114 
iferous limestone of Coonalpyn and Ki Ki has reappeared. This 
deposit descends to 21 feet below sea-level. Then the polyzoal 
limestone succeeds for a thickness of 88 feet, and at 109 feet 
below sea-level the clays and sands begin, the latter in this bore 
containing very few fossils of any sort whatever. The bore only 
goes down 168feet below sea-level, and does not bottom the 
Hocenes. 
The relative positions and depths of these four bores are shown 
on the accompanying horizontal section, together with a well- 
section at Bordertown, and the section of a bore situated four 
miles east of Wellington, the latter recorded by Prof. Tate. 
(Trans. Roy. Soc. vol. IV., p. 144). The mouth of the bore 
near Wellington is near sea-level, and for 56 feet are met the 
polyzoal limestone, and below for a little over 100 feet are sands 
and clays, which, although unfossiliferous, probably correspond to 
the lower of the Eocene beds shown by the four bores ; the bed- 
rock was just about reached at the bottom, 167 feet below sea- 
level. 
If the lines of demarcation are marked out on the map as far 
as possible, they will be found very irregular in shape, and the 
thickness of each bed varies greatly, the irregularity of the line 
of separation of the Eocene polyzoal limestone and the under- 
lying clays, apparently showing that their formation depended 
partly at any rate, on purely local causes, as we cannot consider 
the intercalated sands and clays to have been denuded into their 
present shape to make room for the overlying polyzoal limestone. 
It seems probable that this limestone is a continuation of the 
somewhat similar beds at Bordertown, and unites them to the 
Murray beds at Tailem Bend and Wellington. If this is actually 
the case, we have very good evidence to show that the Aldinga 
and Adelaide gastropod-beds are older than the Eocene beds of 
the Murray since, as mentioned before, the sands of the Ki Ki 
Bore seem to closely approximate in their fossils to the Adelaide 
beds. 
A peculiarity about the more recent deposits overlying these 
Eocenes, is the fact that in the Tintinara Bore alone do we meet 
with recent marine shells, while we get here none of the un- 
fossiliferous limestone which in each of the other beds overlies the 
Eocene limestone. These fossils bespeak an extremely recent 
age, Pleistocene if not Post-pleistocene, and it seems strange that 
they are not met elsewhere. The probabie explanation is, that at 
Tintinara, (as in the other bores) in post-Eocene times the Eocene 
deposits became covered with this unfossiliferous limestone, pre- 
sumably a land formation, but that subsequently it was worn 
away at Tintinara, and with it very likely some portions of the 
polyzoal limestone, which is here reduced to six feet in thickness, 
