Navicula sparsipunctata (shown as Navicula sparsi-punctata on the slide) from Oamaru, New Zealand. Single example on the slide. No makers name but the style and hand writing look like WA Firth, so I am going with that for now, but will leave a question mark after it. 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. 29 images stacked in Zerene (Pmax). This was quite a low contrast slide and hard to details on.
Published in: Grove, E. & Sturt, G. (1886). On a fossil marine Diatomaceous deposit from Oamaru, Otago, New Zealand. Part I. Journal of the Quekett Microscopical Club, Series 2 2 (16)(16): 321-330, pls 18, 19.