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.
Word was also sent round to the states of the Peloponnesus, summoning them to come to the relief of Pylos as quickly as possible, and also to the sixty ships that were at Corcyra.[*](cf. 4.2.3.) These were hauled across the Leucadian isthmus, and without being discovered by the Attic ships, which were now at Zacynthus, reached Pylos, where their land forces had already arrived.
But before the Peloponnesian fleet had yet reached Pylos, Demosthenes managed to send out secretly ahead of them two ships which were to notify Eurymedon and the Athenian fleet at Zacynthus to come at once to his aid, as the place was in danger. And so the fleet proceeded in haste in compliance with Demosthenes' summons;