nov. Holotype, ¥.51758(1). X500. 



Fig. 7. Hystrichosphaera cornuta Gerlach. ¥.51741(2). X550. 



Fig. 8. Hystrichosphaera ramosa var. membranacea (Rossignol). Membrane well 

 developed on the apical pole. London Clay (173 feet above base of London Clay); Sheppey, 

 Kent. Micropalaeont. Lab. Colin., University of Sheffield. X375. 



Fig. 9. Hystrichosphaera ramosa var. granosa nov. Holotype, ¥.51752(2). X500. 



Fig. 10. Poly sphae r idium pastielsi sp. nov. Holotype, ¥.51753(1). X425. 



Fig. 11. Homotryblium tenuispinosum gen. et sp. nov. An isolated plate bearing a 

 single intratabular process. London Clay; Enborne boring (at 53 feet depth). E. 11/61/5(1). 

 X750. 



Fig. 12. Hystrichosphaera ramosa var. membranacea (Rossignol). ¥.51747(2). 

 X500. 



