114 TRICHOMANES. 



Obs. Closely allied as are the genera Hymenophyllum and Trichoimnes, 

 it is rare that one has a difficulty in recognizing them; and yet it is not 

 easy to point out the characters in few words. In our present genus, Tri- 

 chomancs, the involucres are mostly suhcylindrical, narrow-urceolate, the 

 mouth spreading, entire, or cut into two short, usually spreading lips, which, 

 when a little elongated, afford the character o{ Didyrnoglossum of Desvaux; 

 their texture is firm and suhcoriaceous, yet cellular ; they are often quite 

 sunk or immersed in the segment of the frond, in two or three instances ar- 

 ranged in distichous spikes. Receptacles filiform and not only exserted, 

 hut sometimes very much protruded, so as to be several times longer than 

 the involucre: and, either often varying on the same plant, or, by their great 

 fragility, easily broken away and then apparently short. The fronds are 

 more generally erect, as far as can be judged from the dried specimens, 

 and I am not aware that, except in a very few instances, the margins of the 

 segments are ever toothed or serrated, as is common in Hijmenophyllum : 

 but the characters now mentioned are not invariably constant. The spe- 

 cies are I think more remarkable for beauty of form and delicacy of texture 

 than even those of Hymenophyllum. 



Subgen, 1. Hymenostachys. Sterile and fertile fronds dissimi- 

 lar. Involucres arranged in distichous spikes and connate for 

 their ivhole length. Sterile fronds ivith reticulated veins. Hy- 

 menostachys, Bory. 



1, T. elegans, Rudge ; tufted, sterile fronds much shorter 

 than the fertile ones broadly lanceolate pinnatifid the seg- 

 ments nearly horizontal lanceolate subfalcate serrated often 

 caudate and proliferous at the apex, veins reticulated, spike 

 broad-linear acuminated constituting a compact membrane, 

 the margins formed by the connate sunk cylindrical involu- 

 cres. — Rndge, Guian. p. 24, /. 35, [e.vcl. the fertile frond of 

 T. spicatum). Hook. Gen. Fil. t. 108, {not Exot. Fl.) Hy- 

 menostachys diversifrons, Bory in Diet. Class. Hist. Nat. viii. 

 p. 462, cum Ic. 



Hab. Guiana, Martin, Poiteau, Schomburgk, n. 1030. Gorgona and 

 coast of Panama, and Pacific side of Central America, i^arc/ay, Cuming, n. 

 1127. — Fertile frond or spike 6 — 8 or 10 inches long, nearly + an inch wide, 

 with forked transverse veins and closely united involucres forming the edge 

 on each side, which is again, as it were, fringed with the copious slender 

 elongated filiform receptacles, resembling coarse hairs. Stipes nearly equal 

 in length to the spike. Sterile frond a span long : its stipes 2 — 3 inches. — 

 A most elegant and remarkable species, first described and figured by Rudge 

 in the work above quoted : but a spike of the following species was unfor- 

 tunately considered to belong to the same plant, and added to it by the ar- 

 tist. In other respects the representation is excellent. Sometimes the rachis 

 runs out at the apex into a long tail, which roots and becomes proliferous. 



Subgen. II. Feea. Sterile and fertile fronds dissimilar. Invo- 

 lucres arranged in distichous spikes, but free to the rachis for 

 their whole length. Sterile fronds ivith free pinnated veins. 

 Feea, Bory. 

 2. T. spicatum, "R. Hedw.;" tufted, sterile fronds shorter 



