CLASSIFICATION. IX 



The Pterydophyta, on the whole, form a well-defined group, closely connected 

 on one side with Gymnosperms, but on the other no immediate relationship to 

 lower plants can be traced. They may be classified as follows : — 



Class FilicincB (Ferns in the broadest sense). 

 Sub-class Filices (Trne-ferns). 

 Sub-class Sydropteridce (Water-ferns). 



Class Lycopodirue (Club-mosses). 



Sub-class Lycopodiaceai (Homosporous). 

 Sub-class Selaginellaceee (Heterosporus). 

 Sub-class IsoetacecB (Quill-worts). 



