CHAEACTEES OF TRIBES AND GENERA. 83 



glossy, rarely flaccid, from 6 inches to 3 feet higb. Veins 

 forked, venules free ; fertile venules sometimes very sliort, 

 dentiform. Sori terminal. Receptacle punctiform. Spor- 

 angia vertical, included within an urceolate or tuljular indu- 

 sium. 



Type. DavdlUa canarlensis, Smitli. 



Illust. — Hook and Bauer, Gen. Fil, t. 27; Mooro Ind. 

 Kl., p. 75 B. ; J. Sm. Ferns Brit, and For., fig-. 8 ; 

 Hook. Syn. Fil,, t. 2, fig. 18, c. 



Obs. This genus consists of about a dozen or more 

 species, widely distrilDutcd over the Eastern Hemisphere, 

 the extreme western limits being the Azores and Canary 

 Islands. It differs from Uumata in having the indusium 

 attached by its base and sides, impressed in the substance 

 of the fronds, thus forming an urceolate tubular cyst. 



Ex. — D. triphylla, Sool:. ; D. peutaphylla, EL (v v.) ; D. 

 bullata, Wall, (v v) ; D: mauritiana. Hook.; D. fijiensis, 

 Hooh. ; D. solida, /S'(w. (vv.); D. ornata. Wall, (vv.) ; D. 

 pyxidata, Cav. (v v.) ; D. divaricata, Fd. (v v.) ; D. elata, 

 Sw. (vv.) ;'D. elegans, Sw. (v v.) ; D. pallida, Mett. (v v) ; 

 D. nitidula, Eze. (v v.) ; D. Vogelii, Hooh. (v v.) ; D. canari- 

 ensis, Sm. (v v.) ; D. dissecta, /. Sin. (v v.). 



4. — Leucostegia, Presl (1836). 



T)avallia,sp. Ilooh. Sp. Fil. ; Acropliorus, 2Iuore. 



Surculuni slender, or short and thick (hj^wgeous in L. 

 immersa). Fronds lanceolate, bipinnatifid, or deltoid-muL. 

 tifid, generally membraneous and flaccid, from 2 inches to 

 2j feet high, smooth, rarely pilose, the ultimate divisions 

 mostly bifid and soriferous below the sinus. Vcint. 

 forked ; venules free, the anterior ones often very short. 

 Sori terminal, sub-marginal. Beceptades punctiform. 



