Chap. IV.] TRicuiNoroLY district — plant beds. 51 



They occur in beds of the same general lithological character as 

 in other localities, in the Trichinopoly district, where similar plants 

 have been found. 



The gneiss, at the junction with these beds and for some distance from 

 the junction, is in the same general condition, as where seen under the 

 other plant-beds, and has been subject to the same forces (see page 40). 



The beds in which the plants occur have gravels and conglomerates 

 associated with them as in other places. 



Immediately over these beds with plants occur others, which in general 

 aspect, in color, and in composition, resemble those holding plants. But 

 they differ in structure ; the plant- beds are clunchy irregular sands 

 and clays, with a few shaly irregular layers and coarse conglomerates, 

 some of the blocks 6 to 8 feet across. The beds above are in com- 

 paratively regular and thin layers continuously super-imposed, and 

 Avithout conglomerates. There does not appear to be any passage or 

 transition in these respects. There is apparently conformity in dip. 



The plants occur close to the gneiss, and also at intervals up to the 

 latter beds, but in these no plants were traceable ; and with the lowest 

 of these latter are intercalated concretionary calcareous masses with 

 marine shells. The area of the plant-bearing beds is very small, and is 

 confined to the bottom of a little valley or depression in the general sur- 

 face of the country, in which they are exposed in a small water-course, the 

 upper beds lapping over them on either side ujd to junction with gneiss. 



The case appears to be one of apparent conformity and sequence, due to 

 the fact that the lower beds were largely denuded, and furnished the mate- 

 rials from which the upper were formed, but there was found no good 

 evidence of intercalation. This is of course only negative evidence, but 

 taking into consideration the facts very clearly seen elsewhere (at five out 

 of the six different localities where these plants have been found) of 

 marked unconformity and great denudation, I think there can be little 

 hesitation in admitting the plant-beds at Maravattoor as identical with 



