<<the Catholic doctrine on the most Blessed Sacrament of the Eucharist is not left untouched when it is taught inflexibly that the opinion can be accepted which maintains that among the Greeks the words of consecration do not produce an effect unless preceded by that prayer which they call epiclesis,>>
This is by no means an infallible statement for the simple reason that it contains a glaring inaccuracy.
The Epiclesis FOLLOWS the Words of Institution. They do NOT precede it, as Pius X falsely claims here in this quote.
To answer your question, littleflower_24, “Anaphora” is a Greek word that refers to the same prayer that in the Western use is called the Canon of the Mass or Eucharistic Prayer (in the Ordinary Form).
“Epiclesis” is simply a section of this prayer in which (in the Byzantine ones), God the Father is asked to send the Holy Spirit upon the bread and wine to change them into the Body and Blood of Christ.
To try to oppose this prayer to the Words of Institution, especially in terms of which one is consecratory, is to make a false dichotomy. This is the liturgical tradition of the Eastern Churches, which is simply different from the Western ones.
For the Byzantine Churches, the liturgical texts are the ultimate expression of our faith and teaching, not simply quotes from this or that father or this or that council, especially when wrenched from their contexts in handbooks of citations.
It’s PRECISELY in our worship that all of our faith is distilled and expressed.