Plate P3. Sphenolithaceae, Incertae sedis, Ceratolithaceae. Taxonomic organization and concepts are generally comparable to those of Young and Bown (1997) and Young (1998). Images with black background are cross-polarized light images; those with light backgrounds are phase-contrast images. 1–6. Cryptococcolithus mediaperforatus; (1, 2) Sample 198-1208A-24X-CC, (3, 4) Sample 198-1208A-33X-CC, (5, 6) Sample 198-1208A-32X-CC. 7. Umbilicosphaera jafari (Sample 198-1208A-18H-CC). 8–10. Umbilicosphaera sibogae sibogae; (8, 9) Sample 198-1208A-5H-CC, (10) Sample 198-1208A-2H-CC. 11–13. Umbilicosphaera rotula; (11, 12) Sample 198-1208A-27X-CC, (13) Sample 198-1208A-30X-CC. 14. Umbellosphaera tenuis (Sample 198-1208A-1H-1). 15, 16. Coronocyclus nitescens (Sample 198-1208A-33X-CC). 17. Tetralithoides symeonidesii (Sample 198-1208A-14H-CC). 18. Holococcolith (Sample 198-1208A-1H-CC). 19. Sphenolithus abies (Sample 198-1208A-25X-CC). 20–23. Sphenolithus heteromorphus (Sample 198-1208A-33X-CC). 24. Sphenolithus moriformis (Sample 198-1208A-35X-CC). 25. Florisphaera profunda (Sample 198-1208A-7H-CC). 26–28. Minylitha convallis; (26) Sample 198-1208A-28X-CC, (27, 28) Sample 198-1208A-27X-CC. 29. Sphenolithus intercalaris (Sample 198-1208A-35X-CC). 30. Sphenolithus predistentus (Sample 198-1208A-35X-CC). 31–33. Amaurolithus bizarrus (Sample 198-1208A-22X-5). 34–38. Amaurolithus delicatus; (34) Sample 198-1208A-23X-CC, (35, 36) Sample 198-1208A-24X-CC, (37, 38) Sample 198-1208A-19H-CC. 39–42. Amaurolithus primus; (39, 40) Sample 198-1208A-25X-CC, (41, 42) Sample 198-1208A-26X-CC.