Plate P1. Scale bar = 10 µm. 1. Discoaster bellus (Sample 189-1172A-18H-7, 15 cm) (phase-contrast light [Ph]). 2, 3. Discoaster sp. 5-ray (Sample 189-1172A-13H-6, 15 cm); (2) Ph; (3) differential-interference contrast light (DIC). 4. Discoaster challengeri (Sample 189-1172A-18H-7, 15 cm) (Ph). 5. Discoaster exilis (Sample 189-1172A-12H-6, 15 cm) (Ph). 6. Discoaster extensus (Sample 189-1168A-11H-3, 15 cm) (Ph). 7. Discoaster braarudii (Sample 189-1172A-10H-3, 117 cm) (Ph). 8. Discoaster deflandrei (Sample 189-1170A-38X-2, 60 cm) (DIC). 9. Discoaster spp. (Sample 189-1170A-40X-1, 60 cm) (DIC). 10-12. Catinaster coalitus (Sample 189-1168A-19X-1, 15 cm); (10) Ph; (11) DIC; (12) polarized light.

Plate P1. Scale bar = 10 µm. 1. Discoaster bellus (Sample 189-1172A-18H-7, 15 cm) (phase-contrast light [Ph]). 2, 3. Discoaster sp. 5-ray (Sample 189-1172A-13H-6, 15 cm); (2) Ph; (3) differential-interference contrast light (DIC). 4. Discoaster challengeri (Sample 189-1172A-18H-7, 15 cm) (Ph). 5. Discoaster exilis (Sample 189-1172A-12H-6, 15 cm) (Ph). 6. Discoaster extensus (Sample 189-1168A-11H-3, 15 cm) (Ph). 7. Discoaster braarudii (Sample 189-1172A-10H-3, 117 cm) (Ph). 8. Discoaster deflandrei (Sample 189-1170A-38X-2, 60 cm) (DIC). 9. Discoaster spp. (Sample 189-1170A-40X-1, 60 cm) (DIC). 10-12. Catinaster coalitus (Sample 189-1168A-19X-1, 15 cm); (10) Ph; (11) DIC; (12) polarized light.