FILICES. 79 



XXIV. Woodsia R. Br. Indusium roundish or stellate, 

 delicate, cleft into irregular lobes. 



TRIBE X. DICKSONIEJE. Sori roundish or transversely 

 elongate, borne at the ends of the veins or on marginal cross- 

 veinlets, with an indusium attached at the base or base and 

 sides and opening toward the margin of the segment. 



XXV. Dicksonia L'Her. Sori marginal, small, the indu- 

 sium cup-shaped, somewhat two-valved, the under portion con- 

 fluent with a lobule of the frond. 



SUB-ORDER II.-HYMENOPHYLLACEJE Endl. 



Sporangia borne on an elongate, often filiform, receptacle, 

 surrounded by a complete transverse ring, opening vertically. 

 Sori terminal or marginal from the apex of a vein. Indusium 

 inferior, usually of the same texture as the frond. Fronds deli- 

 cately membranous and pellucid. 



XXVI. Trichomanes Sm. Indusia tubular, cup-shaped, 

 or funnel-shaped, sometimes two-lipped. 



SUB-ORDER III.-SCHIZJEACEJE Presl. 



Sporangia ovate, sessile, arranged in spikes or panicles, hav- 

 ing a complete, transverse, articulated ring at the apex, and 

 opening by a longitudinal slit. 



* Stems scandent. 



XXVII. Lygodium Swz. Sporangia borne in a double row 

 on narrow fertile segments, each on a separate veinlet and pro- 

 vided with a special indusium. 



** Stems not scandent. 



XXVIII. Anemia S\vz. Sporangia naked, attached by 

 their bases to the narrow divisions of the panicled fertile seg- 

 ments of the frond. 



XXIX. Schizaea Sm. Sporangia naked, fixed in a double 

 row to the midrib of the narrow fertile segments. Sterile 

 fronds simple or dichotomously forked. 



SUB-ORDER IV.-OSMUNDACEJE R. Br. 



Sporangia naked, globose, mostly pedicelled, with no ring or 



