Two examples of Triceratium condecorum from Maryland, USA. The one on the left is rim upwards (and underside view), while the right one is rim down. As mounted these are further apart, but I have moved them closer together to removed dead space from the image. Sizes have been retained though. Prepared by William Allott Firth. Olympus BHB microscope using 450nm LED light. 40x Leitz Pl Apo NA 1.00 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. 11mm of the tube to the camera removed. Monochrome converted Nikon d850 camera. 104 images stacked in Zerene (Pmax). Couldn’t get close enough to use the 63x Leitz Pl Apo objective.
Trigonium condecorum (Ehrenberg) Hendey 1981. Published in: Hendey, N.I. (1981). Miocene diatoms from the subantarctic southwest Pacific, D.S.D.P., Leg 29, Site 278, Core 10. Bacillaria 4: 65-124, 4 plates. Page 96. Basionym: Triceratium condecorum Ehrenberg 1844. Published in: Ehrenberg, C.G. (1844). Untersuchungen über die kleinsten lebensformen im quellenlande des Euphrats und Araxes, so wie über eine an neuen formen sehr reiche marine tripelbildung von den Bermuda-Inseln. Bericht über die zur Bekanntmachung geeigneten Verhandlungen der Königlich-Preussischen Akademie der Wissenschaften zu Berlin 1844: 253-275, 1 pl. Page 272. This name is currently regarded as a synonym of Sheshukovia condecora (Ehrenberg) Glezer 1984. Published in: Glezer, Z.I. (1984). Znachenie issledovanij po sistematike diatomovych vodoroslej dlia biostrtigrafii i paleogeographii [The importance of research about systematics of diatom algae for biostratigraphy and paleogeography]. Ezhegodnik Vsesoyuznogo Paleontologicheskogo Obshchestva 27: 284-298, 1 figure, 1 table. [in Russian]. Page 293.