64 Sedimentary Formations 
Lower Carboniferous or Tipper Devonian age.” “ Other Beds,” 
he adds, “ of equal importance occur in the Clent Hills, in which 
I gathered a rich harvest of fossil ferns, mostly Pceopteris, 
Tamioptcris, and Camptopferis” (this, however, is not found in 
New South Wales) “ which, according to Professor M‘Coy, are of 
Jurassic age identical with beds belonging to the New South 
Wales Coal-fields ; and although I hclieve this Clent Ilill series 
to be somewhat younger than the Spirifcra beds, I demurred to 
this definition, owing to the fact that the position of the strata 
and the character of the rocks of which they are composed have 
quite a Palaeozoic facies." 
“ Since then it has been shown, and as I think with conclusive 
evidence, that both fossiliferous strata, the Spirifera and Pecop- 
teris beds, occurring together in the New South Wales Coal-fields, 
are of the same age, and alternate with each other. The occur¬ 
rence of Tfoniopteris, which hitherto has been considered only of 
Secondary age,*' seems to apeak against a Pakeozoic origin ; how¬ 
ever, 1 may point out that the same objection was made to the 
Glossopteris in Australia,but which has by overwhelming evidence 
been shown to be also of Pahcozoic'age. I do not think that the 
fragment of a leaf, however distinct, can unsettle all that strati- 
graphieal geology has proved to be correct,” (p. (>-7.) 
Some recent researches made by me, with a view to the con¬ 
sideration of this question of age, render it far from improbable 
that a series of beds lias been swept off the Coal Measures by 
denudation, in which Marine beds may have overlain the now 
existing strata, just as in a lower horizon they do still at Stony 
Creek, Anvil Creek, Mount Wiugcn, and in other localities. The 
facts that the present Coal-seams range in elevation along the 
coast, from below the sea to between 200 and 000 feet only above 
it, and that to the westward they reach an elevation of upwards of 
3,000 feet, still preserving the same plants as below, and with an 
equal almost horizontal level (except in cases where local derange¬ 
ment has occurred from special elevating forces), and moreover, 
that similar scams occur at various other elevations between those 
mentioned, induce me to consider it possible that there has been 
a sinking along the coast-line, allowing denudation to operate. 
At present this hint may not bo worth much, but hereafter 
more may come out of it. I ought also to add that between the 
Hawkesbury rocks and the Coal there is often a series,of beds 
belonging 1o t he Coal Measures in which Marino Pakeozoic fossils 
are stated to have been found. 
* Sclamper says {tome 000), of the genus Tteniopteris—“ Ces Fourjercs 
paraisseut etre prnpres nu terrain houiller Stipe ri&ur el au Permieni.e. t they 
arc Palfcozoie. It is only recently that L lmve obtained not only species of the 
subgenera, but real Tocniopteris from New South Wales, and it is respecting 
such only that I liavo written in using the name, in relation to Palscozoic 
Carboniferous rocks. 
