66 Proceedings of the Royal Society of Victoria. 



lime and magnesia, with a little silica, alumina and iron oxide. 

 It is also very similar in physical appearance. Moreover, the 

 gravels and quartzites ovei'lying the limestone here cannot be 

 distinguished in appearance from the similar beds seen near the 

 quarries. It would thus appear that the limestone cannot be 

 regarded as confined to one horizon. Mr. Ferguson, in the map 

 above referred to, represents the quarry limestone as being 

 overlain with a strong unconformity by the gravels, quartzites, 

 etc. With this conclusion we do not agree ; the limestone must 

 be regarded as part and pai'cel of the beds with which it is 

 associated. 



These deposits can be ti'aced down the Pyrete Valley, out- 

 cropping just below the basalt ; and though they vary consider- 

 ably in character from point to point, we have no doubt that 

 they are continuous. As we leave Coimaidai and approach the 

 Bacchus iNIarsh side of the basalt edge, the beds are found to be, 

 as a rule, less highly cemented, and therefore looser and more 

 incoherent. 



On the Bacchus Marsh side, pipe-clays of a beautifully white 

 colour and pure nature begin to appear. They are associated 

 with considerable thicknesses of fine white sands, grits and 

 gravels. Here and there a bed of hard conglomerate and thin 

 lenticles of white, compact quartzite can be seen, intercalated 

 with softer and even incoherent deposits. Near the Bacchus 

 Marsh Road, and a short distance below the basalt, thin beds of 

 limestone occur. This limestone is essentially of the same 

 character as the quarry limestone, and its occurrence here is 

 strong confirmatory evidence of the continuity of the beds of the 

 Bacchus Marsh side of the district with those of Coimaidai. At 

 a little distance from this limestone outcrop, and at a lower 

 level, a section has been exposed in a road-cutting, in which we 

 find in ascending order : — 



(1) Gravel and sand, 5 feet. 



(2) Thin band of white pipe-clay containing leaf impres- 



sions. 



(3) Gravel and sand, showing much false bedding, S feet. 

 The leaf impressions are somewhat fragmentary, but of such 



distinctive character as to leave no room for doul)t as to their 

 significance. One impression is very similar to that of Lauriis 



