Arctida – a hypothetical northern polar continent which is supposed to have existed in the geological past. The term was suggested in the nineteenth century by a German zoogeographer I. Eger who used this word to refer to “the northern polar land” that presumably connected the New World with Eurasia via circumpolar regions. Later the existence of Arctida was claimed by a Soviet Arctic oceanographer Y. Y. Gakkel, who thought it to be an ensemble of archipelagoes, though. According to him both the New Siberian Islands and Wrangel Island are remnants of the prehistoric land. This land may have surrounded the Svalbard Archipelago, Franz Josef Land Archipelago, Severnaya Zemlya Archipelago, Canadian Arctic Archipelago, and the modern mid-oceanic ridges: the Gakkel, Lomonosov, and Mendeleev ridges dominated these territories as mighty mountain ranges connecting America and Eurasia.