100. FILICES. 
519 
* Capsules with an elastic maryitial riw/. 
Suborder I. POLYPODIACE^. 
Capsules in dorsal or marginal clusters, opening transversely 
or irregularly. Young fronds circinate. 
t Clusters dorml. King vertical, imuilly incomplete. Caps, 
opening transverseli/. 
Tribe I. POLY FOB IE ^E. Clusters nearly circular, without 
an indusium, seated upon the back of the lateral veins. 
1. Cryptogramma. Clusters circular, at length confluent, 
concealed by the reflexed margin of the frond. — Barren 
and fertile fronds dissimilar. 
2. PoLYPODiuM. Clusters circular, naked ; edge of the 
frond fiat, not reflexed. 
-' 3. WooDsiA. Clusters circular, with an inferior involucre 
divided at the edges into many capillary segments. 
Tr. II. ASPIDIE^E. Clusters nearly circular, covered by an 
indusium, seated upon the back of the lateral veins. 
4. Lastrea. Indusium reniform, attached by the notch. 
Veins distinct after leaving the midrib, not uniting with 
those of the adjoining lobe. 
5. Poly sTK HUM. Indusium circular, attached by the 
centre. Veins distinct after leaving the midrib. 
6. Cystopteris. Indusium attached by its broad hooded 
case under the clusters, with a long fringed free extremity 
at first covering the capsules. 
Tr. III. ASPLEN1E.E. Clusters oblong or linear, usually 
covered by an indusium opening longitudinally on one 
side, placed on the side of the lateral veins. 
7. Athyrium. Clusters oblong-reniform. Indusium open- 
ing towards the central vein or midrib, margin fringed. 
8. AsPLENlUM. Clusters long, straight. Indusium opening 
towards the central vein or midrib, nearly flat. 
9. ScoLOPENDRiUM. Clusters long, straight, 2 together. 
Indusia of each pair opening towards each other. 
