Three slides with diatoms from the Red Sea, prepared by Laurence Hardman. Olympus BHB microscope using 450nm LED light. The first is an arrangement with a few different species, with the slide labelled as Navicula clavata.
20x Nikon Plan Apo 0.65 objective. Olympus Aplanat Achromat condenser, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 31 images stacked in Zerene (Pmax).
Navicula clavata W.Gregory 1856. Published in: Gregory, W. (1856). On the post-Tertiary diatomaceous sand of Glenshire, Part II. Containing an account of a number of additional undescribed species. Transactions of the Microscopical Society, New Series 4: 35-48, pl. V. Page 46, Plate V [5], Figure 17. This name is currently regarded as a synonym of Lyrella clavata (W.Gregory) 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.
The label on the back tries to layout what is there. I suspect the following (maybe); 3x Lyrella clavata, 2x Lyrella hennedyi, 2x Auliscus sculptus, 1x Auliscus sp., 1x Surirella sp., 1x (extremely tentative) Coscinodiscus subvelatus.
Second is a nice arrangement of seven Triceratium parallelum var. quadrangular.
40x Leitz Pl Apo 1.00 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. 11mm spacer to the camera removed to increase the field of view. Monochrome converted Nikon d850 camera. 25 images stacked in Zerene (Pmax).
Triceratium parallelum (Ehrenberg) Greville 1865. Published in: Greville, R.K. (1865). Descriptions of new and rare diatoms. Series XVII. Transactions of the Microscopical Society, New Series, London 13: 97-105, 2 pls [VIII, IX]. Page 104, Plate IX [9], Figures 22,23. In this Greville mentions that these are present in the Red Sea dredgings (interesting with the name ‘L. Hardman, Esq.’ after that entry – small world) and are seen as 4 and 6 sided versions. In my copy of this, which is an assembly of the articles from 1968, it mentions that Triceratium parallelum = Stictodiscus parallelus which makes sense based on their appearance.
Third is an arrangement of Surirella sp.
As well as the full arrangement I imaged two of them using the 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. 71 images stacked in Zerene (Pmax).
The slide is labelled as Surirella arabica with a question mark, however as noted on the back these don’t look like S. arabica (Schmidt’s Atlas Plate 20, Figure 5). Nearest I can come up with would be that the left hand one looks like Schmidt’s Atlas Plate 19, Figure 12 (Surirella fastuosa var.) and that the right hand one looks like Schmidt’s Atlas Plate 20, Figure 3 (Surirella lepida var.), but I am not very sure of either of those. So I will leave them as Surirella sp. from the Red Sea for now.