Aulacodiscus formosus (and others) from upper Peruvian guano. Underside view with the rim towards the coverslip. No makers name. Olympus BHB microscope using 450nm LED light. As well as the wider image I imaged the Aulacodiscus using the 40x Leitz Pl Apo 1.4 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. 11mm removed from the tube the camera to increase the field of view. Monochrome converted Nikon d850 camera. 69 images stacked in Zerene (Pmax).
Aulacodiscus formosus Arnott in Pritchard 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 843.