KEYS TO THE FERNS OF BORNEO 
413 
4. D. rigidula (Sw.) Beddome. 
Sarawak, Dutch Borneo. 
Malaya to India and Polynesia. 
69. PHOTINOPTERIS J. Smith. 
P. speciosa (Bl.) Presh 
Sarawak, Dutch Borneo, North Borneo. 
Malaya. 
70. ANTROPHYUM Kaulfuss. 
a. Paraphyses enlarged at the apex. 
b. Apex rounded 
61. Apex acute or acuminate. 
c. Frond elongate. 
d Frond sessile or short-stalked. 
e Costa inconspicuous and only near 
base. 
e*. Costa conspicuous, but only near 
base. 
Costa distinct above middle of 
frond. 
d 1 Frond long-stalked 
a. Frond almost as wide as long 
a 1. Paraphyses not enlarged at apex. 
b. Fronds more than 2 cm broad. 
c. Sori anastomosing freely 
a. Sori free 
Fronds 5—20 mm wide. 
c. Frond moderately thick, sori 2—3 on 
each side 
ci. Frond very thick, sori more numerous 
61. Fronds less than 5 mm wide 
1. A. immersim. 
2. A. parvulum . 
3. A. semicostatum. 
4. A costatum. 
5. A. plantagineum. 
6. A. I at 1 folium. 
7. A. reticulatum. 
8. A . callifolium. 
9. A. subfalcatum. 
10. A. coriaceum. 
11. A. vittarioides. 
1. A. immersum (Bory) Mett. 
Dutch Borneo, Sarawak, North Borneo. 
Malaya, Mascarenes. 
2. A. parvulum Bl. 
Sarawak, North Borneo. 
Java, Penang. 
3. A. SEMICOSTATUM Bl. 
Sarawak. 
Malaya to Ceylon and Polynesia. 
