Of course, as in the Great Office, in every doxology for all psalms, canticles and hymns, in the internal doxology of the Te Deum, as well as in the conclusion of every collect, the Holy Ghost is worshipped and glorified with the Father and the Son; but strangely He, the Third Person of the Trinity, is otherwise hardly mentioned in the Little Office of the Blessed Virgin Mary, despite the obvious fact that she conceived "by the Holy Ghost" (traditionally, the Apostles' Creed, which states this, is said after Compline) - to which the Matins hymn and the collect of the Salve Regina make allusion: Fœcunda Sancto Spiritu; Spiritu Sancto coöperante. (The Benedictus antiphon names Our Lady also as sacrarium Spiritus Sancti.)
Isn't it strange that in none of the collects of the Hours is the Holy Ghost directly mentioned in the body of the prayer?
There are a few extra mentions of Him in Advent (in the second Responsory and third Lesson of Matins - Spiritus Sanctus superveniet in te; in the capitulum used at Lauds, Terce and Vespers - et requiescet super eum Spiritus Domini; in the Gospel canticle antiphon at Lauds, Vespers and Compline - Spiritus Sanctus in te descendet; in the versicle at None - Et concepit de Spiritu Sancto), but by no means many.
To remedy this state of affairs, I add pro pia devotione some extras before and after: as once was the first stanza of the hymn at all the Little Hours, I preface Prime through to None, and Compline, with the first stanza of the Veni Creator Spiritus; and just recently I have begun to add, before the Commemoration of the Saints at the end of Lauds and Vespers (which I append to these, despite its removal in about 1960), a Commemoration of the Holy Ghost, with the usual Veni Sancte Spiritus, Emitte Spiritum tuum, and Collect Deus cui omne cor patet (so dear to St Philip, himself a notable vessel of the Holy Ghost, and a prayer he recommended to his Oratorians to read at Mass).