A selection of diatoms from Cherryfield, Maine. Fossil freshwater material. 2x Neidium sp. (not the usual Neidium tumescens), 3x Brachysira sp. , 2x Frustulia sp.. Mounted in Canada Balsam and dated 1945. No makers name. Olympus BHB microscope using 450nm LED light. As well as the arrangement I imaged one of the Neidium sp. (maybe N. iridis) with the 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. 42 images Pmax. Underside view, rim upwards.
Neidium iridis (Ehrenberg) Cleve 1894. Published in: Cleve, P.T. (1894). Synopsis of the naviculoid diatoms. Part I. Kongliga Svenska Vetenskapsakademiens Handlingar Series 4 26(2): 1-194, 5 pls. Page 69.