Slide labelled as Eupodiscus from Water Canyon (probably Dosados Canyon), Moreno, California. This is likely Eupodiscus lineatus, now known as Praetriceratium lineatus. Prepared by JA Long. Olympus BHB microscope using 450nm LED light. 63x Leitz Pl Apo 1.4 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 45 images stacked in Zerene (Pmax).
Someone has repainted the black ring around the coverslip at some point. Unfortunately the immersion oil removed a lot of this, as can be seen in the image of slide.