An example of Auliscus racemosus from Santa Monica, California, USA. Single example on the slide. Yellowed mountant. Prepared by William Allott Firth. 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. 39 images stacked in Zerene (Pmax).
Auliscus racemosus Ralfs ex Greville, 1863. Original description: Greville, R.K. (1863). A monograph of the genus Auliscus. Transactions of the Microscopical Society, New Series, London, 11(3): 36-53, pls II & III. Page 46, Plate 2, Figure 9.
Also see the page here – https://diatomimaging.com/auliscus-racemosus-ac-cole/