A strew slide from Pensacola Bay, Florida, USA. No makers name. Good array of species on there, and a nice clear mount. There are 2 other slides (one from Mobile Bay and one from Tampa Bay) by the same maker, but I have not included images from those here.
Firstly there are a lot of question marks with my names here. There is an amazing array of Auliscus diatoms on the slide, and I could have imaged another dozen and still had plenty left to look at. I think a lot are Auliscus pruinosus or variants thereof. One was I believe Auliscus confluens, and there were a few Pseudauliscus radiatus (also known as Auliscus radiatus and Mastodiscus radiatus). Also plenty of Eupodiscus argus (Aulacodiscus argus), some nice Navicula / Lyrella sp, and Campylodiscus sp. Lots of question marks though as to specific species.
Olympus BHB microscope using 450nm LED light. 63x Leitz Pl Apo 1.4 obective and 40x Leitz Pl Apo NA 1.00 objective, both with 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).
EDIT 30/10/25. I’ve been sent some background information for these slides by Brian Stevenson. Gatherings seem to have originated from William McNeill, George Tayler, and/or Kevin Cunningham, and possible maker of the slides is Charles Stodder. Refs below;
Notes on Diatomacæ from Tampa Bay, Florida. By Charles Stodder. The American Microscopical Journal. 1883. pp.31-33.
Diatoms of the Gulf. By JD Cox. The American Microscopical Journal. 1885. pp.145-147.
List of Mobile Bay diatoms. By JD Cox. Transactions of the American Microscopical Society. 1885. pp.210-211.