Opal Nodules at Richmond River. 



171 



recognised in it^- Spongilla sp., and this was confirmed by Dr. 

 Hinde, who also determined the presence of amphidiscs, belonging 

 the genus Meyenia}^ The diatomaceous deposits of the War- 

 rumbungle Mountains are, however, of greater age than those 



Fig. 2 Spicules in Opal. 



<iescribed above, for Prof. David has shown^* that they are inter- 

 tedded with a trachytic tuff, which has yielded leaves of Cin- 

 namomum Leichhardti, Ett. 



12. Ann. Rep. Dept. Mines, N.S. Wales for 1887 (1888), pp. 165, 166. 



13. See Card and Dun, Rec. Geol. Surv. N.S. Wales, vol. V., 1897. p. 148. 



14. Proc. Linn. Soc. N.S. Wales, vol. XXI., 1896, pt. 2, p. 265. 



8a 



