Plate 6. All micrographs are in phase contrast light. 1. Discoaster obtusus Gartner, Sample 149-900A-23R-1, 80 cm. 2. Discoaster deflandrei Bramlette and Riedel (5 ray), Sample 149-900A-20R-4, 90 cm. 3. Discoaster aulakos Gartner, Sample 149-900A-27R-3, 33 cm. 4. Discoaster extensus Hay, Sample 149-900A-20R-5, 64 cm. 5, 6. Discoaster deflandrei var. nodosus new variation. (5) Sample 149-898A-25R-1, 105 cm. (6) Sample 149-898A-26R-2, 63 cm. 7. Discoaster druggii Bramlette and Wilcoxon, Sample 149-898A-22R-5, 86 cm. 8. Discoaster variabilis Martini and Bramlette, Sample 149-900A-20R-5, 64 cm. 9, 10. Discoaster micros (Theodoridis) n. comb. (9) (high focus), Sample 149-900A-13R-CC. (10) (low focus). 11. Discoaster musicus Stradner, Sample 149-900A 20R-5, 64 cm. 12. Discoaster kugleri Martini and Bramlette, Sample 149-898A-18R-5, 134 cm. 13. Discoaster bollii Martini and Bramlette, (small), Sample 149-900A-16R-2, 71 cm. 14-19, 21. Discoaster variabilis Martini and Bramlette. (14) (bright tips), Sample 149-900A-14R-7, 44 cm. (15) (3 ray), Sample 900A-14R-5, 142 cm. (16) (3 ray), Sample 149-900A-12R-2, 106 cm. (17) (5 ray), Sample 149-900A-16R-2, 71 cm. (18) (5 ray), Sample 149-900A-14R-6, 66 cm. (19) (5 ray asymmetric), Sample 149-900A-16R-2, 71 cm. (21) (6 ray), Sample 149-900A-12R-1, 48 cm. 20. Discoaster prepentaradiatus Bukry and Percival, Sample 149-900A-12R-1, 48 cm. 22. Discoaster surculus Martini and Bramlette, (early form), Sample 149-900A-12R-1, 112 cm. 23. Discoaster braarudii Bukry, Sample 149-900A-16R-1, 133 cm. 24, 32. Discoaster broweri (Tan) emend. Bramlette and Riedel. (24) (3 ray), Sample 149-900A-14R-7, 144 cm. (32) Sample 149-900A-14R-7, 44 cm. 25, 26. Discoaster tamalis Kamptner. (25) Sample 149-900A-15R-4, 43 cm. (26) Sample 149-900A-15R-1, 16 cm. 27. Discoaster asymmetricus Gartner, Sample 149-900A-14R-6, 112 cm. 28. Discoaster cf. D. bellus Sample 149-900A-16R-1, 133 cm. 29, 30. Discoaster bellus Bukry and Percival. (29) Sample 149-900A-15R-1, 87 cm. (30) Sample 149-900A-15R-4, 43 cm. 31. Discoaster quinqueramus var. A. Sample 149-900A-15R-4, 43cm.