PLATE i 



Fig. i. Hystrichosphaera ramosa (Ehrenberg) var. ramosa nov. Holotype. Slide xxv. 

 Flint from Delitzsch. Humboldt-Universitat, Berlin. X400. 



Figs. 2, 3. Hystrichosphaera ramosa var. reticulata nov. Holotype. PF. 3038(1). 

 X500. Fig. 3. Surface reticulation in focus. x 1250. 



Fig. 4. Hystrichosphaera ramosa var. multibrevis nov. Cenomanian (boring depth, 

 670 feet). PF. 3040(2). X500. 



Fig. 5. Hystrichosphaera ramosa var. gracilis nov. Cenomanian (boring depth, 670 

 feet). PF.304o(3). X500. 



Fig. 6. Hystrichosphaera ramosa var. ramosa nov. Cenomanian (boring depth, 730 

 feet). P.F.3033(3). X500. 



Fig. 7. Hyst richosphaera crassipellis Deflandre & Cookson. PF. 3033(2). X500. 



Fig. 8. Hystrichosphaera crassipellis Deflandre & Cookson. Cenomanian (boring 

 depth, 770 feet). Wall section to illustrate the unusual thickness. FM.77o(i). X975. 



Fig. 9. Hystrichosphaera cingulata (O. Wetzel). PF.3039(i). X500. 



Fig. 10. Hystrichosphaera cingulata var. reticulata nov. PF. 3039(2). X500. 



Fig. 11. Hystrichosphaera crassimurata sp. nov. Holotype, PF. 3040(1). X500. 



