Slide labelled as Cocconeis notabilis from Brünn, Moravia (Brno, Czech Republic). I’ll come back to the name in a minute. Single, partial, example on the slide. Mounted in Styrax and dated September 1932. Some issues with the mountant. Prepared by Samuel Henry Meakin. 63x Leitz Pl Apo NA 1.40 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 40 images stacked in Zerene (Pmax).
Cocconeis notabilis A.W.F.Schmidt, 1894. Published in: Schmidt, A.[W.F.] (1894). Atlas der Diatomaceen-kunde. Series V: Heft [50]. pp. pls 193-196. Leipzig: O.R. Reisland. Expl. Plate 194, Figure 13. The taxonomic or nomenclatural status (or both) of this entity is in some way unresolved and requires further investigation.
Cocconeis notabilis Pantocsek, 1892. Published in: Pantocsek, J. (1892). Beiträge zur Kenntnis der Fossilen Bacillarien Ungarns. Teil III: Süsswasser Bacillarien. Anhang-analysen 15 neuer Depots von Bulgarien, Japan, Mahern, Russland und Ungarn. pp. pls 1-42. Nagytapolcsány Topo: Buchdrucherei von Julius Platzko. Plate 35, Figure 492.
However, is this C. notabilis? It certainly looks similar to the one in Pantocsek, but to me it is a bit narrow in the middle, and the patterning in the middle region looks a little different. While I rarely have reason to doubt Meakin’s naming, I am not 100% on this one.
EDIT – I have recently come across another possible option for this. I think this is more like Cocconeis pellucida Hantzsch & Grunow (in Rabenhorst) (1863–1865), Page 21, Plate 6, Figure 11. It is mentioned in: Cleve, P.T. (1885). On some fossil marine diatoms found in the Moravian “Tegel” from Augarten, near Brünn. Journal of the Quekett Microscopical Club, Series 2 2(13): 165–177, plates 12–13. Page 165. No figure. This would put it in the right deposit for Brünn/Brno.