A strew slide of fossil diatoms from St Peter, Hungary. Great range of species present (most of which I cannot even begin to put names to). Prepared by Watson and Sons Ltd. Olympus BHB microscope using 450nm light. The wider field of view image was done using a 10x Nikon Plan Apo NA 0.45 objective. The two higher magnification ones were done with a 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. Image stacks prepared in Zerene (Pmax).
In the first of the images with the 40x objective, the rounded of rhombus shaped one at the left half way up the image may be Ploiaria petasiformis (Plate XXVIII, Figures 405,406. Beiträge zur Kenntniss der Fosilen bacillarien Ungarns, by Pantocsek, Josef, Th. 2. Brackwasser Bacillarien. Anhang: Analyse der marinen depôts von Bory, Bremia, Nagy-Kürtös in Ungarn; Ananino und Kusnetzk in Russland. 1889.), but that is a very tentative maybe.
In the second image, the one at the lower left of the disc shaped diatom looked to be a Xanthiopyxis sp. and the one peaking out from the upper right of the disc perhaps a Liradiscus bipolaris Lohm. (Plate XXVIII, Figs 13,14, Hajós , M. 1968. Mátraalja Miocén Üledékeinek Diatomái [Die diatomeen der Miozänen Ablagerungen des Mátravorlandes]. Geologica Hungarica, Series Paleontologica, Institutum Geologicum Hungaricum, Budapestini 37:1-401.).