BILLAEUS(Βιλλαῖος), a river of Bithynia, which is the modern Filyás. [BITHYNIA] Near the mouth of the river was the Greek town of Tios. The Billaeus is certainly a considerable stream, but the whole course does not appear to be accurately known at present. It is mentioned by Apollonius (Apollon. 2.792), and in the Periplus of Marcianus (pp. 70, 71), and by Arrian ( Peripl. p. 14). In his list of Bithynian rivers, Pliny's text (5.32) has Lilaeus, which may be intended for Billaeus.
[G.L]