See J. Huskinson, “Some Pagan Mythological Figures and Their Significance in Early Christian Art” Papers of the British School at Rome 42 (1974), pp. 68–97. Of these, Orpheus has the most venerable history of discussion, reaching back as far as A. Bosio, Roma Sotterranea (Rome, 1632), pp. 627 ff. Key discussions include: H. Leclerq, “Orphée,” Dictionnaire d’ archéologie chrétienne et de liturgie 12 (1934–1936), cols. 2735–2755; H. Stern, “Orphée dans l’art paléochrétien,” Cahiers archéologiques 23 (1974), pp. 1–16; M.C. Murray, “Rebirth and Afterlife: A Study of the Transmutation of Some Pagan Imagery in Early Christian Art,” British Archaeological Reports, International Series 100 (1981), pp. 37–63 and pp. 114–121.