Slide labelled as Actinodiscus grayii (fragments). No location give or makers name. Some minor issues with the coverslip adhesive being obvious. Olympus BHB microscope using 450nm LED light. 63x Leitz Pl Apo NA 1.4 objective, oil immersion. Olympus Aplanat Achromat condenser, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 57 images stacked in Zerene (Pmax).
Published in: Ross, R., & Sims, P. A. (2000). A revision of Actinodiscus Greville, Craspedoporus Greville and related genera (Eupodiscaceae). Diatom Research, 15(2), 285–347. https://doi.org/10.1080/0269249X.2000.9705500. The original A. grayii name is assigned to two new names – Actinodiscus corolla and Actinodiscus contabulatus. Based on the appearance I think this is likely A. corolla however I am not 100% on that.
I recently acquired about 60 slides by this maker, so if you want to see others by them, search for AAAAA in the Search option at the top of the page, and I’ll include this in each of the pages for them.