I don't believe that Saint Flavius Clement is buried underneath the main altar of San Clemente. The inscription on the front of the altar reads "SANCTUS CLEMENS MARTYR HIC FELICITER EST TUMULATUS;" (Saint Clement, Martyr, is happily buried here) and not "FLAVIUS CLEMENS MARTYR HIC FELICITER EST TUMULATUS." Also, below the altar on the front it reads "HIC REQUIESCUNT CORPORA SS. CLEMENTIS PAPAE ET IGNATII ANTIOCHENI;" (Here lie the bodies of Saints Clement, Pope, and Ignatius of Antioch). There does not actually appear to be any evidence that Saint Flavius Clement (aka Saint CLEMENT of Alexandria) is buried here with Pope Saint Clement and Saint Ignatius of Antioch.
I would like to propose a more precise translation of the inscription in the apse. While the first and the fourth line seem to me allright, the translation of the second and the third should in my point of view ran like thiss, translated almost litterarly, for better understanding: 'from the wood of the cross, a teeth of James and from Ignatius are laying within the body of the Christ mentioned above'.
So this mosaik represents as well a kind auf reliquary and staurotheque, and the power of the design is underlined by the presence of this holy remains. 126.96.36.199 16:26, January 31, 2010 (UTC) Michael Ogrzewalla