The Feast of St Damasus, PC, IIIrd Class
The Collect from the Roman Breviary:
O eternal Shepherd, do thou look favorably upon thy flock, which we beseech thee to guard and keep for evermore through the Blessed Damasus thy Supreme Pontiff, whom thou didst choose to be the chief shepherd of the whole Church. Through.
The Proper Lessons may be found here.
The article on him from the Catholic Encyclopædia.
From Father Alban Butler's Lives of the Saints.
From Medieval Saints at Yahoo!