Bit of a special one this, as there is are a lot of unusual species on it (and a lot of question marks for the names, and thank you for the advice from those who have looked at them for me). Strew slide labelled as Plagiogramma and Glyphodesmis from Rio de Janeiro. Also says ‘very rare’. I think this is recent material. Prepared by Arthur Charles Cole. Olympus BHB microscope using 450nm LED light. Higher resolution images with a 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).
A range of Plagiogramma, and Glyphodesmis species, along with others including Dimeregramma and Opephora. All in all, quite a special slide given the unusual diatoms present.