162 110 
membrane between them; this membrane is in leaves of thick texture often folded 
and forms on the underside an often hairy keel running from the sinus towards 
the costa and parallel to the costules. Indusium in most species large, reniform, 
as a rule persistent. Sporangia glabrous. 
A natural group including 13 known species of middle-size or large-grown 
and partly closely related to each other. The majority of them resemble in habit 
not a little D. rudis and allied species, in venation, indusium and rhizome D. oli- 
gophylla; the subgenus thus connects the two groups of which the two species na- 
med are typical members. From both it can be distinguished by the characteristic 
carinate fold below the sinus, the grey colour and the pluricellular hairs. From 
the free-veined species of Goniopteris all species are different by the lack of stellate 
hairs. Glands are absent in all species. 
The two last species, D. glandulosa and D. Fendleri, are somewhat different 
from the others. Their position in this subgenus is doubtful; see below. 
Ke y. 
1. Pinne sessile or the lower ones very shortly stalked. All veins free. 
2. Lamina pinnatifid (or pinnate below only) with entire segmehts 
177. D. Wrightii (Mett.) O. Ktze. 
2. Lamina bipinnatifid. : 
3. Lower pinnz more or less reduced. 
4. Lamina suddenly narrowed downwards with several pairs of 
auriculiform, reflexed pinne ......... 178. D. deltoidea (Sw.) O. Ktze. 
4. Lower pinnz abbreviated but not auriculiform. 
5. Lamina membranous-papyraceous, pinnz incised to a narrow wing 
TORCOSUQES Uu eser ET 179. D. L'Herminieri (Kze.) C: Chr. 
5. Lamina rigidly coriaceous; pinne incised about halfway 
tOmbheRcCostale me: a1 UTENTE 180. D. lonchodes (Eat.) O. Ktze. 
3. Lower pinne not reduced, generally reflexed. 
4. Without aérophore. Lamina rather thin. 
5. Rachis and costae beneath with many short hairs with 
some few long, pluricellular hairs intermixed. Pinnz 
incised to a wing 3—5 mm broad; veins 9—10-jugate 
181. D. densiloba C. Chr. 
5. Rachis, margins, coste and veins beneath with many 
very long, pluricellular hairs, short hairs few. Pinnz 
incised nearly to costa; veins 10—11-jugate 
182. D. incana (Christ) C. Chr. 
4. Aérophore present. Lamina firm, membranous or papyra- 
ceous. 
5. Fronds dimorphous. Stipe and rachis very densely clothed 
