CuAi'. XX I X.J 
24-l'.\K(iA.\A,S. 
631 
be very siliceous. As regards quantity, it is possible tiiat a fair amount 
could be collected over the whole of the hill ; but the expense incurred in 
excavating it would ])robably render it unj)i'ofitable to work the occur- 
rence for export, except perhaps at times of high prices such as prevailed 
during the earlier parts of 1907. 
It must be remembered, however, that in dep'.^sits of this tyj)e the ore 
tends to be of the highest grade at the surface ; and if the deposit has been 
subjected to much denudation since its formation, it is probable that the 
best portions of the ore have been denuded away. In this case they would 
probably be foimd on the slopes of the hill ui the form of talus. If any 
attempt be made to work this occurrence attention should be directed to 
the ore in situ on the west side of the hill, where it seems to be of the 
best quality, whilst the talus accumulations should be examined especially 
on the western slopes. 
In mode of occurrence and origin and its situation on the top of a hill, 
this deposit bears a great resemblance to many of those in Mysore. It 
differs from those of the Chaibasa area 'jnly in situation and the somewhat 
different lithological characters of the rocks that have been icplaced. 
An interesting feature of this occurrence is the cavernous character 
of the altered rocks revealed in some of the pits. Thus one pit showed 
slates irregularly replaced by manganese oxide and themselves softened 
and lithomargic. In this were some large flat cavities extending irregu- 
larly for some feet and even yards along the strike of the rocks, but only 
a foot or two wide at right angles to the dip planes. These cavities 
seem to have been formed by the solution or washing away of the 
decomposed slate, leaving the concretionary manganese-ore projecting 
into the cavities. 
The 24-Parganas. 
Mr. T. Munro of the Port Commission has brought to my notice a very 
interesting occurrence of manganese-ore. I have unfortunately not been 
able to visit the place myself. This occurrence is all the more surprising 
because the locality for the ore is in the Gangetic alluvium in the portion 
of Lower Bengal known as the Sundarbans. The actual locality is 
the Silver Tree G.T.S. station, which lies on the east shore of the Hughli 
at a point not quite 3 miles in a straight line N. 17° E. of the telegraph 
station at Mudpoint. A little below the Silver Clif? obelisk are very 
numerous small pisolites scattered on the shore just above high- water 
