Aulacodiscus bonei Woodward, fossil marine diatom from Nancowry, Nicobar Isles, Indian Ocean. Single example on the slide. Prepared by ECP Bone. Mounted in Styrax, dated February 1968. Olympus BHB microscope using 450nm LED light. 63x Leitz Pl Apo NA 1.40 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, brightfield lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 28 images stacked in Zerene (Pmax).