Cymbella cistula from a post glacial lake in Guatemala. Single example on the slide. It says A. Ashe, September 1892, and more on that in a minute. Olympus BHB microscope using 450nm LED light. 20x Nikon Plan Apo NA 0.65 objective. Olympus Aplanat Achromat condenser, brightfield lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 23 images stacked in Zerene (Pmax). I couldn’t get close enough to use either the 40x or 63x Leitz Pl Apo objectives, so resolution is limited.
Cymbella cistula (Ehrenberg) O.Kirchner 1878. Published in: Kirchner, O. (1878). Algen. In: Kryptogamen-Flora von Schlesien. Part 1. (Cohn, F. Eds) Vol. 2, pp. i-iv [vii] 1-284. Breslau: J.U. Kern’s Verlag (Max Müller). Page 189.
The slide also says Quekett Journal 1893. This refers to: AM Edwards. On a diatomaceous earth from Guatemala, and the occurrence of marine diatoms in fresh water. Quekett Journal of Microscopy. 1893, pp202-204. The paper mentions this species and it also says that the material in the article was obtained from Mr A Ashe.
Does the A. Ashe on the slide mean that this was made by him, or was it using material supplied by him? I am not sure so will leave it as ‘unknown maker’ for now.