Omphalopsis australis from Chagos Is (the Chagos Archipelago or Chagos Islands is a group of seven atolls comprising more than 60 islands in the Indian Ocean). Single example on the slide, mounted at an approximately 45 degree angle. Prepared by WA 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. 18 images stacked in Zerene (Pmax).
Omphalopsis australis Greville, 1863. Original description: Greville, R.K. (1863). Descriptions of new genera and species of Diatoms from the South Pacific. Part 1. Edinburgh New Philosophical Journal, New Series, 18: 34-43, pl. I. Page 37, Plate 1, Figures 10,11.