PREFACE. 



In extenuation of the incompleteness of the following E-epoxt, 

 I would wish my readers to bear in mind the circumstances 

 under which the observations on which it is based were made. 

 Not only is the country so densely covered with vegetation, 

 that for whole days one may march without seeing a single 

 rock ; not only is vegetation so dense that it is impossible for 

 the most part to leave the narrow foot-path; not only is 

 the structure of the country complicated and without any 

 beds of marked individuality by which this structure could 

 be unravelled, but my movements had necessarily to be guided 

 by political exigencies rather than by geological necessities. 



In a country partly depopulated and for the rest inhabit- 

 ed by savages of doubtful temperament, and where one's 

 presence is decided by the accidental and temporary presence 

 of an armed force brought there for objects among which 

 geology, if regarded at all, is considered last of all, one cannot 

 enjoy the same freedom and ease of movement as in the more 

 quiet and settled districts of British India. 



To Colonel J. Johnstone, Political Agent at Manipur, and 

 to Mr. K/. B. McCabe, C.S., Deputy Commissioner of the Naga 

 Hills, I owe my sincerest thanks for the assistance I received 

 at their hands. 



E. D. OLDHAM. 



Geological Survey Office; 

 Calcutta , 3 1st July 1882. 



