E D 
FILICES. (FERNS.) 587 
Trewer VII. ASPIDIEN AL. — Fruit-dots at or below the ends of the veins, round, or 
somewhat oblong and then placed across the vein. Indusium round or nearly so, fixed 
in the middie and opening at the margin, or reniform and fixed at the sinus. 
* Fertile and sterile fronds alike. 
12. CYSTOPTERIS. Indusium on the back of the veinlet, hood-shaped, fixed at the base 
partly under the fruit-dot, opening toward the apex of the segment. 
13. ASPIDIUM. Indusium mostly on the back of the veins, orbicular or round-reniform, 
fixed in the middle or at the sinus, opening all round the margin. 
M. NEPHROLEPIS. Indusium at the end of a free vein, reniform, fixed at the sinus or by 
the arcuate base, opening toward the margin of the frond. 
* * Fertile and sterile fronds different. 
15. ONOCLEA. Fertile fronds contracted, the divisions rolled up and berry-like. 
Trie VII. WOODSIEZE.C- Fruit-dots round, borne on the back of a free vein. In- 
dusium fixed beneath the fruit-dot, saucer-shaped, or globose and bursting at the top. 
16. WOODSIA. Indusium divided into irregular lobes, or a capillary fringe. 
Tans IX. DICKSONTEE, — Fruit-dots marginal, roundish, borne at the ends of the 
free veins. Indusium cup-shaped or two-valved, its outer part composed of a reflexed 
lobe of the frond, or more or less united with it. 
17. DICKSONIA. Indusium (in our species) small, nearly globular, membranaceous. 
SUBORDER IL. HYMENOPHYLLEZE. Sporangia borne on a seti- 
form or slender receptacle, cellular-reticulated, surrounded by a complete 
transverse ring. Involueres marginal, at the ends of the veins, C nod 
or two-valved. Fronds delicately membranaceous and pellucid. 
` 18. TRICHOMANES. Involucre cup-shaped or funnel-shaped, sometimes 2-lipped. 
Susorper HI. SCHIZZEINEZE. Sporangia large, borne on narrow 
segments of the frond, oval, cellular-reticulated, crowned by the converg- 
ing stris of a complete apical ring, opening longitudinally. 
19. LYGODIUM. Sporangia attached laterally in two rows to the narrow divisions of the 
pinnze, each one covered by a scale-like indusium. 
20. ANEIMIA. Sporangia attached by their bases to the narrow divisions of the panicled 
fertile branches of the frond. Indusium none. 
Suporper IV. OSMUNDINEZ. Sporangia large, nearly sessile 
on the back or margins of the mostly contracted fertile fronds, two- 
valved, opening vertically at the apex. Ring rudimentary or none. 
21. OSMUNDA. Sporangia globular, covering the contesta finde or sce, “ad fronds. 
SUBORDER V. OPHIOGLOSSE X.  Sporangia very large, sessile, 
spiked or panicled, coriaceous, not reticulated, on narrow divisions of the 
frond, destitute of a ring, transversely two-valved. Fronds not circinate 
in vernation. 
2. RommYcurvw. Aporengia 1 aniei quii. Starile part of the frond pinmately di 
m . oPmoLoSSUM. Spornga tu a simplo spi Starile part of tho trond simple inour 
