THE PENNSYLVANIAN PERIOD 643 



on the other. The Carboniferous of some parts of China has been 

 reported to contain coal-beds of great thickness. The Carbonif- 

 erous system is also present in India. 



The -Carboniferous formations of northern Africa correspond in 

 a general way with those of southern Europe. They are generally 

 of marine origin, so far as now known, and without coal, but in 

 southeastern Africa, a coal basin has been reported in Zambesi. 1 



The Carboniferous (Permo-Carboniferous) system is well 

 developed in Australia where it attains a thickness of 11,000 feet or 

 more. It is partly marine and partly non-marine, and contains 

 coal. The system is remarkable because of its singular conglome- 

 rates, some of which are of glacial origin. These will be referred 

 to again in connection with the Permian. 



In South America, rocks of Late (Upper) Carboniferous age 

 are somewhat widely distributed, though less so than those of the 

 Devonian period. The system has wide distribution in the lower 

 part of the basin of the Amazon, where it rests on older formations 

 unconformably, and is not generally coal-bearing, but is so in 

 places. In southern Brazil the system contains much coal. 2 



THE LIFE OF THE PENNSYLVANIAN PERIOD 

 I. THE PLANT LIFE 



With the opening of the Carboniferous period the supreme 

 biological interest shifts from the sea to the land, and centers in 

 the vegetation and in the amphibians. 



Plant life was very abundant in the Pennsylvanian period, and 

 the record of it is unusually full and perfect. This completeness 

 has doubtless given the flora of this period an undue prominence 

 over those which preceded ifc and succeeded; yet it was really a great 

 period in the history of plant life. Angiosperms, the dominant 

 plants to-day, had not yet appeared. Gymnosperms including 

 the so-called "seed-ferns," held an important place. Pterido- 

 phytes probably made their greatest display at this time. All the 



1 Kayser, Geologische Formationskunde, p. 207. 



2 White, I. C. Commissao de Estudos das Minas de Carvao de Pedra da 

 Brazil, 1908. 



