472 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Juiie 21, 



scattered the superincumbent rocks, or to have raised them horizon- 

 tally above the level of the plain, forcing itself between the sandstone 

 and the freshwater deposit. This thin fossiliferous band, when not 

 tilted up altogether, is often entangled in this lower trap and much 

 altered in lithological character. 



The authors notice the apparent absence of craters throughout the 

 great trap district of Central India. Nor is any spot known where 

 either of the two trap-rocks could be said to have come up from 

 below. 



The upper trap appears to have flowed along for immense distances, 

 filling the great ancient lake or lakes, and forming flat and arid 

 plains ; and the lower trap, as above stated, appears to have been 

 perhaps nearly as co-extensive in its subterranean intrusions and 

 superficial outbursts. Thus both traps are regarded by the authors 

 as of more recent date than the freshwater formation. 



Sandstones and shales of variable character, but possibly referable 

 to one and the same formation, occur in four districts, viz. : 



1st. In the vicinity of Nagpur the sandstone occupies a compara- 

 tively narrow and irregular stripe along the eastern border of the 

 great trap region, under which it is seen to pass. 



2nd. Isolated patches on the south appear to connect the Nagpur 

 sandstone with the extensive sandstone district of Chanda, above and 

 below the junction of the Wardha and Pranhita Rivers, extending to 

 Kota, near the junction of the latter river with the Godaveri. 



3rd. To the east of Nagpur there are some outlying patches east- 

 ward of the Wein Ganga River. 



4th. To the north-west, at the distance of thir yor forty miles 

 from the Nagpur sandstone, there is a broad tract of sandstone around 

 the Mahadewa hills. 



The exact relations of these several areas of sandstone and shale 

 are not yet quite settled ; but the following is the descending order 

 of the series according to the observations of the authors. 



1 . Soft ferruginous sandstone ; sometimes hard, with iron bands, 

 and affording millstone. This contains fragments of the underlying 

 sandstone, large plant-remains and numerous leaves. 



2. Fine and coarse argillaceous sandstones, rich with plant remains. 

 These have affbrded 



Labyrinthodont reptile* (from Mangali). 



Fishes ; Lepidoid scales. 



Crustaceans ; Estheria. 



Plant-remains. 



Fruits and seeds ; numerous and undescribed. 



Leaves ; Conifer, Zamites, Poacitcs, and Ferns (Pecopteris, Glns- 

 sopferis, TcEiiiopteris, Cyclopteris, Sphenopteris). 



Roots, exogenous and endogenous. 



Acrogens : Aphylhun ?, Equisetlfes ?, Phyllotheca, Vertehraria ?. 



The thicknej;s of Nos. 1 and 2 together, near Nagpur, is about 

 300 feet; and in the Mahadewa Hills it is estimated bv Lieut. Sankey 

 at 2700 feet. 



* See the next following paper. 



