Firstly, I want to say that I think this a historically very interesting slide, and the reason for this will be explained in a minute. It is labelled as ‘Stictodiscus buryanus‘ from Jérémie, [Haiti]. The slide also says ’18t5′ but I don’t know what that refers to. It also says ’10 sides’ with a little drawing of it. There is no makers name. However all is not as it seems, as it is not S. buryanus, but a fragment of Stictodiscus multiplex. This is all that is on the slide. I have no reason to doubt the location it is from, as this would be found there. 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. 50 images stacked in Zerene (Pmax). It just fit in the field of view of the 63x objective, so the main image is uncropped (with little extra border added at the bottom of it). Some of the individual frames had some amazing patterning which didn’t come across in the stack, so I have included a crop of one of the frames, and boosted the contrast to show what I mean.
So, why do I say this is historically interesting? Well, I am confident that this fragment is the same one that was used to create one of the illustrations in Schmidt’s Atlas – Atlas der Diatomaceenkunde. Specifically Plate 75, Figure 1. I’ll take a step back for a moment. I knew this wasn’t S. buryanus when I looked at it. Looking through Schmidt’s Atlas I came across Stictodiscus multiplex, Plate 451, Figure 10, which looked to be the right diatom. Also this refers back to two other images of which it says was Triceratium multiplex; Plate 75, Figure 1, and T. multiplex forma minor Plate 84, Figure 14. Plate 75, Figure 1 shows a fragment of the diatom, and I thought it looked like the one on this slide. I put them side by side and yet they looked very similar. I then put them into Powerpoint, and made Schmidt’s image partially transparent and overlayed it on mine, and was amazed to see a pretty much exact match, from the outline to the dot pattern. I am confident in saying that the diatom on this slide was the fragment used to make the illustration for Schmidt’s Atlas, Plate 75, Figure 1. Cool…..
This is the translation of Plate 451, Figure 10 in the Atlas;
“Jérémie, Haiti, f.m. [fossil marine]. Stictodiscus multiplex (Jan.) Truan & Witt. See Triceratium multiplex Jan. T. 75, F. 1, T. 81, F. 14. In Mills, Index Diat., p. 1497, this species is grouped with Stictodiscus (Pseudo-Stictodiscus) Eulensteini. However, the midfields of the two species are very differently structured, so I cannot agree with this grouping.”
I am assuming T. multiplex is the older name, and S. multiplex the newer.
It is also referred to in Truan y Luard, A. & Witt, O.N. (1888). Die Diatomaceen der Polycystinenkreide von Jérémie in Hayti Westindien. pp. [1]–38, incl. 7 pls [I-VII]. Berlin: Verlag von R. Friedländer & Sohn. Page 21 and Plate V, Figure 7. Where it says (translation);
“Shell polygonal. Margin and center exactly as in the preceding species. Folds are absent. Dots are irregular and evenly healed across the shell, with a ring of radial rows of dots along the margin.
Very rare. Plate V, Figure 7.
This form is already known from Jérémie, as well as from the Pacific Ocean.”
I’ve included screenshots of this above.
Overall, a fabulous piece of history, and I am surprised it was incorrectly named. I wonder who the slide maker was?