Deposits, Limestone Greek. 17 



fossils common to the Devonian and Silurian systems. He 

 also states that some crinoidal stems — which are very 

 abundant in the Stony Creek beds — are apparently " Acti- 

 nocrinus," aod that there is a small undescribed species of 

 Atrypa and a species of Beyrichia. He also remarks that 

 the evidence points to these specimens being either Upper 

 Silurian or Lower Devonian, the geological interval between 

 these two being very small. Among many highly scientific 

 problems arising out of an examination of the rock masses 

 in this rugged portion of our Australian Alps, that which 

 relates to the metamorphism of the sedimentary rocks into 

 crystalline schists is, perhaps, one of the most important. 

 Of the relations between the palaeozoic sediments of the 

 Limestone Creek and the regional metamorphic schists of 

 the Mitta Mitta source basin, I shall, I hope, have more to 

 say when dealing with the geological structure of the Indi 

 Eiver and the Mitta Mitta source basin. The facts elicited 

 in this paper may pave the way for more extended observa- 

 tions and determinations in that respect. 



