638 THE TERN EAMTLT. 



1. European Trichoxnanes. Trichomaues radicans, Sw. 



{Eymenox)hyU'am elatum, Eng. Bot. t. 1417. Bristle Fern.) 

 Eootstock creeping, often to a considerable extent. Eronds usually 6 to 

 8 inclies high, including the rather long stalk ; broadly ovate lanceolate in 

 general outline, twice or thrice pinnate, of a dark green, with rather stout 

 stalks and branches. Segments numerous and crowded, thin, pellucid, ob- 

 long, more or less toothed, narrowed at the base. Involucres in the axils of 

 the small ultimate segments or lobes, cylindrical, about a line long, the cen- 

 tral bristle projecting 4 to 1 line more. 



In moist, sheltered, shady places, widely distributed over the tropical 

 and hotter regions of both hemispheres, bvit confined in Em-ope to a few lo- 

 calities in western Spain and Ireland. Fr. summer. 



XYII. HYMENOPHYIiL. HYMENOPHYLLUM. 



Half-pellucid Fei-ns, closely i-esembhng TVic/iomaMes, but usually smaller ; 

 tlie involucres deeply divided into 2 lobes, and the bristle or receptacle 

 usually concealed within them. 



A large genus, with nearly the same range as Trichomanes. 



1. Tunbridge Hymenophyll. Hymenopliylluna tunbridgense^Linn. 



(Eng. Bot. t. 162. Filmy-Fern.) 



Eootstock very slender, creeping, and much branched with numerous 

 fronds, forming broad, dense, almost moss-like patches. Eronds pinnate, 

 seldom above 2 or 3 inches long, lanceolate in general outline ; the stem very 

 slender; the segments deeply divided into 3 to 8 or more oblong-linear 

 lobes, which appear minutely toothed when seen through a lens. Involucres 

 at the base of the segments or then- lobes, on their inner edge, ovate, about 

 a line long, deeply divided into 2 flattish lobes, often minutely toothed round 

 the edge. 



In moist, rocky, or shady situations, dispersed over most of the warmer 

 mountain districts of the old world, especially in the southern hemisphere ; 

 more rare in America, extending fi'om the Canai-y Islands and north-western 

 Africa along western Europe to Belgium and Norway, but not recorded 

 ■ from eastern Europe or any part of the Russian dominions, nor from 

 North America. Grciierally distributed over the greater part of Britain, 

 but more frequent in Scotland, northern and western England, and Ireland, 

 than in eastern England. Fr. summer and autumn. A variety with the 

 valves of the involucre entire, not toothed, is usually distinguished as a spe- 

 cies, under the name of M. imilaterale or S. Wihoni (Eng. Bot. Suppl. t. 

 '2f586), but the other characters, said to accompany this one, such as the 

 narrower involucres, the different direction of the lobes of the fronds, etc., 

 are certainly not constant, and the teeth of the valves, when present, are 

 very variable. The entire-valved form is the most common in Scotland and 

 Ireland, but the two are often intermixed. 



