An arrangement of three Coscinodiscus omphalanthus. Prepared by Samuel Henry Meakin. Mounted in Sirax and dated April 1943. Slide is labelled as ‘Test’. Olympus BHB microscope using 450nm LED light. 10x Nikon Plan Apo NA 0.45 objective (for the arrangement of the three diatoms), 20x Nikon Plan Apo NA 0.65 objective (for the whole single diatom), and 63x Leitz Pl Apo NA 1.40 objective with oil immersion (for the central part of one diatom, showing the full frame and a crop). Olympus Aplanat Achromat condenser, oil immersion for the 63x Leitz objective, brightfield lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. Images stacked in Zerene (Pmax).