According to one tradition a son of king Numa, who chose this name because one of the sons of Pythagoras likewise bore it. (Plut. Num. 8; Paul. Diac. p. 23, ed. Müller.) Another tradition made Mamercus a son of Mars and Sylvia. (Plut. Parall. Gr. et Rom. 26.) Festus says that Mamercus was a praenomen among the Oscans,who called the god Mars, Mamers. But it would seem that Marcius or Mamercus was the common name for indigenous soothsayers and founders of new forms of religious worship, for it occurs in many instances of this kind. (Hartung, Die Rel. der Röm. vol. i. p. 129.)