The country north of the Chang-peh shan as far as the Stanovoi Mountains is drained by one river, viz., the Sagalien, Amur, Kwăntung, or Hehlung kiang (for it is known by all these names), and its affluents; _Sagalien ula_ in Manchu and _Hehlung kiang_ in Chinese, each mean ‘Black’ or ‘Black Dragon River.’ The Amur drains the north-eastern slope of Central Asia by a circuitous course, aided by many large tributaries. Its source is in lat. 50° N. and long. 111° E., in a spur of the Daourian Mountains, called Kenteh, where it is called the Onon. After an east and north-east course of nearly five hundred miles, the Onon is joined in long. 115° E. by the Ingoda, a stream coming from the east of Lake Baikal, where it takes its rise by a peak called Tshokondo, the highest of the Yablonsi Khrebet Mountains. Beyond this junction, under the Russian name of Shilka, it flows about two hundred and sixty miles north-east till it meets the Argun. The Argun rises about three degrees south of the Onon, on the south side of the Kenteh, and under the name of Kerlon runs a solitary north-east course for four hundred and thirty miles to Lake Hurun, Kerlon, or Dalai-nur; the Kalka here comes in from Lake Puyur or Pir, and their waters leave Lake Hurun at Ust-Strelotchnoi (the Arrow’s Mouth) under the name of the Argun, flowing north nearly four hundred miles to the union with the Shilka in lat. 53°; from its exit as the Argun and onward to the entrance of the Usuri, it forms the boundary between China and Russia for 1,593 versts, or 1,062 miles.