one of the seven Greek writers on music whose works are collected and published, with a commentary and explanatory notes, by Melibomius. The time in which he flourished cannot be precisely ascertained. He is said to have written before Euclid and Ptolemy; and Cassiodorus arranges his work, entitled Introduction to Music, between those of Nicomachus and Gaudentius. In this work is to be found the most complete nomenclature of all the sounds of the different scales and modes in the ancient Greek music which have escaped the wreck of time.

ALYPIUS of Tagasta, a Christian divine of the fourth century. He was baptized at Milan in 388, and consecrated bishop of Tagasta in Africa in 394. He assisted his friend St Augustine in opposing the tenets of the Donatists, who claimed the exclusive honour of being the true Church. In 419 he was sent by the African bishops to Honorius, and was employed by Pope Boniface against the Pelagians. Alypius died in 430. There is extant an epistle of his in Greek addressed to St Cyril, on the heresy of Nestorius.