NOTES ON THE CREMORNE BORE. 445 
(5) Lower Marine Series. Each of the three groups of productive 
coal measures above: mentioned, is specially characterised by the 
enormous predominance of Glossopteris or of Gangamopteris in its 
flora. 
Summarising the result of his later researches Mr. Clarke 
classifies the productive Glossopteris coal-beds of Australia and 
their associated strata as follows :—-1. Upper Coal Measures. 
2. Upper Marine Beds. 3. Lower Coal Measures. 4. Lower 
Marine Beds.* | 
These productive coal measures are most extensively developed 
in the Hunter River or Northern Coal-field, the Lithgow or 
Western Coal-field, and the Illawarra or Southern Coal-field. Mr. 
Clarke did not definitely state his views as to the correlation of 
these various coal-fields, but it is clear that he regarded the 
Illawarra Coal Measures as being newer than the Upper Marine 
Series and than the Lower (the Greta) Coal Measures, inasmuch 
as in the work above referred to (loc. cit., p. 169, Section to 
illustrate the structure of Burragorang), he speaks of the marine 
beds underlying the coal measures of the Mittagong Coal-field as 
the ‘‘ Muree Beds,” a name which he had previously given to the 
Upper Marine Series, or at any rate to a portion of them, which 
in the type district at Greta in the Hunter River Coal-field overlie 
the Lower Coal Measures, as illustrated by Mr. Clarke in another 
Section (loc. cit., p. 171). Mr. Clarke also in his Section of Mt. 
Victoria (Joc. cit., p. 167), refers to certain hard shales occurring 
there as being like the ‘‘Silicated clay of Nobby Island.” The 
island of Nobbys at Newcastle is formed of Upper Coal Measures. 
It is evident that Mr. Clarke considered the productive coal 
measures of the Neweastle, the Lithgow, Mittagong, and Illawarra 
Coal-fields as belonging to the Upper Coal Measures, and Mr. 
Mackenzie concurred with him in this opinion. 
Mr. C. 8. Wilkinson, the late Government Geologist subse- 
quently adopted the following divisions for the Glossopteris Coal 
* Remarks on the Sedimentary Formations of New South Wales, Fourth 
Edition.—Gova@rnment Printer, Sydney 1878, p. 66. 
