678 UNDERWOOD: FERNS OF THE PHILIPPINES 
gramma by two each, Stenochlaena, Thamnopteris and Athyrium by 
four each, Stegania by five, and Blechnum by six ; the larger genera 
are Callipteris with twelve species, Diplazium with twenty-one, and 
Asplenium with thirty-three. These numbers, however, represent 
nominal species and yet are not likely to be much reduced, and 
will be varied only by future discoveries. 
Tribe 7. Dipterideae 
This tribe is represented only by a single species of the curious 
fan-shaped Dipteris, perhaps one of the most unique among the 
ferns of the islands. Its leaves are often two or three feet broad. 
Tribe 8. Dryopterideae 
Related to our wood-ferns are a large number of species in all 
tropical regions and the Philippines come in for their share. The 
sixteen genera are distinguished as follows: 
I. Veins normally free, simple, forked, or pinnately branched. 2 
Veins connivent, 7. ¢., the branches from contiguous pinnate groups uniting to form 
one or more arches.* x 
Veins copiously anastomosing. 6. 
2. Leaves dimorphons ; sori extending from the veins to the parenchyma so as to 
appear continuous. - 
Leaves uniform or nearly so. 3: 
3. Indusium wanting ; margins of segments plane. PHEGOPTERE: 
Indusium circular, peltate. 86 
Indusium oval, attached by a central axis to a thickened linear receptacle. 
DIDYMOCHLAENA. 
Indusium cordate-reniform, attached by the sinus; veins distinct. | DRYOPTERIS. 
4. Indusium wanting. 5: 
Indusium cordato-reniform, attached by the sinus. CYCLOSORU™ 
5. Sori round, punctiform. GOMIOET ERE: 
Sori elongate on the more or less parallel transverse arches. MENISCIUM. 
6. Indusium wanting. . 
Indusium cordato-reniform, attached by the sinus. - 
Indusium orbicular, centrally peltate. gee 
7. Leaves dimorphous ; sori extending to parenchyma so as to appear continuous. - 
Leaves uniform. ARCYPTERIS. 
* The genus Dictyopteris Pres] (1836) is antedated by a genus of the same name 
among the algae. We therefore propose the name Arcypteris, with the same mean- 
ing. It is not the exact equivalent of Dictyopteris Presi, the first species of which was 
Polypodium attenuatum R. Br., which does not belong to the 3 Dictyopteris as taken up 
by Synopsis Filicum. Aspidium difforme Blume'(Enum. Pl. Jav. 160. 1828) may be 
considered as the type of Arcypteris. 
