70 
Sedimentary Formations 
Oolitic or Jurassic, iustead of “Triassic or Permian”? Sir p 
Egerton lias shown that, with Palasoniscus, occur other genera* 
closely related to Pygopterus, Acrolepis, and Platysomus, all 
•either Upper Carboniferous or Permian genera in other parts of 
the world. 
Then again, why should the Urosthenes of Dana, from a 
prominent part of the Newcastle local beds, be left out of th 0 
same category? 
The view then is, that all these beds, ranging in succession one 
over the other, and being all as I believe of fresh water origin 
(for the Hawkesbury rocks contain plants, but no animal remains 
except fishes), have a common relationship, and yet with no 
pretext for a Jurassic origin on the score of animal co-existences 
of that era. When we consider that the lislies alluded to, in 
connection with Coal and Coal-plants, occur at different altitudes, 
and are all heterocercal Ganoids, we must conclude that there 
have been physical disruptions, and that there are gaps in the 
succession occasioned by following denudation, or that there 
have been repetitions of strata now only partly traceable. 
Eor instance, the fish beds are at Cockatoo Island 10 feet 
below the sea; at Sydney less than 100 feet above it; 100 feet 
at Parramatta; 250* feet above it at Campbelltown; 7S0 feet 
above at Eedbank near Picton ; 1,100 feet on llazorback ; 2,800 
feet at the Gib Tunnel; and 8,450 feet on the Blue Mountains ; 
the lowest two stations and the highest being in the Hawkesbury 
series, and the others in the Wianamatta beds above the Hawkes¬ 
bury ; whilst at Newcastle, the Urosthenes was the deepest below 
the sea, and the oldest in position. 
As necessary to explain still further the succession of strata, 1 
introduce here some additional remarks on the Supra-Carboni- 
ferous rocks in the province of New South Wales. 
Ilawkcslury Rocks . — Over the uppermost workable Coal 
Measures, which are of considerable thickness, is deposited a 
series of beds of sandstone, shale, and conglomerate, oftentimes 
concretionary in structure and very thick-bedded, varying in 
•composition, with occasional false-bedding, deeply excavated, 
and so forming deep ravines with lofty escarpments,—to the 
upper part of which series L have given the name of Hawkesbury 
rocks, owing to their great development along the course of the 
river-basin of that name. These beds are not less in some places 
than from SOO to 1,000 feet in thickness, containing patches of 
shale, occasionally with fishes, with fragments of fronds and stems 
of ferns, a few pebbles of porphyry, granite, mica, and other 
■quartziferous slates, and assume in surface outline the appearance 
of granite, from the materials of which and associated old deposits 
they must in part have been derived. On the summit of the 
