S5 s Essay, Cc. 
becomes moreabrupt; here it is bounded in the 
North by the small tract of Kumutuk, beyond 
Which, the South side of the mountain has not 
been examined: the territory also consists of 
x Tufa resembling that of Purwo-kerto, but 
from the natural inclination of the district, all 
thesmall and loose fragments have been washed 
down towards the southern valley. It is cover- 
ed by a deep soil, accumulated chiefly from a 
very luxuriant vegetation during a long period. 
In some parts a lava is exposed in the rivulets 
resembling the more compact kinds of Aji-T 
barang. 
The constitutionof Probolingo resembles that 
of Passir; towards the eastern boundary the 
quantity of sand and gravel on the surface is 
less abundant, but at the banks of the river 
Kelawing, near the chief village of this district, 
immense > piles of Tufa are exposed, often to the 
depth of 30 feet, which, as well as that found 
near Suko-rojo, has compactness enough to be 
«ut into tables or slabs, and employed in floor- 
ing the dwellings of the natives and for various 
similar purposes. In the pebbles of this river, 
“carried down by the current, 1 also noticed the 
indication of extensive beds of siliceous stones 
*$n the central ranges: with the common round- _ 
ed fragments of Lava, Basaltes and Sand-stone, 
were mixed Agates of various kinds, Prase, 
simple Hornstone, Hornstone-porphyry of great 
. wariety of colour and fracture, and a species - 
: pom ofa SS "n ung 
a Exp. Cat. No 4r. 
maf Exd. Cat. No. 42. 
$ Exp. Cat. No. 25, 
