License, verbatimCC0
The Metropolitan Museum of Art: Open Access, Creative Commons Zero (CC0). Flagged isPublicDomain=true in the museum's own record.
Stefano della Bella. A triton in the water, facing left, holding up an eel in his right hand and two other eels underwater in his left hand, plate 7 from "Second collection of various doodles and etching proofs" (Second recueil de divers griffonnements et preuves d'eauforte), ca. 1646. The Metropolitan Museum of Art.