a town formerly of note, on the left or fourth side and at the mouth of the Tiber, whence its name; the first Roman colony led by Ancus Martius, called Colonia Ostiensis. At this day it lies in ruins, only retaining its name. There were salt-works there, called Salina Ostiensis, as early as the times of Ancus Martius, (Livy); from which the Via Salaria, which led to the Sabines, took its name, (Varro) It gave name to one of the gates of Rome, which was called Ostiensis, (Amian).