Chap. I.] historical summary. 13 



It now only remains to mention those gentlemen who have been 



„ , . , ^ , associated with me in the present survey, and to 



Geological Survey of a. ^ 



1^58. ascribe to each that portion of the work to which 



he has mainly devoted himself. The Survey commenced in January 



1858, and during the working season of that year, Messrs. Charles 



Oldham, King, and Geoghegan, with myself, mapped a large portion of the 



sedimentary rocks to the North of the Vellaur, and in part the boundary 



of the Cretaceous rocks in Trichinopoly. A series of fossils was also 



collected from all the localities visited. This first season was brought to 



an abrupt close at the latter end of April, by the sad loss of Mr. 



Geoghegan, who received a sun-stroke while engaged in his duties, and 



expired in the course of a few hours. Mr. Geoghegan had joined the 



Survey about a twelvemonth previously, and had been our companion 



in the Survey of the Nilghiris and in the Trichinopoly district up to the 



date of his untimely death. 



In the month of June, Mr. Willson assumed temporary charge of 



the party, (while I visited Calcutta, in order to commence the examination 



of the fossils we had collected,) and in conjunction with Messrs. Oldham 



and King he mapped the alluvium to the North of the Coleroon, 



between the Yellaur and Lalgoody, and the granitic area of Thutchun- 



coorchy, I returned to Madras in December with Mr. Bruce Foote, who 



had recently joined the department, and undertook the detailed survey of 



the Cretaceous rocks of Trichinopoly. Messrs. 

 Season of 1859. 



King and Foote continued to examine and map 



the alluvium to the West of Trichinopoly, and subsequently that of the 



Vellaur, the sands of the Coast, and the whole of the country to the 



South of the Cauvery included in Sheet 79 of the Atlas Map. Mr. 



Charles Oldham joined us in March, and in the following months 



collected a most extensive series of fossils. My brother, Mr. W. T. 



Blanford, at the close of the working season in Bengal, passed a couple of 



months in Trichinopoly, and mapped the crystalline rocks to the West and 



