228 FERNS : BK1TISH AND FOEEIGN. 



116. HEMIDICTYTTM, Fred. 



Vernation fasciculate, erect. Fronds pinnate, 10-14 feet long ; 

 pinna? 1-2 feet long, 8-5 inches wide. Veins forked ; venules 

 parallel till near the margin, then anastomosing and reticulated, 



Genus 1 16.— Poition of fertile pinna, ond-'f side. Nq> ]. 



combined by a transverse, continuous, marginal vein. Sporangia 

 produced on the superior side of the parallel veins, constituting 

 unilateral, linear sori. Indusium plane, 



1. H. marginatum, Fresh SaoJe. Gen. Fil. I. 55, A. Asple* 

 nium marginatum, Linn. (Plum. Fil. t. 106) ; Hooh. 

 Fil. Exot. t. 78 ; Lowe's Ferns, 5, t. 53. Diplaziuni 

 giganteum, Sort. Linden. — Tropical America, 



117. CETEBACH, Willd. ; J. Sm. 



Vernation fasciculate, erect, cajspitose. Fronds 2-12 inches 

 long, smuose-pinnatifid or pinnate, the under side densely squa- 

 raose. Veins forked, anastomosing. Sporangia unilateral 

 protruding through the dense squama?, forming oblong S ori' 

 Indusmm obsolete. *< 



