influenco of tlio reported observation of a boulder bed* in tlie Hawke sbury 
beds, compared this boulder bed with that in the Talcliir, and placed there- 
fore the Newcastle beds ou a lower horizon. 
The relations of the distribution of the genus Hhiptozamites, 
Sclimalh., and Noggcraihiopsis, Eeistm., which I intended to illustrate in 
the tabular view in the above work ( p. 57) remain, however, undis- 
turbed. 
(47.) 1879. Wilkinson (C. S.) Notes on the Occurrence of Remarkable Boulders in tlie 
Hawkesbliry Rocks. Joum. and Proc. Roy. Soc. N. S. Wales, 1879, Vol. XIII, pp. 105-107. 
(48.) 1880. Feistmantel (Dr. 0.) Further Notes on the Correlation of the Gondwana 
Flora with that of the Australian Coal-bearing System. Records Geol. Survey , India, Vol. XI II, 
part 4, pp. 250-253. 
According to the recent observations of Mr. It. I). Oldham, which X 
shall mention later on, the Hawkesbury boulder bed cannot be correlated 
with that in the Bacchus Marsh beds, this being now said to be con- 
temporaneous with a similar boulder bed in the marine beds below the 
Newcastle coal beds.f 
The tabular view in my above note (p. 253) can, however, easily be 
adapted to this new observation by shifting somewhat higher the sequence 
in the fourth (right) column, under the heading “ New South Wales” 
so that opposite the boulder bed in Victoria w 7 ould be placed the marine 
beds, below the Newcastle beds ; these themselves would stand opposite the 
Bacchus Marsh beds (above the boulder bed), and opposite the Talchir- 
* [The term “boulder bed” is, in this case, hardly applicable. The so-called “boulders” embedded in the 
Hawkesbury Sandstone are angular fragments of shale, of all sizes up to thirty feet thick, which have evidently 
been torn up by ice moving ujjon beds of shale, and mingled in an irregular manner with the drifted sand which 
has formed the bed of sandstone immediately overlying the shale bed. These angular boulders have not been 
removed far from their source ; in some sections they are seen to have been piled up upon the undisturbed 
portions of the shale beds from which they have been derived — so that their origin is apparent. The shales are 
contemporaneous with the sandstones, being interstratifiecl with them at various horizons throughout the 
Hawkesbury formation, in which there are also occasional beds of pebble conglomerate. The beds of sandstone 
containing these angular fragments of shale cannot, therefore, strictly speaking, be termed “boulder beds,” or 
compared with the conglomeratic beds of the Lower and Upper Marine Carboniferous Series of New South Wales, 
or those of Bacchus Marsh in Victoria, which consist chiefly of rounded and sub-angular boulders of all sizes, 
some being several tons in weight, down to pebbles, sand, and earthy material, and in places form true 
conglomerates ; in others fine sandy sediments, with the boulders and pebbles sparingly scattered through them. 
Some of the boulders have been drifted for a considerable distance, as they are composed of rocks not known 
in situ in the locality. 
The evidence of ice action in these boulder beds is of much interest and importance, as indicative of 
certain physical conditions, such as those of climate, or of the transporting oceanic currents ; but apart from 
palaeontological and stratigraphical data it can only be adduced for the provisional correlation of formations in 
widely separated localities. — C. S.W.] 
t [These beds are only “similar” in lithological character, viz., in the mode of occurrence in them of 
erratic boulders, which has led to the belief that the transporting agency of ice has been concerned in their 
deposition. It is doubtful, however, if this evidence alone should be considered sufficient to justify the 
correlation of the two formations ; further examination of them is, I think, necessary. The marine fauna and 
boulders, scratched, it may be by ice, which have been found in the Marine .Series of New South Wales, have 
not yet been detected in the boulder beds of Bacchus Marsh, in Victoria.- C.S.W.] 
