( 4 ° ) 
* " 
shape; margins serrated, and fringed with 
sharp, stiff spines. The pinnules overlap 
each other and continue nearly down to the 
crown. Stipes very short and covered with 
t 
scales. 
Growth. Very erect and rigid. Prickly to the touch. 
Height. From four to twelve inches. 
Colour. Dark, shining green. 
Habitats. The rocky, mountainous districts of York¬ 
shire, N. Wales, Scotland and Ireland. 
(See also page 55.) 
GROUP I; GENUS XIII. 
PTERIS. 
Sori. Marginal, growing in a continuous line on a 
marginal vein, which is joined to the mid-vein 
by lateral branches. Indusium formed by the 
prolongation of the upper skin of the revolute 
margin of the pinnule. A peculiarity of this 
