Strew slide from Bain’s North, Oamaru, New Zealand. Wide variety of species. Mounted in Styraclor and dated February 1998. Prepared by Bernard Hartley. Olympus BHB microscope using 450nm LED light. I chose a couple of diatoms for high magnification imaging. 40x Leitz Pl Apo 1.00 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 50 images stacked in Zerene (Pmax). High coverslip ring prevent me from using the 63x Leitz objective.
The Podosira is perhaps P. argus.
The Hyalodiscus I am less sure about. Maybe Hyalodiscus franklinii var. robusta (although it is a bit small for this). Hyalodiscus franklinii? This is an underside view, with the rim towards the coverslip.