A nice strew slide of diatoms and sponge spicules from St Laurent La Vernède, France. No makers name, but there is what looks to be a date – 10/[19]41. Some letters ‘S’ and ‘CB’. Whether these are the makers initials I am not sure. Olympus BHB microscope using 450nm LED light. As well as the image of the strew at low magnification I am imaged a couple with the 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. Images stacked in Zerene (Pmax).
The first is a bit of an unknown diatom, and I have no name for it yet. It is dome shaped, with a slight dip in the middle. Central rimportula? 61µm (left to right) 56µm (top to bottom). There were a few of these on the slide, although this was the best preserved. No idea as to what it is. If you have any ideas, then please let me know.
The next is an example of Biddulphia fortiana. There’s a Paralia species (Paralia sulcata ?) on the left, and a sponge spicule on the right. The B. fortiana example is slightly damaged but reasonably intact. Biddulphia fortiana Tempère. Original description: Forti, A. (1913). Contribuzioni Diatomologiche XIII. Diagnoses Diatomacearum quarumdam fossilium italicarum. Atti del Reale Istituto Veneto di Scienze Lettero ed Arti, 72(2): 1535-1701. Page 1601, Plate 8, Figures 1,5,20,24. My ID for this one comes mainly from Sims, P.A., Ashworth, M.P., Theriot, E.C. & Manning, S.R. (2022 ‘2023’). Molecular and morphological analysis of Biddulphia sensu lato: a new diagnosis of Biddulphia, with a description of the new genera Biddulphiella and Neobrightwellia. Marine Micropaleontology 178(102186): 1-21, 21 figs. Page 9, Figure 4. I do have a slide with two examples of this one the site, so search for ‘fortiana’ to see that.
Overall a very nicely made strew, with a clear mount and lots of lovely diatoms to image.