r9tt] CHRIST—FILICES WILSONIANAE 357 
related but perfectly distinct; two species extend beyond China, A. venustum of 
northern India and A. monochlamys Eaton of Japan. Our species is nearest 
to A. Davidi Franch., but differs in its larger dimensions, more rounded, 
monosorous pinnules, with numerous and aristate teeth. 
Dryopteris pseudocuspidata H. Christ, n. sp.—Rhizomate 
repente, fere digiti minoris crassitie, brunneo, sublaevi, radicoso, 
stipite subsolitario, anguloso, 55 cm. longo, sublucido, dilute 
brunneo, pennae cygni crassitie, versus basin squamis ovatis 
obtusis brunneis deciduis sparso, planta caeterum laevi. Fronde 
36 cm. longa 22 cm. lata, basi haud angustata, late ovato-del- 
toidea, acuminata, pinnata, pinnis ca. 18 utrinque, patentibus, 
12 cm. longis 1.5 cm. latis lanceolato-acuminatis, vix petiolulatis, 
basi rotundato-truncatis, superioribus sensim diminutis nec adnatis, 
suprema petiolata valde diminuta. Pinnis dentatis, dentibus 
decumbentibus acutis interdum serrulatis. Costa manifesta pro- 
minente. Nervis ca. 40 utrinque, patentibus. Nervulis plerumque 
6 utrinque, omnibus arcu acuto junctis. Soris minutis 6 utrinque 
medialibus brunneis, rotundis, separatis, exindusiatis. Textura 
papyracea, colore opaco, obscure viridi. 
Has.—W. Szech’uan, woodland, Mupin, 6000 ft., August 1908, no. 2603. 
Habit of D. cuspidata (Aspidium Metten.) syn. D. khasiana C. Chr. Ind. 
272, but belonging to the group Nephrodiwm with six lateral united veinlets. 
PTERIS CRETICA L. var. subserrulata H. Christ, n. var.—A 
typo differt foliis papyraceis nec subcoriaceis dimorphis, fertilibus 
valde angustatis, sterilibus magis compositis, pinnis inferioribus 
basi bi- aut tripartitis, pinnulis lateralibus abbreviatis, rachi superi- 
ore late alata, marginibus acute et grosse biserratis. 
Has.—Shady rocks, Fang Hsien, 3000-5000 ft., July 1907, no. 2670. 
In China P. cretica varies much and approaches P. serrulata L. fil. There 
are also forms of the latter species that approach P. cretica (Filic. Shen-si 
Septentr. a P. J. Grratpr lectae in Nuov. Giorn. Bot. Ital. IV. 1:6. 1897; 
Pleris serrulata var. intermedia Chr.), so that it is sometimes difficult to main- 
tain a difference between the two species. 
The starch of Pteridium aquilinum (L. Kuhn) 
The specimen of starch from the rhizome of Pteridium from 
Ichang, below the famous gorge of the upper Yang-tze, Province 
Hupeh, that Mr. E. H. Witson sent to Harvard University, con- 
