A CONTRIBUTION TO THE STUDY OF AUSTRALITES.. 
37 
the button form, which exhibits such a remarkable hanging 
drop inside the bubble, while in the conical it is the outer disc 
that is rather flatter and less hemispherical than the inner, and 
the apex of the cone must have pointed outwards in the latter 
and inwards in the former, though this is only apparently so, 
as if the hanging drop of the button form is regarded as repre- 
sented by the comparatively small curved inner surface of the 
Western Australian form the two cones are comparable and both 
point towards the outside of the bubble, the fracture facets sloping 
in that direction in both (Plate XYII 1 , Figs. 3 and 4). Another 
reason is that the button form is curiously absent with us. If 
our conical shape, which is the commonest found over here, were 
derived from a button form, some of the latter must have been 
found in Western Australia. 
As I have said before, it is almost certain that the type from 
which these Western Australian conical forms have been derived 
is the tabloid and the obsidian forming them has been less fluid 
than that producing the button form. 
There may be, of course, a form of similar shape to the 
conical that is the core of the button Australite. The large 
Australite I have shown you seems to answer to Mr. Dunn’s 
description, but this may be due to sand friction or extra fusion 
of its surface from its bubble having burst at a greater height 
in the atmosphere. There is no question, however, that the 
Australite figured by Dr. Suess is the centre of a button form 
with the ring detached. 
It would be interesting to have it explained how a hollow 
conical shaped body, with moreover a septum in it, or even 
without the septum, could be accounted for as a rotation body. 
The dumb-bell form, which in no way resembles an hour glass 
as it should, according to the rotation theory would consist of 
two spheres revolving on their own axes, as well as round each 
other, so closely as to raise a tidal wave of molten matter suffi- 
ciently high to join them, is quite inexplicable in this way, as 
the two ends are themselves not symmetrical, nor do they lie 
in relation to each other in the same plane, but are inclined 
towards one surface, as you will see quite clearly in these speci- 
mens. Even if they be regarded as simple rotation bodies of 
unstable form their want of symmetry and deviation from a true 
plain would quite put them out of court. 
I must express my conviction, however, that the latter is 
simply a way of begging the question regarding them as, when 
a prolate spheroid (which in this case would have the poles in 
the centre of its length) tends to become dumb-bell in form from 
increased rapidity of rotation it really means that the two ends 
are concentrating to form two globular bodies tending to become 
