A strew slide from False Bay, South Africa. Nice array of species present along with sponge spicules. Clear mountant and the slide not being too dense made imaging easier. Prepared by Bernard Hartley. Mounted in Aroclor and dated May 1975. Olympus BHB microscope using 450nm LED light. 40x Leitz Pl Apo NA 1.00 objective, oil immersion (unless noted). Olympus Aplanat Achromat condenser, oil immersion, brightfield lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. Image stacked prepared in Zerene (Pmax).
I chose three Arachnoidiscus diatoms for further imaging. The two complete ones I think could be Arachnoidiscus ornatus, one viewed from below and one from above. The other in unusual and could be an aberrant structure (especially obvious towards the rim). This one was close to the edge of the slide and I could only image it with the 20x Nikon Plan Apo NA 0.65 objective hence the reduced resolution in the image.