Aporodiscus simbirskianus. No collection location given. Single example on the slide. I believe was prepared by J Tempère based on the handwriting and style. There seem to be various names for this – Rattrayella simbirskiana, Eupodiscus simbirskianus, Glyphodiscus simbirskianus. Olympus BHB microscope using 450nm LED light. 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. 31 images stacked in Zerene (Pmax).