DELPHINIA, a festival of Apollo Delphinius held annually on the 6th (or 7th) of the month Munychion (April) at Athens. All that is known of the ceremonies is that a number of girls proceeded to his temple (Delphinium) carrying suppliants' branches and seeking to propitiate Apollo, probably as a god having influence on the sea. It was at this time of the year that navigation began again after the storms of winter. According to the story in Plutarch (Theseus, 18), the festival was instituted by Theseus (q.v.) to commemorate his voyage to Crete.