Three examples of Heliopelta metii from Patuxent, USA. Prepared by Barbour brothers. Olympus BHB microscope using 450nm LED light. As well as the arrangement I imaged one 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. 11m removed from the tube to the camera to increase field of view. Monochrome converted Nikon d850 camera. 79 images stacked in Zerene (Pmax).
Heliopelta metii Ehrenberg, 1844 (1845). Original description: Ehrenberg, C.G. (1844). Untersuchungen über die kleinsten Lebensformen im Quellenlande des Euphrats und Araxes, so wie über eine an neuen Formen sehr reiche, marine Tripelbildung von den Bermuda-Inseln. Bericht über die zur Bekanntmachung geeigneten Verhandlungen der Königlich-Preussischen Akademie der Wissenschaften zu Berlin, 1844: 253-275, 1 pl. Page 268. This name is currently regarded as a synonym of Actinoptychus heliopelta Grunow 1883. Published in: Van Heurck, H. (1882). Synopsis des Diatomées de Belgique. Atlas. pp. pls LXXVIII-CXXXII [78-132 and supplementary pls 22 bis, 82bis, 83bis, 83ter, 95bis], tables genres. Anvers: Ducaju et Cie. Plate 123, Figure 3.