Mercury with the characteristic heralds staff. He's however not having winged feet here. Compare to this, somewhat more offensive, version.
Grandson of Atlas, wise of tongue,
O Mercury, whose wit could tame
Man's savage youth by power of song
And plastic game!
Thee sing I, herald of the sky,
Who gav'st the lyre its music sweet,
Hiding whate'er might please thine eye
In frolic cheat.
Horatius - Odes X
Translated by J. Conington