272 Notes upon the Geology of the Rajmahal Hills. [No. 3. 



volcanic forces, were in most active and powerful operation, some 

 where within, or near to the district, now forming the Eajmahai 

 hills ; that these forces were exerted at successive intervals after 

 periods of repose, throwing out immense flows of molten lavas ; while 

 during these periods of repose, the deposition of clays, gravels and 

 sands, arising from ordinary causes continued to proceed. And that 

 these intervals were sufficient to admit of a growth, and in some 

 cases a luxuriant growth, of the plants then existing to take place. 



In these upper beds, no coal has been found, but that the condi- 

 tions for its formation still existed, is evident from the frequent 

 occurrence of thin layers or beds of bituminous shale ; and in several 

 cases of carbonized stems and fragments of plants. In many of 

 these beds, the vegetable remains are very abundant, and furnish a 

 most important link in the chain of evidence determining the period 

 of the formation of these rocks. 



A few of the more remarkable of these fossils were figured by 

 Br. MacClelland, and described in his report (1848-49,) under the 

 names of Zamia, Taniopteris, &c. He referred the beds in which they 

 occurred to the epoch of the Oolitic rocks of Europe, and distin- 

 guished them altogether from the beds with which coal was found 

 associated, which latter were referred to the coal measure epoch. 

 So far as his researches extended, this conclusion appears justified. 

 But a more extended examination of the district proves that these 

 so-called Zamias, (Ptilophyllum of Morris,) are associated in the 

 same beds with fossils hitherto only found associated with the sup- 

 posed carboniferous rocks of Dr. MacClelland's report. (Tseniopteris, 

 Pecopteris ; Glossopteris, Zamia, and Vertebraria being all found in 

 the same beds,) This is an important fact bearing on the determi- 

 nation of the long unsettled question of the true geological era of 

 the Bengal coal-yielding series of rocks. 



Some of these Zamia-like fossils from the Eajmahai district 

 appear, so far as can be determined from a comparison with drawings 

 alone, to be identical with the fossils found in Cutch and described 

 by Professor J. Morris in the London G-eological Transactions 

 Volume V. under the name of Ptilophyllum ; and which Cutch 

 fossils are associated with many other organic remains (animal as 

 well as vegetable) which appear to be unquestionably of the Oolitic 



