Essay, Gt. 257 
The extermal surface of this lava is rugged 
and cellular, the excavations are deep, and often 
confined by a narrow corresponding margin ; it 
has a particular disposition to burst into irre- 
gular, rhomboidal, oblong or cubical masses, 
some of which are very large: the fracture of 
separate particles is observed to be compact or 
finely vesicular, and contains much Feldspar 
and occasionally Zeolites. The whole groupe 
must be reckoned to the class of submarine lavas, 
_ The appearance they exhibir to view is very 
striking; an extensive field in contact with the 
Ocean is here covered by rugged lava, and al- 
though the groupe is highly irregular, the dis- 
position to separate into rhombs and cubes is 
distinctly observed in the larger masses, which 
in alternate. projections contribute to form a 
very irregular scene. 
. From Ujung-agung towards the furthest 
North-East point, I noticed, in contact with the 
Ocean, only calcareous rocks, excepting the peb- 
bles on the strand, which were similar to those 
“of Banjar: ai Brambang the piles are very 
T precipitous and the strata inclining: towards 
Karang-bollong near the point mentioned) the 
surface of the rocks is very unequal, cellular, 
and excavated with cylindrical furrows. Ire- 
fer for their particular description to the expla- 
natory Catalogue, see No. 17 to 24 E 
From the river Serayu ina direction Eastward 
to the foot of the hill Badagangan, the tract 
is level, and at the present period (in contact 
* Exp. Cat. No. 22. : 
f Exp. Cat. No, 23. 
