1. CY^THEACE^B (*). 



Sori globose or ellipsoid, dorsal or terminal on the veins; sporangia 

 numerous, sessile or stalked, furnished with a complete, oblique (subvertical) 

 ring, which is sometimes interrupted at the place of the stomium by a row 

 of depressed, transversally oblong cells; stomium opening at i-ight angles to 

 the ring; receptacle often elevated. Indusium wanting or more generally 

 present and then scale-like, 2-valved, suhcupuliform or globose, but then after- 

 wards evanishing or becoming cup-shaped, sometimes consisting of a whorl 

 of hairs or fibres, always fastened beneath the sorus. 



Caudex arborescent, sometimes subarborescent. Fronds often very large, 

 mostly compoundly divided; veins free or the costal ones sometimes anasto- 

 mosing in Hemitelia. 



Tropical and subtropical. 



Arrangement of the tribes. 



§ 1. CYATHEAE. Sori dorsal, placed on the back or at the forking of 

 a vein. Annulus not interrupted by a row of depressed cells. 



§ 2. DICKSONIEAE. Sori terminal on the veins. Annulus interrupted 

 by a row of depressed cells at the place of the stomium. 



Key to the tribes and genera. See | Supplement 1, p. 22. 



-f. — Sori on tho back or at the forking of a vein . 



CYATH E AE 



Sori indusiate. 



b. Indusium distinct, globose, quite enelosii^TIie sorus when young, 

 bursting down irreguladyrTrtterwards evanishing or becoming + 

 cup-shaged<— "Receptacle central. No. 1. Cyatbea.. 



lo^um distinct, squamiform, convex, placed at the inner side of 

 the rer,eptar,lR CIa_2 — lIejMit.glia. 



(*) The species of this family are difflcuh of determination ynless the whole stipe and 

 the lowest pinnae besides the central pinna and a portion of the main rachis are present. 



