), a river on the Atlantic coast of Gallia, which Ptolemy (2.8.2
) places between the Staliocanus Portus and Argenus, or the outlet of the river Argenus, if that is the true reading.
It is impossible to determine what river is the Tetus. D'Anville assumes the place to be the bay of Seu,
which receives the rivers Sée
Others take the Tetus to be the Treguier