KEYS TO THE FERNS OF BORNEO 
321 
b. Sori dorsal on frond 57. Polypodiuv?. 
(Myrmecophila). 
fri. Sori single on specialized lobes 65. Lecanopteris. 
a. 2 . Neither humus-gatherers nor myrme- 
cophilous. 
b. Stipe not jointed. 
c. Epiphytes 57. Poly podium (part), 
a. Terrestrial plants. 
d. Quadripinnate with one ^orus on 
each ultimate pinnule 33. Monachosorum. 
di. Sori not solitary on the pinnules. 
e. Veins free or uniting regularly 
in pairs 34. Dryopteris (part). 
e*. Veins uniting but not regularly 
. in pairs. 
/. Frond not dichotomous 40. Tectaria (part). 
/i. Frond dichotomously forked 53. Diptens. 
61. Stipe articulate, or showing traces of a 
joint; mostly epiphytes. 
c. Sori in deep marginal or submarginal 
pits 58. Prosaptia. 
c 1 . Sori dorsal or superficial. 
d. Pubescence on fr-ond peltate, 
shield-shaped or stellate 61. Cyclophoms. 
di. Pubescence on frond none or not 
peltate 57. Polypodium . 
D. “ ASPIDIE.ZE.” 
Sori round, indusiate, dorsal, indusium fixed by a point, 
a. Veins free. 
b. Stipe articulate to rhizome. 
c. Frond compound 
c l . Frond simple 
D. Stipe not articulate. 
c. Pinnae articulate to rachis. 
d. Indusium not peltate 
di. Indusium peltate. 
e. Sori in one row remote from costa 
£i. Sori costular or in several rows 
a. Pinnae not articulate. 
d. Indusium peltate 
d*. Indusium cordate or reniform, fixed 
by the sinus. 
e. Indusia uniform 
19. Davallodes (part), f 
22. Oleandra. 
29. Nephrolepis (part). 
29. Nephrolepis (part). 
38. Cyclopeltis. 
36. Polystichum. 
34. Dryopteris (Lastraea). 
f Arthropteris, with simply pinnate fronds, will probably be found 
in Borneo; its number would be 29A. 
