A collection of diatoms from Capri, Naples aquarium tank. Wide range of species. Mounted in Styrax and Piperine and dated 6/10/[190]1. Some yellowing of the mountant, and it has degraded quite badly over most of the arrangement. Lower label has ‘? Melosira‘, ‘Glyphodesmii williamsonii‘ and ‘Navicula crucifera (=nostellaria)’. Not sure on what the word in the brackets is. No makers name, but there is a squiggle at the bottom right which could be a signature. Olympus BHB microscope using 450nm LED light. As well as the arrangement, I imaged a couple of them using the 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. Image stacks prepared in Zerene (Pmax).
The first one is (I think) Perissonoë trigona (Grunow) G.W.Andrews & Stoelzel 1984: 227, fig. 29. Published in: Andrews, G.W. & Stoelzel, V.A. (1984). Morphology and evolutionary significance of Perissonoë, a new marine diatom genus. In: Proceedings of the Seventh International Diatom Symposium. (Mann, D.G. Eds), pp. 225-240. Koenigstein: Koeltz Scientific Books. Page 227, Figure 29. Basionym: Rhaphoneis amphiceros var. trigona Grunow. Although cannot access the 7th International Diatom Symposium proceedings to check. Underside view with the rim upwards towards the coverslip. 28 images stacked.
The second is a Lyrella sp. again an underside view with the rim upwards towards the coverslip. As for what it is, I’m not sure, but Schmidt’s Atlas Plate 3, Figure 27 Navicula polysticta var. circumsecta is a good match visually. This should be named Navicula circumsecta according to Mann 1925. Overall I am not sure, but I think this would now fall under Lyrella, so will leave it as Lyrella sp. for now. In a partially edited image for this one you can see the issues with the mountant which are unfortunately present across most of the diatoms.
I’m not sure on the maker for this, but I have just imaged a few of them by the same maker, and they are all interesting slides. If you want to see others by this maker search for BBBBB in the search function.
EDIT – based on the handwriting and style, and some conversations with experts, I this could be by Edmund Grove (of Grove and Sturt). But I have no 100% proof of this at the moment.