Ill 
Geological History during Tertiary Epoch. 
old lines of drainage, and sometimes establishing independent 
courses. In some places, as near Daylesford, the existing streams 
eroded their courses through, and to a deeper level than, the upper 
portions of the Tertiary rivers ; in others, as at Ballarat, the latter 
are hundreds of feet below the present water-courses. To action 
which took place during Post Tertiary times are also due the 
surface layers of the great plains of the Murray, Gippsland, and 
other low-lying tracts. 
1 he sand rocks of Post Tertiary age along portions of the coast- 
line, as at Warrnambool and Cape Otway, are aerial deposits formed 
by the action of wind blowing sand into duties and hillocks which 
subsequently consolidated owing to the presence of calcareous 
matter derived from the shell fragments associated with them. 
These rocks have been partly denuded, and their materials are 
now in course of fresh distribution by every wind. In some 
places the sand is encroaching on and covering large areas of what 
was in my own recollection good pastoral land. The method 
of deposit in sloping layers, the variations in direction of the 
slopes, the ribbed appearance due to certain winds, and the inter- 
mixture of shell fragments, can all be observed, and to such 
action we can infallibly refer the origin of the consolidated 
beds, to which the operations now in progress present an exact 
counterpart. 
Though, geologically, the deposits since the newer lava-flows 
are of very recent date, tho time that has elapsed since volcanic 
action entirely ceased must be very great, as may be seen by the 
depths to which the present water-courses have cut their way 
through layers of hard basalt deep into older rocks, and by the 
deposits which have since accumulated in low-lying tracts. ' 
It is interesting to consider the character of" the fauna which 
flourished in Victoria and Australia generally during Upper, and 
even Post Tertiary times. The fossil remains found are those of 
animals of genera analogous to those now existing, but of vastly 
greater size. The Diprotodou, for instance, is described by Pro- 
fessor McCoy as having belonged to the same family as that now 
represented by our native bear or sloth ; but the size of the bones 
fotiud indicate that the animal was about 10 feet in length and 6 
fee t In height, and was able partly to gnaw and partly to tear down 
large-sized trees for tho purpose of feeding on the leaves. Various 
gigantic representatives of the kangaroo tribe, some of thorn 
approaching 20 feet in height, inhabited the country, and the 
marsupial lion, an animal akin to our small carnivores, but equal 
in size to an ordinary lion, preyed upon the huge vegetable-eating 
denizens of tho plains and forests. 
The present ago is essentially one of denudation as regards the 
land surface of Victoria. Yearly, daily, hourly, solid matter is 
being carried away from our mountains, and though some of it 
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