Heidegger's Bible Handbook: NT Apocrypha: The Liturgy of St. Peter
11. To Peter.
The Liturgy ascribed to Saint Peter was published from the translation of William Lindanus, and is extant in Tome I of the Bibliothecæ Patrum, published at Cologne. But, that it does not belong to Saint Peter, many things contribute to the argument: especially that in it mention is made of Linus, Cletus, Clement, Cornelius, Cyprian, etc., and that in it prayers are poured out for our venerable Patriarch, which was non-existent at that time; and for our Most Pious Emperors. In the time of Peter there was no ἱερεὺς/priest in the service of the Christian Church; even the language of Θεοτόκου, the mother of God, was unknown. And, if it were written by Peter as author, the Roman Church would have been obliged to receive it. Yet the Mass of Gregory, or of some Scholastic, was preferred to this, banished to Apulia. Neither does Bellarmine dare to cite this Mass anywhere, although he searched resourcefully and thoroughly enough for ancient Masses.
 Linus served as Bishop of Rome from 67 to 76.  Anacletus served as Bishop of Rome from c. 79 to c. 92.  Cornelius served as Bishop of Rome from 251 to 253.  A province in south-eastern Italy. It is reported that Saint Peter’s Liturgy was rediscovered there.