276 C. A. SUSSMILCH AND T. W. E. DAVID. 



a very persistent horizon, consisting of a very thick bed of 

 natrolite basalt, and shown by Professor David in his 

 geological map and section of the Hunter River coalfield. 

 In following the junction of the Carboniferous and Permo- 

 Carboniferous strata from the sea-coast to Paterson, a dis- 

 tance of about 35 miles, the outcrops of this basalt and 

 that of the Kuttung glacial beds always occupy the same 

 relative positions with regard to one another. If a thick 

 series of strata had atone time existed between these two 

 horizons it is hardly likely that it would have been denuded 

 down to exactly the same geological level over such a 

 wide area. 



From no other part of the State have any beds yet been 

 found of Carboniferous age occuring above the Kuttung 

 Series and below the Lower Marine Series. It seems improb- 

 able therefore that there has been any important removal 

 of strata of Carboniferous age from the top of the Kuttung 

 Series. This being so, and assuming that the Lower Marine 

 Series are retained in the Permo-Carboniferous System,, 

 then the Kuttung Series represents the whole of the time 

 interval from the beginning of the Middle Carboniferous 

 Epoch up to the end of the Carboniferous Period. The 

 Neuropteris-Alethopteris flora which characterises the 

 Upper Carboniferous Coal Measures of North America and 

 England does not appear to have found its way into Eastern 

 Australia, and it would appear that the Rhacopteris flora 

 of the Kuttung Series, which is typical of the Middle 

 Carboniferous Epoch only, in the Northern Hemisphere,, 

 survived longer in New South Wales, being replaced not 

 by the Neuropteris-Alethopteris flora of Upper Carbonifer- 

 ous time in the Northern Hemisphere, but by the Glos- 

 sopteris-Gangamopteris flora so typical of the Permo-Car- 

 boniferous period in tbf> Southern Hemisphere. Should it 

 however, be decided to transfer some part of the Permo- 

 Carboniferous formation into the Carboniferous Period, then* 



