An arrangement of Actinocyclus barkleyi (more in a minute on that). No makers name, but this style is that of Arthur Charles Cole. Olympus BHB microscope using 450nm LED light. As well as the arrangement I imaged one using a 63x Leitz Pl Apo NA 1.4 objective, oil immersion. Olympus Aplanat Achromat condenser, oblique lighting.2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 117 images stacked in Zerene (Pmax).
Ok, the name. The slide says ‘Actinoptychus Barkleyii‘. I have seen this also described as ‘Actinodiscus‘, however it is I understand an Actinocyclus (see the typical Actinocyclus hole just inside the rim at the 2 o’clock position in the high magnification image). I have also seen Barkleyii (the plural of Barkleyi) with and without the capital B, and also as barklyi. So I’m going with Actinocyclus barklyi Kitton 1878. Published in: Kitton, F. (1879). Notes sur quelques Diatomées. Bulletin de la Société Belge de Microscopie 5: XXXI-XXXVI, 2 figs. XXXVI, no fig. (as ‘Barklyi‘). Homotypic synonym: Actinoptychus barklyi (Kitton) Habirshaw 1888. Published in: Habirshaw, F. (1877). Catalogue on the Diatomaceae, with reference to the various published descriptions and figures, Pt. I. pp. [1-272]. New York: Reproduced by the Edison Electric pen process. Page 30. Not really sure why this would have been described as an actinoptychus. This isn’t an actinoptychus.