68 FOOTE : GEOLOGY OF MADURA AND TINNEVBLLY DISTRICTS. 



OHva, 2 sp. 





Nucula. 



Sigaretus, sp 





Donax. 



Terebi-a, sp. 





Cytherea. 



Ostrea, sp. 





Corbula. 



Plicatulaj sp. 





Tellina spengleri 



Pecten, sp. 





» sp. 



Cardium, sp. 





„ sp. 



. Pectunculus, 



sp. 



Meroe picta ? 



„ 



tenuistriatus. 



„ sp. 



A broken outcrop of the gritty beds may be traced for some distance 



below the ford cliff section, but a gap of about 

 Gondar estuary section. ., . ,„ ,. 



hair a mile or more intervenes beiore reaching the 



estuary of the river, which reveals two bands of hard, more or less shelly 



sandstone forming very low causeway-like ridges, which stretch nearly 



across the backwater formed by the bar at the mouth of the river. 



The strike of the beds is east-by-south to west-by-north, and the dip 



varies from 5" to 10° south-by- west. The beds have been cut through 



in several places by the erosive action of the river when in flood, and 



several small islands have thus been formed. All the fossil shells seen 



belonged to living species. The path leading to Mukkurpatanam (Mook- 



oorputnumchary) crosses these beds. 



The next show of rocks containing living species of marine shells 



occurs at Valimukkam (Vaulimookum), some 9 

 Valimukkam cliffs. c ■» zr i i 



miles to the eastward or Mukkurpatanam, 



in the form of a low rocky spit jutting out into the sea for fully two- 

 thirds of a mile. I refer these rocks with some hesitation to the 

 present group, as I am not quite sure whether they may not owe 

 their origin to sub-aerial action rather than to deposition on the bed 

 of the sea. In parts certainly they bear a strong resemblance to 

 a consolidated coast dune. The distinction is one not always easy to 

 make, and the cursory examination I had to be content with did not 

 suffice to settle the question to my satisfaction. On the northern side of 

 the spit, the beds show a coarse shelly friable sandstone of brown colour, 

 mostly horizontally bedded^ and showing but little false bedding. The 

 included shells are mostly comminuted. The beds are exposed in a low 

 cliff facing north, but are completely covered up by blown sands to the 

 ( tiS ) 



