124 Frederick Chapman.: 



plant Bi/thofrejjhis lesquereuxi, together with a few water-worn 

 specimens of Orthoceras. The writer has elsewhere^ discussed at 

 length the significance of this unique fauna and bionomic con- 

 ditions which it indicates. The very thin shell of these pulmonate 

 gastropods may be taken as a slight bit of additional evidence to 

 that given in the paper above referred to in support of the view 

 that the Bertie waterlime was deposited not in marine water, but 

 in brackish or fresh water, and that the Hercynellas, as well as 

 euryjDterids, were carried into the Bertie muds by the rivers. If, 

 on the other hand, Ilercynella is to be regarded as a marine genus, 

 then we have here another case of intermingling of marine and 

 fluviatile species in the region of deposition at their junction." 



The sediments in which the Yeringian (newer Silurian) fossils are 

 found in the Upper Yarra district are mudstones. This fossil 

 collection was made prior to 1856 by the Geological Survey of Vic- 

 toria, the locality number being B 23. and the exact position, near 

 Stewart's station, at the junction of the Woori Yallock Creek and 

 the Yarra River. These mudstones are olive-brown in colour, 

 varied w^ith dark grey streaks, and distinctly micaceous. The 

 structure appears to indicate that the rock was either deposited 

 in shallow water or in areas subjected to currents. From the 

 occurrence of corals and gasteropods in this fauna one is inclined 

 to infer that the water was not very shallow, but that periodic 

 incursions of mud took place. That there may also have been a 

 fair amount of decaying matter brought down to this area by streams 

 is evident from the abundance of ostracods (Beyrichia), for these 

 little crustaceans probably fed on the drifted weed and similar 

 pabulum. 



The following is a list of fossils associated with HercyneUa 

 victoriae in the mudstone at the junction of the Woori Yallock and 

 the Yarra : — 



Coral — 



Lindstroemia, sp. 



Worm — 



Trachyderma cf. squamosa, Phillips. 



Polyzoan — 



Fenestella inargaritijera, Chapra. 



Bracliiopods — 



Camarotoeehia, sp. 

 Nucleospira australis, McCoy. 

 Orthis nctoniae, Sow. 



1 Bull. Geol. Soc. Aiueiica, vol. xxiv., 1913, pp. 499-516. 



