In the middle of the left wall there is the the original Roman sarcophagus that belonged to the ancient monument of Saint Monica. The surmounted recumbent statue was carved by Isaia da Pisa in 1455. The frescos on the side are by Pietro Gagliardi from the middle of the 19th century.

On the pillar to the left are the epitaph and portrait of Cardinal Gregorio Petrocchini O.E.S.A., cardinal protector of the Augustines and patron of the chapel, who died in 1612.

(Better photos of the frescoes here and here)
(Better photo of the tomb monument here.