An arrangement of Cestodiscus superbus. No location or makers name. One has gone walkabout from the rest. Olympus BHB microscope using 450nm LED light. As well as the arrangement I imaged the one by itself using the 63x Leitz Pl Apo NA 1.4 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 41 images stacked in Zerene (Pmax). This is an underside view with the rim upwards towards the coverslip.
I think a synonym for this is Cestodiscus pulchellus Greville 1866. Published in: Greville, R.K. (1866). Descriptions of new and rare Diatoms. Series XX. Transactions of the Microscopical Society, New Series, London 14: 121-130, pls XI, XII. Page 123, Plate XI, Figure 5. See also: Fenner, J. (1978). Cenozoic diatom biostratigraphy of the equatorial and southern Atlantic Ocean. Initial Reports of the Deep Sea Drilling Project 38-41 Supplement(1): 491-623, 7 figures, 5 tables, 37 plates. Page 516, Plate 13 Figures 1-5, Plate 14 Figures 1-4.