Aulacodiscus pallidus from Sendai, Japan. Single example on the slide. Synonymised name: Tripodiscus pallidus (Greville) Kuntze, 1898. Prepared by Arthur Cottam. The diatom is tipping downwards towards the right hand side. Olympus BHB microscope using 450nm LED light. 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. 96 images stacked in Zerene (Pmax).
Described in Greville, R.K. (1863). Descriptions of new and rare Diatoms. Series IX. Transactions of the Microscopical Society, New Series, London, 11(3): 63-76, pls IV & V. page(s): p. 72; pl. V, fig. 17.