Type slide from Oamaru, New Zealand. No details on the mountant, maker, date etc. Mountant is severely degraded, leading to a ‘crinkly look’ across the surface. Also some issues with the adhesion of the diatoms to the coverslip. Olympus BHB microscope using 450nm LED light. The wide field image of the whole arrangement was done using two images with a 4x Nikon Plan Apo NA 0.2 objective, brightfield lighting. I selected three for imaging at higher resolution. 63x Leitz Pl Apo 1.4 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. Image stacks prepared in Zerene (Pmax).
Navicula variolata fragment. 16 images stacked. Slightly unusual this one, with which bits are missing (not just the rim, but the bits either side of the raphe).
Brightwellia coronata. 45 images stacked. There are two of these in the arrangement, this one was in better condition.
Podosira argus fragment. 28 images stacked for the full view, 4 images for the partial view. Underside view, missing the rim. I am a bit unsure of this one. The full stack failed to show the ‘pock marks’ which were visible in the individual frames, so a smaller stack was done to bring these out. It looks like Podosira argus based on the images in Desikachary and Sreelatha’s book on Oamaru diatoms (Plate 90, Figures 5 and 6) but will leave it with a question mark for now.
I have about 80 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.