Two examples of Actinoptychus boliviensis from Mexillones, Bolivia. Very yellowed mountant. Prepared by William Allott Firth. Olympus BHB microscope using 450nm LED light. As well as the arrangement, I imaged the left hand one using the 63x Leitz Pl Apo NA 1.4 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 99 images stacked in Zerene (Pmax).
Actinoptychus boliviensis Janisch, 1874. Published in: Schmidt, A.[W.F.] (1874). Atlas der Diatomaceenkunde. Series I, Heft 1. pp. pls 1-4. Aschersleben: [Verlag von Ernst Schlegel]. Plate 1, Figure 23.