What we see is a Chimera attacking Bellerophon. Of the latter we only see the feet of his ride, Pegasus and the tip of a spear he directs at a goat's head on the Chimera's back. The "lion" is special: it has a three-forked tongue, and from its back a goat's head is protruding. And its tail has a snake's head, the third of the three animals consistuting this Chimera.

The catalogue comes with a plan of the mosaics, that however has empty areas where I know there are mosaics, so I think it it outdated. I group this in sector E, but may be wrong.