A very early mention of these tombs, however, we find in the so-called “Liberian” or “Philocalian” Catalogue, which was partly composed or put together not later than the year of grace 334. The alternative name of the Catalogue is derived from Filocalus, the famous calligrapher of Pope Damasus, who most probably was the compiler of the work, which consists of several tracts chronological and topographical of the highest interest, some originally doubtless composed at a very early date. It contains, among other pieces, a Catalogue of Roman Bishops, ending with Liberius, and a piece termed “Depositio Martyrum,” in which the burying-places of the seven sons of Felicitas are carefully set out. This ancient memorandum has been of the greatest assistance to De Rossi and Marucchi in their identification of the original graves of the “seven.” When De Rossi had penetrated into the cemetery of Prætextatus on the Appian Way, he came upon what was evidently a highly decorated chamber, once lined with marble, and carefully built and ornamented. It was, he saw, an historic crypt of the highest interest. The vault of the chamber was painted, and the fresco decorations were still fairly preserved. The paintings represented garlands of vines and laurels and roses, executed with great taste and care; the style and execution belonged to work which must be dated not later than the second century. Below the beautifully decorated vault was a long fresco painting of the Good Shepherd with sheep; one sheep was on his shoulders. This painting has been sadly interfered with by a loculus, or grave, of later date, probably of the fourth or fifth century; on the loculus in question could still be read the following little inscription--perfect save for the first few letters: . . MI RIFRIGERI JANUARIUS AGATOPUS FELICISSIM . . . MARTYRES Some sixth-century Christians, anxious to lay their beloved dead close to the martyrs, had caused the wall of the chamber to be cut away, for the reception of the body, regardless of the painting, and then while the plaster was still fresh had cut these words of prayer, which may be translated, “May Januarius, Agatopus,[139] and Felicissimus refresh (the soul of ...).” Agatopus and Felicissimus were two of the deacons of Pope Sixtus II, who had (probably in the same catacomb) suffered martyrdom, A.D. 258. Their sepulchral chambers were subsequently identified. The question at once presented itself to De Rossi--was not this chamber ornamented with paintings clearly of the second century, the crypt where S. Januarius had been laid? All doubt on this point was subsequently cleared up, for eventually in many fragments the original inscription which Pope Damasus had caused to be placed over the door or near the altar was found. The inscription ran thus: