Note: From Patricia Lawrence on the Forum Classical Numismatics Discussion Board, July 2007: "Oh, bless Gallienus. One never knows what gem will come up next. There is a Polykleitan athlete statuary type of an athlete, probably the one that had won with the discus, which in a lovingly detailed copy (the head survives in Berlin) is transformed into a Hermes with a Purse and given wings on his head, which was OK with the Romans (the Greeks put the winglets on his petasos). The Mercury on this coin is based on that Polykleitan athlete converted into an Imperial period Hermes, or, to be most accurate, made into a Mercury. The head in Berlin, which earlier scholars thought was elaborated by showing the line of inlay on the lips and the inset eyes, actually is very true to the mid-5th century BCE, early Polykleitos, as we now know from actual original bronze statues with inlaid copper lips and inset eyes of bone or ivory and glass or semi-precious stone.

BUT THOSE WINGLETS ARE AN ADDITION, even though the head itself seems to be consistent with the best copies of Polykleitos (such as the Naples Doryphoros). The Berlin head, in my opinion, is not later than mid-2nd century CE and could be earlier.

Anyhow, your coin shows a Mercury with winglets on his head."