The fragment consists of a band of egg and dart surmounted by bead and reel; there is a pendant palmette at the corner. The piece comes from the capital of an anta (pilaster) on the east portico of the Erechtheum on the Athenian Akropolis.
From the Erechtheum on the Athenian Akropolis
Richter, Gisela M. A. 1953. Handbook of the Greek Collection. pp. 94, 234, pl. 74e, Cambridge, Mass.: Harvard University Press.