POLYPODIACE.E. 215 



nent, with a shallow furrow on the upper side, paleaceous-hirsute, the 

 scattered and slender, fimbriate palea3 intermingled with the hairs. 

 Veins sometimes simple, but usually forked once or twice ; and some- 

 times two opposite venules are angularly united, thereby forming elon- 

 gated areoles. Sori solitary, forming a transverse and prominent 

 irregular line, which sometimes appears as if double, parallel with 

 the costa and 2 to 3 lines distant from it. Indusium of a brown 

 colour, reni/orm and entire, with a few hairs near its centre. 



This is nearly related to the 0. pilosa of Hooker, the base of a 

 frond of which, with a section of the same showing the sori, is figured 

 in his Genera Filicum. Our plant has a longer stipe, articulated 

 about the middle ; the fronds have a long attenuated base, and an 

 entire, not ciliated indusium. 



Plate 29.— Fig. 1. Portion of the plant, of the natural size. 1 a. 

 Section of a frond. 1 b. Smaller portion, with a single sorus. 1 o. 

 Scale from the rootstock. 1 d. Hairs from the surface of the frond. 

 1 e, e. Sporangia. — The details more or less magnified. 



Tribe YL DICKSONIEvE, J. Sm. 

 67. ISOLOMA, J. Sm. 



(Linds^je Spec. Wall., Presl, Hook. & Grev.) 



1. ISOLOMA LANUGINOSA, /. Sm. 



I. rhizomate brevi erecto; stipite semitereto antice unisulcato paleaceo 

 hirsuto; frondibus co3spitosis lineari-lanceolatis pinnatis; pinnis plu- 

 rimis approximatis subcoriaceis oblongo-ellipticis lanceolatisve sub- 

 falcatis obtusis vel subacutis basi truiicato-auriculatis articulatis lana 

 decidua utrinque tomentosis; costa centrali; venis patentibus apice 

 intra marginem cretaceo-pwnctigeris ; soris tnarginalibus continuis. 



