6 GENERAL OBSERVATIONS ON THE 



boundary of the great table-land and the northern barrier of the remark- 

 able valley of Koimhatur, from the opposite side of which proceeds the 

 continuation of the mountain chains in one central range to the southern 

 extremity, as already described. The whole of this western chain, and 

 the narrow coast which lines its base, is remarkable for the absence of 

 rivers and vallies of denudation, and, consequently, of alluvial plains or 

 deposits of any extent. The precipitous sides of the mountains rising in 

 some places, (to the south of Goa,) almost from the sea, are, nevertheless, 

 covered in general by forests of the tallest trees and impenetrable jun- 

 gles, which admit of gaining but a vague and scanty knowledge either 

 of their geological features, or the mineral treasures with which they may 

 abound. 



The Island of Ceylon presents so much the appearance of having 

 once formed part of the Continent of India, and there is such a striking 

 similarity in the nature of its principal rocks (which are chiefly primitive,) 

 to those of the mainland immediately opposite to it, that some notice of 

 its geological structure should not here be omitted, of which Dr. Davy's 

 valuable work affords the following interesting and scientific description. 



" In Ceylon, nothing is to be observed of that order of succession of 

 rocks that occurs in Saxony and England, and many other parts of 

 Europe. Uniformity of formation is the most remarkable feature in the 

 geological structure of the Island ; the whole of Ceylon, with few excep- 

 tions, consists of primitive rock unconnected with any other class of rocks, 

 exclusive of those of very recent formation. Another remarkable geolo- 

 gical circumstance is, that though the varieties of primitive rock are ex- 

 tremely numerous, almost infinite, yet the species are very few and sel- 

 dom well defined. 



The 



