512 MR. C. B. CLARKE ON THE FERNS OF NORTHERN INDIA. 
cannot satisfactorily separate the two: in A. assamicum the secondary pinna is divided 
less unequally by its midrib than in 4. biaristatum. 
Subgenus II. Cyrtomium. Veins uniting (sometimes only a few unite close to 
the margin). 
11. A. cApucuM, Wall. Cat. 381. Primary veins from the midrib of the pinnæ repeatedly 
dichotomous at an acute angle into subequally strong veins, not anastomosing usually 
till near the margin of the frond, many of them free to the margin.—Hk. & Grev. 
Ic. Fil. t. 171; Mett. Farngatt. Pheg. & Asp. 35; Hook. Sp. Fil. iv. 39; Hk. & 
Baker, Syn. Fil. 257. Cyrtomium caducum, Presl; Bedd. Ferns Brit. Ind. t. 45. 
Polypodium polyodon, Wall. Cat. 7079. 
Himalaya, alt. 4000-7000 feet; from Nepaul to Bhotan, common. Khasia, alt. 3000- 
5000 feet; common. 
Main rhachis sometimes with a subterminal rooting bud. Pinnz sometimes subentire, 
sometimes pinnatifid deeply. Sori (in the type) large, in two rows halfway between the 
rhachis of the pinna and margin ; in other cases there is a row (or two rows) of sori close 
round the margin of the pinna following the sinuosities of the outline; in other cases 
there are 2-5 rows of sori (rather small) scattered throughout the pinna. The pinnee are 
usually narrow-lanceolate, but sometimes broader; not seldom are they broader than in 
some forms of 4. falcatum. 
12. A. FALCATUM, Swartz, Syn. Fil. 43. Primary veins from the midrib of the ginn 
carried nearly straight parallel to each other nearly to the margin, throwing off 
pinnately 1, 2, or 3 times inarching veins.—Langsd. & Fisch. Voy. Russ. t. 15; 
Mett. Fil. Hort. Lips. 87; Hook. Fil. Exot. t. 92, Sp. Fil. iv. 40; Hk. & Baker, Syn. 
Fil 257. .4. caryotideum, Wall. Cat. 376; Hk. & Grey. Ic. Fil t. 69; Mett. 
Farngatt. Pheg. & Asp. 35; Hook. Garden Ferns, t. 13, Sp. Fil. iv. 40. 4. anomo- 
phyllum, Zenk. Pl. Ind. t. 1; Mett. Farngatt. Pheg. & Asp. 34. Polypodium 
falcatum, Thunb. Fl. Jap. 336, t 96. Cyrtomium falcatum and del duode e Presl ; 
Bedd. Ferns South. Ind. t. 119. 
Himalaya, alt. 3000-8000 feet; from Gurwhal to Bhotan, extending further west than 
A. caducum, but much less common than 4. caducum eastwards. Khasia, alt. 3000—4000 
feet, not common.—Distrib. South India and Ceylon, China, J apan, Polynesia, South 
Africa. 
Usually can be distinguished from 4. caducum by the broader pinnæ with more nume- 
rous rows of sori; the margin also is generally more finely and sharply serrated. 
29. NEPHRODIUM, Richd. 
Subgenus I. Lastrea. Veins free. 
* Frond 1-pinnate ; pinne lobed less than halfway to the midrib, or subentire serrate. SC 
i. Ei s cow Hk. & Baker, Syn. Fil. 260. Main rhachis and rhachis cot iai c 
