FILICES. 927 
Indusium altogether wanting . .. 6, ALSOPHILA. 
Indusium 2-valved, the upper valve continuous with the 
margin of the frond oe be .. 7. DicKsonta. 
Suborder III. Poutypropiace™. Sori dorsal or marginal, naked or furnished 
with an indusium. Sporangia with a short or long stalk, girt by an in- 
complete vertical ring, bursting transversely. Habit various. 
* Indusium present, at least when the sorus is young. 
+ Sori dorsal or marginal. Indusium opening outwards, or towards the 
margin of the frond. 
Sori globose or oblong, submarginal. Indusium often 
cup-shaped, attached by a broad base and sometimes by 
the sides as well .. . 8. DAVALLIA. 
Sori subglobose, dorsal, remote from the margin. In- 
dusium ovate-deltoid, membranous, attached by a broad 
base a0 .. 9. CYSTOPTERIS. 
Sori linear, marginal. Indusium linear, membranous, 
opening outwards .. te ae Si .. 10. Linpsaya. 
++ Sori variable in shape, linear to globose, marginal. Indusium com- 
posed of the more or less modified edge of the frond, which is reflexed 
over the sorus, opening inwards. 
Sori reniform or globose or oblong, distinct in the New 
Zealand species. Indusium an altered and reflexed 
lobe or tooth of the frond, bearing the sorus on its 
under-surface oe be dip .. 11, ADIANTUM. 
Sori subglobose, distinct, in the notches of the ultimate 
divisions of the frond. Indusium a slightly modified 
and reflexed portion of the margin of the frond . 12. Hypoueris. 
Sori subglobose or oblong, often confluent into linear 
masses. Indusium composed of the modified and re- 
flexed margins of the frond . . 13. CHEILANTHES. 
Sori confluent, forming a linear band extending along the 
greater part of the edge of the pinne, placed on the 
tips of the transverse veins . 14. PeLuma. 
Sori linear, extending along the greater part of the edge of 
the pinnz or segments, placed on an intramarginal 
longitudinal vein .. . 15. PrERis. 
Sori linear, on the contracted pinne “of fertile fronds 
differing much from the sterile ones, covering the whole 
under-surface os or oF 50 .. 16. Lomarta. 
ttt Sori linear or oblong, dorsal (or submarginal when the frond is much 
divided). Indusium the same shape as the sorus, laterally attached to a 
vein, opening inwards (or towards the costa). 
Sori oblong, on short cross veinlets enue the primary 
veins, parallel to the costa . Sele DOODTA: 
Sori oblong or linear, on the primary veins, oblique to the 
costa 58 ie : .. 18. ASPLENIUM. 
tttt Sori globose, dorsal. Indusium orbicular or reniform, peltate or 
affixed by the sinus, opening all round the margin. 
Indusium orbicular and peltate oe oc .. 19. ASPIDIUM. 
