Passage 3.21.6
Γύθιον δὲ ἀπέχει μὲν σταδίους τριάκοντα Αἰγιῶν, ἐπὶ θαλάσσῃ δὲ ᾠκισμένον ἔστιν ἤδη τῶν Ἐλευθερολακώνων, οὓς βασιλεὺς Αὔγουστος δουλείας ἀφῆκε Λακεδαιμονίων τῶν ἐν Σπάρτῃ κατηκόους ὄντας. θαλάσσῃ μὲν δὴ πλὴν τοῦ Κορινθίων ἰσθμοῦ περιέχεται πᾶσα ἡ Πελοπόννησος· κόχλους δὲ ἐς βαφὴν πορφύρας παρέχεται τὰ ἐπιθαλάσσια τῆς Λακωνικῆς ἐπιτηδειοτάτας μετά γε τὴν Φοινίκων θάλασσαν.
Gythium is thirty stades distant from Aegiae. Situated on the sea, it now belongs to the Eleutherolakones, whom the emperor Augustus freed from their subjection to the Lacedaemonians who dwelt at Sparta. The whole of the Peloponnese is surrounded by sea except for the Corinthian Isthmus; and the coastal areas of Laconia supply the best shellfish for producing purple dye, second only to those from the sea of Phoenicia.