242 VITTARIOID FERNS [CH. 



borne above the veinS; may be sunk in grooves, or superficial. They are 

 more or less reticulate, as in Hemionitis {¥\g.y/i^2). The sporangia are as in 

 Vittaria, but the spore-counts may vary from 48 to 64. 



Fig. 742. Autrophyiivi semicostatiim Bl. Leaf 

 of natural size, showing reticulation, and sori : 

 also a single scale detached. (After Blume, from 

 Christ. ) 



