280 TAKEDA—ASIATIC POLYPODIUMS. 
As the characteristic features of this species we may mention 
that the frond is very thin, herbaceous, distinctly showing the 
veins and venules; the sori are arranged in a row quite close 
to the midrib and immersed, and the ramenta are ovate, acu- 
minate, and entire. The sorus is, when young, completely 
covered with a number of large peltate scales, which are usually 
pale brown, or in the variety, dark in the centre. 
P. excavatum can readily be distinguished from P. nudum 
by the very thin frond, which, being deciduous, does not roll up on 
the margin, and by the sori, which are situated nearer the 
* midrib than in the other species, often larger, and obliquely 
oval in shape, while those of P. nudum are strictly round. 
The ramenta on the rhizome vary in colour from pale brown 
to dark brown, or in the case of the variety, they are light 
brown in the margin, and black in the centre. 
The synonymy of this species is as follows :— 
P. excavatum, Bory, apud Willd. Sp. Pl. v, p. 158 (1810). 
Syn. :—P. simplex, Sw. in Schrad. Journ. 1800, p. 158 eo) 
non alior.; Blanf. in Journ. As. Soc. Bengal, lvii, p. 313, t 
xx (optim m.) 
P. lineare 8 simplex, Bak. in Hook. Bak. Syn. Fil. p. 345 
(1883). 
P. Scolopendrium, Ham. apud Don, Prodr. Fl. Nepal. p. 1 
(1825). 
P. sesquipedale, Wall. List, n. 275 (1828). 
Drynaria phlebodes, Fée, Gen. Fil. p. 270 (1850-52). 
P. phlebodes, Kze. apud Mett. Polyp. p. 92 (1857). 
P. bullatum, Bak. in Journ. Linn. Soc. xv, p. 420 (1876). 
P. lineare et forma major Christ, in Bull. Acad. Intern. Geogr. 
Bot. xvi, p. 105 (1906), non Thunb. 
P. maculosum, Christ, l.c. nec Christ, 1898. 
a. concolor, Takeda. 
Ramenta rhizomatis concoloria fusca vel nigro-fusca, margine 
pallidiora. 
8. bicolor, Takeda. 
Ramenta laete brunnea et medio nigra. 
Monstr. polymorphum, (Clarke) Takeda. 
Syn. :—P. lineare var. polymorphum, Clarke, Ferns N. India, 
Pp. 559 (1880). 
Distr. spec.—India (Punjab, Nepal, Kumaon, Sikkim, 
— Khasia), Ceylon, China, Africa trop., Madagascar, Ins. 
As in P. nudum, the frond of this species is extremely variable 
