F I L I C E S B R I T A N N I C iE. 71 
each furrounded with a ihort lax vagina, black at the bafe and margin, 
but of a pale green in the middle. 
The fpaces between the joints are of a ftrong bluifh green, channelled 
with twelve or lixteen furrows, and having alternate ridges, which are 
armed with hard, fliort, rough fpines, regularly placed in one line, along 
each ridge, as is expreffed at b ; where a vagina, a, and part of the ftem 
are magnified. 
The ftem, as in the other fpecies, confifts of a number of fiftular 
tubes, which are bound together by an external and internal bark, and 
form one general fiftular tube. In this fpecies the inner bark is fmooth 
and white. 
The barren leaves in this fpecies are not to be diftinguiftied from the 
fertile in any thing, but the want of frudification, and in their upper 
extremities terminating in a fine point. 
Both the one and the other are moft commonly fimple, but fometimes 
emit one or two branches from the lower joints, as is exprefted in the 
plate. Thefe are of the fame figure and ftrudure as the primary leaves, 
only fmaller, and confifting of fewer joints. 
This fpecies is diftinguiftied by the fliort obtufe dents of the vaginae, 
by the remotenefs of the joints, by the roughnefs of the touch, and by 
being an evergreen. 
The only places where I have feen it grow, are amongft the bufhes 
clofe by the brook at the lower end of the Helk^ near Ingleton ; and in 
a field, belonging to an eftate called Upper Brier^ in Northowram^ near 
Halifax. 
P 
PILUL ARI Ao 
