Asteromphalus elegans from Rio de Janeiro. Single example on the slide. Mounted in Styrax. Looks to be some issues with the dye from the ring around the diatom which has crystallized out, unfortunately partly across the diatoms itself. Prepared by Laurence Hardman. Olympus BHB microscope using 450nm LED light. 63x Leitz Pl Apo NA 1.4 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 69 images stacked in Zerene (Pmax). Quite ‘dome’ shaped.
Asteromphalus elegans Greville 1859. Published in: Greville, R.K. (1859). Description of Diatomaceae observed in Californian guano. Quarterly Journal of Microscopical Science 7: 155-166. Page 161, Plate 7, Figure 6.