J^"-^ 1 Chapman, The Palrroznic Flora. 145 



Upper Devonian species, L. nothnm, from Thiiringia, may be 

 identical, as well as the Canadian species, L. rhombicum. In 

 New South Wales Lepidodendron is used as an index fossil, 

 the Lower Carboniferous being distinguished by L. aiistrale, 

 and the Upper scries by L. W'Wicimianitm, together with 

 Rhacopteris : whilst L. aiistrale is an abundant fossil, repre- 

 sented by stem, leaves, and sporophylls, in the Star series 

 (Lower Carboniferous) of Queensland.* 



The typically Carboniferous type of fern, Rhacopteris, is 

 represented in New South Walc^s by several species — R. 

 septentrionalis , R. intermedia, and R. Roemeri. It is a handsome 

 fern, with Adiantum-VikQ leaflets and spreading veins, and is 

 referred by Stur to the Ophioglossace(e,'\ to which the livnng 

 Adder's Tongue Fern belongs. The better-known " Rhacop- 

 teris " incsquilatera has been shown by W. S. Dun % to be 

 synonymous with Aneimites ovata. This latter genus is referred 

 by Seward to the Schizccacece, of which the Climbing Fern 

 {Lygodiiim) is a familiar example. 



From the Rhacopteris beds of Paterson, New South Wales, 

 W. S. Dun has obtained Cardiopteris, cf. polymorpha, Goppert, 

 a sp. cies which is found in the Carboniferous of Europe. 

 Seward has compared this genus with Neiiropteridium. It 

 may possibly be related to the earliest seed-bearing plants, the 

 Cycadofdices, which were abundant at this time. 



Although vegetation was abundant in the Australian Car- 

 boniferous, the physiographic features and geological events 

 of the continent at this time were not favourable for the 

 formation of coal measures. This will be readily conceived 

 when we remember that during this epoch there was a great 

 effusion of volcanic lavas and tuffs following, after some con- 

 siderable break, those of the Devonian, but with less counter- 

 active subsidence, only limited areas like that of the New England 

 plateau being transgressed by the sea. In New South Wales 

 alone there is a scries of lavas and tuffs which show a thickness 

 of at least 20,000 feet. (^wing to the general tendency of 

 uplift, and the greater permanency of land masses in Carbon- 

 iferous times, the only coal accumulated is in thin seams, too 

 poor to be of economic value. But this great effusion of 

 volcanic rocks in the Upper Carboniferous undoubtedly pro- 

 duced the oscillatory effect of intermittent subsidence through- 

 out the succeeding Carbo-Permian period in New South Wales, 

 resulting in its rich and x'aluable development of coal seams. 

 In Victoria, deposits belonging to the Caihoniferous period are 



* Chapman, " Proc. Roy. Soc. Vict.," v(j1. xvi., pt. ii., 1904, p. 309, pi. 

 xxvii., figs. 1-5. 



t Abhandl. k.k., " Geol. Reichs.," 1885, vol. xi., pt. i. 



:J: " Rec. (leul. Surv. N.S.W.." vol. viii.. pt. ii., 1905, p. 157. 



