Ptolemaic Kings Of Egypt. Ptolemy I Soter 305-282 BC. AE  hemiobol. 17mm, 4.84 g. Alexandria. Struck circa 294-285 BC BC. 

Diademed head of Alexander III right, wearing horn of Ammon, hair long.
BASILEWS PTOLEMAIOY, Eagle standing left on thunderbolt, wings spread. XA monogram and helmet in left field.

Svoronos 163; SNG Cop 43.

With permission of cngcoins.com, auction 420, Lot 275, May 2018.