A nice but slightly frustrating slide. Strew from Inza, Russia. Prepared by Bernard Hartley. Mounted in Aroclor and dated May 1975.
This slide is the one which had the example of Truania archangelskiana on it (shown here). I was lucky with that one as it was close to the middle of the slide, and I could use a high magnification objective for it. The coverslip on the slide is quite small, and the ring around it is quite high. This prevented me from using anything more than a 20x objective over most of the slide. As such these images are relatively low resolution. Olympus BHB microscope using 450nm LED light. 20x Nikon Plan Apo NA 0.65 objective. Olympus Aplanat Achromat condenser, brightfield lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. Some just single images, other stacks (Zerene, Pmax).
I’ve used 3 sources to try and identify these;
Die Diatomeen der Fur-Formation (Alttertiär) aus dem Limfjord-Gebiet, Nordjütland/Dänemark [Diatoms from the Early Tertiary Fur Formation, Limfjord region, Northern Jutland, Denmark], 1991.
Chambers, Paul Martin; (1997) Late Cretaceous and Paleocene marine diatom floras. Doctoral thesis (Ph.D), UCL (University College London).
Some Cretaceous and Palaeogene Trinacria (diatom) Species. Patricia A. Sims, Robert Ross. British Museum (Natural History), 1988.