CHARACTERS OF TRIBES AND GENERA. 175 
anastomose, but agrees in the sporangia being seated in a 
marginal groove., The upper of these is the largest, repre- 
senting an indusium analogous to that of Lindsca, with 
which it is associated in the “Species Filicum,” but its 
-= very different habit prevents its being associated with 
- Lindsea. It is otherwise peculiar in being the only Fern 
in Desmobrya having transverse marginal sori, and com- 
pound. anastomosing venation. r 
Sp. D. panamense, Hook (v. v.)., Hook. Fil. Exot., t. 54. 
Tribe 11.—PLEUROGRAMME (Plate 11). 
Fronds simple, 1 to 10 and 12 inches in length, entire, 
serrate, rarely dentate orlaciniated. Sori linear, transverse 
costal, or oblong sub-linear, oblique. | 
Oss.—This tribe contains about thirty small, and with 
the exception of a few, grass-like Ferns, and although the 
character of the sori does not technically differ from 
Gymnogramme, they nevertheless are so different in habit 
that they do not form a natural connection with that 7 
genus; I therefore deem it best to characterise them as a | 
distinct tribe. 
83.—Monoaramma, Schk. (1809). 
Vernation uniserial sarmentum slender. Fronds simple, 
distant, linear, graminoid, 1 to 4 inches high. _Veinless. 
Costa sporangiferous on its disk, or seated in a deep groove 
' on one or both sides, forming a continuous or interrupted 
linear soris near the apex of the fronds, the margins of 
which are generally more or less incurved, 
Type. Monogramma graminea, Schk. 
