A diatom strew from Totara, Oamaru, New Zealand. Wide range of species present. Mounted in Naphrax and dated 27th July 1979. Olympus BHB microscope using 450nm LED light. I selected 3 diatoms for higher magnification imaging. 63x Leitz Pl Apo NA 1.4 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. Image stacks prepared in Zerene (Pmax).
Brightwellia coronata. 32 images stacked. Top view. Some ghosting artefacts along strongly contrasting edges. Brightwellia coronata (Brightwell) Ralfs 1861. Published in: Pritchard, A. (1861). A history of infusoria, including the Desmidiaceae and Diatomaceae, British and foreign. Fourth edition enlarged and revised by J. T. Arlidge, M.B., B.A. Lond.; W. Archer, Esq.; J. Ralfs, M.R.C.S.L.; W. C. Williamson, Esq., F.R.S., and the author. pp. [1]-xii, [1]-968, 40 pls [I-XV]. London: Whittaker and Co.. Page 940.
Coscinodiscus diversus ? 29 images stacked. Good visual match. Coscinodiscus diversus Grunow 1884:. Published in: Grunow, A. (1884). Die Diatomeen von Franz Josefs-Land. Denkschriften der Kaiserlichen Akademie der Wissenschaften. Mathematisch-Naturwissenschaftliche Classe, Wien 48(Abt. 2): 53-112, 5 pls. Page 72 (no figure). Maybe Schmidt’s Atlas, Plate 62, Figures 13-15 (as ‘new species’). I had originally put this down as Craspedodiscus coscinodiscus, but I think C. diversus is a better visual match.
Hyalodiscus radiatus ? 23 images stacked. Good visual match. Underside view. Some debris hiding part of the diatom. Hyalodiscus radiatus (O’Meara) Grunow 1879. Published in: Grunow, A. (1879). Algen und Diatomeen aus dem Kaspischen Meere. New species and varieties of Diatomaceae from the Caspian Sea, translated with additional notes by F. Kitton. Journal of the Royal Microscopical Society 2: 677-691, pl. 21. Page 691.