60 i'OOTE : GEOLOGY OF MADUEA AND TINNEVELLY DISTRICTS. 



which runs along the coast at a small distance from the shore, A 

 small rido-e of gneiss also runs out into the sea immediately south 

 of the villages and checks very greatly the force of the heavy rollers 

 which break on this coast during the south-west monsoon. 



The shells and corals obtained from the calcareous sandstone are the 

 following :— 



Turritella. 



Area, sp. 



Trochus. 



Ostrea, sp. 



Nerita albicilla. 



Balanus, sp. 



Ancillaria albifasciata ? . 



Astrea, sp. 



Euclielus cariuatus. 



Pontes, sp. 



Most of these were got from the upper part of the beds along the 

 rido"e of the cliff. The fossils seen plentifully in the lower part were 

 out of reach of hammer and chisel unless a ladder had been available. 

 Many were also exposed along the lower surface of the bed where under- 

 mined by the surface, but to extract them by hammering, unless the pro- 

 iectinc mass had been carefully shored up with strong timbers, would be 

 very dangerous, and pretty though they are they are not worth risk- 

 ino" one^s life for, even if time allowed of one's trying to obtain them. 



Immediately north and east of the mouth of the Viziapatti creek, 

 and only about a quarter mile east of the eastern 



Viziapatti limestoue. . p ,i xr i rr i l ^ l 



extremity or the Jiudung Kulam eastern plateau is 

 a patch of dark, impure, marine limestone abounding in shells of living 

 species. The limestone lies on a flat and is greatly hidden by a dense 

 thicket of Acacia planifrons and other thorns, and by the village which 

 stands on it. This limestone seems to rest directly upon the gneiss, 

 reefs of which appear close by in the bed and at the bar of the creek. 

 I was unfortunately unable to spare the time to re-visit this patch and 

 make a collection of the enclosed shells. From its position this lime- 

 stone may very likely be an extension of the gritty limestone at the 

 easternmost end of the Kudung Kulam plateau. 



The next show of marine beds is at the mouth of the Nambi-Ar 

 4 miles to the north-east of Viziapatti. The 



Nauibi-Ar section. ,, - , f ^ -> i i j. e 



beds consist or calcareous grits and sandstones or 

 ( 60 ) 



