298 



MOSSES AND FERNS 



CHAP. 



the sporangium wall. This may have been due to different 

 conditions under which the plants were grown, or to a possible 

 difference in the species. 



There is frequently found surrounding the synangium, hairs 

 or scales which form a sort of indusium (Fig. 165), In 

 Dancra, the leaf tissue between the synangia grows up as a 

 ridge, with expanded top overarching them. This ridge in sec- 

 tion appears T-shaped (Fig. 166, A). 



Fig. 169. — A small plant of Dancra alata, X /^ ; st, stipules. 



Classification of the Marattiace^ 



The living Marattiacese (Bitter (i)) may be divided into 

 four sub-families, of which the first, Angiopterideae includes 

 two genera, Angioptcris and Archangioptcris, while the others, 

 Marattie?e, Kaulfussiese, and Danaease, contains each but a 

 single genus. 



