Triceratium tabellarium from Newcastle, Barbados. Single example on the slide. Mounted in Styrax. Some minor issues with the mountant, but not enough to spoil the image. Prepared by RI Firth (no makers name on the slide, but I am going off style and handwriting for this). 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).
Triceratium tabellarium Brightwell 1856. Published in: Brightwell, T. (1856). Further observations on the genus Triceratium, with descriptions and figures of new species. Quarterly Journal of Microscopical Science, London 4: 272-276, 1 pl. [pl. XVII]. Page 275, Plate XVII [17], Figure 15. This name is currently regarded as a synonym of Entogoniopsis tabellaria (Brightwell) J.Witkowski, P.A.Sims, Strelnikova & D.M.Williams 2015. Publication Details: Entogoniopsis tabellaria (Brightwell) J.Witkowski, P.A.Sims, Strelnikova & D.M.Williams 2015. Published in: Witkowski, J., Sims, P.A., Strelnikova, N.I. & Williams, D.M. (2015). Entogoniopsis gen. nov. and Trilamina gen. nov (Bacillariophyta): a survey of multipolar pseudocellate diatoms with internal costae, including comments on the genus Sheshukovia Gleser. Phytotaxa 209: 1-89, 253 figures, 1 table. Page 25.
I have a couple of other examples of T. tabellarium on the site.
It is similar to this one – https://diatomimaging.com/triceratium-grave-wa-firth/
But slightly less similar to this one – https://diatomimaging.com/triceratium-grave-unknown-maker/