CLASSIFICATION 
59 
COHORT II. LYCOPODIALES. Sporangia arranged singly in the 
axils of leaves or bracts. (Lycopodium, Selagmella and 
Isoetes.) 
COHORT III. SPHENOPHYLLALES. Sporangia united 3 together 
to form a 3-lobed 3-celled sporangiophore. Leaves scattered. 
(P silo turn.) 
COHORT IV. EQUISETALES. Sporangia united 6 to 9 together 
under a stalked peltate receptacle, these receptacles forming 
a cone terminal to the stem. Leaves (or teeth of sheath) 
whorled. (Equisetum.) 
Key to the Orders and Genera. 
COHORT I. FILICALES. 
Division I. PTlicales Leptosporangiatae. 
ORDER I. FILICES. Ferns. Foliaceous plants having distinct 
crowns or stems, roots, and leafy fronds with 
circinate vernation. Capsules in groups (sori), 
mostly in lines or dots or scattered, on the under- 
surface of the frond, either with or without indusia. 
Capsules very small, all alike in one species, one- 
celled, and containing minute uniform spores 
without filaments. Vernation of plant circinate. 
This Order includes all the plants usually regarded 
as ferns. These differ immensely among them- 
selves in the form, cutting and texture of the 
fronds, and in the arrangement and protection of 
the sori. 
Sub-Order I. Hymenophyllaceae. Filmy ferns. Rhizome ex- 
tending, often branched. Fronds delicate, pellucid, 
usually much cut. Capsules roundish or flattened, 
surrounded by an obliquely transverse entire ring. 
Capsules enclosed in a foliaceous cup, and sur- 
rounding an elongated receptacle, which is terminal 
on a vein, and marginal on the frond. Sori abun- 
dant, either sunk into or extending beyond the 
lamina of the frond. 
