I 9 2 °] 



WRIGHT— PIT-CLOSING MEMBRANE 



247 



Fig. 8. — Helminthostachys zeylanica: metaxylem of root showing torus; 

 X900. 



Fig. 9. — Botrychium obliquum: rhizome, tangential section showing 

 torus; X735- 



Fig. 10. — Helminthostachys zeylanica: rhizome, longitudinal section; 

 X825. 



Fig. 11. — Botrychium obliquum: transverse section of leaf trace in cor- 

 tex; X425. 



Fig. 12. — Botrychium obliquum: part of fig. 11 more highly magnified; 



X875. 



Fig. 13. — Botrychium obliquum: tangential section of rhizome showing 

 thickened membrane ; X 5 2 5 . 



t. 



