Aulacodiscus decorus from Crescent City, California, USA. Single example on the slide with 8 processes (2 broken). Prepared by William Allott Firth. Olympus BHB microscope using 450nm LED light. 63x Leitz Pl Apo NA 1.4 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 107 images stacked in Zerene (Pmax).
Aulacodiscus decorus Greville 1864. Published in: Greville, R.K. (1864). Descriptions of new and rare Diatoms. Series XII. Transactions of the Microscopical Society, New Series, London 12: 81-86, pls. X, XI. Page 82, Plate X, Figure 2.