Asteromphalus ralfsianus from guano from Gensino (not been able to find reference as to where Gensino is). Single example on the slide mounted between two disc diatoms, presumably to aid visibility and finding it. Prepared by WA Firth. Olympus BHB microscope using 450nm LED light. 63x Leitz Pl Apo NA 1.40 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 10 images stacked in Zerene (Pmax).