Of the manifold Syrian Anaphoras, the Catholics use seven only those of St . James, St . John, St . Peter, St . Chrysostom, St . Xystus, St . Mathew, and St . Basil.
12.
Thus the churches in Asia appealed to the Apostle John in support of their practice, while Sozomen wrote that the Roman custom ( observed, according to Irenaeus, since at least the time of Bishop Xystus of 115 25 ) was believed to have been handed down by the Apostles Peter and Paul, and Eusebius states that in Palestine and Egypt the Sunday observance was also believed to have originated with the Apostles.
