Navicula [Caloneis] alpestris from Buckden, Yorkshire, UK. Single example on the slide. Mounted in Hyrax. Prepared by Dingley P Fuge. 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. 25 images stacked in Zerene (Pmax).
Navicula alpestris Grunow 1860. Published in: Grunow, A. (1860). Über neue oder ungenügend gekannte Algen. Erste Folge, Diatomeen, Familie Naviculaceen. Verhandlungen der kaiserlich-königlichen zoologisch-botanischen Gesellschaft in Wien 10: 503-582, pls III-VII. Page 545, Plate 3, Figure 4. This name is currently regarded as a synonym of Caloneis alpestris (Grunow) Cleve. Caloneis alpestris (Grunow) Cleve 1894. Published in: Cleve, P.T. (1894). Synopsis of the naviculoid diatoms. Part I. Kongliga Svenska Vetenskapsakademiens Handlingar Series 4 26(2): 1-194, 5 pls. Page 53.