Geology of Mooruodac. 93 



Didymograptus, sp. indet. 



Temnograptus, sp. 



Dendrograptus (■/). 



Rhinopterocaris maccoyi. 



Braohiopod cast, 

 and indeterminate Hexactinellid sponge spicules were also recog- 

 ni>ed from among the collection made by Mr. Ferguson at this 

 locality. The credit, then, for first finding fossils "in situ" in 

 the Palaeozoic rocks of the Mornington Peninsula belongs to 

 Mr. Ferguson, and for determining their Lower Ordovician 

 (Bendigonian) age to Mr. Hall. 



The Agk of thh Olokh Skdimkntahv Kocks of Moorooduc. 



The fore'roiiio' account of the geolotrical literature dealing 

 with the district shows the progi-e-s already made towards deter- 

 mining the age of the Palaeozoic rocks of the Mornington Pen- 

 insula. The records from Balnarring and Bulldog Creek defi- 

 nitely established the Lower Ordovician age of the rocks of the 

 southern part of the Mornington Peninsula, but the age of the 

 serie.i near Moorooduc remained still in doubt, as it lies about 

 ten miles to the north of the localities mentioned above, and, 

 moreover, the graptolites found in the boulders of the conglo- 

 merates of Grice"s Creek and near Frankston showed only that 

 the rocks might be CTrdovician or Lower Silurian. 



The area near Moorooduc does not look j^romising, as apart 

 from the highly altered rocks in the quarry north of Moorooduc 

 station, rock exposures are veiy few, and several observers had 

 already searched the locality wath negative results. Thi^ also 

 was our experience in 1905, but on the second visit in 190G we 

 were more fortunate. We were searching the hillside about a 

 third of a mile north-east of the large quarry at about an eleva- 

 tion of 350 feet above sea level, and almost due \\&>X of a slight 

 bend in the road which runs north towards Frankston. Here the 

 uprooting of a tree had exposed a very limited area of the elates, 

 and from this and another small exposure close at hand we 

 found a number of graptolites. They were clearly of Lower 

 Ordovician age, a>s forms belonging to Didymograptus and 

 Tetragraptus were recognised. On returning to Melbourne I 



