XLl] 



ACROSTICHOID DERIVATIVES 



135 



Fig. 667. A, B = Stenoseinia aurita (Sm.) Presl. A =habit of sterile and fertile 

 leaves. ^ = partof a sterile segment with venation. C=Polyboi>ya Caenopteris 

 (Kze.) Klotzsch, part of a primary pinna, with venation. (After Diels.) 



Fig. 668. Sfenosemia aurita. .-:/ = transverse section through a normal sporophyll. ^ = the same 

 near to the apex. C= transverse section through the blade of a young middle-form between 

 sterile and fertile. A' = marginal cell of the blade. ( x about 77. After Frau Eva Schumann.) 



