(2) SS. Gordianus and Epimachus; and (3) S. Tertullinus. These cemeteries have never been carefully examined, and even the site of the third has not yet been identified.
The Via Labicana
Leads from the Porta Maggiore, the ancient Porta Prænestina, to Palestrina. The Itineraries tell us of two cemeteries on this road, that of S. Castulus and that of SS. Peter and Marcellinus. The Catacomb of S. Castulus has only been very partially examined. It is in a ruinous condition, and is not at present accessible. S. Castulus suffered martyrdom in the persecution of Diocletian.
The Catacomb of SS. Peter and Marcellinus, sometimes called "ad duas lauros," from the original name of the district, is in the immediate neighbourhood of the famous Torre Pignatara, the tomb of S. Helena, this appellation being derived from the pignatte or earthen pots used in the building. The magnificent porphyry sarcophagus now in the Vatican was removed from this tomb. SS. Peter and Marcellinus, from whom this once celebrated catacomb is named, suffered in the persecution of Diocletian. S. Peter was in orders as an exorcist. S. Marcellinus was a priest. Pope Damasus, in his inscription originally placed on their crypt, tells us he learned the particulars of their martyrdom from the executioner employed by the State. This cemetery has lately been partially explored. The bodies of the two saints who gave their names to the catacomb were carried away, and are now in Seligenstadt, near Mayence. The saints termed "the Quatuor Coronati" were in the first instance buried here, but their remains were subsequently translated by Pope Leo IV to the church on the Cœlian. This cemetery is of considerable extent.
The Itineraries enumerate the names of several martyrs once evidently well known. They also speak of many other martyrs buried here, using such expressions as "innumerabilis martyrum multitudo sepulta jacent"—"alii (Martyres) innumerabiles," etc.
