A bust of the gorgon Medusa occupies the center of this Roman mosaic floor. Although early Greek representations of Medusa emphasized her hideous and monstrous appearance, a more human-appearing figure had become the norm by the time of this mosaic in the 100s A.D. Medusa's former snaky locks are now just wild curls and she even takes on traits derived from representations of Alexander the Great and Hellenistic kings, like her wind-blown hair and turned head. In this mosaic, Medusa is placed in a shield of concentric circles, whose alternating black and white triangles create an optical illusion of continuous motion. An outer square encloses the shield and kantharoi or drinking cups fill the outer corners. This spinning shield motif with the gorgon's head as its central point appears frequently on Roman mosaic floors. The basic design derives from Athena's aegis, the scaly protective cloak decorated with Medusa's decapitated head.
Mosaic floors executed in only black and white were favored in Italy in the 100s A.D. This floor combines this Italian black and white style used for the shield with the polychrome mosaic style of other parts of the Roman Empire used here for Medusa.