In the great basins and hollows from Rugen to the Gulfs of Bothnia and Finland the upper layers of water, from 30 to 70 metres (16 to 38 fathoms) in thickness, have almost the same salinity throughout.
B~t in the time of that historian, as well as of Thucydides, the names of Oenotria and Italia, which appear to have been at that period regarded as synonymous, had been extended to include the shore of the Tarentine Gulf as far as Metapontum and from thence across to the gulfs of Laus and Posidonia on the Tyrrhenian Sea.
It predominates along the Ligurian Riviera from Bordighera to Spezia, and on the Adriatic, near San Benedetto del Tronto and Gargano, and, crossing the Italian shore of the Ioian Sea, prevails in some regions of Calabria, and terminates around the gulfs of Salerno, Sorrento and Naples.
The Tunisian coast between the gulfs of Hammamet and Gabes.
Where the great continental sag sinks below the ocean level, we have our gulfs and our Mediterraneans, seen in our type continent, as the Mexican Gulf and Hudson Bay.