Lewis & Short

2. Pontia, ae, f., = Ποντία, an island in the Tuscan Sea, now Ponza, Suet. Tib. 54.
Plur.: Pontiae, ārum, the group of little islands which includes Ponza, Liv. 9, 28; Mel. 2, 7; Plin. 3, 6, 12, § 81; Varr. L. L. 3, 5, 7.