Pala' ontology of Upper Silurian Rocks, Victoria. 85 



Acidaspis, Cromus, Tiirrilepas, etc. He says the "specimen has 

 cells over half an inch in diameter, and the whole specimen 

 measures two inches across," and surmises that it may be the 

 same as Sir Frederick McCoy's P. inegasioniuin. I have recorded^ 

 a species from near Fifield, New South Wales, and in the Mining 

 and Geological Museum, Sydney, are specimens preserved in a 

 ferruginous grit from Sebastopol showing very large coi'allites. 



Pleurodictyiim is usually considered to be a Devonian fossil, Imt 

 it is possible, according to Nicholson's remarks, that many of the 

 species of Alichelinia described by Rominger from the Niagara 

 (Upper Silurian) Beds of N. America, ntay be PleurodiciyuDi. 

 The horizon of P. zorgeiise and P. selcanum is in beds which are 

 considered by some to be Lower Devonian, though perhaps it 

 would be better to consider them as passage beds — equivalents 

 of those called by Dr. J. M. Clarke the Helderbergian of North 

 America and the Hercynian of Europe.'-^ So, though Pleurodict)2im 

 by itself may not be a very definite index of Upper Silurian age, 

 stiil in its association with foi-ms such as those occurring at 

 Kilmore, Mansfield and Yass there is nothing anomalous. 



Sub-Ordei- — Zoantharia Perforata. 



Group— Cyathophylloidea. 



Family — Cyathophyllida?. 



Genus — Cyathophyllum, Goldfuss, 1826. 



(Petrefacta Germania?, i., p. ot). 



Cyathophyllum elegantulum, sp. nov. 



(PL III., Figs. 5, G). 



Several fragments of an exceedingly elegant astra^oid Cyatho- 

 phyllum from Mansfield occur in the collection. This form is 

 made up of corallites about one-eighth of an inch in maximum 

 diameter, and five, six or seven sided, more commonly the 

 latter. 



There is no apparent ditierence in dimensions between the 

 primary and secondary septa. The septa are slightly flexuous, 



1 Ann. Kept. Dept. Mines and A^ric. N.S. Wales for 1895 [1896], p. 189. 



2 The Hercynian Question. Report of the State Geolojfist, New Yor k, for 18SS [1889], 

 pp. 408-437. 



