VILNA, or WILN0  , a Lithuanian government of West Russia, having the Polish government of Suwalki on the W., Kovno and Vitebsk on the N., and Minsk and Grodno on the E. and S . Area, 16,176 sq. m.; pop . (1906 estimate) 1,806,300 . Vilna lies on the broad marshy swelling, dotted with lakes, which separates Poland from the province of East Prussia and stretches E.N.E. towards the Valdai Plateau . Its highest parts are a little more than loon ft, above sea-level . On its western and eastern boundaries it is deeply trenched by the valleys of the Niemen and the S . Dvina . It is chiefly built up of Lower Tertiary deposits, but in the north Devonian sandstones appear on the surface . The Tertiary deposits consist of Eocene clay, slates, sandstones, limestones and chalk, with gypsum, and are partly of marine and partly of terrene origin . The whole is overlain with thick layers of Glacial boulder clay and post-Glacial deposits, containing remains of the mammoth and other extinct mammals . Interesting discoveries of Neolithic implements, especially of polished stone, and of implements belonging to the Bronze Age and the early years of the Christian epoch, have been made . Numerous lakes and marshes, partly covered with forests, and scarcely passable except when frozen, as well as wet meadow-land, occupy a large area in the centre of the government .

The Niemen, which flows along the

southern and western borders for more than 200 m., is the chief artery of trade, and its importance in this respect is enhanced by its tributary the Viliya, which flows west for more than 200 m. through the central parts of Vilna, receiving many affluents on its -course . Among the tributaries of the Niemen is the Berezina, which acquired renown during Napoleon's retreat in 1812; it flows in a marshy valley in the south-east . The S . Dvina for 5o in. of its course separates Vilna from Vitebsk . The climate of the government is only slightly tempered by its proximity to the Baltic Sea (January, 210.8; July, 64°.5); the average temperature at the town of Vilna is only 430.5 . But in winter the thermometer descends very low, a minimum of -3o° F. having been observed . The flora and fauna are inter-mediate between those of Poland and middle Russia . The government is divided into seven districts, the chief towns of which are Vilna, Vileiki, Diana, Lida, Oshmyany, Zventsyany and Troki .