president’s ADDRESS — SECTION C. 
95 
Hallett’s Cove the pavement probably extends for below sea-level. 
This, of course, may be only a coincidence, as great changes of level 
may have taken place since Permo-Carboniferous time, and the low 
elevation of the glaciated pavements may be due to the fact that only 
such low-lying areas would be likely to escape destruction by denuda- 
tion. 
(x.) Observations made during the “Challenger” and “Erebus” and 
“ Terror” expeditions to the Antarctic regions show that a boulder- 
bearing clay, soft mud, and sand is at the present moment being laid 
down over a large area of the ocean floor, which, if it be nearly 
eo-extensive with the area over which icebergs constantly drift, may 
possibly be equal to that of the continent of Africa. These deposits, 
if consolidated, would perhaps somewhat resemble the Bacchus Marsh 
glacial deposits ; but it is very doubtful whether they would contain 
the persistent beds of conglomerate characteristic of the latter locality; 
and they certainly would contain a more or less abundant protozoan 
fauna, which, as far as at present known, the glacial beds of Bacchus 
Marsh and Hallett’s Cove do not. 
As arguments against the hypothesis that all the Permo- 
Carboniferous glacial phenomena were produced b} r drift ice alone, the 
following might be adduced : — 
(i.) No marine fossils, macroscopic or microscopic, have as yet 
been detected in the boulder beds proper, or in the associated sand- 
stones and conglomerates. Marine fossils have as yet been found 
only in the Permo-Carboniferous mudstones which contain the erratics. 
(ii.) Land, or lacustrine, or swamp plants, such as Ganqamopteris, 
are associated with the glacial beds, and small fragments of plants are 
distributed through the groundmass of the boulder beds. 
(iii.) The glaciation of every nook and corner of the pavement, 
even where its surface is extremely uneven, is suggestive of the 
searching action of land ice. 
(iv.) The local character of the material composing the ground- 
mass, a feature specially noticeable at Ilallett’s Cove, is rather in 
favour of its having been produced by land ice. 
(v.) Erratics, now found at Maitland, and derived probably 
from Mount Lambie, almost necessarily demand carriage by land ice, 
or by an ice foot. The chances of the erraticshaving fallen from high 
cliffs, with water sufficiently deep at their bases to float bergs of any 
thickness, and of their having then been transported by bergs to 
Maitland, seem rather small. 
As regards (6) the possibility of all the Permo-Carboniferous 
glacial phenomena being referable to the action of laud ice alone, it 
appears to me that in view of the close resemblance of these glacial 
deposits of Australia to the far newer Pleistocene evidences of glacia- 
tion m Europe and America, and in view of the now generally received 
opinion that the latter are chiefly attributable to land ice, it is not 
improbable that this explanation will serve also for the former. The 
stratification of the conglomerates and lamination of the sandstones 
and mudstones may have been the work of sub-glacial streams and 
sub-glacial lakes. Unfortunately a copy of the new edition of Pro- 
fessor James Geikie’s Great Ice Age, &c., has not yet reached me, so that 
I am unable to quote from the information which he has gathered on 
