84 CHAEACTERS OF TRIBES AND GENERA. 



Indusium sub-reniform, oblong or nearly orbicular, 

 plane, interiorily attached by its base, and partly by 

 its sides, equal with, or shorter than the margin, thin, 

 scariose. 



Type. Davallia immersa, Wall. 



Illust. Hook and Bauer, Gen. Fil, t. 52, A ; Moore, Ind. 

 Fil., p. 73, B. ; J. Sm., Ferns Brit, and For., fig. 4. 



OBS. This genus as founded by Presl consisted of only 

 one species, namely Davallia immersa of Wallich, which has 

 pale deciduous fronds, rising from a hypogeous creeping 

 caudex. Although the character of the sori differs little 

 from that of Humata, its distinct habit does not allow it to 

 be associated with that genus or with Davallia ; which is 

 also the case with other species of Davallia of authors, which 

 I here place under Leucostegia. They are widely distributed 

 throughout the same countries as those of the preceding. 



Sp. L. parvula (Wall.) (v v.) ; L. falcinella (Pr.) ; L. 

 affinis (Hook.) (vv.);L. Grimthiana (Hook.) ; L. cheero- 

 phylla (Wall.) (v v,) ; L. pulchra (Don.) (v v.) ; L. immersa 

 (Pr.) (v v.) ; L. membranulosa (Wall.)', L. hirsuta (/. Sm.) 

 (v v.) ; L. borneensis (J, Sm.) (Nephrodium, Hook.) ; 

 L. assamica (v v.) (Bedd. F. Brit. Ind. Fil. 94). 



OBS. In Moore's " Index Filicum," the above species 

 are all placed in the genus Acrophorus of Presl, which is 

 founded on Aspidium nodosum of Wallich, a large growing 

 Fern of peculiar habit, and having no natural affinity with 

 the species of Leucostegia, its vernation being adherent and 

 fasciculate (see Acrophorus). 



* * Sori destitute of Indusium. 



Tribe 3. POLYPODIES. (Plate 3.) 

 Veins free or anastomosing in various ways. Sori 



