xxv] 



BOTRYOPTERIS 



441 



stage in subdivision. At sp in fig. A the section has cut 

 through a single sporangium characterised by a group of larger 

 (" annulus ") cells on one side of the wall. 



C D 



Fig. 306. A — D. Botri/opteris ramosa; stem and frond axes. (Ax 7; Bxl.5; 

 Cx26; D X 13. From sections in the Cambridge Botany School 

 Collection.) p.r, protoxylem ; sp, sporangium ; e, epidermis. 



This slender fern with its numerous repeatedly branched 

 leaves may perhaps have lived epiphytically on more robust 

 plants. 



