166 
Geology of Sydney. 
Phyllotheca is also a common fossil in the shales 
about Sydney. It is also found in the Newcastle Beds, 
and, on this account, when found in association with a 
thin seam of coal at Blacktown, near Sydney, persons 
were led into the mistake of thinking that the coal 
seam in question was an outcrop of the true Coal 
Measures. Phyllotheca is connected somehow, or has 
much in common, with the Equisetaceae or Horsetails. 
Fig. 41. — Macrozamia, a living Cycad ; common in the Tllawarra 
coastal district, and known as far west asDubbo. 
Visitors to the Blue Mountains will remember the 
bundles of so-called moss sold at the railway station ; 
this is commonly known as “ Mountain Moss,” but is 
in reality a Lycopod. In former periods of the earth’s 
history Ly copods, with stems forty and fifty feet high, 
formed vast forests, and we only know their life- 
