32 Sedimentary Formations 
gathered a rich harvest of fossil ferns, mostly Pecopteris, 
TaBuioptcris, and Oamptopteris” (this, however, is not; found in 
?few South Wales) “ which, according to Professor M‘Coy, are of 
Jurassic age identical with beds belonging to the New South 
Wales Coal Fields, aud although I believe this Clent Hill serios 
to be somewhat younger than the Spirifera 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 Paloeozoic facies.” 
“ Since then it has been shown, and as I think with conclusive 
evidence, that both fossiliferons 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 Ticniopteris, which hitherto has been considered only of 
Secondary age/* seems to speak against a Paleezoie origin; however, 
I may point out that, the same objection was made to the 
Grlossopteris in Australia, but which lias 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- 
grapbical geology has proved to be correct.” (p. 0-7.) 
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 has been swept oft' 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 Wingen, 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 300 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 eases where local derange¬ 
ment has occurred from special elevating forces), and moreover, 
that similar seams 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 to the coal measures in which marine Pabeozoie fossils 
are stated to have been found. 
In the sections published some years ago by Mr. J. Mackenzie 
and myself, and in subsequent sections by the former, as given in his 
Report to Government, it will be seen that the number and thick¬ 
ness of the seams vary considerably in different localities. The 
former circumstance may be accounted for by the fact that the 
* Schimpcr says (tom. 1, p. 600) of the genus TreniopterSs—“ Ces Fougercs paraissent 
ctre propres au terrain houiller supcrieur ct aw permien,” i.c., they are l’akcozoic. 
