930 FILICES. | Hymenophyllum. 
Fronds 6-20in., ovate-lanceolate, brownish-green ; stipes 
and rhachis bristly. Sori terminal; indusium orbicular 9. H. scabrum. 
Fronds 3-9in., pale glistening-green; lower pinne often 
flabellate. Stipes woolly at the base. Sori terminal, 
small; indusium broadly ovate or orbicular .. . 10. H. flabellatum. 
Fronds If in., deltoid, very delicate. Stipes, rhachis, 
and coste with silky flexuous hairs. Sori terminal, 
small, partly immersed ; indusium ovate-orbicular .. 11. H. rufescens. 
** Fronds with the margins and both surfaces densely clothed with stellate 
hairs. 
Fronds 2-6in., oblong; rhachis broadly winged through- 
out, the wing decurrent along the upper part of the 
stipes. Sori terminal, immersed mn ths .. 12. H. ciliatum. 
Fronds 2-10in., oblong-lanceolate ; rhachis winged only 
towards the top; stipes naked. Sori terminal, im- 
mersed .. sc 3 30 4c .. 13. H. swbtilissimum. 
Fronds 2-8in., linear-oblong, rigid and coriaceous, every- 
where hidden by dense tomentum ; rhachis not winged. 
Sori terminal, free .. be ae ee .. 14. A. Malingiz. 
B. Leptocionium. Margins of the frond spinulose-dentate. 
Fronds minute, $-lin., simple or forked or Ustiataly 4 
divided. Indusium with entire valves 5. H. Cheesemanit. 
Fronds minute, }-1in., pinnatifid. Sori solitary, free, ter- 
Minating the main rhachis ; indusium with’ the valves 
spinulose on the back and margins .. . 16. H. minimum. 
Fronds 1-4in., pinnate; pinne divided. Sori lateral, near 
the base of the pinne, free; indusium with the valves 
smooth on the back, spinulose-dentate onthe margins .. 17. H. Tunbridgense. 
Fronds 1-4 in., pinnate; pinne divided. Sori lateral, near 
the base of the pinne, free; indusium with the valves 
smooth on the back ; margins entire .. 18. H. unilaterale. 
Fronds 4-8 in., 3—4- pinnatifid. Sori lateral, near the base 
of the pinne, free ; indusium large, often decurved, obo- 
void ; valves with entire margins 6c .. 19. H. multifidum. 
Fronds 6-12 in., 3-4-pinnatifid. Sori terminal, ‘immersed 
in the tips of the segments ; indusium ovate- orbicular, 
valves with entire margins .. Bs at .. 20. H. bivalve. 
1. H. rarum, f. Br. Prodr. 159.—A very delicate pale glistening- 
green pellucid species, forming matted patches on the trunks of 
trees or on rocks. Rhizomes creeping, much branched, very 
slender, wiry, black. Fronds very variable in size and shape, 
usually from 1 to 4in. long, but sometimes dwarfed to $in., and 
occasionally lengthened out to 6 or 8in., broadly oblong to linear- 
oblong, 2-pinnatifid, in large specimens pinnate at the base, pen- 
dulous, membranous, flaccid, quite glabrous. Stipes extremely 
slender, capillary, often half the length of the whole frond; main 
rhachis usually winged throughout. Pinne close, often overlap- 
ping, once or twice forked Ps pinnatifid, rarely simple. Segments 
erecto-patent, ¢-31n. long, ;4,in. broad, flat, obtuse, quite entire. 
Sori mostly near the summit of the frond, sunk in the tips of the 
segments. Indusium large, almost as broad as the segments, 
