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



10. If it may be concluded that the whole of the Hunter 

 River "Permo-Oarboniferous" Series is really Permian, 

 and the Rhacopteris-bearing Kuttung Series is Middle 

 Carboniferous, what then has become of the equivalents of 

 the Pennsylvaniai], the Stephanian, the Ottweiler and all 

 the other representatives of the Upper Carboniferous rocks 

 of the Northern Hemisphere? 



(i.) Are they represented by the unconformity between 

 the "Permo-Carboniferous" (Lower Marine) Eurydesma 

 beds and the Rhacopteris beds at Pokolbin etc. (in spite of 

 the fact that elsewhere as atSeaham and Paterson the two 

 series of the Kuttung and the Lower Marine appear to be 

 quite conformable)? 



(ii.) or does the disconformity come at the base of what 

 we have included as the topmost tillite of the Kuttung, 

 and is this particular tillite to be included in the Uraliau 

 rocks rather than at the top of the Kuttung? (See Plates 

 XIX and XXII.) In West Australia marine fossils such as 

 Keenia, Avlculopecten tenuicollis etc. occur in the same 

 matrix with the Pre-Greta marine glacial beds, and for 

 reasons already given indicate the age of the tillite of 

 West Australia to be probably Uralian rather than Permian. 

 In this case one introduces a disconformity, or slight uncon- 

 formity in the lower glacial series itself as developed in the 

 Lower Hunter area, making the top tillite of the Lower 

 Glacial Series Uralian, and the lower tillites associated 

 with Rhacopteris Moskovian. This at first sight appears 

 improbable. Nevertheless it is the fact that at Wynyard 

 in Tasmania, at Bacchus Marsh in Victoria, as well as at 

 the Irwin River a Pre-Greta tillite lies at the base of the 

 whole "Permo-Carboniferous" System, and is proved by 

 the presence of the already quoted marine fossils and the 

 Oangamopteris of Bacchus Marsh to be part and parcel of 

 the " Permo-Carboniferous." One would expect therefore 



