An arrangement of Aulacodiscus quadrans from Simbirsk, Russia. Includes a partial one with 5 processes, which seems to be unusual. Prepared by Arthur Cottam. Olympus BHB microscope using 450nm LED light. As well as the arrangement I imaged the smaller one at the left 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. 75 images stacked in Zerene (Pmax).
Aulacodiscus quadrans A.W.F.Schmidt 1876. Published in: Schmidt, A.[W.F.] (1876). Atlas der Diatomaceen-kunde. Series I: Heft 9. pp. pls. 33-36. Aschersleben: Verlag von Ernst Schlegel. Plate 35, Figure 10; nomen.