There is a confusing difference in the numbering of the Psalms, which is
caused by the fact that Hieronymus in his numbering of the Psalms for the
Vulgata (Latin Bible) took over the numbering of the Greek translation of
the Bible (Septuaginta). Every Psalm in Latin follows this numbering
(V). Protestants and protestant composers returned to the numbering of the
Hebrew Bible (H). Almost all modern bible-editions use the Hebrew
numbering.
Example: The famous penitential psalm Miserere mei, Domine is psalm
50 in the Vulgata, but will be found sub Psalm 51 in any modern bible. The
other famous penitential psalm De profundis is psalm 129 in the
Vulgata and psalm 130 for protestants. A psalm very dear to protestants like
psalm 116 (f.i. very famous because almost all German composers were invited
in the around 1618 to make a musical score of this psalm (Schütz, Schein,
Praetorius) has its counterpart in the Latin psalms 114 and 115.