I´DACUS(Ἴδακος), a town of the Thracian Chersonese, mentioned by Thucydides (Thuc. 8.104) in his account of the manoeuvres before the battle of Cynossema, and not far from ARRHIANAA lthough nothing whatever is known of these places, yet, as the Athenians were sailing in the direction of the Propontis from the Aegaean, it would appear that Idacus was nearest the Aegaean, and Arrhiana further up the Hellespont, towards Sestus and the Propontis. (Arnold, ad loc.)
[E.B.J]