GNEISSIC ROCKS. 17 



dence of the north-east and south-west extensions of these beds disagrees ; 

 the north-east beds seem to dip eastward under the upper granite gneiss 

 series as seen to the north of Kotampatti (Cotaumputty),but the southern 

 extension dips north-westerly. Unfortunately time did not admit of my 

 following up the extension beyond the south end of the AUagiri mass and 

 working out its relation to the great gneissic masses forming the Waggat 

 Malai and the Serumalai. I feel strongly persuaded, however, that the 

 Allagiri granular quartz beds are a bond fide higher lying group, and will, 

 when an exhaustive survey of that region is made, be found to overlie the 

 granitoid gneiss beds forming the western side of the Serumalai, which 

 beds are really extensions of the upper granite gneiss series of the 

 Melur-Madura plain, the beds of which have trended round on the north 

 side of the Vaigai valley. The rocks overlying the Allagiri beds I am 

 not as yet acquainted with. 



In the south-western corner of the space which lies between the 

 Granular quartz rock northern part of the Nagamalai and the south- 

 at Ammanayakaiiur. western part of the Serumalai is a great show of 



granular quartz rock well exposed in strongly curved beds. These are 

 well seen in the low ridge west of the railway station at Ammanaya- 

 kanur (Ammanaikoor) which extends northward into the much higher 

 Reshmullay Trigonometrical Station hill and south-westward into the 

 Pulianattara (Poolianutthum) hills ; the north-westerly extension of the 

 granular quartz beds beyond the two last named hills has not as yet been 

 worked out. The relation of these beds with another rather important 



outcrop of granular' quartz rock 3 miles to the 

 At Ramrajpurara. 



south-east at Ramrajpuram is obscured by the in- 

 tervening spread of the Vagai alluvium. The extension of the beds seen 

 in the latter outcrop is also speedily lost sight of to the eastward under 

 the superficial deposits. 



The broad belt of granite gneiss which forms the mass of the Seru- 

 malai belongs doubtless to the Melur or third group of that variety of 

 the gneissic rocks. Unfortunately want of time prevented my examining 

 that very hilly tract ,• the westward extension of the Allagiri granular 

 B ( 17 ) 



