An example of Hyalodiscus franklinii var. robusta (also seen it as Hyalodiscus subtilis var. robustus) from a strew slide from Oamaru, New Zealand. Viewed from the underside. Prepared by William Henry Barrow (more on him here). Olympus BHB microscope using 450nm LED light. 63x Leitz Pl Apo 1.4 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, brightfield lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 56 images stacked in Zerene (Pmax). Also part of a very large Hyalodiscus (I guess around 300 microns across) in the 10x objective image.