Pelopidas (16.2-16.3)

and when he heard that its garrison had made an expedition into Locris, he hoped to find the city without defenders, and marched against it, having with him the sacred band and a few horsemen. But when, on approaching the city, he found that its garrison had been replaced with other troops from Sparta, he led his army back again through the district of Tegyra, that being the only way by which he could make a circuit along the foot of the mountains.

For all the intervening plain was made impassable by the river Melas, which no sooner begins to flow than it spreads itself out into navigable marshes and lakes. A little below the marshes stands the temple of Apollo Tegyraeus, with an oracle which had not been long abandoned, but was flourishing down to the Persian wars, when Echecrates was prophet-priest. Here, according to the story, the god was born; and the neighbouring mountain is called Delos, and at its base the river Melas ceases to be spread out,