An arrangement of Actinoptychus (and one Biddulphia) from what looks to be Cambridge, Barbados. Unknown maker. Olympus BHB microscope using 450nm LED light. A low magnification image with a 4x Nikon Plan Apo NA 0.20 objective shows the linear arrangement, but also I liked the shape and structure of the ring around the diatoms. To capture the diatoms I did three stacks, each capturing a few diatoms, with a 20x Nikon Plan Apo NA 0.65 objective, and then pasted them together in Photoshop. I then selected one (middle row, middle diatom of the arrangement image) which I think is Actinoptychus stella var. clevei (Schmidt’s Atlas, Plate 91, Figure 1 as A. clevei) for imaging further. This was done with a 63x Leitz Pl Apo 1.4 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, brightfield lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 60 images stacked in Zerene (Pmax).
I recently acquired about 60 slides by this maker, so if you want to see others by them, search for AAAAA in the Search option at the top of the page, and I’ll include this in each of the pages for them.