The "Acta Martyrum" state that Flavia Domitilla, niece of Flavius Clemens, was buried at Terracina, with her attendants, Theodora and Euphrosyne; and that her body-servants, or _cubicularii_, Nereus and Achilleus, who were executed for the same reason, were laid to rest in the crypts of the Villa Amaranthiana, half a mile from Rome, near the tomb of Petronilla, the so-called daughter of S. Peter. In the early itineraries the place is also indicated as the "cemetery of Domitilla, Nereus, and Achilleus, near Santa Petronilla." Bosio discovered it towards the end of the sixteenth century, and mistook it for the Cemetery of Callixtus. The discoveries made in 1873 leave no doubt as to its identification with the famous burial-place of the Flavians; they brought to light, not a crypt of ordinary dimensions, but a basilica equal in size to the one dedicated to S. Lorenzo by Constantine. [Illustration: Basilica of Nereus, Achilleus and Petronilla.] The pavement of the basilica is sunk to the level of the second floor of the catacombs, in order that the graves of Nereus, Achilleus, and Petronilla could be enclosed in the altar, without being raised, or touched at all. The body of the church is divided into nave and aisles by two rows of columns, mostly of _cipollino_, some of which were stolen in 1871 by the farmer; the others were found in 1876 lying on the floor, in parallel lines from northeast to southwest, as if they had been overthrown by an earthquake. A fragment of one of the four columns which supported the ciborium above the high altar has been found in the apse. This fragment contains a bas-relief representing the execution of a martyr. The young man is tied to a stake, which is surmounted by a cross-beam, like a [Symbol: T], the true shape of the _patibulum cruciforme_. A soldier, dressed in a tunic and mantle, seizes the prisoner with the right hand, and stabs him in the neck with the left. The weapon used is not a lictor's axe, nor the sword of a legionary, but a sort of cutlass, which would be more likely to cut the throat than to sever the head from the body. The cross is crowned by a triumphal wreath, as a symbol of the immortal recompense which awaits the confessor of the Faith. The historical value of this rare sculpture is determined by the name, ACILLEVS, engraved above it. [Illustration: The Execution of Acilleus.] The character of the letters and the style of the bas-relief are those of the second half of the fourth century. Of the sister column, with the name and martyrdom of NEREVS, only a small bit has been found. Another monument of equal value is a broken slab containing, in the first line, the letters ····RVM; in the second, the letters ····ORVM; and below these, the cross-shaped anchor, the mysterious but certain emblem of Christian hope. As the position of the symbol determines the middle point of the inscription, it is easy to reconstruct the whole text, by a careful calculation of the size of each letter:--