Exhibition catalogue, Köstlichkeiten aus Kairo!, Antikensmuseum Basel und Sammlung Ludwig und Museum August Kestner Hannover, 2008, p. 76, no. 26.
Cf. an identical fragment missing the upper part, formerly in the Momelian collection, Paris, in E. M. Stern and B. Schlick-Nolte, Early Glass of the Ancient World, 1600 B.C.- A.D. 50, Ernesto Wolf Collection, Ostfildern, 1994, no. 122.
The ibis was a manifestation of the moon-god Thoth, the god of knowledge, writing, time, mathematics, and the patron god of scribes, later identified with the Greek god Hermes.