an extensive marshy lake in Etruria, situated near the sea-shore between Populonium and the mouth of the Umbro, now called the Layo di Castiglione.
It communicated with the sea by a narrow outlet, where there was a station for shipping, as well as one on the Via Aurelia. (Itin. Ant. pp. 292, 500.) The “amnis Prille,” mentioned by Pliny (3.5. s. 8
), between Populonium and the Umbro, is evidently a corruption of Prilis, and it is probable that the Prelius Lacus noticed by Cicero (pro Mil.
27), is only another form of the same name. [PRELIUS LACUS