462 MR. C. B. CLARKE ON THE FERNS OF NORTHERN INDIA. 
rhizome throwing up solitary fronds, the rhizome and the stipe without scales, the frond 
with simple linear pinnz, the lowest pinnz not shortened, the veins all undivided, the 
involueres as in P. longifolia.. It appears from Wallich's Herbarium, that even in his 
day Hamilton could not make out what P. vittata, Roxb., was, unless = P. longifolia, 
Linn. 
** Frond 1-pinnate or subdigitate ; some of the lower pinne often 2-3-fid, scarcely 
2-3-partite. | 
2. P. cRETICA, Linn. Mant. 130. Lowest pair of pinnz (and often 1-4 other pairs 
2-3-fid; margin of the frond (where barren) closely or remotely spinulose-serrate; 
. lower barren pinnz usually acute ; veins forked and simple, diverging nearly at right 
angles from the midrib, often very close together.—Don, Prodr. Fl. Nepal. 15; 
Blume, Enum. Pl. Jav. Fil. 209; Hook. Sp. Fil. ii. 160 ;; Carr. in Fl. Viti. 348; 
Bedd. Ferns South. Ind. t. 39; Milde, Fil. Europ. 41; Hk. & Baker, Syn. Fil. 154. 
P. leta, Wall. Cat. 95. 
From Kashmir to Assam and Chittagong, alt. 0-6000 feet, commion; extending far 
into the plains as at Dacca, and obtained at 8000-9000 feet alt. in Sikkim by Sir J. D. 
Hooker.—Distrib. Deccan and Ceylon; Malay Peninsula; and in all the quarters of we 
globe in tropical and warm temperate climes. 
The above diagnosis is intended to separate the species from P. pellucida and 
P. crenata, The species is very variable, and does not always satisfy the diagnosis of 
Mr. Baker. The barren segments are not always much broader than the fertile; the 
veins are often wide apart in the narrow-segmented forms, very close together in the 
broad-segmented forms. The fertile segments are sometimes 7 by A in., sometimes 4 by 
iin. The stipe is often densely clothed at the base with lanceolate persistent scales. 
The serrations of the barren margin are sometimes jy in. deep, close together, with 
white rigid points; at other times the teeth are distant, only a few to be found. ‘The 
fronds are usually more dimorphic than those or E crenata. 
3, P. PELLUCIDA, Presl, Rel. Hænk. 55. Pinnæ acute, sometimes numerous, sometimes 
7, 5, 3, or 1, all simple, or the lowest pair 2-fid; margin of the frond (where 
barren) entire, undulate, crisped, or crenulate; veins forked and simple, diverging 
nearly at right angles from the midrib, always close together.—Hook. Sp. Fil. ii. 161, — 
t. 1295; Bedd. Ferns South. Ind. t. 38; Hk. & Baker, Syn. Fil. 154. P. venulosd, 
Blume, Enum. Pl. Jav. Fil. 209; Hook. Sp. Fil. ii. 162. P. nervosa, Wall. Oat ^ 
as to the type sheet. 
From Sikkim and Bhotan to Chiittagionjs alt. 0-3000 feet; extending far into Bengal S 
Plain, as at Dacca.—Distrib. Deccan Mts.; Malay Peninsula and Islands; Guinea coast: ` ` 
Pinne usually larger and broader than those of P. cretica. The forms with 5 pinnæ. 
are always (from the area given) distinctly pinnate, never digitate. ‘The forms with 3. — 
pinnæ from Chittagong and the Philippines are identical, and have the fertile pinmte ` ` 
Z in. broad, the barren pinnz 1-12 in. broad. Major F. Henderson has collected a form 
