Campylodiscus horologium from the Red Sea. Prepared by WA Firth. Two examples on the slide (shown in an image with a 10x Nikon Plan Apo NA 0.45 objective). Main stack is the of the smaller of the two examples. 63x Leitz Pl Apo NA 1.40 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, slightly oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 39 images stacked in Zerene (Pmax).