The medieval names of this church, in Cosmedin, and in Schola Græca, seem to point to the possession of the church by Greek monks after the division of the empire, and the piazza in which it stands is called Bocca della Verità from the strange figure of a head under the modern portico of the church, in the mouth of which it is said that persons whose veracity lay under suspicion, were required to place their hands while making oath, in the belief that the mouth would close upon their hands if the oath taken was a false one. [Sidenote: Carceres of the Cirrus Maximus.] Immediately behind the church are the arched buildings of travertine blocks which have already been mentioned as belonging to the Carceres of the Circus. The largest of these is now used as a store-room for articles of church furniture, and stands on the right side of the tribune of the church. They are perhaps situated too far towards the river to be portions of the actual Carceres from which the chariots started, but they may have formed one side of a courtyard behind the Carceres, in which the harnessing and preparation for the races took place. [Sidenote: Theatre of Marcellus.] The ruins of the Theatre of Marcellus which are still standing in the Piazza Montanara afford us a fixed point from which to begin our survey of the region of the Circus Flaminius, which lies to the north-west of the Velabrum. For it appears certain that the ancient half columns, arches, and other ruins evidently belonging to a semicircular theatre, which are now covered by the Palazzo Orsini Savelli, belonged to the theatre of Marcellus. Suetonius distinctly places this theatre under the Tarpeian hill, and of the other two stone theatres at Rome we know that the Pompeian lay further to the north-west, and that the theatre of Balbus was near the Ponte Sisto. The masonry and architectural details of this building, though corresponding in many respects with the Coliseum are more carefully worked, and show an earlier and better period of art. [Illustration: Theatre of Marcellus.] There had previously been a stone scena built near this spot by Æmilius Lepidus, which was perhaps used by Julius Cæsar who first began to build this theatre. It was not finished until the year B.C. 11 when Augustus opened it, and named it after his nephew Marcellus, son of Octavia. In the time of the Flavii the scena was restored, having perhaps suffered from the fire which burnt the Porticus Octaviæ, and it seems to have again required repairs in the time of Alexander Severus, who is said to have wished to restore it.[83]