Aulacodiscus catenarius from Mejillones, Brazil (Chile?). Single example on the slide. 7 processes. Shown in Schmidt’s Atlas, Plate 106, Fig 3. Slide is oversized (wider than usual) and looks a bit roughly cut at the edges. No makers name, but I am fairly sure this is by Sidney Chaffers. Olympus BHB microscope using 450nm LED light. 40x Leitz Pl Apo NA 1.00 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, slightly oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted d850 camera. 80 images stacked in Zerene (Pmax).
I hadn’t expected much from this slide – it looked a bit rough – but the detail is amazing. Definitely zoom in and look at the structures.