From the "Four Seasons" mosaic. The mosaic, inv. 1018, is from Harbiye, from the second century A.D. It's named after the winged figures representing the seasons. This is a detail of the scene between Summer and Autumn, "Bellerophon and Steneboia".

From the Enc. Britt.: Bellerophon, also called Bellerophontes,hero in Greek legend. In the Iliad he was the son of Glaucus, who was the son of Sisyphus of Ephyre (traditionally Corinth). Anteia(or Stheneboea), wife of Proetus, the king of Argos, loved him; when her overtures were rejected, she falsely accused him to her husband.