Coscinodiscus superbus (Cestodiscus written above in pencil) from Newcastle, Barbados. Single example on the slide. Mounted in Styrax. No makers name but this is one by JA Long. 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. 82 images stacked in Zerene (Pmax).
A quick note about the name. I fully agree that this looks more like a ‘Cestodiscus‘ than ‘Coscinodiscus‘, so maybe Cestodiscus pulchellus var. novazealandica (?).