Anaulus obtusus Bone & Gosden, fossil marine diatoms from Division Hill, Oamaru, New Zealand. Two slides, each with one example on them. Slide 1, 69µm x 42µm. Slide 2, 55µm x 33µm. Prepared by ECP Bone. Both mounted in Naphrax and dated March 1968. Olympus BHB microscope using 450nm LED light. 63x Leitz Pl Apo NA 1.40 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, brightfield lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. On slide 2 the mountant has gone orange which blocked more of the 450nm light – exposure times for each image were about 4x those of slide 1. Stacked in Zerene using Pmax (24 images slide 1, 17 images slide 2).