CHARACTERS OF TRIBES AND GENERA, 83 



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

 forked, venules free ; fertile venules sometimes very short, 

 dentiform. Sori terminal. Receptacle punctiform. Spor- 

 angia vertical, included within an urceolate or tubular indu- 

 sium. 



Type. Davallia canariensis, Smith. 



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

 Fil., p. 75 B. ; J. Sm. Ferns Brit, and For., fig. 3 ; 

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



OBS. This genus consists of about a dozen or more 

 species, widely distributed over the Eastern Hemisphere, 

 the extreme western limits being the Azores and Canary 

 Islands. It differs from Humata 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, Hook. D. pentaphylla, SI. (v v.) ; D. 

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

 Hook. ; D. solida, Sw. (vv.); D. ornata, Wall, (vv.) ; D. 

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

 Sw. (vv.) ;^D. elegans, Sw. (v v.) ; D. pallida, Hett. (v v) ; 

 D. nitidula, Kze. (v v.) ; D. Vogelii, Hook, (v v.) ; D. canari- 

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



4. LEUCOSTEGIA, Presl (1836). 

 Davallia, sp. Hook. Sp. Fil. ; AcropJiorus, Moore. 



Surculum slender, or short and thick (hypogeous in L. 

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

 tifid, generally membraneous and flaccid, from 2 inches to 

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

 mostly bifid and soriferous below the sinus. Veins 

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

 Sori terminal, sub-marginal. Receptacles punctiform. 



