Two examples of Coscinodiscus elegantulus from Chalky Mt, Barbados. Prepared by William Allott 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. 36 images stacked in Zerene (Pmax).
Coscinodiscus elegantulus Greville, 1861. Original description: Greville, R. K. (1861). Descriptions of new and rare Diatoms. Series I. Transactions of the Microscopical Society, New Series, London. 9: 39-45. Page 42, Plate 4, Figure 8. Synonymised name: Azpeitia elegantula (Greville) P.A. Sims in Fryxell, Sims & Watkins, 1986 (and this definitely looks more like an Azpeitia than a Coscinodiscus to me).