An unrelated sidebar, perhaps coming soon to an FR topic near you:
Fascinating mention of Scylax, right in Herodotus, I don't think I'd noticed it before.
Of the greater part of Asia Darius was the discoverer. Wishing to know where the Indus (which is the only river save one that produces crocodiles) emptied itself into the sea, he sent a number of men, on whose truthfulness he could rely, and among them Scylax of Caryanda, to sail down the river. They started from the city of Caspatyrus, in the region called Pactyica, and sailed down the stream in an easterly direction to the sea. Here they turned westward, and, after a voyage of thirty months, reached the place from which the Egyptian king, of whom I spoke above, sent the Phoenicians to sail round Libya. After this voyage was completed, Darius conquered the Indians, and made use of the sea in those parts. Thus all Asia, except the eastern portion, has been found to be similarly circumstanced with Libya.
The Histories of Herodotus, Book IV, Melpomene, tr by George Rawlinson