A strew slide from Marshy Pit No.2, Charlwood, Surrey. Collected by AG Greenfield. Mounted in Aroclor and dated May 1975. Range of species present including Surirella peisonis and Nitzschia spectabilis. No makers name but this is by Bernard Hartley. Olympus BHB microscope using 450nm LED light. I chose a fragment of Nitzschia spectabilis for imaging at high magnification. 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. 38 images stacked in Zerene (Pmax).
Nitzschia spectabilis 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 39, Plate XIV [14], Figure 116.
There is an entry from Bernard Hartley’s Sample and Strew Slide Collection PDF for this – slide 488 – accessed from here (also screenshotted above).