378 TERAL Chap. XVII. 



of Indian timber, is conspicuous in most parts, though not 

 now in Sikkim, where it has been destroyed. The Terai 

 soil is generally light, dry, and gravelly (such as the Sal 

 always prefers), and varies in breadth, from ten miles along 

 the Sikkim frontier, to thirty and more on the Nepalese. 

 In the latter country it is called the Morung, and supplies 

 Sal and Sissoo timber for the Calcutta market, the logs being 

 floated down the Konki and Cosi rivers to the Ganges. 

 The gravel-beds extend uninterruptedly upon the plains 

 for fully twenty miles south of the Sikkim mountains, the 

 gravel becoming smaller as the distance increases, and 

 large blocks of stone not being found beyond a few miles 

 from the rocks of the Himalaya itself, even in the beds of 

 rivers, however large and rapid. Throughout its breadth 

 this formation is conspicuously cut into flat-topped ter- 

 races, flanking the spurs of the mountains, at elevations 

 varying from 250 to nearly 1000 feet above the sea. These 

 terraces are of various breadth and length, the smallest 

 lying uppermost, and the broadest flanking the rivers below. 

 The isolated hills beyond are also flat-topped and terraced. 

 This deposit contains no fossils ; and its general appearance 

 and mineral constituents are the only evidence of its origin, 

 which is no doubt dne to a retiring ocean that washed the 

 base of the Sikkim Himalaya, received the contents of its 

 rivers, and, wearing away its bluff spurs, spread a talus 

 upwards of 1000 feet thick along its shores. It is not at 

 first sight evident whether the terracing is due to periodic 

 retirements of the ocean, or to the levelling effects of rivers 

 that have cut channels through the deposit. In many 

 places, especially along the banks of the great streams, 

 the gravel is smaller, obscurely interstratified with sand, 

 and the flattened pebbles over-lap rudely, in a manner 

 characteristic of the effects of running water ; but such is 



