PTERIDOPHYTA 



157 



Angiospermse 



HeterosporesB 



Leptosporangiatae 

 Isosporese 



HeterosporesB 



Cycadacese 



HelerosporeEe 



Isosporefe 



Isosporese 



Comfera}(?)^ 



HeterosporesB 



Isosporese 



Eusporangiatse 



Horsetails Ferns Club-mosses 



(Equlsetinese) (Filioineas) (Lycopodinese) 



Liverworts 

 (Hepaticse) 



Diagram to illustrate the relationships between the three existing 

 classes of Pteridophytes and the Spermatophytes. 



