An arrangement of two Navicula praetexta from San Redondo, California, USA. Prepared by WA Firth. Olympus BHB microscope using 450nm LED light. The larger one was imaged 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. Monochrome converted Nikon d850 camera. 35 images stacked in Zerene (Pmax). I did remove the dark dust spec on this one before stacking. 11 images stacked for the image of the arrangement.
Navicula praetexta Ehrenberg 1841. Published in: Ehrenberg, [C.G.] (1840). [Characteristik von 274 neuen Arten von Infusorien]. Bericht über die zur Bekanntmachung geeigneten Verhandlungen der Königlich-Preussischen Akademie der Wissenschaften zu Berlin 1840: 197-219. Page 214. This name is currently regarded as a synonym of Lyrella praetexta (Ehrenberg) D.G.Mann.