XVIII] 



BOTRYOPTERIUEAE 



material closely associated with a rachis of Botryopteris antiqua (Fig. 317)'. 

 Not only do they show the sporangia cut transversely with multiseriate 

 annuli, and very numerous spores (probably at least 500 — 1000 in each), 

 but the sporangia appear to be naturally grouped round a centre, with the 

 thinner region of the wall, where dehiscence would occur, directed outwards. 

 Between the sporangia lies what Scott describes as an "indusium-like" 

 structure. This suggests comparison with those irregular laciniate growths 

 seen at the distal end of the sporangiophores of Heluiinthostachys. Except 

 for the elongation of the stalk of the sporangiophore and the absence of an 

 annulus in Helviinthostachys, the similarity is very striking. (Compare Bauer 

 and Hooker's Genera Filiciun, PL 47, Fig. B, 3-8.) 



Fig. 317. Group of four annulate sporangia in close association with the 

 rachis of Botryopteris antiqua. i, indusium-like structure between two 

 sporangia. /, represents a foreign body. Drawn by Mrs D. H. Scott, 

 F.L.S. (x about 100.) Scott Collection 2496. 



Comparison 



The characters thus shown by the Botryopterideae, their megaphylly, 



the circinate vernation, their anatomy, the vestiture of hairs, the numerous 



sporangia borne upon the large leaves, their sporangial structure, and homo- 



sporous spores, all point to them as undoubted Ferns. On the other hand, 



^ Scott, A)ui. of Bot. xxiv, 1910, p. 819. 



