J. SMITH ON THE GENERA OF FERNS. 45 



Sect. I Orthophlebie.i:. J. Sm. 



Veins simple, forked or costac form and pinnate^ the ichole 



direct, and free. 



1. MONOGRAMMA. Schk. 



(Grammitidis sp. Sw. Cochlidium. Kauif.) 

 Casta sporangiferous longitudinally on its centre, forming a 

 solitary, continuous or interrupted, linear sorus — Fronds 2 to 

 4 inches high, linear, simple or forked, furnished with a midrib 

 only, concave towards the apex, which includes the sporangia. 



Examp 1. M. graminea. Schk. 2. M. furcata. Desv. 3. M. 

 triclioidea. J. Sm. — Illust. Schk. Crypt, t. 87. Schott. Gen. Fil. 

 t. 17, c5- 18. Uook. Gen. Fil. t. 84. 



Obs. This genus represents the simplest form of ferns — the 

 fronds being so very small and narrow, that no lateral veins are 

 produced; the whole structure being supported by the midrib. 



2. Pleurogramma. Presl. J. Sm. 

 (Taenitidis sp. Kaulf. Hook. Grev. 



Veins simple, sterile. — Costa sporangiferous longitudinally on 

 its sides, forming two continuous, linear, costal sori, which 

 become confluent. — Fronds 3 fo 6 inches high, linear, simple 

 or forked, veins sometimes obsolete in the upper or fertile portion 

 of the frond. 



Examp. 1. P. linearis. — Illust. Uook. et Grev. Ic. Fil. t. 

 77. Hook. Gen. Fil. t. 12 &, Lib. A. 



Obs. Differing from Monogramma by the presence of lateral 

 veins, and in the sporangia, being produced in a line on each 

 side of, and close to, tlie midrib. 



3 Grammitis. Sw. 

 (Xiphopteris. Kaulf. Micropteris. Desv.) 



Veins simple or forked, internal. Sporangia lateral. Sori oval, 

 oblong, oblique. — Fronds simple, margin entire or serrulate, 

 plane or the apex concave, the soriferous venule sometimes verif 

 short, or dentiform and conniving with the costa. 



Examp. 1. G. linearis. Siv. 2. G. raarginella. Sw, 3. G. 



australis. R. Br. 4. G. serrulata »Si!^? lUust. Schk. Crypt, t.^ 



7. Hook. Grev. Ic Fil, t, 6-2. Hook, gen. fil. f. 82. B. 



