64 J. SMITH ON THE GENERA OF FERNS. 



Dicksonia; and therefore may be considered to bear the same 

 analogy in the structure of its sori to that genus as Polypodi- 

 nm contiguum does to Davallia. 



25. DicTYOPTEUis. Presi. 

 Polypodii sp. Auth. 



Venation uniform, internal, reticulated. Sporaiigia pro- 

 duced on the confluence of the venules, or medial. Sori 

 round, rarely oblong, transverse, uniserial or irregular. 

 Fronds entire, linear-lanceolate or deltoid and bipinnate; 

 smooth^ coriaceous. Pinnae sinuose or pinnatifid. 



Species 1. lanceolata ; (Grammitis; Cunn.) 2. D. attenu- 

 ata; {R. Br.) 3. D. macrodonta; [Reinw.) 4. D. pteroides; 

 {Presl.) 



lllust. Hook. Gen, JiL t. ined. 



Obs. Tiiis genus is distinguished from Drynaria and its 

 associates, by having no irregular, free veinlets, terminating 

 in the areoles, the whole ramifications of the veins anastomos- 

 ing. 



26. LoxoGRAMMA. Presl. J. Sm. 



(Grammitidis sp. Sw.) 



Ve7iation uniform, internal, reticulated. Sporangia pro- 

 duced on the elongated sides of the areoles, forming linear, 

 oblique sori. Fronds simplcy linear lanceolate, coriaceous. 



Species. L. lanceolata; {Sw.) lllust. Hook, et Grev. Ic. 

 Fil. t. 53. Hook. gen.Jil, t. ined. 



Obs. The absence of costaeform veins and free veinlets, 

 terminating in the areoles, distinguishes this genus from the 

 following. I formerly considered that Grammitis invaluta of 

 Don, and G. flavescens of Wailich, belonged to this genus; 

 but on a re-examination of specimens, I am induced to place 

 them in Selliguea. 



27. Selliguea. Bory. J. Sm. 



Peins costaeform. Venules compound, anastomosing, pro- 

 ducing variously directed, free veinlets. Sporangia produ- 



