6 Proceedings of the Royal Society of Victoria. 



on the north of the river. The sloping surfaces of the hills 

 are seen to be nearly in one plane, including that visited by- 

 Mr. Cresswell, to the west, and the Hat Hill. It reveals 

 also the chief cause of their isolation, which is clearly the 

 extensive denudation which has taken place during the slow 

 elevation of the land through the waters, intensified by more 

 recent causes. The action referred to has removed the rock 

 for a depth of one hundred and thirty feet from the top of this 

 hill (marked Z'^ on sketcli) to the flats below^, exposing a 

 series of twenty-four beds of varying thickness. 



As will be observed from the specimens exhibited, the 

 prevailing rock of the north-east of this declivity of the hill 

 is a rubbly and nodular shale or mudstone, of chocolate, 

 claret, or purplish-red, and in one or two cases of a pale 

 green and greenish-blue colour, so much so, that of the 

 twenty-four beds of rock, thirteen, having an aggregate 

 thickness of one hundred and flfty-two feet, are of this 

 character, interstratified with eleven beds of different rocks. 



These eleven contain a thickness of only eight feet six 

 inches, giving a total thickness of beds of all kinds of one 

 hundred and sixty feet, but which, owing to the inclination 

 of the beds, and the five upper beds not being found till the 

 summit of the hill is passed, gives but one hundred and 

 thirty feet as the altitude of the hill above the river flats. 



Let me now direct attention to the various strata, their 

 general character, and the fossils found in each, beginning at 

 the lowest stratum observed, at the north-east of the hill 

 indicated by Z^ on the line Z Z" 7}. 



The lowest member of the series observed (Plate 2, A) was 

 a dull red dense micaceous sandstone. In this, no fossil 

 remains were detected, and the lower limit was not seen, but a 

 few feet being exposed. Resting on this is a bed, thirty feet 

 thick, of the dull purplish, rubbly, nodular, and calcareous 

 shale or mudstone before referred to. Next, we reach six 

 feet (B) of a bluish-green calcareous mudstone shale, slightly 

 micaceous, and retaining the rubbly and nodular character 

 of the thirty feet bed of mudstone rock on which it rests. 

 Then follow fifteen feet (C) of rock similar to A, bearing on 

 it one foot (D) similar to B, and then another fifteen feet 

 (E) similar to A. We now reach a six inch stratum (F) of 

 much harder rock, which has resisted the action of the 

 weather more than any of those named, and projects out in 

 a long yellow line. This, when broken into, displays a 

 bluish-grey arenaceous limestone, slightly micaceous, chang- 



