216 J. T. Jatson: 



information, as a rule, to determine it. IX. represents two 

 sections, whose fossils have become mixed, but they are both in 

 the Yeringian area. The fossils from section X. Mr. Chapman 

 classes a,s of doubtful horizon, no doubt from their scarcity and 

 want of charaot eristic fossils ; but the map shows that these 

 rooks oome within the Yeringian area. Section XI. has not been 

 carefully examined, but will probably be found to be Yeringian. 



Age, Extent and Thickness of the Beds. 



Mr. Chapman has sihown in the Appendix that the fossils col- 

 lected indicate rocks of Melbournian and Yeringian age. with 

 probable Passage beds. With this assistance, I have been 

 enabled to indicate the areas of the respective series on the map 

 attached. The Melbournian is practically coincident with the 

 Whittlesea Anticlinal. There is in addition the small trianaailar 

 block betwean the fault and the Passage beds. The rocks of 

 this piece of country form part of the Merriang Synclinal, and 

 are conformable to the Passage beds and the Yeringian. As 

 they are below the Passage beds they must, for the present, be 

 regarded as Melbournian. This will be an interesting point to 

 settle, as if it is Melbournian, we shall then have Melbournian, 

 Passage beds and Yeringian all conformable to one another. 



The Passage beds occur at sections VI. and YIL, and their 

 field relations justify the view that the rocks at these sections 

 form part of the siame set of beds. I have therefore connected 

 them on the map. 



The area of the undoubted Yeringian rocks is small, forming 

 part only of the Memang Synclinal ; but their northward exten- 

 sion will no doubt subsequently be proved. 



As regards thickness, allowing an average inclination of 50 

 deg. for the beds in the Whittlesea Anticlinal, and assuming 

 there is no undiscovered repetition of the bedSi, I estimate the 

 thickness of the exposed Melbournian series at between 70UU feet 

 and 8000 feet. 



Taking the average angle of the known Yerinfrian beds at 

 10 deg., and with the Passage beds as a base, the thickness of 

 the Yeringian sea'ic'S, as comprised witliiu the area of the i'ossil- 

 iferous scctitms, would be about 750 feet. 



The rocks along the Cemetery Hill Hoad between the fault and 

 the probaMe Passage beds, liave a tliickness of ab uit 600 feet. 



