CHARACTERS OF TRIBES AND GENERA. 259 



Trile 17. SACCOLOME^E (Plate 17). 



Vernation uniserial sarmentose, rarely fasciculate. Sori 

 marginal. Special and accessory indusium forming marginal 

 exserted or sub-marginal cysts, containing the sporangia. 



OBS. As stated under Dicksonice I deem it best to cha- 

 racterise the following genera as representing a distinct 

 tribe, the sarmentose habit of growth being quite at 

 variance with that of Dicksonice. The number of species 

 amounts to about forty, which are widely distributed 

 throughout the warm and temperate regions of both hemi- 

 spheres, growing on the ground, rarely epiphytal, the 

 greater number of species being retained in the genera 

 Dennstcedtia and Microlepia. 



141. SACCOLOMA, Kaulf. (1820). 

 Davallia sp. t Hook. Sp. Fil. 



Vernation erect or sub-decumbent. Fronds 4 to 6 feet 

 long, pinnate, smooth ; pinnao linear lanceolate, acuminate, 

 8 to 12 inches long, serrated at the apex. Veins simple, 

 rarely forked, direct, parallel, free. Sori punctiform, con- 

 tiguous, laterally coalescing and forming a compound, 

 marginal, continuous line of sori. Special indusium small, 

 transverse, elongated, sub-scyphiform ; accessory ones uni- 

 versal, formed of the continuous reflexed margin. 



Type. Saccoloma elegans, Kaulf. 



lllust. Hook, and Bauer., Gen. Fil., t. 58 B., figs. 1, 2 ; 

 J. Sm. Ferns, Brit, and For., fig. 123. 



OBS. This genus is represented by probably two species, 

 the typical species being a very elegant Fern, a native of 

 the West Indies and tropical America, having resemblance 

 to Pteris longifolia and P. moluccana, with which its reflexed 



