AGONALIS CIRCUS, now La Piazza Navona, a long, wide, and beautiful street in the centre of Rome, adorned with fountains, and with the obelisk of Caracalla. The reason of the name Agonalis is either unknown or doubtful. Ovid derives it from the agones, or solemn games, there celebrated, supposed to have been the Ludi Apollinares, or Actiæ, instituted by Augustus; whence the circus was called Apollinaris; also Alexandrinus, from the emperor Alexander Severus, who either inclosed or repaired it.