"Fig. 117. Uxmal. House of the Governor. Upward opened serpent jaws. Bas-relief, footstand for the center figure of the frieze of the east facade (main front) of the northern wing of the middle structure.
a. From a photography by LePlongeon. b. From photographs and a drawing by the author."
Scanned from Eduard  Seler, “Die Ruinen von Uxmal,” 1917 (fig. 117); closely based on photographs and Seler’s on-site drawing.