78 
THE CRESTED BLCKLER FERN. 
somewhat spinulose ; those toward the apex of each 
pinna, as well as the basal ones of the pinnae nearer 
the apex of the frond, become gradually less and less 
compound, so that, although the margins are still fur¬ 
nished with spinulose teeth, they gradually lose the 
deep lobes which are found on the lowest pinnae. In 
all the more compound Ferns there is a similar differ¬ 
ence of form according to the disposition of the pin¬ 
nules, and in all such cases it is usual only to describe 
the most complete — that is, those at the base of a 
few of the lowermost pinnae. The venation in the less 
divided pinnules consists of a midvein giving off 
branched venules, the sori borne on the lower anterior 
venules proceeding from these, about midway between 
the vein and the margin, thus forming an even double 
row on each pinnule. The same arrangement occurs 
on the lobes when the pinnule is more divided. The 
indnsia are kidney-shaped, with the margin entire. 
L. spinulosa is common over the whole of England, 
generally in nioist shady places, ranging from the sea- 
level to an elevatien of 600 feet. In Scotland, Wales, 
and Ireland it is rare. In the Lake Country it is 
common in bogs and damp woods throughout the 
district. 
