An arrangement of three Actinoptychus heliopelta from Dunkirk, Maryland, USA. Fossil marine material. Mounted in Hyrax and dated March 1962. Right hand one is tilted down to the right. Prepared by ECP Bone. Olympus BHB microscope using 450nm LED light. 20x Nikon Plan Apo NA 0.65 objective. Olympus Aplanat Achromat condenser, slightly oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 28 images stacked in Zerene (Pmax).
Actinoptychus heliopelta Grunow 1883. Published in: Van Heurck, H. (1882). Synopsis des Diatomées de Belgique. Atlas. pp. pls LXXVIII-CXXXII [78-132 and supplementary pls 22 bis, 82bis, 83bis, 83ter, 95bis], tables genres. Anvers: Ducaju et Cie. Plate 123, Figure 3.