A nice arrangement of four Actinocyclus rotula from Cayenne. Mounted in Hyrax. Prepared by JA Long. 63x Leitz Pl Apo 1.4 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. 11mm removed from the tube to the camera to increase the field of view. Monochrome converted Nikon d850 camera. 25 images stacked in Zerene (Pmax).
Actinocyclus rotula Brun. Published in: Brun, J.-J. (1891). Diatomées espèces nouvelles marines, fossiles ou pélagiques. Mémoires de la Société de Physique et d’Histoire Naturelle de Genève 31(part 2, no. 1): 1-47, pls 11-22.