The so-called Paris Psalter is best known for the Old English Prose Psalms and their vernacular introductions, but the Latin tituli that run through both the prose and verse potions of the psalter reveal much about the compilation of the manuscript and the way its sources were used. The compiler has been sufficiently attentive to the Latin tituli introductions to the first fifty psalms to be able to draw on their source, the pseudo-Bedan In psalmorum librum exegesis, in composing the tituli. In some cases, the compiler has incorporated material to fill gaps where the introductions did not utilize historical or other material from the pseudo-Bedan Argumenta, whereas the compiler has, in other cases, adjusted material from the Argumenta in order to bring it into alignment with the Old English introductions.