CREMERA, a small stream in Etruria (mod. Fosso della Valchetta), which falls into the Tiber about 6m. N. of Rome. The identification with the Fosso della Valchetta is assured by Livy's statement that the Saxa Rubra were not far off, and this we know to be the Roman name of the post station of Prima Porta, 9m. from Rome on the Via Flaminia. It is famous for the defeat of the three hundred Fabii, who had established a fortified post on its banks. (See FIDENAE. )