Stauroneis fulmen from Yarra River, Australia. Single example on the slide mounted with the rim facing the coverslip (underside view). Mounted in Hyrax. Prepared by JA Long. 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. A big diatom – 354µm long (as measured in ImageJ).
Published in: Brightwell, T. (1859). On some of the rarer or undescribed species of Diatomaceae. Part I. Quarterly Journal of Microscopical Science, London 7: 179-181, pl. IX. Page 180, Plate IX (9), Figure 6 (a really nice image of it).