long or linear). Involucres of the same-shaped portions of a reflexed 
and altered margin of the frond, hearing the capsules upon them. 
11. Cryptogramme. — Sori oblong or linear, situated towards the 
apex of the veins, and covered by the involucre formed of the broad re¬ 
volute margin of the frond. Fronds dimorphous. 
12. Blechnum. — Sori linear, continuous, parallel with and near 
the costa, running transversely, with the veins rarely submarginal . In¬ 
volucre of the same shape. 
B. Capsules opening irregularly, placed on a columnar or filiform recep¬ 
tacle, and terminating a vein at the margin of the frond, having a 
transverse ring and included in an involucre. Fronds delicate, 
membranaceous. 
13. Trichomanes. — Involucre subcylindrical, nearly entire. Re¬ 
ceptacle usually exserted. 
14. Hymenophyllum. — Involucre 2-valved. Receptacle rarely. ex¬ 
serted. 
Subord. II. Osmundeas. —Capsules clustered at the margin of a trans¬ 
formed frond or portion of a frond, reticulated, opening by two 
regular valves; ring almost obsolete. Fronds circinate in ver¬ 
nation. 
15. Osmunda. 
Subord. III. Ophioglosse^e. —Capsules globose, between coriaceous and 
fleshy, sessile, forming a simple or compound pedunculated spike, 
distinct from the sterile frond, and opening transversely by two 
equal valves. Fronds straight in vernation. 
16. Ophioglosstjm. — Capsules connate on a 2-ranked spike. 
17. Botrychium. — Capsules free, arranged on one side of a pinnated 
spike or rachis. 
Subord. IV.— Lycopodie^:. — Capsules without a ring, coriaceous, ses¬ 
sile, in the axils of leaves or bracteas, \-celled, 2-3 -valved. Stems 
leafy. Vernation not circinate. 
18. Lycopodium. 
Subord. Y. Isoete^e.— Capsules without a ring, indehiscent, immersed 
in a cavity at the base of long subulate radical leaves. Seeds on 
filiform receptacles. Vernation involute. Aquatics. 
19. Isoetes. 
Subord. YI. Marsile^e. —Fructification of two kinds. Capsules with¬ 
out a ring, in globose coriaceous involucres near the root of the 
plant. Vernation involute. Aquatics . 
20. PlLULARIA. 
