at Mittagong Range. It is there traversed by
a dike of whinstone, of which that range is wholly composed. The change of
soil and of vegetation are equally remarkable at this place; the one being
a rich, greasy, chocolate-coloured earth, the other partaking greatly of
the intertropical character. In wandering over them, I noticed the wild
fig and the cherry-tree, growing to a much larger size than I had seen
them in any other part of the colony. Upon their branches, the satin bird,
the gangan, and various kinds of pigeons were feeding. Birds unknown to
the eastward of the Blue Mountains, were numerous in the valleys; and
there was an unusual appearance of freshness and moisture in the
vegetation.

These signs of improvement, however, vanish the moment Mittagong range is
crossed, and sand-stone again forms the basis of the country to a
considerable distance beyond Bong-bong. At a small farm called the
Ploughed Ground, it is again traversed by a dike of whinstone, and a rich
but isolated spot is thus passed over. With occasional and partial
interruption, however, the sand-stone formation continues to an abrupt
pass, from which the traveller descends to the county of Argyle. This pass
is extremely abrupt, and is covered with glaucus, the low scrub I have
noticed as common to the sand-stone formation. A small but lively stream,
called Paddy's River, runs at the bottom of this pass, and immediately to
the S.W. of it, an open forest country of granite base extends for many
miles, on which the eucalyptus manifera is prevalent, and which affords
the best grazing tracts in Argyle. At Goulburn Plains, however, a vein of
limestone occurs, which is evidently connected with that forming the
ShoalHaven Gully, which is perhaps the most remarkable geological feature
in the colony of New South Wales. It is a deep chasm of about a quarter of
a mile in breadth, and 1200 feet in depth. The country on either side is
perfectly level, so much so that the traveller approaches almost to its
very brink before he is aware of his being near so singular an abyss. A
small rivulet flows through the Gully, and discharges itself into the sea
at ShoalHaven; but this river is hardly perceptible, from the summit of
the cliffs forming the sides of the Gully, which are of the boldest and
most precipitous character. The ground on the summit is full of caves of
great depth, but there has been a difficulty in examining them, in
consequence of the violent wind t