An arrangement of three Podosira argus. No makers name, but prepared by Samuel Henry Meakin. Some degradation of the mountant. The largest one in the middle was imaged at higher magnification. It is viewed from the underside with the rim facing the coverslip (as were the other two as well). 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. 63 images stacked in Zerene (Pmax). I initially assumed this was a Hyalodiscus, but apparently P. argus is the accepted name.