Magistrate attested in Apollonia Pontica in 425-339 BC. See E. Paunov, The tetradrachm coinage of Apollonia Pontica: Iconography,
issues and magistrates, in: D. Boteva (ed.), Ex Nummis Lux: Studies in Honour of Dimitar Draganov (2017), 59-87, p. 68 n.
28, p. 74 issue 20 ([Σ]ΩΣΙΑΣ). cp. M. Fraser / E. Matthews, A Lexicon of Greek Personal Names. Vol. IV Macedonia. Thrace.
Northern Regions of the Black Sea (2005), p. 323 s.v. ΣΩΣΙΑΣ (inscription)