Triceratium arcticum var. californica from Palos Verdes, California, USA. Single example on the slide, mounted with the rim towards the coverslip (underside view). Some debris present, especially in the upper right quadrant. Prepared by JA Long. Olympus BHB microscope using 450nm LED light. 63x Leitz Pl Apo NA 1.4 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 51 images stacked in Zerene (Pmax).
Trigonium arcticum var. californica (Grunow) Wornardt, 1967. Original description: (of Triceratium arcticum f. californica Grunow in Schmidt et al., 1882) Schmidt, A. (1882). Atlas der Diatomaceen-kunde. Aschersleben, Commissions-Verlag Von Ludwig Siever’s Buchandlung. Series II (Heft 20): pls. 77-80. Plate 79, Figures 5,6.