ANNIVERSARY ADDRESS. 49 
c. The Hawkesbury Series can be separated into three divisions, 
which in ascending order are as follows :— 
1. Narrabeen Beds. 
2. Hawkesbury Sandstone. 
3. Wianamatta Shales. 
This series is classed, provisionally, as Triassic, partly on 
account of its fossil flora in which Thinnfeldia, Teniopteris, and 
Phyllotheca predominate ; partly on account of its fossil fauna 
which numbers Cleithrolepis, Paleoniscus, etc., amongst its fish, 
and several species of Mastodonsaurus amongst the reptiles, while 
Estheria is very abundant chiefly in the Narrabeen Beds. For 
descriptions of the fossil flora and fauna the works mentioned 
below may be consulted. 
1. The Narrabeen Beds succeed the Permo-Carboniferous Coal- 
measures apparently without unconformity in the Blue Mountains; 
traced, however, to the Hunter River district a distinct uncon- 
formity may be observed, in the neighbourhood of the Pokolbin 
Hills. The existence of this unconformity might have been 
inferred from the very strong break between the fossil flora and 
fauna of these Triassic rocks and those of the Permo-Carboniferous 
system. The Narrabeen Beds consist in their lower portions of 
sandstones and shales, and in their upper portions purplish-red . 
shales are developed, which, although not more than ten feet or so 
in thickness, in the western portion of the Blue Mountains, never- 
theless form a conspicuous feature in the landscape. If the 
observer looks across one of the vast amphitheatrical depressions, 
1 Mem. Geol. Sur. oe S. Wales, Paleontology No. 1—The Invertebrate 
Fauna of the Hawkesbu ay a Series, by Robert Etheridge, 
Junr. By svchost, Sydney, 1888. 
Mem. Geol. i aS. Wi wis , Paleontology, No. 3—Geological and 
Paleontological Sl ssinias of the Coal and Plant-bearing Beds of Paleozoic 
and Mesozoic Age in Eastern Australia and Tasmania, by Ottokar Feist- 
mantel. By Authority, Sydney, 1890. 
Mew. Geol. Sur. N. S. Wales, Palewontology No. 4—The Fossil Fishes 
of the Hawkesbury Series at Gosford, by A.S. Woodward. By Authority 
Sydney, 1890. 
D—May 20, 1996, 
