The Siberian Islands, lying north of the delta of the Lena, answer to the Parry Islands on the American side, the two groups being separated by that wide stretch of the Arctic Ocean communicating with the Pacific through Bering Strait. At first the Asiatic group was officially named after Liakhoff, then it was called after the unwisely named New Siberia, but, under any designation, it took half a century to find the different islands, and considerably more to land on them. [Illustration: THE LENA DELTA] When Liakhoff discovered the one named after him by the Empress Catherine, he also went north to Moloi, and he seems to have visited Kotelnoi to the north-west. In 1775 Chvoinof was sent to survey these three, but he devoted most of his attention to Liakhoff Island—fifty miles across—which he found to consist, as reported, of hills of granite rising from a mass of mammoth bones, sand, and ice, some of the ice ancient enough to carry a deep covering of moss. Though he stated that other islands could be made out in the distance, nothing was done to verify his discoveries, real or imaginary, until thirty years had passed, when Thaddeus and Stolbovoi were reached. Next year (1806) New Siberia, to the eastward, was discovered by Sirovatskof, and two years afterwards Bjelkof was added to the southerly portion of the archipelago. In 1809 Hedenström, assisted by Sannikof, began his series of surveys extending over all these, and cleared up much of the mystery concerning them. From Thaddeus, Sannikof sighted, away to the northward, what is now known as Bennett Island; and, from New Siberia, Hedenström sighted Henrietta and Jeannette Islands, and set out for them, and would have reached them had his sledges not been stopped by open water. Like his predecessors he was astonished at the mammoth remains on Liakhoff Island.