Baring-Gould’s sources: No ancient Martyrology. Introduced into the Roman Martyrology in z6o8. There is no ancient authority for his having ever existed and been bishop of Ravenna. RubseUs in his “ History of the Church of Ravenna, " was the first to speak of him.] The Church of Ravenna is said to have possessed this remarkable privilege, that on the death of a bishop of the see, his successor was designated by the fluttering of a white dove above the head of the person who was to succeed him. Datus is said, on no ancient authority, to have been seventh bishop of Ravenna, after S. Appolinaris, to have succeeded S. Probus, and to have governed the Church in Ravenna nine years. He was indicated for election by the appearance of the dove. At Ravenna is, or was, an ancient mosaic representing the eleven first bishops of that see, each with the dove, but Datus is not included among them. There can be little doubt that these ancient representations originated the story of the miraculous apparition of the white dove. S. EULOGIUS, M.

(uncertain.) [Roman Martyrology, Usuardus [a 9th-century monk of Paris who compiled a list of saints for each day]; the lesser ancient Roman Martyrology. j Usuardus on this day, following the lesser Roman Martyrology, says, “At Constantinople, S. Eulogius.” The modern Roman Martyrology says, “At Constantinople, S. Eulogius and his companions, martyrs.” On what authority he is asserted to be a martyr and to have had companions, we do not know.