XXXIl 
CONNECTION BETWEEN THE 
Hawksbury and the Hunter ; the latter on the 
limestone formation of Wellington Valley and 
in the better portions of Argyle ; whilst the cu- 
pressus calytris seems to occupy sandy ridges 
with the casuarina. It was impossible that these 
broad features should have escaped observation ; 
it was naturally inferred from this, that the trees 
of New South Wales are gregarious; and in fact 
they may, in a great measure, be considered so. 
The strong line that occasionally separates dif- 
ferent species, and the sudden manner in which 
several species are lost at one point, to re-ap- 
pear at another more distant, without any visible 
cause for the break that has taken place, will 
furnish a number of interesting facts in the 
botany of New South Wales. 
It was observed both on the Macquarie river 
and the Morumbidgee, that the casuarinae ceas- 
ed at a particular point. On the Macquarie 
particularly, these trees which had often excited 
our admiration from Wellington Valley down- 
wards, ceased to occupy its banks below the 
cataract, nor were they again noticed until we 
arrived on the banks of the Castlereagh. The 
blue-gum trees, again, were never observed to 
