Another less extensive ridge branches off nearly due east from the Bayan-kara Mountains in Koko-nor, and forms a moderately high range of mountains between the Yellow River and Yangtsz’ kiang as far as long. 112° E., on the western borders of Nganhwui; this range is called Ko-tsing shan, and Peh ling (_i.e._, Northern Mountains), on European maps. These two chains, viz., the Yun ling--with its continuation of the Mei ling--and the Peh ling, with their numerous offsets, render the whole of the western part of China very uneven. ~HING-AN AND HIMALAYA RANGES.~ On the east of Mongolia, and commencing near the bend of the Yellow River, or rather forming a continuation of the range in Shansí, is the Nui Hing-an ling or Sialkoi, called also Soyorti range, which runs north-east on the west side of the basin of the Amur, till it reaches the Wai Hing-an, in lat. 56° N. The sides of the ridge toward the desert are nearly naked, but the eastern acclivities are well wooded and fertile. On the confines of Corea a spur strikes off westward through Shingking, called Kolmin-shanguin alin by the Manchus, and Chang-peh shan (_i.e._, Long White Mountains) by the Chinese. Between the Sialkoi and Sihota are two smaller ridges defining the basin of the Nonni River on the east and west. Little is known of the elevation of these chains except that they are low in comparison with the great western ranges, and under the snow line. The fourth system of mountains is the Himalaya, which bounds Tibet on the south, while the Kwănlun and Burkhan Buddha range defines it on the north. A small range runs through it from west to east, connected with the Himalaya by a high table-land, which surrounds the lakes Manasa-rowa and Ravan-hrad, and near or in which are the sources of the Indus, Ganges, and Yaru-tsangbu. This range is called Gang-dis-ri and Zang, and also Kailasa in Dr. Buchanan’s map, and its eastern end is separated from the Yun ling by the narrow valley of the Yangtsz’, which here flows from north to south. The country north of the Gang-dis-ri is divided into two portions by a spur which extends in a north-west direction as far as the Kwănlun,[6] called the Kara-korum Mountains. On the western side of this range lies Ladak, drained by one of the largest branches of the Indus, and although included in the imperial domains on Chinese maps, has long been separated from imperial cognizance. The Kara-korum Mountains may therefore be taken as composing part of the boundary of the empire; Chinese geographers regard them as forming a continuation of the Tsung ling. ~PUMPELLY’S SINIAN SYSTEM.~