Astrosphaera. / Spumellaria. – Schaumstrahlinge. – fig. 1
From Kunstformen der Natur
This is a figure on plate 91, one of the 100 pop science biology illustrations that were published from 1899 – 1904 in Leipzig by Ernst Haeckel through Verlag des Bibliographischen Instituts, Giltsch Lithografische Anstalt Jena.
We've scanned the original lithography, you can download it by clicking on the picture.