Navicula hennedyi from Virginia, USA (can’t read exactly where unfortunately – any ideas, let me know). Single example on the slide. Prepared by John Henry Day. Olympus BHB microscope using 450nm LED light. 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. 51 images stacked in Zerene (Pmax).
Navicula hennedyi W.Smith 1856. Published in: Smith, W. (1856). A synopsis of the British Diatomaceae; with remarks on their structure, functions and distribution; and instructions for collecting and preserving specimens. The plates by Tuffen West. In two volumes. Vol. II. pp. [i]-xxix, 1-107, pls 32-60, 61-62, A-E. London: John van Voorst, Paternoster Row. Page 93 (as ‘Hennedyi’). This name is currently regarded as a synonym of Lyrella hennedyi (W.Smith) Stickle & D.G.Mann 1990. Published in: Round, F.E., Crawford, R.M. & Mann, D.G. (1990). The diatoms. Biology and morphology of the genera. pp. [i-ix], 1-747. Cambridge: Cambridge University Press. Page 672.