BORNEAN FERNS. , 139 
mm lata, basi abrupte cuneata et anguste paullo decurrcnte, deinde 
sensim ad apicem angustata,, Integra, glabra, dura. 
Biingo Range, alt. 900 m» Brooks ii. 
RecogTiizable by the narrow, acuminate, not cordate, very rigid fronds. 
Polypodium sparsipilum Copel. spec. nova. Plate XXIII. B. 
Eiipolypodium rhizomate paleis brTinneis nitidis late lanceolatis 1.5 
mm longis dense obtecto; stipitibus confertis, filiformibus G-9 mm altis, 
pilis borizontalilnis 1.5 mm longis ornatis; froude ca. 5 cm alta, 3-1 mm 
lata, subintegra, lierbacea., diapliana, pilis sparsissimis vcstita; vcnif; 
plerisquc furcatis; soris orbienlaribiis, snbsuperficialibus, siibcostalibiis. 
Bengkarum, alt. 900 ni, Brooks J'f. 
This little fern seems to be nearest to P. trichopodum F. Mueller, of Xiw 
Guinea. The veins terminate in hydathodes. 
I 
Polypodium setaceum Copel, spec. nova. Plate XXIV. 
Enpolypodiun rhizoniate repente nsqne ad 2.5 mm crasso, paleis fer- 
rngineis linoarilnis 2-3 mm longis vestito; frondibus ad ramos breves 
artieulatis, confertis, setaceis, 55 cm et ultra longis, 1.5 mm latis, in 
stipitcm brevem attenuatis, intcgris, glabris, opaeis, costa infra promi- 
nento, snpra sulcata, lamina utroque latere costae supra convexa, infra 
concava, venis occnltis ; soris fere costalibus elongatis. 
Triiigos, Sarawak river, BrooI,s G. 
This suggests P. bisulcatmn Hooker, but lias the fronds decidedly more slender 
and very different in cross section, and closely clustered. 
THE DRYNAIUA GROUP. 
There is probably no group of organisms known wliich are more 
distinct in appearance but more evidently homogenetic than these are. 
Polypodium lieraclcum may stand in the place of the parent. By diag- 
nosis and by unquestionable affinity it is a Polypodium; or if Poly- 
podium be broken up it is still in whatever division contains P. musae- 
folium. But it is no less certainly related to Drynnria qwrcifoha. 
The status wliich shall be given to the individual members of this 
group, and the size of the minor groups are purely matters of judgiiient. 
We may keep all these ferns in one genus, even in Polypodium, and hnd 
justification enough in their obvious bomogeneity— and this is the most 
important single criterion ; or we may recognize one distinct daughter- 
genus, and include in it P. Jicrachum or leave the latter with its for- 
bears. At the other extreme, we may recognize a considerable number 
of genera, most of them of a single species each; and these genera ^ull 
have distinguishing characters as obvious as anyone can reasonably 
demand. Polypodium coronaus, Dnjostachyum pilosum, and the Bor- 
nean fern, to "ho described below will each constitute a new genus it 
this plan be followed. 
