341 
of Pumice . 
and “on one piece was found a sea centipede, about four 
inches long, covered with fine bristly hair; it was feeding 
upon two barnacles (Lepos anatifera) which had at¬ 
tached themselves to the stone.” (Vol. i. p. 124.) 
It is very clear, that this pumice must have been some 
time at sea. 
Almost all the pieces I have found are water-worn and 
round; many smooth: in colour, it is whitish, and 
brownish grey ; and contains often traces of crystals of 
augite or hornblende. Many of the pieces are extremely 
small; others are very large. There must be enormous 
quantities along the coast; for it is imbedded in the drift 
sand, and is as numerous as any of the more frequent 
litoral relics. On many of those I picked up at Bondi 
Baj , and near Red Head, there are small Serpulce and 
otliei marine exuviae; proving, I think, satisfactorily, 
that they must have lain a long time near the level of 
the sea : but whether in the localities whence they came, 
or hince they have been drifted hither, cannot be shown. 
Knowing that the currents along the east coast of 
Australia run from south and north with great velocity, 
the probable explanation is, that the pumice drifts from 
the north, and when caught by a strong east gale may be 
driven obliquely across the current, so as to be lodged on 
the north side of the places where it occurs. Its origin 
may be in the Solomon Islands, or in New Caledonia, 
or some other of the volcanic islands; such as the 
Friendly or Sandwich groups, from which latter it has 
been asserted, without proof, that it does come. Another 
origin may be assumed in a sub-marine volcano not far 
from our coast; but in that case one would naturally con¬ 
clude that the source might be discovered. It would be 
an interesting enquiry to trace the source whence it is de¬ 
rived, and whether it does actually (as suggested by Mr. 
Wilton) come on shore, after easterly winds, in a state 
