A strew slide of Pleurosigma angulatum (and others) from Pilling, Lancashire. Dry mounted on cover(slip). Prepared by Stanley Meakin. Olympus BHB microscope using 450nm LED light. I chose an example of Pleurosigma angulatum 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. 29 images stacked in Zerene (Pmax). There looked to be some structure around the top right of the diatom, perhaps where the droplet of water it presumably was in evaporated and left something behind? Not sure.
Pleurosigma angulatum (J.T.Quekett) 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 7, Plate 1, Fig. 7, 8 [as var. beta], 9 [as var. gamma].