Coscinodiscus symmetricus from Chalky Mt, Barbados. Single example on the slide. Rim upwards, towards the coverslip. Prepared by WA Firth. Olympus BHB microscope using 450nm LED light. 63x Leitz Pl Apo 1.4 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 26 images stacked in Zerene (Pmax).
Coscinodiscus symmetricus Greville 1861. Published in: Greville, R.K. (1861). Descriptions of new and rare Diatoms. Series II. Transactions of the Microscopical Society, New Series, London 9: 67-73, pl. VIII. Page 68, Plate 8 (VIII), Figure 2.