MIN ERA LOG I CAL DESCRIPTION OF THE ISLAND OF BANKA. 7^5 
raent exists very copiously, anil these resemble the masses of clay 
found in various parts of the Island. 
The last veins which are in conjunction with the Poudingues are 
particularly beautiful. In some portions the white or yellow sub¬ 
stance of the sand-stone is intersected by delicate veins of a sub¬ 
stance resembling 1 the uniting cement of the Poudingues, and various 
angles and figures present themselves on the fracture: others are 
already formed into regular Poudingues, and the white sand-stone is 
united to nodules of Black-Iron-stone. 
