An arrangement of five Janischia antiqua (and two Eupodiscus) from Jutland. No makers name on the slide. Olympus BHB microscope using 450nm LED light. I went to town a bit on this one. An image of the entire arrangement was done with a 4x Nikon Plan Apo NA 0.2 objective and brightfield lighting. The I just imaged the Janischia. This was done with a 10x Nikon Plan Apo NA 0.45 objective and oblique lighting. I had to rotate the camera to fit it all in one frame. Next I imaged a single one (the round one at the top of the 4x image) using a 20x Nikon Plan Apo NA 0.65 objective and oblique lighting. Finally I settled on imaging parts of one (the large one at the bottom of 4x image) at higher magnification to show more details. 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. Image stacks prepared in Zerene (Pmax), 124 images for the one which shows the features nearer the edges and 46 for the one looking at the middle of the diatom. The patterning is, I think, amazing, and can be seen to radiate from the centre in branched forks.
Original description: Van Heurck, H. (1880). Synopsis des Diatomées de Belgique. Atlas. Ducaju & Cie., Anvers. page(s): pl. 95Bis, fig. 10, 11. I’ve included screen shots of this above. Synonymised name: Fenestrella antiqua (Grunow) Swatman. Publication Details: Fenestrella antiqua (Grunow) Swatman 1948: 53, pl. 2, figs 10-11. Published in: Swatman, C.C. (1948). Note on the Genus Fenestrella Greville. J. Roy. Micr. Soc., ser. 3, 68 : 51-54, pl. 1,2.
This was one of my ‘wish list’ diatoms, having only seen fragments in strews. It has not disappointed.