president’s ADDRESS — SECTION C. 
97 
from floes of shore-ice or small bergs. Every winter the shore-ice 
became attached to boulders, and in the spring these boulders are 
carried out to sea and along the coast, when the ice becomes detached 
from the shore.” 
(9.) Duration of the Per mo- Carboniferous Glacial Period. — That 
glacial conditions prevailed throughout a long period of geological 
time, about the close of the Palaeozoic Era, is proved by ( a ) the 
great thickness (at least 8,500 feet) of the glacial beds at Bacchus 
Marsh; ( b ) the great number of boulder bed horizons (probably at 
least twenty, but this is only a very rough estimate by me) in the 
same glacial series, each boulder bed separated from the one above 
and below it by strata of conglomerate and sandstone ; (c) in New 
South Wales glacial conditions obtained while (i) several hundred 
feet of sandstones and mudstones of the Lower Marine Series of the 
Permo-Carboniferous System were being deposited, (ii) while, after an 
interval sufficient to allow of the formation of 50 feet of coal, in the 
succeeding Permo-Carboniferous Greta Coal Measures (for the sake of 
argument, 50,000 years), the last 1,000 feet of the lower 2,000 feet 
of the Upper Marine Series were being formed. 
If glacial conditions continued in Australia down to Triassic 
time, as the evidence quoted already from the Hawkesbury Series 
renders not improbable, further time must be allowed for the great 
biological break in the fauna and flora, which in Australia separates 
the Permo-Carboniferous from the Triassic period. 
(10.) Pliocene or Pleistocene Glaciation the WorJc of Land Ice . — 
That during Pliocene or Pleistocene time the Australian Alps 
harboured glaciers, which descended at Kosciusko to within about 
5,200 feet above the sea, on the assumption that the earth’s crust at 
Kosciusko has been practically stationary from the last epoch of 
glaciation down to the present time. That in Victoria, near Mount 
Bogong, at Mountain Creek Valley, morainic (?) material extends 
down to a level of 2,000 feet above the sea, and possibly only 1,000 
feet in the Keewa Valley. Synchronously, the \V estern Highlands of 
Tasmania, from an elevation of 4,000 feet or 5,000 feet down to about 
2,000 feet, were covered with snowflelds and glaciers. This glaciation 
of South-eastern Australia and Tasmania was effected entirely by 
land ice. 
(11.) That there is as yet insufficient biological evidence to prove a 
ref rigeration of the sea during the above glacier epoch. The abundance 
of Mytilus minJceanus in the raised beaches of Maitland, in New South 
Wales, and its large size, has been suggested as in favour of there 
having been a cooling of the waters of the South Pacific; but I am 
informed by Messrs. G. B. Pritchard and T. S. Hall that the above 
species ranges as far north as Port Adelaide Creek, near Adelaide, in 
St. Vincent’s Gulf, and specimens as large as those of the Maitland 
raised beaches are met with, as stated by the abovo observers, on the 
South Australian coast. 
The occurrence of Siphonalia maxima in the Pleistocene delta 
deposits of the Hunter Kiver, near Newcastle, in New South Wales, 
can likewise be explained away without perhaps necessitating a cooling 
of the sea water. Messrs. Hall and. Pritchard inform me that 
S. maxima ($. tasmaniensis') occurs along the Victorian coast, and 
G 
