Navicula durandii (I think this might be N. durandii var. rhomboidea, more on that in a minute). Single example on the slide, from Batavia (present day Jakarta). There is an ‘S.C.’ on the slide, and I think this is by Sydney Chaffers. On the back it says Schmidt’s Atlas 129.1 referring to Plate 129, Figure 1. Olympus BHB microscope using 450nm LED light. 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. 43 images stacked in Zerene (Pmax).
Back to the name. Navicula durrandii Kitton 1885: 1042, no fig. (as ‘Durrandii‘). Published in: Kitton, F. (1885). Navicula Durrandii n. sp. F.K. Journal of the Royal Microscopical Society, Series 2 5: 1042 only. Schmidt’s Atlas, Plate 129, Figure 1, 1a. This correlates with the label on the back of the slide.
However, I think this looks more like N. durandii var. rhomboidea, Schmidt’s Atlas, Plate 129, Figure 2. Another potential variant of the name. Navicula durandii f. rhomboidea (Castracane) Hustedt 1964. Published in: Hustedt, F. (1964). Die Kieselalgen Deutschlands, Österreichs und der Schweiz unter Berücksichtigung der übrigen Länder Europas sowie der angrenzenden Meeresgebiete. Bd. VII: Teil 3: Lieferung 3. In: Rabenhorst’s Kryptogamen Flora von Deutschland, Österreich und der Schweiz. (Anon. Eds), pp. 349-556. Leipzig: Akademische Verlagsgesellschaft m.b.h. Page 487, Figure 1541.