A slide labelled Triceratium sp. Single example. I think this is likely Triceratium (Trigonium) sparsipunctatum. Shown on Schmidt’s Atlas Plate 469, Fig 29 and is a good match. Synonym: Sheshukovia sparsipunctata. Dated 1966. Prepared by RI Firth. 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. 35 images stacked in Zerene (Pmax).