A strew of predominantly Biddulphia obtusa from Oamaru harbour, New Zealand. Mounted in Hyrax. Prepared by JA Long. Olympus BHB microscope using 450nm LED light. Higher resolution image using a 40x Leitz Pl Apo NA 1.00 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 31 images stacked in Zerene (Pmax). I couldn’t get close enough with the 63x Leitz Pl Apo objective so resolution is limited.
Biddulphia obtusa (Kützing) 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 848, Plate 13, Figures 30-32. This name is currently regarded as a synonym of Odontella obtusa Kützing 1844. Published in: Kützing, F.T. (1844). Die Kieselschaligen Bacillarien oder Diatomeen. pp. [i-vii], [1]-152, pls 1-30. Nordhausen: zu finden bei W. Köhne. Page 137, Plate 18/8, Figures 1-3,6-8.