History of the Peloponnesian War
Thucydides
Thucydides, Vol. 1-4. Smith, Charles Foster, translator. London and Cambridge, MA: Heinemann and Harvard University Press, 1919-1923.
Eurymedon, who commanded the right wing of the Athenians, wished to surround the ships of the enemy, and had therefore steered his ships out from the line rather too near the shore, when the Syracusans and their allies, after they had defeated the Athenian centre, cut off him also in a recess of the inner bay of the harbour and destroyed both him and the ships that followed him; and after that they set about pursuing the entire Athenian fleet and driving them ashore.
Now Gylippus, when he saw the ships of the enemy being defeated and driven ashore at a point beyond the stockades and their own camp, wishing to destroy the men as they landed, and also that the Syracusans might more easily tow the ships away from a shore that would be friendly to them, came down to the causeway[*](A quay which ran along by the swamp Lysimeleia toward the Athenian camp.) with part of his army to assist them.
The Tyrrhenians, however, who were guarding the causeway for the Athenians, saw these troops rushing to the attack in disorder and went out against them, and falling upon the first comers put them to flight and drove them into the marsh called Lysimeleia.
But afterwards, when a larger force of the Syracusans and their allies had now arrived, the Athenian troops also went out against them and, fearing for their ships, engaged in battle with the enemy, whom they defeated and pursued, killing a few hoplites; and as for the ships, they saved most of them and assembled them at their camp, but eighteen were captured by the Syracusans and their allies and their crews slain to a man.