ON GENERA AND SPECIES. 35 



Sect. 1. Symplophlebiese. Veins anastomising in various 



ways. 



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

 Sect. 2. Orthophlebieae. Veins free. 

 Ex. Lastrea, Bory., Polystichum, Roth., Didymochlaena, Desv. 



Tribe VI. DICKSONIE M, J. 8m. 



Sori marginal, round or linear, furnished with a special 

 and accessory indusium, which united form a cyst or groove 

 including the sporangia, and opening exteriorly. 

 Sect. 1. LindsseaB, J. Sin. Sori linear, rarely round. 

 Ex. Lindseea, Dry., Dictyoxiphium, Hook, Odontoloma, 



J. 8m. 



Sect. 2. Davalliese, /. Sm. Sori round or vertically oblong. 

 Indusium cystiform, cuculate or tubula^r. 



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

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

 columnar receptacle included in or inserted along the 

 cyst. 

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



phyllum, Sm. 

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



bilabiate, or calyciform, reflexed cyst. 

 Ex. Sitolobium, Desv., Dicksonia, L'Herit., Cibotium, Kaulf. 



Tribe VII. OATHEJ:, /. Sm. 



Sori round intramarginal, receptacle elevated. Indusium 

 calyciform, or lateral, trichiform or absent. 

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



DIVISION II. GLEICHENIACB^}, R. Br. 

 Sporangia furnished with a transverse ring. Sori round 

 intramarginal. 

 Ex. Platyzoma, R. Br. Gleichenia, Sw., Mertensia, Willd. 



