The central aisle of the Mithraeum di Felicissimus has a mosaic pavement with the symbolic representations of the different mithraic grades:
- Near the entrance is a stylized tree.
- In the middle of the floor, in the space between the entrance and the niche, is a krater.
- Before the niche is a burning altar.
- Avobe the crater and then in the direction of the backwall the following figures, separated form each other by black bands: Two phrygian caps surmonted by a crescent.