179 
Veins reticulated and wholly covered by 
sporangia, the sori being in fact reticulated. 
Fronds either simple, pinnatifid or pinnate. 
Fic. 42.—Vittaria elongate Sw. 
(z) Complete plant ( x }). 
(b) Vertical section through frond showing the position 
of the sori (much magnified). 
