STEVENSON— INTERRELATIONS OF FOSSIL FUELS. 511 



sulphur. The natural coal is inferior everywhere ; evidently, the 

 swamps, in which it was formed, were subject to frequent overflows 

 of muddy water. There is no reason for believing that the sea 

 invaded the region during the Permian. 



D. White,^^^ in the same volume, publishes an elaborate discus- 

 sion of the plant remains and conditions. A shale in the Bonito 

 Coal is crowded with megaspores, probably of Sigillaria, and a fine- 

 grained flinty fireclay is filled with roots tentatively referred to Ver- 

 tebraria. He found Vertebraria in the Barro Branco-Sao Jero- 

 nymo Coal as well as in shale near Minas and in roof of the Irapua 

 Coal, Reinschia australis Bert, and Ren., was observed in a frag- 

 ment of boghead picked up on the coast. This material, he is con- 

 vinced, is not from Brazil but was dropped from an Australian 

 vessel carrying Kerosene Shale. 



The roof of the Irapua Coal contains Glossopteris and Nocg- 

 gerathopsis; that of the Sao Jeronymo, at one locality, contains car- 

 bonized roots along with matted leaves of Noeggerathopsis, while, 

 at another, it is an impure coal, whose dull layers are full of leaf 

 and wood material in charcoal, and at a third, the dull layers consist 

 largely of charcoal derived from Lepidodcndron, Sigillaria, etc. 



He finds Gondwana forms in the lowest portion of the coal 

 measures. He is convinced that the Tubarao Series is practically 

 equivalent to the Talchir-Kharharbari of India, Newcastle of New 

 South Wales, Bowen of Queensland, etc. The Passa Dois Series 

 is most probably equivalent to the Damuda Series. 



119 D. White, The same, pp. 337-607. 



