Two examples of Arachnoidiscus indicus from San Redondo, California, USA. Olympus BHB microscope using 450nm LED light. As well as the arrangement I imaged the larger one at the left using the 40x Leitz Pl Apo 1.00 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 48 images stacked in Zerene (Pmax).
Arachnoidiscus indicus Ehrenberg 1854. Published in: Ehrenberg, C.G. (1854). Mikrogeologie. Einundvierzig Tafeln mit über viertausend grossentheils colorirten Figuren, Gezeichnet vom Verfasser. pp. [1]-31, 40 pls [Taf. I-XXXX]. Leipzig: Verlag von Leopold Voss. Plate XXXVI [36], Figure 34.