The Apse Mosaic at Santa Cecilia in Trastevere: Detail, the right side
St. Peter is identified by the keys in his left hand and by his short, square beard. Like St. Paul on the left side and unlike all the others, he wears a white toga in the manner of Roman authorities. As he presents Saints Cecilia and Valerian to Christ they in turn present Christ with their martyr's crowns.
Cecilia's pearl-studded collar is worn by her and other virgin martyrs in early portraiture.
View the whole apse.
Photographed at the church by Richard Stracke, shared under Attribution-NonCommercial-ShareAlike license.