106 
The Queensland Naturalist August, 1938 
At Peregian a biotite trachytic rock with well de- 
veloped fluxion structure occurs. This mass which is 
about half as high as Coolum, is in type almost indentical 
with that at Mt. Timbeerwah, 3 miles or so west of 
Tewantin. 
The rock is composed essentially of sanidine, but 
there are also crystals of hornblende, probably soda-rich 
and occasional large flakes of biotite. The rock may well 
be termed a Biotite Trachy-Rhyolite. 
At Eurungundcr the Trachy-Rhyolite is according to 
Jensen of a similar character. 
THE PLANT COMMUNITIES IN THE NEIGHBOUR- 
HOOD OF COOLUM. 
The Botanical Report of the Easter Camp of 1938. 
By S. T. Blake, M.Sc., Department of Biology, 
University of Queensland. 
A great deal of interesting variety is to be found in 
the neighbourhood of Coolum, a small township situated 
on the coast about 65 miles north of Brisbane, and pos- 
sessing an average annual rainfall of about 65 inches. 
The details for Coolum itself are lacking, but at Caloundra 
about 15 miles further south, the driest months are July- 
October inclusive, in which the average monthly rainfall 
is 23 inches. The plant-communities are varied, and there 
is a noticeable mingling of northern and southern species. 
Specimens collected during the camp provide the most 
northerly records for some species, and the most southerly 
for others. A few are known to extend a little further to 
the south in the neighbourhood of Buderim or Caloundra. 
A great deal of the country is low-lying and often 
swampy. Bold sandstone cliffs about 50 feet high with 
narrow sandy beaches between the headlands fringe the 
shore for some distance to the south of the township, while 
to the north is an extensive broad sandy beach with dunes 
on the landward edge. Dunes also occur on the top of 
some of the cliffs. An occasional sandstone ridge occurs 
back from the coast, while two isolated trachytic peaks, 
Mt. Perigian and Mt. Coolum, are at no great distance 
from the township. The former is about. 200 feet high, 
and lies to the north, while the latter is rather over 600 
feet high, is much bolder with some fine precipitous rock- 
faces, and lies to the south-east. The soil throughout is 
distinctly sandy in nature, often without any clay content 
at all, while at the time of our visit water was in abund- 
ance, and springs and seepages were very numerous, par- 
ticularly near Mt. Coolum. 
