CLASSIFICATION OF FERNS. 
95 
TABLE OF GENERA. 
Order Filices. 
Suborder 1. Polypodies. — Capsules dorsal or marginal, 
surrounded by an articulated elastic ring, and open- 
ing transversely and irregularly. Fronds circinate in 
vernation. 
A. Capsules opening transversely, arising from the hack of the 
frond ; the ring vertical , usually incomplete . 
* Nudisom :. — Sori destitute of involucre. 
1. Gymnosramme. Sori oblong or linear, on forked 
veins. 
2. Polypodium. Sori subglobose. 
Indusiata :. — Sori furnished with an involucre beneath the sori. 
3. Woodsx a. Sori subglobose. Involucre more or 
less cup-shaped. 
4. Cystopteris, Sori subglobose. Involucre ovate, 
cucullate at the base, and having its origin beneath the 
sorus. 
5. Aspidium. Sori dorsal, subglobose. Involucre 
orbicular and peltate. 
6. Nephrodxum. Sori dorsal, subglobose. Invo- 
lucre subcordate, and fixed by the sinus. 
7. Asplenium. Sori dorsal, linear, or oblong, rarely 
curved or somewhat horseshoe- shaped, attached laterally 
to the veins, and opening towards the midrib. 
8. Scolopendrium. Sori dorsal, linear, in opposite 
pairs, and opening towards each other. 
9. Pteris. Sori continuous, dorsal, but at the margin 
on a marginal receptacle. Involucre formed of the re- 
flexed and generally membranous margin of the frond. 
10. Adiantum. Sori dorsal, roundish. Involucres 
