Watch List notes:

KINGS of MACEDON. Alexander III 'the Great'. 336-323 BC. AR Tetradrachm (25.5mm, 17.19 g, 11h). Babylon mint. Struck under Stamenes or Archon, circa 324/3 BC. Head of Herakles right, wearing lion skin / Zeus Aëtophoros seated left; in left field, horizontal ear above M; monogram below throne. Price 3611 corr. (symbol). Good VF, lightly toned, slight die shift on obverse, reverse a little off center.

Price called the symbol on this issue an astragalos, but an inspection of the plate coin (and it's better version on the BM website), reveals that it is the same symbol that Price calls an ear (Price 3612), but oriented horizontally. It does not resemble an astragalos as it appears on any other coinage.