Note 3167 — BOOK IV. AN ACCOUNT OF COUNTRIES, NATIONS, SEAS, TOWNS, HAVENS, MOUNTAINS, RIVERS, DISTANCES, AND PEOPLES WHO NOW EXIST OR FORMERLY EXISTED.
John Bostock translation
The strait between the island and the mainland is now called the River of Saint Peter. The circuit of the island, as stated by Pliny, varies in the MSS. from fifteen to twenty-five miles, and this last is probably correct.