Plate 1. Middle Miocene silicoflagellates. All specimens magnified at 500×, unless otherwise stated. 1. Distephanus crux crux (Ehrenberg), rounded variety, Sample 162-982B-47X-4, 99-100 cm. 2. Dictyocha sp. 1, Sample 162-982B-43X-3, 99-100 cm. 3. Distephanus stauracanthus (Ehrenberg) f. octagonus, Sample 162-982B-46X-3, 99-100 cm. 4, 5. Distephanus stauracanthus (Ehrenberg) f. stauracanthus, Sample 162-982B-48X-5, 99-100 cm (5 magnified at 1250×). 6, 7. Dictyocha sp. 4, Sample 162-907B-21H-4, 106-107 cm, same specimen at high and low focus, both magnified at 1250×. 8-10. Dictyocha fibula Ehrenberg. (8) Sample 162-907B-21H-1, 106-107 cm; (9) Sample 162-907B-20H-1, 109-110 cm, five-sided variety; (10) Sample 162-907B-20H-1, 109-110 cm, three-sided variety. 11. Dictyocha sp. cf. D. rhombica, Sample 162-907B-21H-6, 109-110 cm. 12-15. Distephanus crux lockerii n. ssp.; (12) five-sided variety, Sample 162-907B-21H-4, 106-107 cm; (13) holotype, Sample 162-907B-20H-5, 109-110 cm; (14, 15) three-sided variety, Sample 162-907B-20H-5, 109-110 cm, same specimen at high and low focus. 16. Dictyocha arcuata Curto, Sample 162-982B-53X-4, 99-100 cm. 17. Bachmannocena elliptica miniformis Bachmann and Papp, Sample 162-982B-50X-3, 99-100 cm. 18-21. Bachmannocena elliptica elliptica (Ehrenberg). (18) Sample 162-982B-51X-3, 99-100 cm; (19) Sample 162-982B-52X-2, 99-100 cm; (20) Sample 162-982B-55X-1, 99-100 cm; (21) Sample 162-982B-55X-4, 99-100 cm. 22. Corbisema triacantha (Ehrenberg), Sample 162-982B-55X-1, 99-100 cm. 79