Plate P7. Discoasteraceae IV, Diatoms. 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. 1–11. Discoaster pentaradiatus; (1–4, 7–11) Sample 198-1208A-20H-CC, (5, 6) Sample 198-1208A-24X-CC. 12–17. Sample 198-1208A-29X-CC. 18–23. Catinaster coalitus; (18, 19) Sample 198-1208A-31X-2, (20–22) Sample 198-1208A-30X-CC, (23) Sample 198-1208A-30X-2. 24–29. Catinaster calyculus; (24–27) Sample 198-1208A-30X-CC, (28, 29) Sample 198-1208A-30X-4. 30. Denticulopsis sp. (Sample 198-1208A-19H-CC). 31. Actinoptychus sp. (Sample 198-1208A-23X-CC). 32. Diatom (Sample 198-1208A-30X-CC). 33, 34. Thalassiosira sp.; (33) Sample 198-1208A-8H-CC, (34) Sample 198-1208A-4H-CC. 35. Cyclotella sp. (Sample 198-1208A-1H-CC). 36. Discoaster ?variabilis (Sample 198-1208A-28X-CC). 37, 38. Discoaster variabilis; (37) Sample 198-1208A-28X-CC, (38) Sample 198-1208A-30X-CC.