GEOLOGY AND VEGETATION. 
XXXI 
was travelling, from the kind of tree or herbage 
that flourished in the soil above it. The euca- 
lyptus pulv., a species of eucalyptus having a 
glaucus- coloured leaf, of dwarfish habits and 
growing mostly in scrub, betrayed the sand- 
stone formation, wherever it existed. This was 
the case in many parts of the County of Cum- 
berland, in some parts of Wombat Brush, at 
the two passes on the great south road, over a 
great extent of country to the N.W. of Yass 
Plains, and at Blackheath on the summit of the 
Blue Mountains. On the other hand, those 
open grassy and park-like tracts, of which so 
much has been said, characterise the secondary 
ranges of granite and porphyry. The trees 
most usual on these tracts, were the box, an 
unnamed species of eucalyptus, and the grass 
chiefly of that kind, called the oat or forest grass, 
which grows in tufts at considerable distances 
from each other, and which generally affords 
good pasturage. On the richer grounds the an- 
gophora lanceolata, and the eucalyptus mammi- 
fera more frequently point out the quality of the 
soil on which they grow. The first are abun- 
dant on the alluvial flats of the Nepean, the 
