ISIDORE of Seville († 658).—_De Officiis Ecclesiasticis._ MIGNE, _Patr. Lat._, lxxxiii. AMALARIUS SYMPHOSIUS (“chor-episcopus” at Metz, † between 850 and 853).—_De Officiis Ecclesiasticis libri quattuor._ MIGNE, _Patr. Lat._, cv. RABANUS MAURUS (Abbot of Fulda, later Archbishop of Mainz, † 856).—_De Officiis Ecclesiasticis._ MIGNE, _Patr. Lat._, cvii. ADO (Bishop of Vienne, † 875).—_Libellus de Festivitatibus SS. Apost._ MIGNE, _Patr. Lat._, cxxiii. JOHANNES ABRINCENSIS (Bishop of Rouen, † 1079).—_De Officiis Ecclesiasticis._ MIGNE, _Patr. Lat._, cxlvii. _Ordinarius Canonicorum Reg._, _ib._ 188-191. PSEUDO-ALCUIN (middle of the eleventh century).—_De Officiis Ecclesiasticis._ Incomplete in MIGNE, _Patr. Lat._, ci. 1175. According to Bäumer, Amalarius Fortunatus is really the author. BERNO of Reichenau († 1045).—_De Officio Missæ_, and two small tracts on Advent and the Embertides. MIGNE, _Patr. Lat._, cxlii. LANFRANC († 1089).—_Decreta pro Ord. S. Benedicti._ MIGNE, _Patr. Lat._, cl. BERNOLD of Constance († 1100). According to Bäumer, the author of the _Micrologus_. MIGNE, _Patr. Lat._, cli. _De Cærimoniis, Sacramentis, Officiis et Observantionibus Ecclesiæ libri tres_, by HUGO (Canon of St Victor in Paris, † 1118), or by ROBERTUS PULLUS. MIGNE, _Patr. Lat._, clxxvii. 381. RUPERT of Deutz († 1135).—_De Divinis Officiis._ MIGNE, _Patr. Lat._, clxx. GUIGO I. DE CASTRO (Prior of the Grande Chartreuse about 1137).—_Consuetudines Carthusienses._ MIGNE, _Patr. Lat._, clii. 631-759. HONORIUS of Autun († _circ._ 1145).—_Gemma Animæ._ MIGNE, _Patr. Lat._, clxxii. JOHANNES BELETH (Professor of Theology at Paris, † 1190).—_Rationale Divinorum Officiorum._ MIGNE, _Patr. Lat._, ccii. _Consuetudines Farfenses_, ed. B. Albers. Stuttgart, 1900. Older editions in MIGNE, _Patr. Lat._, c. 4, and (HERGOTT) _Vetus Disciplina Monast._ Paris, 1776. SICARDUS (Bishop of Cremona, † 1215).—_Mitrale._ MIGNE, _Patr. Lat._, ccxiii. INNOCENT III. (Pope, † 1216).—_De S. Altaris Mysterio libri sex._ MIGNE, _Patr. Lat._, ccxvii. ODERICUS (Canon of Siena, 1213).—_Ordo Officiorum Eccl. Senensis._ Ed. Trombelli. Bononiæ, 1766. CODINUS.—_Curopalates s. de Officialibus Palatii Constantinopolitani et de Officiis Magnæ Ecclesiæ._ Rec. Imm. Bekker. Bonn, 1839. (B) MORE RECENT WORKS EMPLOYED OR REFERRED TO (_a_) BY CATHOLIC AUTHORS ALLATIUS, LEO.—_De Dominicis et Hebdomadibus Græcorum Recentiorum._ Col., 1648. ARENS, FRANZ.—_Der Liber Ordinarius der Essener Stiftskirche_, Essen, 1901. ASSEMANI, JOS. SIM.—_Kalendaria Ecclesiæ Univ._ Romæ, 1730. Six vols. BAILLET, ADRIEN († 1706).—_Les Vies des Saints._ Paris, 1703; second ed. 1739, in ten vols. 4to. Vol. ix. contains a history of the movable feasts. BÄUMER, SUITB.—_Geschichte des Breviers_, etc. Freiburg, 1895. BENEDICT XIV. (Prosper Lambertini).—_De Festis D.N. Jesu Christi et B. Mariæ Virginis libri duo._ Patavii, 1756. ⸺ _Commentarius de Festis B. Virg. Mariæ_, etc. Dillingen, 1754.