Tetradrachm of Ptolemy I, uncertain mint (Memphis?)

Obv.: Head of the deified Alexander wearing elephant's skin and aegis r., with horn of Zeus Ammon around the ear; dotted border. Rev.: Athena Alkidemos, r., holding spear r. and shield l.; to r., eagle clutching thunderbolt r.; border of dots; to l. monogram; to r., monogram.