BUG, the name of two rivers of Europe. (I) A stream of European Russia, which rises in the Avratynsk hills near the Polish frontier and flows generally south-east through Podolia and Kherson, to enter, at Nikolayev, the liman or lagoon into which the Dnieper also discharges. Its upper part is beset with rapids and its lower has numerous sandbanks and rocky stretches which prevent navigation. (2) A tributary of the Vistula, rising in eastern Galicia east of Lwow (Lemberg) and flowing north north-west to Brest-Litovsk, where it becomes navigable as it turns west between the provinces of Siedlce, Grodno and Lomza, to join the Vistula, 23m. below the city of Warsaw.