Oh hey, just saw this. I always have trouble with abbreviated church latin, so I'm going to skip the first part, but the second part (Quodcumque vinclis super terram strinxerit erit in astris religatum fortiter et quod resolvit in terris arbitrio erit solutum super caeli radium in fi(ne mundi judex erit saeculi (missing from your pages)) is a hymn rendering of Matthew 16:19, "I will give you the keys of the kingdom of heaven; whatever you bind on earth will be bound in heaven, and whatever you loose on earth will be loosed in heaven."
btw, the first part isn't Matthew 16:18, has something to do with the Feast of the Chair of Peter (cathedra petri), here my knowledge of catholic doings gets a little fuzzy.