Interesting forum post about a c. 1420 illuminated manuscript (Apostolica Vaticana, Cod. Pal. Lat. 1066) of the Fulgentius metaforalis, here seen in the context of Tarot, with many illustrations and links.
Fulgentius metaforalis is a c. 1331 work by John Ridewall (Joannes Ridevallus) that interprets antique mythology (mainly based on Ovid) in a Christian way. The name is derived from Fabius Planciades Fulgentius, who had written similar works around 500 AD.
The illumination above shows Apollo and the muses.