SELEUKID KINGS of SYRIA. Antiochos I. 281-261 BC. AR Drachm (16mm, 4.13 gm). Aļ Khanoum mint.

Diademed head right.
Horned and bridled horse head right; D in O monogram before horse's forehead. 

SC 452; cf. SNG Spaer 325 (placement of monogram).