Eighty years have gone by since F. E. Warren published his work on The Liturgy and Ritual of the Celtic Church. Two years before that date Warren had published the full text of a very puzzling Irish missal which had been in the library of Corpus Christi College, Oxford, probably for some three hundred years. Since Warren wrote, the manuscript has been transferred from the library of Corpus Christi College to the Bodleian Library, where it is kept in a box which contains the missal and its satchel of leather. Its class-number is C.C.C. 282. In 1892 an English Jesuit scholar, H. Lucas, made a careful collation of Warren’s readings with the manuscript text; a note in his handwriting, which records a few minor errors, is preserved in the box with the manuscript.