The Zakro sealings were excavated at Kato Zakros in eastern Crete by David Hogarth in 1900. They show a variety of composite forms. The Ashmolean holds over 30 of these sealings so it is not clear which of them was on display in the Exhibition.
Bibliography
Myres, John (ed.). 1936. British Archaeological Discoveries in Greece and Crete 1886-1936, p. 24