From Art to Artifact:  Making Sense of Roman Coins

Each of the nine muses featured on Musa’s reverse types are identifiable by their attributes. Thalia, muse of comedy, is identified here by the comic mask which she holds in her outstretched right hand. Other variations of this type also show her with a shepherd’s crook, indicating her role as muse of bucolic poertry. The remaining eight muses can be identified as follows:
Calliope (Epic Poetry) with lyre (on column)
Clio (History) with scroll
Erato (Erotic Poetry) with lyre (facing)
Euterpe (Lyric Poetry) with flutes
Melpomene (Tragedy) with tragic mask and club
Polymnia (Rhetoric) with wreath
Terpsichore (Dance) with lyre and plectrum
Urania (Astronomy) with wand and globe