An arrangement of three Aulacodiscus argus from Holland. Mounted in Styrax and dated 18/9/1994. Prepared by Klaus Kemp. Olympus BHB microscope using 450nm LED light. As well as the arrangement I imaged the lower left one using the 40x Leitz Pl Apo 1.00 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 44 images stacked in Zerene (Pmax). This is normally a very dark diatom in light microscopy, like the other 2 on the slide. Not seen one like this before. Looks like it could be one in the early stage of development (see: Mary A. Tiffany (2008) Valve Development in Aulacodiscus, Diatom Research, 23:1, 185-212, DOI: 10.1080/0269249X.2008.9705746)
Aulacodiscus argus (Ehrenberg) A.W.F.Schmidt, 1886. Published in: Schmidt, A.[W.F.] (1886). Atlas der Diatomaceen-kunde. Series III: Heft 27/28. pp. pls 105-112. Aschersleben: Verlag von Ludwig Siever. Plate 107, Figure 4. Homotypic synonyms: Tripodiscus argus Ehrenberg 1839, Eupodiscus argus (Ehrenberg) W.Smith 1853.