This page has three strews by Richard Suter. Olympus BHB microscope using 450nm LED light. Olympus Aplanat Achromat condenser. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. Image stacks prepared in Zerene (Pmax). First up one from Sysran, Russia. I think this is fossil marine material.
A rather busy strew, but with lots to see. I selected two for imaging.
Aulacodiscus septus A.W.F.Schmidt 1876. Published in: Schmidt, A.[W.F.] (1876). Atlas der Diatomaceen-kunde. Series I: Heft 9. pp. pls. 33-36. Aschersleben: Verlag von Ernst Schlegel. Plate 36, Figures 19-21. For more information see Strelnikova, N. I., Fourtanier, E., & Kociolek, J. P. (2004). Morphological studies of Aulacodiscus species from the “Russian collection” of the California Academy of Sciences. Diatom Research, 19(2), 283–310. https://doi.org/10.1080/0269249X.2004.9705876. 55 images stacked. 40x Leitz Pl Apo NA 1.00 oil immersion objective. A view from the underside with the rim upwards towards to the coverslip. Dipping downwards towards the upper left. Very close to the coverslip, so I couldn’t use the 63x Leitz objective.
Rattrayella sp.. I think this is Rattrayella rattrayi (Pantocsek) P.A.Sims 2006. Published in: Sims, P.A. (2006). A revision of the genus Rattrayella De-Toni including a discussion on related genera. Diatom Research 21(1): 125-158. Page 133, Figures 25-38. 51 images stacked. 63x Leitz Pl Apo NA 1.4 oil immersion objective. A view from the underside with the rim upwards towards to the coverslip. Debris present within it which made stacking a challenge.
Next a strew from Siena, Italy (spelt Sienna on the slide). I think this is fossil freshwater material.
I selected an Epithemia for imaging at higher resolution. 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 Nikon d850 camera. 30 images Pmax.
Maybe Epithemia adnata (Kütz.) Bréb. 1838 or Epithemia adnata (Kutzing) Brebisson var. porcellus.
Epithemia adnata (Kützing) Brébisson 1838. Published in: Brébisson, [L.] A. de (1838). Considerations sur les diatomées et essai d’une classification des genres et des espèces appartenant à cette famille, par A. de Brébisson, auteur de la Flore de Normandie, etc.. pp. [i], [1]-20 [error pages bound?]. Falaise & Paris: Brée l’Ainée Imprimeur-Libraire; Meilhac. Page 16.
Epithemia adnata var. porcellus (Kützing) R.Ross 1950. Published in: Ross, R. (1950). Appendix. In: Studies in the post-glacial history of British vegetation. XI. Late-glacial deposits in Cornwall (Ann P. Connolly, H. Godwin and E.M. Megaw (eds.), eds). Philosophical Transactions of the Royal Society of London, Series B 234: 461-464. Page 464. This name is currently regarded as a synonym of Epithemia porcellus Kützing.
Final one is from Szakal, Hungary (spelt Szacal on the slide). Fossil marine material.
I selected an Actinoptychus for imaging at higher resolution. 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 Nikon d850 camera. 47 images Pmax.
Maybe A. splendens, or A. splendens var. halionyx.