A selection of Aulacodiscus angulatus from Yokohama, Japan. No makers name, but based on the style this is by Laurence Hardman. Olympus BHB microscope using 450nm LED light. As well as the wider array I imaged two using the 40x Leitz Pl Apo NA 1.00 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 42 images stacked in Zerene (Pmax). Based on the label I am assuming (always dangerous) that these are both A. angulatus, but they do have very different appearances….
Aulacodiscus angulatus Greville, 1863. Published in: Greville, R.K. (1863). Descriptions of new and rare Diatoms. Series IX. Transactions of the Microscopical Society, New Series, London 11: 63-76, pls IV, V. Page 71, Plate 5, Figure 15.