Aulacodiscus superbus from Joe’s River, Barbados. Single example on the slide. Mounted in Styrax/Aroclor and dated 23-3-[19]65. Ex Adams. Prepared by Richard Gosden. 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. 71 images stacked in Zerene (Pmax). I got a bit lucky with this, and just managed to get deep enough for imaging with the 63x Leitz objective.
Aulacodiscus superbus Kitton 1873. Published in: Kitton, F. (1873). A description of some new species of Diatomaceae. Monthly Microscopical Journal, London 10: 205-207, pl. 38. Page 205, Plate 38, Figure 1.
I have a couple of other examples of this amazing looking diatom on the site (check with Search on the menu above).