Navicula spectabilis var. excavata from Palos Verdes, California, USA. Single example on the slide. Mounted in Styrax. Prepared by RI Firth. 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. 32 images stacked in Zerene (Pmax).
Navicula spectabilis var. excavata (Greville) Cleve, 1895. Published in: Cleve, P.T. (1895). Synopsis of the naviculoid diatoms. Part II. Kongliga Svenska Vetenskapsak Akademiens Handlingar 27(3): 1-219, 4 pls. Page 61. This name is currently regarded as a synonym of Lyrella excavata (Greville) D.G.Mann, 1990. Published in: Round, F.E., Crawford, R.M. & Mann, D.G. (1990). The diatoms. Biology and morphology of the genera. pp. [i-ix], 1-747. Cambridge: Cambridge University Press. Page 672.