A diatomaceæ test of Pleurosigma attenuatum. Prepared by WH Darlaston. Olympus BHB microscope using 450nm LED light. As well as the wider field view with the 20x objective, one was selected for imaging at higher resolution using a 63x Leitz Pl Apo 1.4 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. 11mm spacer to the camera removed to increase the field of view. Monochrome converted Nikon d850 camera. 42 images stacked in Zerene (Pmax).
Pleurosigma attenuatum (Kützing) W.Smith 1852. Published in: Smith, W. (1852). Notes on the Diatomaceae with descriptions of British species included in the genus Pleurosigma. Annals and Magazine of Natural History, Series 2 9: 1-12, 2 pls. Page 11, Plate 2, Figure 11. This name is currently regarded as a synonym of Gyrosigma attenuatum (Kützing) Rabenhorst 1853. Published in: Rabenhorst, L. (1853). Die Süsswasser-Diatomaceen (Bacillarien.): für Freunde der Mikroskopie. pp. [1]-xii, [1]-72, 10 plates [I–X]. Leipzig: Eduard Kummer. Page 47.