This exquisite fragment belongs to one of the decorative moldings of the Erechtheum, the building on the Athenian Akropolis that accommodated a variety of venerable cults and sanctuaries. The molding consists of a row of egg and dart framed above and below by bead and reel. Originally it would have been painted.
From the Erechtheum on the Athenian Akropolis
Richter, Gisela M. A. 1953. Handbook of the Greek Collection. pp. 94, 234, pl. 74d, Cambridge, Mass.: Harvard University Press.