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Geology of Sydney. 
Fossils. 
It is well to bear in mind, when speaking of the 
fossils of the Hawkesbury series, we are speak- 
ing of all that is left to us of the animals and plants 
that peopled and clothed the earth in Triassic times. 
There is a danger of looking on fossils as geological 
specimens merely. But, in truth, is this shattered 
bone merely a specimen ? Piece it together ; find the 
next bone which should join it, and gradually a thing 
of life takes shape, of which these dried bones are the 
mere frame-work. The beautiful impressions of ferns 
found in our shales are valuable specimens, but their 
great lesson is lost if we cannot in the mind’s eye 
picture them as they lived. The geologist can conjure 
back again that ancient morass on whose banks they 
grew long, long ago. He can see their feathery forms 
tangled in a wealth of green along the ancient valleys. 
The fossils show us also fishes gliding through the 
lagoons, and the giant salamanders basking on the 
muddy flats or crashing through the undergrowth. 
The first remains of Labyrinthodonts were dis- 
covered while a dock was being excavated at Cockatoo 
Island, and then it was that we got to see some simi- 
larity between the Triassic rocks of Australia and those 
of Europe and America. As is well known, Triassic 
rocks in the Northern Hemisphere are identified with 
reptiles, the remains of which abound. No reptilian 
remains had, however, been discovered up to this date 
in Australian Triassic rocks. Secondary rocks of 
