Trinacria heibergii. Single example on the slide. No makers name, but I understand this is by Frederick Marshall. Olympus BHB microscope using 450nm LED light. 40x Leitz Pl Apo NA 1.00 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, brightfield lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 77 images stacked in Zerene (Pmax).
There was some really nice subtle patterning on the central region of the diatom which was visible in the original images, but which was unfortunately lost in stacking. This didn’t seem to be textural, as visibility wasn’t improved by using oblique lighting.