Black Soil Plains. These " leads " of most recent age are 

 characterised by the presence of Myrtaceous trees, of 

 Banksias, of Casuarinas, and by other ]>lant tonus almost 

 indistinguishable from the present day vegetation. The 

 younger "leads" of the Pre- Kosciusko Period are capped 

 by basalts and their floras are quite unlike those to be 

 found in Eastern Australia at the present day. The"Leads'' 

 occur frequently in regions possessing a rigorous winter 

 climate, nevertheless the plant remains contained in them 

 find their nearest analogues in the tropics. 



The oldest of the "leads" also exist under basalt cover- 

 ings on the plateau and are characterised by floras quite 

 unlike those of the younger "deep leads," or of those of 

 the present day. Lauraceous leaves and leaves of ,SV///.s- 

 buria are common. The "leads " only of the second period, 

 however, are here considered in detail, the earlier Tertiary 

 history of Eastern Australia being reserved for 'a later 

 paper. Several points of importance iv. connection with the 

 late and post Tertiary history of Eastern Australia may be 

 gathered from a study of these "leads" of the second period. 



(a) Distribution of " leads."— By the geologists of Vic- 

 toria these leads are known as those of the "Newer Volcanic 

 Period." They have been described from Tasmania, from 

 Ballarat, Daylesford, Gippsland, Orange (Forest Reefs), 

 Gulgong, .New England, and the Darling Downs; while 

 "leads" of similar appearance and under similar basalts, 

 but without the definite and characteristic flora of the 

 newer volcanics, have been described from the Oairns 

 district in north Queensland, by .lack and Kt heridge (pp- 

 582-588). Their distribution is therefore all along the 

 eastern side of Australia. 



(b) Geology of the "leads" of the "Newer Volcanic" 

 Period. — In every instance the leads are auriferous. Th& 

 buried deposits lie in definite chaunels, the rims of which,. 



