Antoninus Pius AD 138-161. Bi. tetradrachm of Alexandria, Egypt. 24-25mm; 15.31g. Year 23. AD 159-160. 

ANTWNINOC CEB EVCEB, laureate, draped and cuirassed bust right.
L KG, Isis, wearing crown, seated right, suckling Harpokrates. 

Milne 2403; BMC 990; Dattari 2257; Geissen 1842.

With permission of cngcoins.com, the AK collection sale.