Two example of Coscinodiscus subtilis from Moron, Spain. Cover slip 0.004” (0.10mm) – thin coverslip. Dated March 1894. Label on the back says “2 valves. Rattray 46 (?). Curious: v. fine markings and dots.”. Prepared by WA Firth. Olympus BHB microscope using 450nm LED light. As well as the arrangement I imaged the left 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. 39 images stacked in Zerene (Pmax).
Coscinodiscus subtilis Ehrenberg 1843. Published in: Ehrenberg, C.G. (1843). Verbreitung und Einfluss des mikroskopischen Lebens in Süd- und Nord-Amerika. Abhandlungen der Königlichen Akademie der Wissenschaften zu Berlin 1841: [291]–445 + [1, Berichtigungen], pls 1–4. Page 412, Plate 1, Figure 3.