Russian Empire Bolsheviks followed in 1918. The administrative boundaries of European Russia, apart from Finland and its portion of Poland, coincided approximately with the natural limits of the East-European plains. In the North it met the Arctic Ocean. Novaya Zemlya and the Kolguyev and Vaygach Islands also belonged to it, but the Kara Sea was referred to Siberia. To the East it had the Asiatic territories of the Empire, Siberia and the Kyrgyz steppes, from both of which it was separated by the Ural Mountains, the Ural River and the Caspian Sea — the administrative boundary, however, partly extending into Asia on
Arctic lemming Arctic lemming The Arctic lemming ("Dicrostonyx torquatus") is a species of rodents in the family Cricetidae. Although generally classified as a "least concern" species, the Novaya Zemlya subspecies "(Dicrostonyx torquatus ungulatus)" is considered a vulnerable species under Russian nature conservation legislation (included in Red Book of Russian Federation since 1998). It is found only in the Arctic biomes in the Russian Federation, and it is the commonest mammal on Severnaya Zemlya. Specimens were once found in England, but they are now extirpated. For the most part, lemmings of the genus "Lemmus" can coexist with those of genus "Dicrostonyx". Arctic lemmings