12 
BRITISH FERNS .. 
VII. ADIANTE^E. 
The margins of the fronds reflexed,\ forming indusia, 
which bear the sori beneath. 
9. ADIANTUM.—Sori dorsal, in patches, covered 
with a reflexed indusium. 
VIII. C YSTOPTERIDEiE. 
Sori with special ovate indusia attached behind, and 
inflected hood-like over them. 
10. CYSTOPTERIS. —Sori dorsal, with a cucullate or 
hood-like indusium. 
IX. WOODSIEiE. 
Sori having a roundish indusium springing from the 
back of the veins . 
11. WOODSIA. —Sori dorsal, with an indusium 
attached beneath them. 
X. HYMENOPHYLLE^E. 
Sori produced at the end of the veins , and project¬ 
ing from the margin, and surrounded by urn-shaped 
and 2-valved membranes. 
12 . TRICHOMANES. —Sori marginal, covered by 
urn-shaped expansions of the frond. 
13. Hymenophyllum. —Sori marginal, surrounded 
by 2-valved expansions of the frond. 
OSMUNDACE^E. 
Fronds circulate, sori destitute of an elastic ring, 
and bursting vertically by two regular valves. 
14. OSMUNDA. —The only genus. 
