EGERIA, the spirit or Lumpa (see NYMPHS) of a stream just outside the Porta Capena of Rome in the grove of the Camenae; also of a stream in the grove of Diana near Aricia. A wholly artificial story makes her the wife and counsellor of king Numa; they met in the grove of the Camenae, and on his death she retired to Aricia, where because of her lamentations Diana changed her into a stream. She was worshipped by preg nant women, and apparently as a prophetic goddess, in connection with Diana and the Camenae. She seems to have had a masculine counterpart Egerius, at Aricia.
See Wissowa, Religion and Kultus, 2nd ed. (1912), p. 248, and in Roscher, Lexikon; Buchmann, De Numae regis Romanorum fabula , p. 38 ff.