Antiochos I, AE21. 280-261 BC. Dura mint. 21 mm, 3.87 g.

Horse's horned head right.
BASILEWS ANTIOXOY, bow. PMYR monogram below.

SC 367-368; Hoover 151 or 173; Dura Hoard 37-39; Newell WSM 882.

Image courtesy of the Yale University Library, Numismatic Collection, 2001, Yale-French Excavations at Dura-Europos. Acc. No. 2001.87.25081

Yale has a second example with the monogram mostly off flan: Accession Number 1938.6000.43.