(Τυρρηνός or Τυρσηνός), a son of the Lydian king Atys and Callithea, and a brother of Lydus, is said to have led a Pelasgian colony from Lydia into Italy, into the country of the Umbrians, and to have given to the colonists his name, Tyrrhenians. (Hdt. 4.94; Dionys. A. R. 1.27.) Others call Tyrrhenus a son of Heracles by Omphale (Dionys. A. R. 1.28), or of Telephus and Hiera, and a brother of Tarchon. (Tzetz. ad Lyc. 1242, 1249.) The name Tarchon seems to be only another form for Tyrrhenus, and the two names represent a Pelasgian hero founding settlements in the north of Italy. (Comp. Müller, Die Etrusker, vol. i. p. 72, &c.)
[L.S]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890