An example of Triceratium hardmanianum from Springield, Barbados. Single example on the slide. Prepared by WA Firth. Olympus BHB microscope using 450nm LED light. 63x Leitz Pl Apo NA 1.40 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, slightly oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 31 images stacked in Zerene (Pmax).
There seems to be two possible spellings for this diatom – should be T. hardmannianum and T. hardmanianum. It was reported in Greville, R.K. (1865). Descriptions of new and rare diatoms. Series XVI . Transactions of the Microscopical Society, New Series, London 13: 43-57 [last page as “75”], 2 pls [pls V, VI]. It is also known as Crawfordia radiata and is discussed in; Sims, P.A., Witkowski, J. & César, E.A. (2021). Crawfordia gen. nov.: solving the riddle of Triceratium hardmannianum Grev. (Bacillariophyta). Nova Hedwigia, Beiheft 115: 205-221, 7 pls, 2 tables. I understand this is an extremely rare diatom.