40 Proceedings of the Royal Society of Victoria. 



Tlu' limestone strata are separated at intervals by five 

 dark shaly or mudstone partings, averaging Irom 18 inches 

 to 4 feet across ; the tliickest one, which is of a dark brown 

 or claret coloui-, is npwards of 4 feet, and in this one is an 

 almost perj^endicnlar shaft-like cave, 91 feet deep, apparently 

 caused b}^ the action of running water. 



I am informed by the owner, Mr. David Mitchell, of 

 Burnley, that the limestone of his quarry has been long ago 

 analysed, and runs to 95 or 96 per cent, of calcium carbonate. 

 The limestone is in high esteem as the best and purest 

 source of lime for building purposes in the colony. It has 

 also been lately turned to profitable account in the manu- 

 facture of cement, and the owner informs me that the force 

 required to ])ull it apart is 985 lbs. The stone has not been 

 directly used for building purposes, but some slabs, which, 

 when polished up, have an ornamental appearance, have been 

 occasionally used for marble mantelpieces. Upon the whole, 

 I think, therefore, we may congratulate Mr. David Mitchell 

 upon having a more payable thing in his possession than 

 many a gold mine. "When the quarry has been in full work 

 in prosperous times, he tells me that he has had as many as 

 120 men employed on it, and has been able to send away 

 the almost incredible amount of 70 tons of lime a day. In 

 these days of depression, however, when there is so little 

 demand for lime, 20 men are found quite sufficient to do all 

 the work of the quarry that is required. 



The limestone of Cave Hill, like most other limestones, 

 contains occasional patches of crystalline calcite, mostly in 

 rhombohedrons or in modified scalenohedron.s. It also con- 

 tains segregated lumps and layers of chert, in which corals 

 and other small fossils are sometimes beautifully preserved 

 (specimens of both calcite and chert are exhibited). Associ- 

 ated with this same limestone, the following minerals have 

 been ibund, but not in sufficient quantity to be of any 

 commercial importance : — Galena, malachite, azurite, and 

 copper and iron pyrites (specimens on the table). The great 

 interest, however, of the Lilydale limestone lies in its fossils 

 — of which, indeed, the limestone itself is largely composed — 

 and which constantl}' attract scientific visitors from Melbourne 

 and other places, and indeed from the neighbouring colonies. 



In lact, one of my chief reasons in writing this paper is to 

 take possession, in the name of Victorian geologists, of the 

 priority in describing some of the fossils, as at present so 

 many of them have been described by geologists outside the 



