An arrangement of three Triceratium parallelum (?) from Oamaru, New Zealand. Prepared by Clarke and Page. Olympus BHB microscope using 450nm LED light. 20x Nikon Plan Apo NA 0.65 objective. Olympus Aplanat Achromat condenser, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 15 images stacked in Zerene (Pmax).
I’ve put a question mark after the name for this one, mainly because it doesn’t look like a Triceratium. T. parallelum is discussed in Greville, R.K. (1865). Descriptions of new and rare diatoms. Series XVII. Transactions of the Microscopical Society, New Series, London 13: 97-105, 2 pls [VIII, IX], but it only mentions 4 and 6 lobe versions. To me this looks as though it is Stictodiscus parallelus var. parallelus as seen in Plate 100, Fig 15 of Desikachary and Sreelatha’s book ‘Oamaru Diatoms’.