MR. C. B. CLARKE ON THE FERNS OF NORTHERN INDIA. 463 
in the Nilgherries the pinnz whereof attain 18 in., which he thinks as well separated 
from P. pellucida as is. P. pellucida from P. cretica. | 
Var. stenophylla, (sp.) Hk. & Grey. Ic. Fil. t. 130. Pinns 3-4, sometimes 2-1, sub- 
digitate; fertile pinnz very long and narrow.— P. digitata, Wall. Cat. 91. 
Gurwhal to Nepaul, alt. 3000-4000 feet.—The localities Khasia and Philippines 
added by Sir W. J. Hooker are errors; the Khasia specimens are P. dactylina; the 
Philippine are P. pellucida, with 3 pinnz. In P. pellucida, when with few pinne, the 
barren pinns are much broader than the fertile; in var. stenophylla the pinnæ, both 
barren and fertile, are, when 8-9 inches long, hardly 3 in. broad. In fairly developed 
var. stenophylla the stipe is often scabrid, the veins are not less marked than in the 
type. The stipe is usually pale straw-coloured, sometimes yellow, sometimes nearly 
black.—P. scabripes, Wall. Cat. 94, has dimorphic fronds, the stipe very scabrous, but 
will probably be brought as a var. under P. pellucida, Presl. 
4. P. nAcTYLINA, Hook. Sp. Fil. ii. 160, t. 130 a. Pinne 7-1 (usually 5), digitate, linear ; 
margin (where barren) crenate-serrate, scarcely spinulose, veins wide apart.—Bedd. 
Ferns, Brit. Ind. t. 28; Hk. & Baker, Syn. Fil. 155. 
Khasia, Griffith ; alt. 4200 feet, C. B. Clarke. Sikkim and East Nepaul, Sir J. D. 
Hooker. 
Fertile pinne in Griffith’s example 9 by yy in, and the barren pinne 9 by j in. 
Neither Hooker’s nor Beddome’s figure shows the extreme form of the species. Sir J. 
D. Hooker’s specimens have been so thoroughly mixed with P. cretica in the mounting 
that I do not feel sure of the locality East Nepaul; nor do I feel sure that the figures 
were prepared without an eye to the examples of P. cretica mixed. The coriaceous 
texture and thick veins of P. dactylina are not much like P. pellucida, var. stenophylla; 
and it has been confounded with P. cretica, never with P. pellucida. 
5. P. enstFormis, Burm. Fl. Ind. 230; Thes. Zeyl. t. 87. Lowest pair of pinnæ 2-3-fid ; 
. margin of the frond (where barren) regularly crenate-serrate ; lower barren pinnæ 
usually obtuse; veins forked and simple, diverging at about $ of a right angle from 
the midrib, very close together.—Ham. in Wall. Cat. 7085; Hk. & Baker, Syn. Fil. 
155; Benth. Fl. Austral. vii. 730. P. crenata, Swartz ; Blume, Enum. PI. Jav. Fil. 
209; Hook. Sp. Fil. iii. 163, t. 127 4 ; Carr. in Fl. Viti. 349; Bedd. Ferns South. 
Ind. t. 35. P. multidentata, Wall. Cat. 2681. 
From Bhotan to Chittagong, alt. 1000 feet, throughout the plain of East Bengal; 
common.— Distrib. South Deccan and Ceylon, Malay Peninsula, China, Tropical Aus- 
tralia, Polynesia. , 
Not easily separated from P. cretica. I have found the angle of the veins the best 
character. P. ensiformis has the lowest pinnæ often 3-fid (whereas in P. cretica they 
are commonly 2-fid), and the lowest pinnæ of the fertile pinne have often shortened 
rounded barren segments; also the lowest pinnz are not rarely completely pinnate. 
Pt. ensiformis, Ham. in Wall. Cat. 2181, was probably Burmann’s species; but that 
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