160 
IX ASP1.KXIUM. 
the variety acutmii, the pinnae take a much narrower 
and more acute and elongated form. The margin i.s 
creuately serrate, sometimes doubly crenato-berrate, occa- 
[Asplenium inarinum.j 
sionally lobed. The venation is tolerably distinct, not- 
withstanding the leathery texture of the frond s ; the mid- 
vein is prominent, and the venules become forked soon 
after leaving it, and bear on the anterior branch scarcely 
midway to the margin, a linear sorus which is covered by 
a pale-coloured persistent indusium, opening on the side 
towards the apex of the pinnse. In some cases the sorus 
extends almost the whole length between the mid-vein 
