Sithonius
Could not find Sithoni in Logeion dictionaries.
Sithoni proper-name adjective neuter genitive singular, proper-name adjective masculine genitive singular of Sithonius
Sīthŏnĭus, (14) a, um, de Thrace : Virg. B. 10, 66 ; Hor. O. 3, 26, 10.