An arrangement of three Aulacodiscus longicornis from Singelevo, Russia. Two normal (3 processes) and one abnormal (2 processes). Fossil marine material. Sty.mix (Styrax mix) mountant, and dated September 1966. Prepared by ECP Bone. Olympus BHB microscope using 450nm LED light. I imaged two of them at higher resolution. 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. Image stacks prepared in Zerene (Pmax).
Aulacodiscus longicornis J.W.Barker & Meakin 1947. Published in: Barker, J.W. & Meakin, S.H. (1947). New diatoms from the Moreno shale. J. Quekett Micr. Club, ser. 4 2(3): 143-144. Page 177, Plate 24, Figure 5.
When I first looked at the stacks I thought there were a little soft. I think this is more to do with detail present at different depths in the diatom, rather than movement during stacking.