Science Art: Zanclus cornatus and Acanthurus nigra, by Josef Maria Eder and Eduard Valenta.

from https://publicdomainreview.org/collections/early-experiments-with-x-rays-1896/
http://www.metmuseum.org/art/collection/search/660047

from https://publicdomainreview.org/collections/early-experiments-with-x-rays-1896/ Click to embiggen
Two fish from one of the first collections of X-ray photographs, published in Versuche über Photographie mittelst der Röntgen’schen Strahlen, 1896.

From the “Early Experiments with X-Rays” article at Public Domain Review. The collection also has cameos, newborn animals and young girls’ hands and feet.