18 PILIOES. 



consisting of 2 — 12 sporangia; receptacle inconspicuous, dot-like ; indusium 

 wanting. — Engl. & Prantl, 1. c, fig. 186; Hk. Bk., 1. c, tab. I, fig. 2. 



FAMILY IV. Hysiienoplayllaeeae. Ring large, circular, hori- 

 zontal or very oblique, surrounding the sporangium like an equatorial 

 belt; stomium vertical. Sori terminal or marginal, rarely spicate or pani- 

 culate, consisting of several to many sporangia ; receptacle distinct, elevated ; 

 indusium present. — Engl. & Prantl, 1. c, fig. 72, 75 D; Hk. Bk., 1. c, 

 tab. II, fig. 16—17. 



FAMILY lYa. ItfOxsoniaceae. Ring small, circular, oblique, 

 subvertical, placed on a dorsal increasing of the sporangium, the cells 

 only partly thickened; stomium vertical. Sori marginal, consisting of 

 several or many sporangia; receptacle distinct, elevated; indusium pres- 

 ent. — Engl. & Prant, 1. c, fig. 77; Hk. Bk., 1. c, tab. II, fig. 15 not 

 quite correct). — Not in Malaya. 



FAMILY V. iSeEiBxaeaceae. Ring small, opercuUform or con- 

 sisting of a group of thickened cells crowning the sporangium; stomium 

 longitudinal. Sporangia either solitary and terminal on the veins or placed 

 in 2 or 4 rows along the central veins of the fertile segments; indusium 

 wanting or present. — Engl. & Prantl, 1. c, fig. 191, 192 ^— (?;Hk. Bk., 

 1. c, tab. Vni— IX, fig. 64—68. 



FAMILY VI. Poly podiaceae. Ring long, vertical, incomplete ( '), 

 the extremities sometimes separated by the base or the stalk of the sporang- 

 ium only; stomium horizontal. Sori definite, various in shape and size, 

 if indefinite, then the sporangia densely crowded over the' parenchyma 

 or rarely scattered between the veins ; indusium wanting or present. — No 

 arborescent ferns, or, if so, then only in forms with no marginal cup-shaped 

 or 2-valved indusia. Engl. & Prantl, 1. c, fig. 57, 87 B & H; Hk. Bk., 

 1. c, tab. I, fig. 7d. 



FAMILY VII. Parkerlaceac. Ring long, vertical, incomplete, 

 with the extremities separated by the base of the sporangium only, 

 sometimes wanting (in American material' ; stomium transversal. Sori 

 indefinite, consisting of many sporangia scattered irregularly along the 

 few longitudinal veins, protected by the much recurved margin of the 

 frond when young. — Engl. & Prantl, 1. c, fig. 178—179; Hk. Bk., 1. c, 

 tab. Ill, fig. 32. 



(') Ring exceptionally oblique and complete, but only in forms with marginal, 



' inrlnsia.. ^ 



linear indusia 



