Roman Republic Æ sextans(5.48g, 19mm), anonymous(corn-ear KA series), 207-206 B.C., Sicilian(Catania?) mint. Head of Mercury right; above, •• / Prow right with flat deck structure; above, corn-ear/wheat-ear; below, Roma; before, KA or IC ligate(off flan). Crawford 69/6.
Overstruck on: Hieron II Poseidon/Trident Æ, 275-215 B.C.
The overstriking is very evident on the reverse at approximately 8 o'clock but a close inspection reveals several hints of the undertype on the obverse as well.