A strew from Newport, California, USA. Fossil marine material (Miocene). 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 26/5/2026. Prepared by Michel Haak. Olympus BHB microscope using 450nm LED light. As well as the wider view I imaged an example of what I think is Coscinodiscus pilosus 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. 29 images Pmax. Underside view with the rim upwards towards the coverslip.
Coscinodiscus pilosus Schmidt in Schmidt et al., 1890. Original description: Schmidt, A. (1890). Atlas der Diatomaceen-kunde. Leipzig. Fues’s Verlag (R. Reisland), Series IV(Heft 37-38): pls. 145-152. Plate 148, Figure 8. Also see: Barron, J.A. (1975). Late Miocene-Early Pliocene marine diatoms from southern California. Palaeontographica Abteilung B Palaeophytologie 151: 97-170. Plate 7, Figure 8. It looks like a good match with the image in Barron 1975, however I’ve not seen many examples and will leave it with a question mark for now.