THE FAMILIES, GENERA AND SPECIES OF PTERIDOPHYTA. 459 



Sporangia sessile, or nearly so. 



Sori scattered or crowded on the underside of 

 the ordinary leaf. 



Leaf dichotomous; rhizome creeping"; 

 sporangia opening vertically, with a 

 broad, traverse, complete ring. 



Family VI. GLEICHENIACEJE. 

 Leaf not dichotomous; sporangium opening 

 at the apex, with an incomplete, horizontal 



ring Family YIL OSMUNDACEAi. 



Sori on the margins of distinct leaves or the 

 upper portion of the ordinary leaf. 



Family VIIL SCHIZ^ACEJE. 



Family IL— A'//l RA TTIA CEJE. 



X'ernation circinate. Sporangia combined into 2 masses 

 (synangia) on the back of ordinary pinna?, in ours opening by a 

 slit down the inner face. — Large ferns, with a stout, succulent, 

 tuberous stem on which the stipes are articulated. Leaves 

 large, pinnate, with a pair of stipules. Only one genus. 



I. Marattia. 

 I. Marattia, .Smith. 



Sporangia sessile, 10-12 together, concrete in boat-shaped 

 masses, which consist of 2 opposite rows of sporangia. 

 Stipules large, flap-like, leathery. 



Crown erect, large, irregular; leaves 6-15 ft. long, 2-3 ft. 

 broad, usually bipinnate, with a very stout paleaceous stipe 

 1-3 ft. long, swollen at the base and articulated to the crown; 

 pinnse 1-2 ft. long, i ft. broad i. fraxinea. 



I. il/. fraxiiico. Smith. — Mountain kloofs, rather rare. 

 iJrakensberg (Ly. ?). McLca, 53; Houtboschberg, Ze., East- 

 zvood in hb. Sim, 158; Marovuni. near Shiluvane, Ze., Juiiod. 

 233, Namotsuiri. Ze., Junod in T.M.H., 357. 



Family III.— HYMEN OPHY LLACEJE. Filmy Ferns. 



Vernation circinate. Sori at the leaf-edge, terminating the 

 vein, surrounded by a cup-shaped indusium. Sporangia sessile, 

 with oblique or transverse complete ring, and opening by a 

 longitudinal fissure. — Small, delicate plants, chiefly found' in 

 humid, shady places. Stem very slender, often creeping; some- 

 times it bears roots, in other cases only root-hairs; it grows 

 more rapidly than the fronds, so that its leafless tip appears 

 naked like a root. Leaves pinnate, filmy in texture (being" 

 only one cell thick, except at the veins), with no stomata. The 

 prothalli are capable of long life; in some species they produce 

 gcmni(c, or buds, on the margin, and may thus multiply vege- 

 tatively to a considerable extent. 



Indusium deeply 2-lobed i. Hymenophyllum. 



Indusium cup-shaped, entire or only slightly lobed. 



2. Trichomaxes. 



