156 TIBET. Chap. XXIII. 



bound the sand, like the Car ex arenaria of our English 

 coasts. 



A more dismally barren country cannot well be con- 

 ceived, nor one more strongly contrasting with the pastures 

 of Palung at an equal elevation. The long lofty wall of 

 Kinchinjhow and Donkia presents an effectual barrier to 

 the transmission of moisture to the head of the Lachen 

 valley, which therefore becomes a type of such elevations 

 in Tibet. As I proceeded, the ground became still more 

 sandy, chirping under the pony's feet ; and where harder, 

 it was burrowed by innumerable marmots, foxes, and the 

 " Goomchen," or tail-less rat {Lagomys badius), sounding 

 hollow to the tread, and at last becoming so dangerous 

 that I was obliged to dismount and walk. 



The geological features changed as rapidly as those of the 

 climate and vegetation, for the strike of the rocks being north- 

 west, and the dip north-east, I was rising over the strata 

 that overlie the gneiss. The upper part of Kinchinjhow is 

 composed of bold ice-capped cliffs of gneiss; but the 

 long spurs that stretch northwards from it are of quartz, 

 conglomerates, slates, and earthy red clays, forming the 

 rounded terraced hills I had seen from Donkia pass. 

 Between these spurs were narrow valleys, at whose mouths 

 stupendous blocks of gneiss rest on rocks of a much later 

 geological formation. 



Opposite the most prominent of these spurs the river 

 (16,800 feet above the sea) runs west, forming marshes, 

 which were full of Zannichellia palustris and Ranunculus 

 aquatilis, both English and Siberian plants : the waters 

 contained many shells, of a species olLymnaa ;* and the soil 



* This is the most alpine living shell iu the world ; my specimens being from 

 nearly 17,000 feet elevation; it is the Lymncea Hookeri, Reeve ("Proceedings of 

 the Zoological Society," No. 204). 



