67 



HYPOLEPIS: 



11 13 





"• * " 1 r. 







m^ 





A B C D 



Fig. 122. Sclerine stratification in Hypolepis. A, H. repens. B, H. temiifolia. 

 C, H. rugosula. D:a, H. distans. ( x 2000). — LO-patterns at liigh (left) and 

 low (right) focus in H. distnns arc shown in D:l). 



ISOETES:— 



Megaspores: Isoetes duriein (Fig. 123), /. echinosponim (Figs. 124, 125). 

 Microspores: Isoetes adspersa (Fig. 126), /. baetica (Fig. 127). 



Fig. 123. Isoetes diirieui, part of megaspore wall (section), x 1000. 



Fig. 124. Isoetes echinosponim; part of megaspore wall (optical section). The 

 inner contour of the sIHcified perine is faintly seen left and right of the cf. 

 sexinous outgi'owth in the centre of the figure. The "sexine" is underlain 



by thinner "nexine". x 2000. 



