Art. VIII. — Remarks on the Proposed Siibdivisio)i of the 

 Eocene Rocks of Victoria. 



By T. S. Hall, M.A. 



(Demonstrator and Assistant Lecturer in Biology in the University of 



Melbourne), 



Aud G, B. Pritchard 



(Lecturer in Geology in the Working- Men's College, Melbourne). 

 [Read December 12th, 1895.] 



Last year we contributed a paper to this Society in which, 

 when discussing the older tertiary rocks of Maude, (1) we indi- 

 cated what we believed to have been the general order of succes- 

 sion of the eocene rocks of Victoria. During the present year a 

 paper by Professor Ralpli Tate and Mr. J. Dennant (2) has 

 appeared, in which our conclusions are objected to and a number 

 of arguments are brought forward in opposition to them. The 

 number and variety of the interpretations of tlie succession of 

 the rocks in question already advanced show the difficulty of the 

 subject, and an historical account of the \'arious views held has 

 been given by one of us elsewhere (3). 



Before considering the objections of Messrs. Tate and Dennant 

 it will be better perhaps to state briefly the steps by which we 

 arrived at our conclusions. For a fuller statement of the case 

 reference must be made to our former article (1). "VVe recognised 

 three horizons, characterised by differences in their fauna, and as 

 types of these horizons we took those deposits which had been 

 most fully elaborated, namely. Lower Muddy Creek, Waurn 

 Ponds, and Spring Creek. We found that where the " Muddy 

 Creek " and " Waurn Ponds types " occurred together, the latter 

 was the underlying deposit, and that beds of the "• Waurn Ponds 

 type " in several places overlay the older volcanic rock. At 

 Maude we found that the latter rock was undez^lain by a series 

 of beds which, on paheontological grounds, we correlated with 

 the Spring Creek beds. As a further confirmation of our view 

 we calculated the percentage of recorded living species in the 



