MISCELLANEOUS NOTICES &C, 
167 
brownish red and reddish brown colours. Minute pyrites and specs 
of similar reddish hues are also seen scattered in the dark part of 
the rock in several places. 
The same gradations from a light dull rust coloured, to a black¬ 
ish shining, ore of iron, produced by the slow and increasing 
hydrous peroxidation of the iron of the decomposed pyrites, are 
observable in specimens from Pulo Besar. 
Similar phenomena may be remarked in the ferruginous granite 
of Pulo Mallang, a small islet off the N. E. coast of Pulo Pom- 
pong or Baltftm Island (in the Archipelago on the south side of 
the Straits of Singapore) accompanied by a dyke of hydrated per¬ 
oxide of iron. 
Although shells were not found in the layers overlying the coal 
visited by the Gunboat, they exist in abundance in the calcareous 
beds associated with the imperfect coal of Tamah. Slabs taken 
from these have an earthy base consisting of a tough indurat¬ 
ed limestone with a specific gravity of 2. 5. The shells im¬ 
bedded are mostly filled with crystallized carbonate of lime having 
a specific gravity of about 2 . 9. All the shells appear to be fresh 
water species, as the paucity of species and multitude of indivi¬ 
duals might lead us to conjecture. Dr. Traill has detected at least 
three species; one of which is a longitudinally furrowed Melania 
and another apparently a Paludina. The largest and most com¬ 
mon shell belongs to the same Family and bears a considerable 
resemblance in the general form of the shell to some figured spe¬ 
cies of Trochus and Pleurotoma, but the apertures are not well 
preserved. Dr. Traill, however, seems inclined to think it is also;*:,., 
a Paludina. 
It will be seen from the preceding details that the information 
hitherto obtained is so fragmentary and meagre as to serve only to 
excite our curiosity, without enabling us to draw any conclusion 
respecting the probability of the existence of deposits of workable 
coal. Even at the places where carbonaceous rocks have been 
found we are without any accurate description of the thickness, dip, 
strike and apparent extent of the layers, or of the nature and posi¬ 
tion of the associated rocks; and, in fact, are entirely wanting in 
all those data necessary to hazard even a surmise as to the value s k 
of the deposits, and the propriety of incurring the trouble of enter- 
