Three examples of Pinnularia alpina from Inverness (presumably Inverness in Scotland). Prepared by William Allott Firth. Olympus BHB microscope using 450nm LED light. 40x Leitz Pl Apo 1.00 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 45 images stacked in Zerene (Pmax). Not the best stacked image (some quite jaggy looking features). There’s not really any sign of movement of the slide during the stacking, but the images were quite low contrast, which might be a cause of some of the issues.
Pinnularia alpina W.Smith 1853. Published in: Smith, W. (1853). A synopsis of the British Diatomaceae; with remarks on their structure, function and distribution; and instructions for collecting and preserving specimens. The plates by Tuffen West. In two volumes. Vol. I. pp. [i]-xxxiii, 1-89, pls I-XXXI. London: John van Voorst, Paternoster Row. Page 55, Plate XVIII [18], Figure 168.