Triceratium araneosum from Chalky Mt, Barbados. Single example on the slide, dipping slightly down away from the coverslip towards the left hand side. I think this was prepared by William Allott Firth (but no name on the slide, basing this on style and handwriting). 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. 53 images stacked in Zerene (Pmax).
Triceratium araneosum Greville, 1865. Published in: Greville, R.K. (1865). Descriptions of new and rare diatoms. Series XV. Transactions of the Microscopical Society, New Series, London 13: 24-34, 2 pl.s [III, IV]. Page 33, Plate III [3], Figure 17. Synonymised name: Pseudotriceratium araneosum (Greville) Grunow, 1884.