A fascinating slide labelled as Auliscus sp. from Bermuda Core, Ex Reed. Single example on the slide. Fossil marine material. Mounted in Styrax/Aroclor, and dated October 1976. Prepared by Richard Gosden. Olympus BHB microscope using 450nm LED light. 63x Leitz Pl Apo NA 1.4 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 116 images stacked in Zerene (Pmax). A very 3D shape. Quadrants at 3 and 9 o’clock (with the ocelli) are raised above the rim, those at 6 and 12 are below the rim. Features (rimoportulae?) at 11 and 1, and 5 and 7.
Back to the name. I asked around and was pointed towards Auliscus actinoptychoides as a possible relation to this. The structure is very similar (see Jakub Witkowski’s great picture here) but obviously this example just has 2 ocelli. Another contact has provided a similar image, and based on discussions, based on the lack of a formal description, this one should be described as “related to Auliscus actinoptychoides but undergoing revision.”. For more on Auliscus actinoptychoides Gleser in Gleser & Posnova, 1964 see the original description: Gleser, S.I. (Glezer, S.I. or Z.I.) & Posnova, A.N. (1964). Diatomeae novae marinae ex eoceno Kazachstaniae Occidentalis. Novitates Systematicae Plantarum Non Vascularium (Academia Scientiarum URSS Institutum Botanicum Nomine V.L. Komarovii) (Novosti Sistematiki Nizschikh Rastenii), 1964: 59-66, available online at https://www.binran.ru/en/publications/novosti-sistematiki-nizshyh-rastenij/1902/10148/.