ee och See © etm Seer 
THE HAWKESBURY SANDSTONE. 57 
a coniferous structure could be made out—at least in some speci- 
mens from Double Bay which I examined. In the same sandstone 
fossil fishes have been found, ranging from 16 feet below the 
sea (at Biloela) to over 3,400 feet on the Blue Moun ier 
species have been determined, Cleithrolepis granulatus, Egert. 
Myriolepis Clarkei, Egert. "The former is not heternoarcal-; oo 
measures, * eenes from one to another is almost imper- 
ceptible—it is difficult to draw any well-defined line. The false 
bedding disappears as well as the layers, and soon a very hard and 
Coarse conglomerate succeeds, with beds of shale and impure coal. 
Escarpments.—A peculiarity of the Hawkesbury sandstone i is its 
precipitous character. Wi herever: iti 
faces ; even where outliers are 
seen on the s summits of hills they have the same character, and, 
when the formation abuts on _ coast, cliffs and gorges such as are 
seen in Port Jackson are sent. Mount Pigeon House, so 
named by Cook ome si som et of the summit of this moun- 
tain to a dove-cote acase in point. The cliffs at J ervis Bay, 
belonging g to the game S eniidan: are much like those at Sydney 
Heads, “Rocks very like the Hawkesbury sandstone are found in 
Yarious places on the eastern side of Australia and in the interior. 
They are largely developed in the neighbourhood of the Endeavour 
River, and northwards in Northern Queensland. They also lie on 
8 coal: formation, but not eunformelly 5 ; ee they are ares similar in 
e Ise bedding. 
ey ‘ha 
a “ede have also beds of acm de aad are cut hao, precipitous 
aes as in Sydney. A mountain called O’Connor’s Nob is very 
koi e undulating layers are on 
The highest parts of the main range west of thicbios 
PL ite OPE NTE. SAE 
except in the Blue Mountains the sandstone is not constantly con- 
