"Fig. 37. Uxmal. House of the Nuns. West building. Main facade facing
the courtyard and the east. a. The remaining head on the northern frieze remnants of one of the two serpent bodies surrounding the frieze quadrant. b. Head of the feather serpent from the damaged frieze on the southern section of the building. Now in the Museum in Merida de Yucatan."
Scanned from Eduard Seler, Die Ruinen von Uxmal, 1917; closely based on Selers on-site drawing (fig.37a, b).