PROCEEDINGS OF SECTION C. 209 



of Warrandyte as the oldest beds in the area examined by him. The 

 fossils which occur there are in the form of casts, some of which I have 

 lately had the privilege of examining for Mr. Jutson. Two of these 

 are corals, belonging to the genera Thecia (Woolhope Limestone or 

 Wenlockian) and Lyellia (Valentian and Wenlockian). This curious 

 mixture of faunal stages in the Australian Silurian is similar to that 

 which is met with in the Melbournian of South Yarra, where Wenlock 

 species are commingled with Llandovery, and emphasises the difficulty 

 of an exact homotaxial comparison between the Lower Palaeozoic of 

 the southern and northern hemispheres. It may further be noted 

 that, in the same stage, the Melbournian, the archaic trilobite Ampyx 

 is not infrequent, and this in a measure serves to counterbalance the 

 otherwise youthful aspect of that fauna. This evidence of greater age 

 is further strengthened by the occurrence of Illaenus jutsoni in a quarry 

 on the Koonung Koonung Creek between Templestowe and Heidelberg, 

 and is a form nearest related to the I. davisii, Salter, of the English 

 B.ila beds. 



A notable piece of work in connexion with the passage of the 

 Melbournian anticlinal rocks, into the Yeringian trough on the west 

 side of the Whittlesea anticline, has been carried out by Juteon.* The 

 beds of the Yan Yean and Whittlesea axis are clearly Melbournian ; 

 whilst to the west a passage-bed series crops out, containing Dalmanites 

 meridianus, Eth. fil. and Mitchell sp., together with otherwise typical 

 Yeringian species of brachiopods, as Stropheodonta alata and Orthis 

 testudinaria ; whilst still further to the west the Merriang syncline 

 yielded an abundant Yeringian fauna. Jutson estimated the thickness 

 of the Melbournian series at this locality to be between 7,000 and 8,000 

 feet, whilst the Yeringian is about 750 feet. To the east of the Warran- 

 dyte anticlinal the thickness of the Yeringian series is much greater, 

 as shown by the deeper development of the synclinal folds in the section 

 by Selwynf relating to that part of the country between Lilydale and 

 the Dandenong Ranges. 



(6) Yeringian. — The beds comprised in this series consist, in the 

 neighbourhood of Melbourne, of mudstones, sandstones, and limestones. 

 At the base of the Yeringian series at Wombat Creek andWalhalla 

 there is a well-marked fossiliferous conglomerate bed, with Atrypa 

 reticularis. 



For a detailed study of the succession of the Yeringian strata, it 

 is probable that the country east from Warrandyte, through Lilydale 

 and the Yarra Flats towards Warburton would yield some good results. 

 This would be practically along the line of section given by Gregory 

 in his horizontal sketch-section from Keilor to Mount Wellington. 



• Jutson ('08). 



t Selwyn ('56, 67). lection. 



