MR. C. B. CLARKE ON THE FERNS OF NORTHERN INDIA. 555 
351. P.tomentosum, Roxb. in Cale. Journ. Nat. Hist. iv. 483. P. detergibile, Hook. 
Sp. Fil. v. 49. P.’costatum, Wall. Cat. 265, partly. JViphobolus detergibilis, Bedd. 
Ferns Brit. Ind. t. 162. 
Himalaya, alt. 0-5000 feet; from Gurwhal to Bhotan, common. Khasia, alt. 0-4000 
feet, common; extending into Sylhet plain. ` ` 
Often resembles P. Lingua (i. e. Heteractis), but has a much shorter rhizome. 
35. P. Booruir Hook. Sp. Fil. v. 58. Rhizome short, with lanceolate-linear bright 
chestnut-coloured scales; stipes long, often 8-12 in.; frond large, often 12-16 in., 
narrowed hardly attenuate at base, with much tomentum and lax red-brown stellate 
hair on the under surface extending over the broad prominent main rhachis; sori 
more irregularly scattered than in P. flocculoswm, about 6-8 in each row between 
the main veins.—Hk. & Baker, Syn. Fil. 352. Niphobolus Boothii, Bedd. Ferns 
Brit. Ind. t. 258. 
Bhotan, Griffith, Nuttall; 5 sheets in all. 
P. subfurfuraceum has the frond much more attenuated at the base, the tomentum 
beneath whitened: the two are near. 
Subgenus VII. Dipteris. Stipe forked close to its apex, bearing the frond in two 
similar halves. Frond deeply flabellate. Veins looped, forming innumerable 
areole. Sori numerous, scattered, small. 
36. P. WarnLnicur, R. Br. in Hk. & Grev. Ic. Fil. tt. 168, 169. Lower surface whitish 
or subferruginous, margin not toothed.—Wall. Cat. 287 ; Mett. Farngatt. Polypod. 
119; Hook. Sp. Fil. v.99; Hk. & Baker, Syn. Fil. 362. Dipteris Wallichii, Moore; 
Bedd. Ferns Brit. Ind. t. 80. 
Khasia ; alt. 0—4000 feet, in several places. Nearly all the material has come from 
the Iron Bridge at the Bor-pani, alt. 2000 feet. Hook. f. & T. Thoms. obtained it at 
Luckipoor, in Cachar, alt. 0-250 feet. I have also met with it in Jaintea at several 
places to the borders of the Naga country, alt. 4000 feet; and in quantity in Sylhet 
station, alt. 0—50 feet. 
Rhizome stout, extensively creeping, hypogeous ; scales black, very stiff, bristly. Stipes 
distant, erect, standing in groves, like those of Nephrodium heterosorum, in wet flats. 
Subgenus VIII. Drynaria. Fronds dimorphic, the barren one like an oak-leaf, the 
fertile much larger, pinnatifid (or in P. conjugatum, Lamk., these two kinds of 
fronds appear as though fused into one). Veins copiously inarching. 
37. P. QUERCIFOLIUM, Linn. Sp. Fil. 1547. Rhizome stout, abbreviated; scales at the 
foot of the stipe linear, hair-pointed, pubescent, from a small ovate, fimbriate 
base; frond glabrous; lobes of the barren frond obtuse, main veins of the fertile 
. distinct, carried in parallel lines to the margin.—Schk. Krypt. Gew. t. 13 ; Roxb. in 
.. Cale. Journ. Nat. Hist. iv. 484, t. 30; Wall. Cat. 291, chiefly; Hook. Sp. Fil. v. 96, 
