A strew slide from Saco River, New Hampshire, USA. Prepared by John Thomas Norman. Nice array of species. Olympus BHB microscope using 450nm LED light. As well as the wider field of view, I imaged a couple using 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. Images stacked in Zerene (Pmax). Quite low contrast – I’m assuming Canada Balsam for the mountant.
Neidium sacoense Reimer 1966. Published in: Patrick, R.[M.] & Reimer, C.W. (1966). The diatoms of the United States exclusive of Alaska and Hawaii. Volume 1: Fragilariaceae, Eunotiaceae, Achnanthaceae, Naviculaceae. Monographs of the Academy of Natural Sciences of Philadelphia 13: 1-688. Page 402, Plate 37, Figure 3.
Tabellaria flocculosa (Roth) Kützing 1844. Published in: Kützing, F.T. (1844). Die Kieselschaligen Bacillarien oder Diatomeen. pp. [i-vii], [1]-152, pls 1-30. Nordhausen: zu finden bei W. Köhne. Page 127, Plate 17, Figure 21.
I’m reasonably happy with both of these identifications.