CHARACTERS OF TRIBES AND GENERA. 259° 
Tribe 17.—SACCOLOME (Plate 17). 
Vernation uniserial sarmentose, rarely fasciculate. Sori 
marginal. Special and accessory indusium forming marginal 
exserted or sub-marginal cysts, containing the sporangia. 
Oss.—As stated under Dicksonie 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 Dicksonie. 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 
Dennsteedtia and Microlepia, 
141.—Saccoroma, Kaulf. (1820). 
Davallia sp., Hook. Sp. Fil. 
Vernation erect or sub-decumbent. Fronds 4 to 6 feet 
a long, pinnate, smooth ; pinne linear lanceolate, acuminate, 
. 8to 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. 
Illust. Hook. and Bauer., Gen. Fil., t. 58 B., figs. 1, 2; 
J. Sm. Ferns, Brit, and For., fig. 123. 
Ozs.— 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 
