Its position, at the point where the Volscian Hills reach the coast, leaving no space for passage between them and the sea, commanding the Pomptine Marshes (urbs **pron** g in paludes, as Livy calls it) and possessing a small harbour, was one of great strategic importance; and it thus appears very early in Roman history.

**Pron** (1908), and B.

The first member of the series is 3; the second is the product of n 1 two numbers, each equal to 3; the third is the **pron** e duct of three numbers, each equal to 3; and so on.