e of a thin layer of the
lowest, a nearly decomposed trap, projected over the stream; the other
lay in rounded blocks in the face of the hill above, and appeared to be
decomposed amygdaloid, principally felspar. The river ran through a
valley where the forest land was remarkably open, being sprinkled with
only a few trees as in a park, and this stream appeared to fall into the
head of the extensive swamp already mentioned. About a mile beyond the
river (which I named the Shaw) we came upon the extremities of Mount
Napier, for at least so I considered some rough sharp-pointed fragments
of rock laying about in heaps, which we found it very difficult and
tedious to ride over: indeed so sharp-edged and large were these rocks on
the slopes of the terraces they formed that we were often obliged to
dismount and lead our horses. In these fragments I recognised the
cellular character of the rocks I had noticed in the bed of the Shaw. The
rock here might have been taken for decomposed amygdaloid but, having
found the vestiges of an old crater in the summit of the hill, I was
induced to consider it an ancient lava. The reefs at Portland Bay consist
of the same rock in rounded nodules, a more compact trap-rock consisting
principally of felspar lying above them, as was observable in the section
of the coast. In some of the fragments on Mount Napier these cells or
pores were several inches in diameter and, unlike amygdaloidal rocks, all
were quite empty. The surface consisted wholly of this stone, without any
intermediate soil to soften its asperity under the feet of our horses,
and yet it was covered with a wood of eucalyptus and mimosa, growing
there as on the open forest land between which and this stony region the
chief difference consisted in the ruggedness of surface, this being
broken as already stated into irregular terraces where loose stones lay
in irregular heaps and hollows, most resembling old stone quarries. We
travelled over three miles of this rough surface before we reached the
base of the cone.

CRATER OF MOUNT NAPIER OR MURROA.

On the sides of it we found some soft red earth mixed with fragments of
lava and on reaching the summit I found myself on the narrow edge of a
circular crater composed wholly of lava and scoriae. Trees and bushes
grew luxuriantly everywhere except where the sharp rocks shot up almost
perpendicularly. The igneous character of these was so obvious that one
of the men thrust his hand into a c