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
Severnaya Zemlya as Arctic lemming, which is present on all of the large islands and, in some places has been recorded to reach a density of 500 per km (1,300 per sq mi). The Arctic fox ("Alopex lagopus") has been known to den on the islands, with several hundred observed in the 1980s. Other mammals occasionally observed include the wolf ("Canis lupus"), the polar bear ("Ursus maritimus"), ermine ("Mustela erminea"), Arctic hare ("Lepus timidus"), and reindeer ("Rangifer tarandus"). The discovery of Severnaya Zemlya is the subject of Veniamin Kaverin's novel "The Two Captains" as well as its stage adaptation, "Nord-Ost". Severnaya Zemlya