Sonautes
Sonautes according to Pliny (6.1), a river in Pontus; while, according to Apollonius Rhodius (2.747), the Acheron in Bithynia was anciently called Soonautes (Σοωναύτης).
From William Smith (ed.), Dictionary of Greek and Roman Geography. Text provided under a CC BY-SA license by Perseus Digital Library, http://www.perseus.tufts.edu, with funding from the National Endowment for the Humanities and Tufts University. Data accessed from https://github.com/PerseusDL/canonical-pdlrefwk/ on 17 October 2026.