Two examples of Aulacodiscus heterostictus from Singelevo, Russia. Fossil marine. Sty.mix (Styrax mix, presumably). Dated August 1966. Prepared by ECP Bone. Olympus BHB microscope using 450nm LED light. 63x Leitz Pl Apo 1.4 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, slightly oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 44 images stacked in Zerene (Pmax).
Aulacodiscus heterostictus J.W.Barker & S.H.Meakin 1944. Published in: Barker, J.W. & Meakin, S.H. (1944). New genera and species of diatoms from Russia. Journal of the Quekett Microscopical Club, Series 4 1(6): 251-255, pls 38,39. Page 251, Plate 38, Figure 2.