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94. FILICES. 
Order XCIV. FILICES. 
Leafy plants with a rhizoma or trunk. L. or fronds with a 
circinate vernation (Tribe 4T11. excepted), sinijde or divided. 
Fructification springing from the veins on the under side or at 
the edge of the 1. and consisting of 1 -celled thecse stalked and 
with an elastic ring or sessile and without a ring. 
1 
* Theca with an elastic marginal ring. ] 
( 
Suborder I. POLYPODIACE^. . ' 
Thecse in clusters on the hack of the fi’ond, opening trans- ' 
versely ; ring vertical, usually incomplete. 
Tribe I. POLYPODIE.^. Sori nearly circular, without an 
indusium, seated upon the back of the lateral veins. i 
1. Allosorus. Sori circular, at length confluent, concealed 
by the reflexed margin of the frond. 
2. Polypodium. Sori circular, naked ; margin of the frond 
flat not reflexed. 
3. WooDSiA. Sori circular with an inferior involucre divided 
at the edges into numerous capillary segments. 
Tr. II. ASPIDIEjE. Sori nearly circular, covered by an in- 
dusium, seated upon the back of the lateral veins. 
4. Lastrea. Indusium reniform, attached by the sinus. 
Veins distinct after leaving the midrib, not uniting with 
those of the adjoining lobe. 
5. PoLYSTiCHUM. Indusium circular, attached by the Centre. 
Veins distinct after leaving the miihib. 
6. Cystopteris. Indusium attached by its broad hooded 
base under the sori, with a lengthened fringed free extremity 
at first covering the thecae. 
Tr. III. ASPLENIE^. Sori oblong or Unear, covered by an 
indusium opening longitiuUnally on one side, plaeed on the i 
side of the lateral veins. 
7. Athyrium. Sori oblong-reniform. Indusinm opening 
tow ards the central nerve or miihib, margin fringed. 
8. Asplenium. Sori elongate straight. Indusium opening 
towards the eentral nerve or midrib, nearly flat. 
9. ScoLOPENDRiUM. Sori elongate straight, 2 together. In- 
dusia of each pair opening towards eaeh other. 
