Two examples of Coscinodiscus gigas from Crescent City, (presumably California, USA). Prepared by Arthur Charles Cole. Interesting slide – the label is readable through the body of the slide so in the photo above the coverslip is on the underside. Presumably this label change was done by someone at a later date, as it doesn’t look like an original Cole label. Olympus BHB microscope using 450nm LED light. 20x Nikon Plan Apo 0.65 objective. Olympus Aplanat Achromat condenser, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 25 images stacked in Zerene (Pmax). Diameters, measured in ImageJ; 290µm (left) and 263µm (right).
Coscinodiscus gigas Ehrenberg 1841. 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.