I seem to be having a run recently on slides which are not as they are labelled. This one says Triceratium moronense, but as far as I can tell it is an arrangement of Entogoniopsis tabellaria. As for maker, it says ‘Harris’ which from the style and hand writing looks to be George Harris (often labelled as W. White – see here). 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. Monochrome converted Nikon d850 camera. 69 images stacked in Zerene (Pmax).