I believe that’s only if it’s a feast. For memorials, the psalms are always from the propers; you use the memorial’s
antiphons with the psalms from the proper.
Update: The GILH says:
- In the office of readings, at morning prayer, and at evening prayer:
a.
the psalms and their antiphons are taken from the current week and day, unless there are proper antiphons or proper psalms, which is indicated as the case occurs;
b. the antiphon at the invitatory, the hymn, the short reading, the antiphons at the Canticles of Zechariah and of Mary, and the intercessions must be those of the saint if these are given in the proper; otherwise, they are taken either from the common or from the current week and day;
c. the concluding prayer from the office of the saint is to be said;
d. in the office of readings, the Scripture reading with its responsory is from the current cycle. The second reading is about the saint, with a proper responsory or one taken from the common; if there is no proper reading, the patristic reading for the day is used. The Te Deum is not said.
In other words, for memorials of saints, you use whatever is given in the
proper for that saint, but not what is given in the
common of the saint.