84 
Geology of Sydney. 
at once concludes that the rocks around him are Car- 
boniferous. And if he found the fossil, represented as 
it appeared when growing, in Fig. 4, he would feel 
certain the rocks around him were Mesozoic, and 
probably Triassic. In the same way the presence 
of the Spirifers shown in Figs. 56 and 57 would point 
to Devonian beds. Finally, no geologist tinding the 
fossil fern shown in Fig. 38 would for a moment 
doubt, in New South Wales at any rate, that he was 
dealing with Permo-Carboniferous rocks. 
We now come to see the meaning and the impor- 
tance of characteristic fossils , any one of which is 
almost sufficient to identify the formation in which 
it occurs. 
Principal Australian Sedimentary Formations, with some 
Characteristic Fossils. 
f 
i 
I 
I 
I 
I 
d 
3 
ESJ 
o 
o 
a 
o 
> 
rS 
H 
> 
H 
X 
W 
H 
| Recent 
Pleistocene 
Pliocene 
Miocene 
l 
Eocene, 
{ Human bones and implements ; re- 
mains of plants and animals of living 
species; Dinornis, Aptornis, Ornitho- 
rynchus, 
f Diprotodon, Macropus, Thylacoleo, 
I Thylacinus, Notiosaurus, Megalania, 
J Dromornis, Echidna, Meiolania, 
Palorchestes, Dromaius, Mytilus, 
[ Siphonalia. 
/ Spondylostrobus, Wilkinsonia, Pen- 
teune, Plesiocapparis, Unio, Rotella, 
j Pleurotoma, Pecten, Pileopsis, Lu- 
1 cina, Limopsis, Pectunculus, Mesa- 
lia, Triton, Murex, Echidna, 
V Meiolania. 
Squalodon (regarded by some as 
Eocene), Trigonia, Terebratula, Cly- 
peaster, Lovenia (also Eocene), 
Columbella (also Eocene), Pectun- 
culus, Pelicaria, Struthiolaria, Nati- 
ca, Mytilus, Ostrea, Turritella, Corals 
r Fagus, Quercus, Cinnamomum, 
Pteris, Insects, Limopsis, Voluta, 
Cyprasa, Dentalium, Cardium, Trigo- 
nia (3 sp.) Murex (upwards 30 sp.), 
- Triton, Mitra, Fusus, Pleurotoma, 
Natica, Cerithium, Turritella, Wald- 
heimia, Chione, Aturia, Terebratu- 
„ lina, Trachyphyllum. 
