50 INAUGURAL ADDRESS. 



1848. Clakke, W. B. (Quart. Journal. Geol. Soc, iv., pp. 

 63-66), notes discovery of Trilobites, especially Trinuclmis, and 

 other Silurian fossils at Yarralumla. " These and the Yass beds, 

 if not Silurian, are at the very base of the Devonian System." 



1851. Clarke, W. B. (Geol. Surv., Report No. 56, p. 85), 

 refers to the limestones at Buugonia, Shoalhaven River, " as not 

 younger than the Wenlock rocks." 



1856. Salter declared the fossils from Yass to indicate "a true 

 U. Silurian formation." 



1860. Clarke, W. B. ("Researches Goldfiekls of New South 

 Wales"), demonstrated the existence of the U. Silurian rocks at a 

 large number of localities ; he says that the fossils " will still be 

 sufficient to justify the assertions respecting the extent to which 

 rocks of the Silurian Epoch, especially of the upper beds, are 

 developed in the gold-bearing regions to the southward." 



1867. Clakke, W. B. (Intercol. Exh. Essays, pp. 381-382), 

 demonstrated " the existence of at least U. Silurian on both flanks 

 of the southern part of the Cordillera." 



1877. DeKoninck (" Foss. Pal. de la N.G. du Sud") refers the 

 fossils of Burrawang, &c., to U. Silurian. 



1878. Clarke, W. B. (" Sed. Formations," kc, p. 16), declared 

 the formation at Bowning to be Devonian, from the occurrence of 

 Calceola sandalina. 



1878. Jenkins, C. (Proc. Lin. Soc.,N.S.W., vol. in, pp.21-32), 

 describes fossiliferous strata around Yass, diAdding them into Yass 

 and Hume Series, and considers the age to be U. Silurian. 



1879. Taylor, Norman (Geol. Mag., vi., pp. 399 et seq.J, con- 

 siders the bedrock of the Cudgegong diamond field to be either of 

 U. Silurian or Devonian age, more probably the latter, on palseon- 

 tological grounds. 



1880. Wilkinson, C. S. (Report Depart. Mines, N.S.W., p. 

 216), placed the Yass Series in the Silurian. 



1880. Hector, Sir J. (Journ. Roy. Soc. N.S.W., xiii., p. 70), 

 correlates the Yass and Hume beds with U. Silurian. 



1883. David, T. W. E. (Report Depart. Mines. N.S.W. for 

 1882, p. 148), who surveyed the U. Silurian area around Yass, shows 

 that the beds form a continuous series. 



1886. Mitchell, John (Proc. Lin. Soc, N.S.W., pp. 577 and 

 1059), points out that typical U. Silurian trilobites occur at BoAvn- 

 ing with and above the so-called Calceola sandalina [^Rhizophyllum 

 interpunctatum, Dek.~], and that the same beds also yield grapto- 

 lites. [See also, Proc. Austr. Assoc. Adv. Sc. i., pp. 291-297.J 



