HYMENOPHYLLUM UNILATEEALE. 



301 



WILSON'S FILMY FEEN, {natural size) 



Grenus. — Hymenophyllum. (See page 297). 



Species. — UnhjATErale. Rhizome filiform, creeping exten- 

 sively : frond semierect, pinnate : pinnee alternate, secund, uni- 

 lateral, consisting of a dichotomously divided, stiff, wiry vein, 

 accompanied throughout by a membranous wing, serrated along 

 its margin : involucres pear-shaped, seated in the axils of the 

 pinnee, entire at the top until mature, then dehiscent, the valves 

 widely separating. 



B^um'^mtB, Jfipws, fe. 



Trichomanes tunbridgense. Light/. Fl. Scot. 681 ; Huds. Fl. 



Ang. 461, ad partem; Bolt. Fil. Brit. 58, t. 31. 

 Hymenophyllum unilaterale, Willd. Sp. PI. v. 521 ; Newm. 



F. 14, Phytol. App. xxx. ; Moore, 209. 

 Hymenophyllum Wilsoni, Hook. Brit. Flor. 446, E. B. S. 



2686 ; Mack. Fl. Hib. 845 ; Franc. 61 ; Newm. N. A. 39, 



F. 325 ; Hook, and Am. 577 ; Bab. 416. 

 There is a very good figure of this fern in ' English Botany ' 

 (E. B. S. 2686). 



