Oxli. GENEKA OF FERNS : 



CBASPEDOPHYLLUM, Presl; PTYCHOPHYLMJM, Presl ; SPH.EBOCIONIUM, 

 Preil ; MECODIUM, Presl ; DEHMATOPHLEBIUM, Presl. 



Sori involucrate, i.e., seated within an extrorse-marginal ob- 

 long or sub-orbicular two-valved involucre; the veins continued 

 into the receptacle, which is free included cylindrical or globose 

 at the apex, and bears sessile or sub-sessile lenticular or turbinate 

 spore -cases. Veins dichotomously branched, simple and costa- 

 like in the ultimate segments, or simple parallel from a central 

 costa in undivided fronds ; venules free. 



Fronds simple or decompoundly divided, pellucid membrana- 

 ceous. Ehizome creeping, usually filiform. This group, which 

 is rather extensive, is in general well-distinguished from Tricho- 

 manes by the involucres consisting of two separate valves, instead 

 of being blended into a cup. In some few species, however, where 

 the valves are combined below, this difference becomes merely 

 one of degree. 



Hymenoglotsum. Veins simple from a central costa (fronds simple.) 

 Ex. : H. cruentum, Cav. 



Hymenophyllum. Veins simple costa-like in the ultimate segments. 



H. hirsutum, Sw. 

 H. elegans, Spr. 

 H. senceum, Sw. 

 H. tunbridgense, Sm. 

 H. fticiforme, Sw. 

 H. crispatum, Wall. 



H. organense, Hook. 

 H. pulchellum, Schlech. 

 H. seruginosum, Carm. 

 H. unilateral, Willd. 

 H. dilatatum, Sw. 

 H. demissum, Sw. 



Order POLYPODIACEJE. Tribe SCHIZ^EINE.E. 



1 LTGODE^;. 



(a) Veins free. 



158. LYGODITTM, Swartz, Schrad. Journ. 1800, ii. 7, 106. 



UGBNA, Cavanilles; HYDBOGLOSSUM, Willdenow, in part; GISOPTERIS, 

 Bernhardi; ODONTOPTBEIS, Bernhardi ; CTEISIUM, Michaux ; AETHEO- 

 LYGODES, Presl; RAMONDIA, Hirlel; VALLIPILIX, Thouan ; OPHIO- 

 GLOSSI sp., Auct. 



Fructifications forming compressed distichous spikelets, ex- 

 serted on the marginal teeth. Spore-cases included beneath 

 ovate cucullate imbricated persistent scariose bractiform indusio, 



