A strew slide from the Isle of Skye. Good range of species. Material from Prof Trueman, collected 25th August 1942. Mounted in Aroclor and dated May 1975. Prepared by Bernard Hartley. Olympus BHB microscope using 450nm LED light. I chose an example of a Diploneis sp. (I think Diploneis elliptica, although that is a very tentative ID as a lot of these look very similar to each other) for high magnification imaging. 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. 20 images stacked in Zerene (Pmax).
Diploneis elliptica (Kützing) Cleve 1894. Published in: Cleve, P.T. (1894). Synopsis of the naviculoid diatoms. Part I. Kongliga Svenska Vetenskapsakademiens Handlingar Series 4 26(2): 1-194, 5 pls. Page 92.
Although not numbered, based on the description I think this could be slides 665(B) from Bernard Hartley’s Sample and Strew Slide Collection PDF (accessed from here).