A strew slide from Chiloquin, Chemult, Oregon. Nice range of species. Fossil freshwater material. RI Firth’s heavy fraction after re-cleaning by B Hartley. Mounted in Naphrax and dated February 1982. Slide number 1438. Olympus BHB microscope using 450nm LED light.
As well as the strew, I imaged one using the 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. 23 images stacked in Zerene (Pmax).
Looks like a Lindavia sp. to me, something like L. radiosa. A lot of these on the slide.