Pottery fragment with lion and bull's head from Trier

Fragment of pottery (diam. 0.095), find-spot unknown, probably Augusta Treverorum (modern Trier), Belgica.A lion with raised head and tail walks to the right. Before him, a bull's head frontally. Above the lion, five palm-like leaves emerge from a stem; under his tail, a leaf. Loeschcke interprets the lion as a fire-symbol before the head of the killed bull, but the Mithraic attribution is considered too doubtful to accept with certainty.