Arctic Sea, The, is the name given to the great body of water that lies within the Arctic Circle, i.e. N. of 66° 30' N. lat. In common parlance the term is extended to such portions of the ocean as are under the same physical conditions as those actually inside the circle. The region immediately surrounding the Pole has not yet been explored. Lieutenant Markham in Sir George Nares' expedition in 1876 reached 83° 20' 26" N., while Nansen in 1896 reached 85° 57', the highest latitude as yet attained. Sir G. Nares' investigations confirmed the existence of a vast Polar Basin, having an area of one-and-a-half million square miles, to which geographers gave the name of the Palaeocrystic Sea (or sea of ancient ice). This name has, however, since been abandoned by nearly all geographers. The chief entrances to it are by Behring Strait, Smith Sound and Jones Sound at the extremity of Baffin Bay; the channel between Greenland and Spitzbergen; and that, between Spitzbergen and Nova Zembla, into which the Gulf Stream penetrates. From the end of September to the beginning of May no sun is visible in this desolate expanse, and though the heat in summer breaks up the vast covering of ice into fields and floes which partly escape into southern seas, the seven months of winter more than make up for this loss. Animal life exists up to a very far point; Markham found in lat. 83° 20' 26" N., swarms of small crustaceans, and footprints of the Polar hare have been seen as far North as lat. 83° 10'. Cold currents appear to flow downward from the Pole through most of these passages. Numbers of islands form a characteristic feature of this portion of the earth's surface, ranging from the size of Greenland to mere specks in the sea. The sole inhabitants within the circle are the Esquimos, and they spend even the winter in lat. 78° 10'. The white bear, hares, foxes, ptarmigan, and a few aquatic birds constitute the fauna of the lower latitudes, and the sea abounds in seals, walruses, whales, and fish of many kinds.