May, 1909.] THE VICTORIAN NATURALIST. 7 



EXCURSION TO LILYDALE. 



A COOL and pleasant afternoon on Saturday, 27th March, was 

 partly responsible for the large number of members and friends 

 (38) taking part in this excursion, most of whom came down by 

 the 1.22 train from town. On arrival the party turned back up 

 the line towards Mr. Mitchell's limestone quarry. At the 

 entrance we were met by Mr. Mitchell, jun., who very kindly led 

 us round the works, so that we might gain some information as 

 to the method of producing the lime which is prepared in large 

 quantities at Cave Hill. The quarry is an excavation on the 

 northern side of Cave Hill, opened up nearly thirty years ago on 

 the site of the original cave noted by Sir A. R. C. Selwyn on his 

 map published in July, 1856. The note runs as follows: — 

 "Limestone cave 120 feet deep. — Hard, crystalline grey and 

 reddish limestone. Fossils, corals, &c. (Wenlock limestone ?) " 

 This cave yielded the early geological surveyors a small collec- 

 tion of fossils, chiefly corals, which, with its original label, " From 

 a limestone cave in the parish of Yering," is now in the 

 National Museum, Melbourne. We learned from Mr. Mitchell, 

 jun., that when the cave was first opened it was hung 

 with numerous stalactites, which must have presented a 

 striking appearance ; but, alas ! the stalactites were speedily 

 removed, and only a small portion of the original cave 

 remains to view. In all probability there is another cave 

 hidden away behind the quarry face, since Mr. Mitchell informed 

 us that at one particular spot, pointed out to the members, several 

 crowbars have been lost, having dropped into a cavity at about 

 the angle made by floor and wall. Further indication is seen in 

 an extensive pipe of the overlying rock, which forms a huge 

 " swallow hole " leading into the limestone mass. The limestone 

 in this quarry dips at a steep angle (35°-So°). The bedding 

 plane can be easily verified by the growth of corals, &c., such as 

 Favosites and the various stromatoporoids, which may be traced 

 along the planes of sedimentation in their relative position of 

 growth. A large proportion of the limestone is dolomitized by 

 the action of the overlying old volcanic rock which covers this 

 side of the Cave Hill. The dolomitized limestone contains some 

 iron, which renders these altered layers conspicuous by their 

 reddish-brown colour. The opportunity was taken at this stage 

 to point out to members the chief items of interest in regard to 

 the quarry, one of the most important being the close relation- 

 ship it bears in age — or, at any rate, its fauna — to that of Dudley 

 and Wenlock, in England, and to that of the island of Gotland. 



The fossils collected during the afternoon included — Cyatho- 

 jihyUum sp., Favosites grandipora, Eth. fi!., Syringopora sp., 

 ffeliolites sp. ; various stromatoporoids, including Clathrodictyon 

 sp., Euomphalus disjunctus, J. Hall, Trematoiiotus pritchardi, 

 Cress well, Trochus {Scalmtrochus) litidsiroemi, Eth. fil., Cyclonetna 



