§ 40. FLORA OF THE COAL. 



727 



some of the vegetable forms which flourished in the carbo- 

 niferous era, will perhaps prove more illustrative of this 

 phenomenon than mere description {Lign. 167). 



2 3 4 5 6 7 



Lign. 167. — The Flora of the carboniferous epoch. 

 {Designed and drawn by Miss Ellen Maria Mantell.) 

 Fig. 1. Araucaria. 2. Asterophyllites. 3. Pandanus. 4. Equisetum. 5. Arbo- 

 rescent fern. 6. Fern. 7. Calamites. 8. Lepidodendron. 9. Sphenopteris. 



To arrive at any satisfactory conclusions as to the nature 

 of the countries which supported the plants of the coal, we 

 must consider the geographical distribution of the related 

 existing genera, and the circumstances which conduce 

 to their full development. It is well known that a hot 

 climate, humid atmosphere, and the unvarying temperature 

 of the sea, are the circumstances which exert the most 

 favourable influence on the growth of Ferns and other 

 cryptogamic plants ; low islands in tropical latitudes being 



