J. SMITH ON THE GENERA OF FERNS. 191 



cial! included within a globous calyciform indusium, opening 

 irregularly; sori round; rhizoma creeping; fronds decom- 

 pound, multifid, stipes and rachis squamous-glandulous. 



Species. D. aspidioides, Blume. Illust, Hook, Gen. Fit. 

 t. 99. 



Obs. This agrees in every respect with tiie preceding 

 genus, differing only in the sori not being pedicillate : but al- 

 though such appears to be the case, still they are not strictly 

 so, being superficially seated on a slightly elevated point, 

 from which the entire sorus can be freely removed without 

 rupturing the base of the indusium or receptacle of the spo- 

 rangia, a circumstance clearly proving its superficial attach- 

 ment. 



90. WooDSiA, n. Br. 



(Polypodii sp. Auth. Hymenocystis, C. A. Meyer. Pbyse- 



matium, Kaidf.) 



Veins forked ; venides simple ; sporangia terminal or me- 

 dial ; sori round ; indusium calcyciform, its apex open, near* 

 ly entire, or deeply laciniated, the lacinise usually terminating 

 in long hairs, which involve the sporangia. 



Fronds small, from 1 inch to afoot in height, hi-tripinnati- 

 fid, smooth or squamous; veins usually simple or forked, the 

 lower extemor branch soriferous. 



Examp. 1. W. glabella, R. Br. 2. W. ilvensis, R. Br. 3. 

 \V. hyperborea, R. Br.. 4. W. Perriniana, Hook. 5. W. 

 Caucasica, J. Sm. (Hymenocystis, C. A. Meyer.) 6. W. 

 incisa. Hook. T. W. mollis, J. Sm. {rhysemaiium, Kaulf.) 

 Illust. Linn. Tran. vol. ii. t. 2. Hook, et Bauer Gen. Fd. t. 

 3. Hook, et Grev. Ic. Fil. t. QQ, J 91. Kunze Anal. Pterid. t. 

 27. 



Obs. This genus is characterized by its peculiar indusium, 

 which in the original species of the genus (the cup or mem* 

 brane) is very small, and soon becomes hidden by the enlarge- 

 ment of the sporangia ; but the long hairs which fringe its 

 margin remain conspicuous; in some other species the cup is 

 more entire and complete, and in Woodsia mollis and W, 

 Caucasica, the margin is nearly entire and circular, in that 



