Additional Remarks on the Geological Relations, and probable Geological 

 Age of the several systems of rocks in Central India and Bengal, by 

 Thomas Oldham, l. l. d. s f. e. s., &c, &c, Superintendent of the 

 Geological Survey of India. 



In a paper published in the second volume of these Memoirs of the 

 Geological Survey of India,* I endeavored to give, so far as known 

 up to the date of that communication (February 1860), a brief summary 

 of the evidence which had then been accumulated, bearing on the very 

 important and very interesting question of the age of the coal-bear- 

 ing rocks of India ; and their associated groups. The additional data 

 which have been acquired during the examination of the Raniganj coal 

 field, reported on in the preceding pages, render it necessary to add 

 here a few words, so as to bring up the facts to the present state of our 

 knowledge. 



In the accompanying report (pages 132 — 137) Mr. Blanford has 

 briefly entered on this discussion with especial reference to that peculiar 

 group of beds,f which he has for the first time separated as a distinct 

 sub-division in the present Memoir, under the name of Panchet. And 

 in doing so, he has arrived at a conclusion regarding the age generally 

 of the coal-bearing rocks identical with that previously announced by 

 myself in the paper I have referred to. Indeed, there was little addi- 

 tional evidence to bring to the question, with the exception of the 

 abundant occurrence of an Estheria, believed to be identical with others 

 also found abundantly by the Rev. S. Hislop, in the Nagptir country at 

 Mangali. These small entomostracous crustaceans having been submit- 

 ted to the careful examination of Mr. Rupert Jones, of the Geological 

 Society, London, had been identified by him as the Estheria minuta 



* On the Geological Relations and probable Geological Age, &c. &c, vol. ii., page 299. 

 t See also Journal Asiatic Society of Bengal, I860, page 352. 



