462 CXLIII. FILICES. 



Tribe 1. Dicksonieje. 



Frond herbaceous. Sori on the back or at the edge of the 

 frond. Involucre cup- shaped, often more or less completely 

 2-valved. 



4. WOODSIA, E. Br. 



Involucre globose, membranous, cup-shaped, placed on the 

 back of the frond and dorsal also on the veins, the edge 

 fringed or irregularly-lobed. — Hook, and Baker, Si/n. Fil. p. 40. 



Fronds small, herbaceous, ovate-lanceolate, 2- or 3-pinnatifid, the veins 

 always free. — A genus principally inhabiting the high mountains of the 

 northern hemi-jphere, a single species of which has been recently discovered 

 in the !Natal Mountains. 



Teibe 2. Htmenophtlle^. 



Texture of the frond beautifully pellucid and membranous ; 

 the cells larger and laxer than in other ferns ; the sori placed 

 on the edge of the leafy portion, enclosed in tubular or cup- 

 shaped involucres. Capsules seated on a filiform or clavate 

 receptacle, which is often protruded beyond the mouth of the 

 cup. 



5. HYMENOPHYLLUM, Smith. 



Involucre a cup, deeply divided into 2 valves. — Pappe and 

 Itawson, p. 44 ; Hook, and Baker, Syn. Fil. p. 56. 



Fronds small or middle-sized, generally decompound with narrow divi- 

 sions, and only a single vein in the centre. Caudex a wide-creeping, thread- 

 like rhizome. — 3 South Afi'ican species are known, 1 of which represents 

 § Leptocionium, and has toothed segments and involucres. 



6. TRICHOMANES, Linn. 



Involucre a deep tube-like cup, not at all slit or with the 

 mouth only slightly 2-valved. — Pappe and B,awson,p.4ib ; Hook, 

 and Baker, Syn. Fil. p. 71. 



General habit as in Hymeyiophyllum, but frond usually less divided, and 

 the receptacle more constantly and conspicuously protruded. — 5 South 

 African species are known, 3 of which grow nearly everywhere in damp 

 tropical regions. 



Teibe 3. DAYALLiEiE. 



Involucre roundish or oblong, marginal or dorsal on the 

 veins and segments, always attached on the inner side of the 

 sorus by the base, and usually, but not always, by the sides 

 also, leaving the apex free. 



