Slide labelled as Campylodiscus kittonianus (more on this in a minute). Single example on the slide. No location given. Big piece of debris over the top which obscures most of the middle region. No makers name, but the style and hand writing is that of Arthur Charles Cole. Olympus BHB microscope using 450nm LED light. 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 d850 camera. 103 images stacked in Zerene (Pmax).
Campylodiscus kittonianus Greville 1860. Published in: Greville, R.K. (1860). On Campylodiscus etc. Transactions of the Microscopical Society of London, New Series 8: 29-32, pl. 1. Page 32, Plate 1, Figure 7.
However I remain to be convinced about this name. It doesn’t look to be this based on the Algaebase image for C. kittonianus, or the image in Schmidt’s Atlas (Plate 207, Figure 13). It does however look a bit like the image for C. kittonianus in Deby, J., 1891, Analysis of the Diatomaceous Genus Campylodiscus. Privately published, London. Plate X, Figure 52. So, question mark for now.