ON GENERA AND SPECIES. 35 



Sect. 1. SymplophlebieiB. Veins anastomising in various 

 ways. 

 Ex. Aspidium, Sw., Pleocnemia, Pr., Nephrodium, Schott. 

 Sect. 2. Orthophlebieaa. Veins free. 

 Ej;. Lastrea, Bory., Polystichum, Roth., Didymochlaena, Desv. 



Tribe VI. — Dicksonib*, J. Sm. 

 Sori marginal, round or linear, fm-nished with a special 

 and accessory indusium, which united form a cyst or groove 

 including the sporangia, and opening exteriorly. 

 Sect. 1. Lindsisaj, /. Sm. Sori linear, rarely round. 

 Ex. Lindsasa, Dry., Dictyoxiphium, Hook, Odontoloma, 



/. Sm. 

 Sect. 2. Davallieaa, J. Sm. Sori round or vertically oblong. 

 Indusium cystiform, cuculate or tubular. 



Ex. Microlepia, Pr., Davallia, Sm., Loxoma, B. Br. 

 Sect. 3. Triohomaueas, /. Sm. Sporangia seated in a free 

 columnar receptacle included in or inserted along the 

 cyst. 

 Ex. Trichomanes, Linn., Hymenostachys, Bory., Hymeno- 



phyllum. Sin. 

 Sect. 4. Dioksonise. Sporangia included within a concave, 



bilabiate, or calyciform, reflexed cyst. 

 Ex. Sitolobium, Pcsv., Dicksonia, L'Rerit., Cibotium, Kaulf. 



Tribe VII.— Ctathe*, /. Shi. 

 Sori round intramarginal, receptacle elevated. Indusium 

 calyciform, or lateral, trichiform or absent. 

 Ex. Cyathea, Sm., Hemitelia, B. Br., Trichopteris, Presl. 



Division II.— GLEICHBNIACE^, B. Br. 

 Sporangia furnished with a transverse ring. Sori round 

 intramarginal. 

 Ex. riatyzoma, E. Br. Gleichenia, S"'., Jlertensia, WilJd. 



