An arrangement of three Schuettia annulata from Freetown, West Africa. Described as ‘rare’. R.G. and the style makes this look like a Richard Gosden slide to me. The ‘vii. ’55’ may indicate July, 1955. 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. 56 images stacked in Zerene (Pmax).
Published in: De Toni, G.B. (1894). Sylloge algarum omnium hucusque cognitarum. Vol. II. Bacillariaeae. Sect. III. – Cryptorhaphideae. pp. [i-vi], 819-1556 (p. 1396). Patavii [Padua]: Sumptibus auctoris. This name is currently regarded as a synonym of Actinoptychus annulatus (Wallich) Grunow.