NLM: When the Lenten station is held at St. Peter's Basilica, on Ember Saturday and Passion Sunday, and on a few other occasions, the Papal altar is decorated with relics according to a particular arrangement. The relics of martyrs are placed closer to the edge of the mensa, and those of other saints further in; the four corners are decorated with reliquaries shaped like obelisks, with long bones (tibias and such) in them.
On each of the two short sides of the altar is set a rectangular panel containing relics 35 Popes; between the two of them, all of the Sainted Popes except the most recent.
On the long side facing the apse, a bust reliquary of Pope St. Damasus I (366-84, feast on December 11), containing the relics of his skull, is placed in the middle. This is a particularly appropriate choice, since Damasus was a great promoter of devotion to the saints and the cult of the relics, particularly those of the Roman martyrs. Within many catacombs, he rearranged the spaces around the tombs of the martyrs to make it easier for pilgrims to find and visit them, decorating the tombs themselves with elaborately carved inscriptions written by himself in classical poetic meter. For this reason, he is honored as the patron saint of archeologists.