89 



PSILOTUM:— 





so 100 It 



Fig. 166. Psilotnm niidnm; a, laesura (optical cross-section; x 2000); b, lateral, 

 longitudinal view (x 250); c. proximal face (x 250); d, LO-patterns; e, 



sclerine stratification ( x 2000). 



PTERIDIUM:- 



Fig. 167. Pteridium nquilinum. From left 

 to right: lateral view ( x 250); sclerine stra- 

 tification (X 2000); distal face (x 1000). 



PYRROSIA:— 



Fig. 168. Pyrrosia abbreuiata, sclerine stratification, 



(X 2000). 



SACCOLOMA (Fig. 169 A), CYSTODIUM (Fig. 169 B):— 



Fig. 169 A. Snccoloma ele- 

 gans; a, sclerine stratifica- 

 tion (p, perinc?; s, sexine ?; 

 n, nexine ?; x 2000); b, part 

 of proximal face (pr, prox- 

 imal pole); c, part of distal 

 face (b and c x 4250). 



