CXLIII. FILICES. 459 



Suborder 2. Cyatheese. Yernation circulate. Trunk woody. Sori 

 dorsal, of many capsules, which are sessile or nearly so, open at the side, 

 and have a slightly excentric vertical ring. 



Sori at first enclosed in a complete cup .... 2. Cyathea. 

 Cup very incomplete 3. Hemitelia. 



Suborder 3. Polypodiese. Vernation circinate. Ti'unk in none of the 

 Cape species arborescent, the sori usually dorsal, of numerous capsules, 

 which o]ien down the side, and have an incomplete vertical ring, except in 

 Symenophylleoe^ which see. 



Tribe 1. DiczsoNiE^. Frond herbaceous ; sori dorsal enclosed in a 

 complete cup. 

 The only genus 4, Woodsia, 



Tribe 2. Htmenophylle^. Frond beautifully pellucid ; sori terminal, 

 enclosed in a complete cup ; ring of capsule almost transverse, and dehis- 

 cence subvertical. 

 Cup shallow, 2-valved, being split half or quite 



down to the base 5. Hymenophyllum. 



Cup many times deeper than broad, entire or 2- 



valved at the apex only 6. Trichomanes. 



Tribe 3. Day allied. Involucre attached by the base on the side of the 

 soriis furthest from the edge of the frond, roundish or oblong, not forming 

 a complete cup. 

 Involucre (in Cape species) attached by the sides 



and base 7. Dayallia. 



Involucre attached by the base only 8. Cystopteeis. 



Tribe 4. LindsaT-e. A 2-lipped involucre in a line along the edge of 

 the frond, enclosing the linear sori. 

 The only genus 9. Lindsaya. 



Tribe 5. PTEEiDEiE. Sori marginal, round or linear. Involucre formed 

 of the more or less modified edge of the frond, and wrapped over the sorus. 

 Sori from the under side of the recurved edge of 



the frond, in Cape species globose. Texture of 



frond papery, veining fan-like 10. AdiANTUM. 



Sori erect, with the edge of the frond wrapped 

 over them. 



Sori globose, confined to the sinuses of the 



frond, always distinct, veins not uniting . . 11. Hypolepis. 



Sori oblong or linear, confined to the sinuses of 



the frond. Veins joining copiously . . . .12. Lonchitis. 



Sori at first globose, but, together with the invo- 

 lucres, becoming more or less confluent . . 13. Cheilanthes. 



Sori and involucres linear, but not absolutely 



continuous. Fronds small and coriaceous . 14. Pell^a. 



Sori and involucres quite linear and continuous, 

 occupying the edge of the segments only. 

 Fronds large and herbaceous, barren and fer- 

 tile nearly ahke 15. Pteris. 



Like Pteris in the sori, but the frond ainall and 



rigid, and like a Fan-palm in miniature . . 16. Actiniopteris. 



Sori and involucres quite linear and continuous, 



