Scylax Of Caryanda, Carian explorer.
In about 515 BC Scylax was sent by the Persian king Darius I of Persia to explore the course of the Indus River. Scylax returned by sea after 30 months. He is mentioned by Strabo as an "ancient writer".
The Periplus of Pseudo-Scylax which dates from the 3rd century AD is a compilation which seems to have been named in his honour.
See Herodotus 4.44