A strew from Juneau, Alaska. Recent marine material. Diatomite sample from H Jay Margolis. Diatom sample from the collection of Colonel William D Fleming, US Army, MD FRMS. Mounted in Pleurax and dated 29/5/2026. Prepared by Michel Haak. Olympus BHB microscope using 450nm LED light. As well as the wider view I imaged one diatom 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. 87 images stacked in Zerene (Pmax).
I think this is Cerataulus turgidus (Ehrenberg) Ehrenberg 1844. Published in: Ehrenberg, C.G. (1843). Beobachtungen des bedeutenden Einflusses unsichtbar kleiner Organismen auf die untern Stromgebeithe, besonders der Elbe, Jahde, Ems und Schelde. 1843: 259-272. Page 271. This name is currently regarded as a synonym of Odontella turgida (Ehrenberg) Kützing 1844. Published in: Kützing, F.T. (1844). Die Kieselschaligen Bacillarien oder Diatomeen. pp. [i-vii], [1]-152, pls 1-30. Nordhausen: zu finden bei W. Köhne. Page 137, Plate 18, Figure 9.