Stampfle, Felice. Giovanni Battista Piranesi, Drawings in the Pierpont Morgan Library. New York : Dover, 1978, no. 110, repr.
Showing a papal tiara and keys over an oval frame, this quick study is probably related to the Clement XIII commission to redesign the Lateran Basilica: a partial plan of the Lateran appears on the verso, and the sheet was once joined to another drawing at the Morgan, inv. 1966.11:58, a sketch for the choir wall of the church (note the heavy hatching at the sides of both sheets). The monument, which is perhaps an elaborate overdoor decoration, does not correspond to anything in the other Lateran drawings, however, so Piranesi's intentions for the design remain unclear.