GENUS XVI. 
HVMENOPHYLLUM, Smith. 
FILM FERN. 
GEX. CHAK. Sori marginal vertically oblong ; spore- 
cases sessile around a columnar subclavate receptacle 
within an urceolate two-valved involucre of the same pel- 
lucid texture as the frond ; receptacle included. Veins 
direct, free, simple or forked. 
Film-fern seems preferable to Filmy-fern as the English 
name of this group, which includes a large number of 
tropical species, mostly small aad many of them very 
beautiful. 
The name of the genus is derived from the Greek 
hymen a film or membrane, and phyllon a leaf; and is 
admirably characteristic of the membranous texture of 
the fronds. 
1. Hymenophyllum tunbridgense, Smith. 
Tunbridge Film Fern. Fronds membranous pinnate ; pin- 
nae distichous vertical pinnatifid, the segments linear undi- 
vided or bifid, and as well as the axillary solitary com- 
pressed involucre, spinulose-serrate ; rachis winged. 
HYMENOPHYLLUM TUNBRIDGES3E, Smith, Eng., Fl. iv., 326 : 
Eng. Hot. 16-2 : Hook. Sp. Fil i , 95 : Hook and Am. Fl. 577 : 
Hah. Man. 416: Newm. 321: Franc. 60 : Fiorigr. Brit iv., 122. 
TRICHOMAXES IUNBEIDGBSSE, Linux us. 
