104 
EERNY COMBES. 
gant. These two latter have only as yet been 
found in Scotland. 
HtMENOPH YLLUM UNIL ATEEALE . WUsOU's 
Filmy Fern. (Plate IV. Fig. 2.) 
The Symenophyllums resemble the moss tribe 
much more nearly than they do other ferns (with 
the exception of TricTiomanes hrevisetum) in general 
appearance ; and instead of bearing their seed at 
the back of the frond, it is concealed in small cupped 
receptacles, which in unilaterale stand on short 
stalks between the main stem and the branches, 
which always turn in one direction, and the recep- 
tacles conspicuously in another. In Hymenophyl- 
limi Tunbridgense the receptacles are also placed 
between the branch and the main stem, but forms 
as it were a portion of the frond. These two little 
plants are seldom more than two or three inches 
high, with creeping wiry roots, which cling in 
moss-hke patches to rocks in the neighbourhood of 
streams, or twine among the mosses they so much 
resemble at a little distance. 
The frond consists of a midrib and alternate 
branches, which are again ramified on the upper 
side ; these branches are clothed with narrow pel- 
lucid wings. The most sure distinction between 
the two varieties is the shape of the receptacle. In 
