320 
KEYS TO THE FERNS OF BORNEO 
B. VITTARIEiE AND “ GYMNOGRAMMITIDESV 
72, 
7 i- 
59 - 
8 . 
62. 
Sori elongate along veins, linear, without 
a. Sorus borne on the costa; minute epiphytes 73 
ai. Sorus one on each side of costa. 
b. Sori marginal or subraarginal, immersed ; 
epiphytes. 
c. Rhizome erect 
a. Rhizome creeping 
bi. Sori dorsal. 
c. Veins free 
ci. Veins not free. 
d. Frond coriaceous ; terrestrial 
di. Frond thick and fleshy ; epiphytes 
#2. Sori more numerous, veins free ; terrestrial. 
b. Frond simple 6. 
bi. Frond compound, pinnae broad (2 cm. or 
more) 9. 
bz. Frond compound; ultimate divisions 
narrow 
a 3 . Sori more numerous, veins anastomosing. 
b. Frond compound ; terrestrial. 
c. Veins uniting near margin 
ci. Veins uniting everywhere 
bi. Frond simple. 
c. Free included veinlets in areolae 
ci. Without free included veinlets. 
indusium. 
. Mono gramma. 
10. 
7 - 
34 - 
Scleroglossum. 
Vittaria (part). 
Oreogrammitis. 
Tcenitis. 
Drymoglossum. 
Sy ngra m m a (p art). 
C onto gramme. 
Ceropteris. 
C rasp ed odic tyu m . 
Dryopteris (part). 
57. Polypodium (Selliguea), 
d. Sori not anastomosing. 
e Veins uniting near margin only 
ci. Veins uniting everywhere 
d. Sori forming a net. 
e. Stipe reddish ; terrestrial 
ei. Without reddish stipe 
6. Syngramma (part). 
60. Loxogramme. 
6. Syngramma (part). 
70. Antrophyum. 
C. POLYPODIES. 
Sori dorsal, round or not very elongate, without indusium. 
a. Humus-collecting epiphytes. 
b. Humus collected by distinct scarious 
fronds 68, Drynaria. 
bi. Humus collected by scarious bases of 
fronds. 
c. Sporangia restricted to modified apex 66. Aglaomorpha. 
ci. Apex not modified 75. Poly podium, 
ai. Rhizomes inflated and inhabited by ants. 
