MI NERA LOGICAL DESCRIPTION OF THE ISLAND OF BANKA. 703 
gularly truncated and tabular, tlie angles are defined, and the corres¬ 
ponding sides from each angle are completely parallel. If broken 
they exhibit an extensive cavity; the sides consist of several concen¬ 
tric layers of different colours: the interior is vitrious, glossy and 
covered with a grey powder, the surface of this is very uneven and 
often exhibits broken vesicles. They produce, in most cases, the 
same rattling noise which is common in the Geodes of other coun¬ 
tries. Some are entirely compact : they have the same form as the 
others, but when broken exhibit a united mass consisting of stripes 
of different shades of brown and black. 
I had no opportunity to follow the depository to its termination 
in the west: but the examination from Sungie Baru to the western 
extremity of the town of Minto, an extent of nearly 4 miles, was sa¬ 
tisfactory and intructive. In the north it is in conjunction at many 
points with the larg'e stratified belt which surrounds the mountain 
Manumbing. The constitution of the Poudingues frequently has 
the greatest resemblance to that kind of Breccia called by the Ger¬ 
man miners rothe todte Ucgende , which will most distinctly be pointed 
out in another place. 
It remains for me to add a few remarks on the other substances 
which I observed between Sungie Baru and Benting Sarebu,several 
of which occupy the space intermediate between the large Deposito¬ 
ry of Iron and the Poudingues. Many of the observations hitherto 
detailed were made in the vicinity of the shore, where the action of 
the ocean has exposed the different substances and afforded an ex¬ 
cellent opportunity for observation. The sides of the hills extend¬ 
ing through this tract, are mostly covered with soil and sand, through 
which the veins of rocks occasionally project. In pursuing a direc¬ 
tion parallel to the coast on the top of the hill, I traversed, almost 
north of the mouth of Teluk ltobiya river, a vein of Poudingues 
which differs from those above mentioned, near the shore, eontain- 
a smaller quantity of Iron in the composition. One of the rocks 
consisted of small fragments of quartz united by a cement of Iron- 
ore to a Breccia, which appeared almost uuifoi mly variegated on the 
fracture. Another similar vein occurred, about 100 yards to the 
west of the river, in which the same general mass contained large 
fragments of Red-Iron-stone and yellow ochre. In a third the frac¬ 
ture is still more variegated. Large masses of quartz are bedded 
in the ferruginous cement, and many of the fragments of Red-Iron¬ 
stone are regularly striped. After having passed a part of the stra- 
