An arrangement of three Cerataulus thermalis var. chinensis from Colombo, Ceylon (Sri Lanka). No makers name or details on the mountant. Olympus BHB microscope using 450nm LED light. 40x Leitz Pl Apo NA 1.00 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 67 images stacked using Zerene (Pmax). I couldn’t get close enough to focus with the 63x Leitz Pl Apo, hence I chose to image the whole arrangement with the 40x.
Spelling wise, I presume this is equivalent to Cerataulus thermalis var. sinensis. As far as I can tell this is also known as Pleurosira socotrensis (published in: Compère, P. (1982). Taxonomic revision of the diatom genus Pleurosira (Eupodiscaceae). Bacillaria 5: 165-190.).