Hippolytus Portuensis-Date of the Nativity according to Hippo- lytus-Latin Chronicon, ascribed to Hippolytus-Placed the Na-
t
tivity in the spring-Portus Romanus-Siege of Rome by Alaric
-Interval between the Nativity and Passion, according to Hippo- lytus-Paschal calendar of Hippolytus-Nature of the double Oc- taëteric cycle-Notices in the calendar-Γένεσις Χριστοῦ and