114 
HISTORY OF BRITISH FERNS. 
position of the pinnules, and in all such cases it is usual 
to describe only those which are the most complete, namely, 
such as are situated at the base of a few of the lowermost 
pinnae. The venation in the less divided pinnules con- 
sists of a midrib, less tortuous than in cristata, which 
gives off branched veins ; the lower anterior venules 
proceeding from these bear the sori, about midway between 
the rib and the margin ; the clusters of spore-cases thus 
forming an even double row on each pinnule. When the 
pinnule is more divided, the same arrangement of the sori 
occurs on the lobes, the branches of the lateral veins or 
venules being then more numerous. The sori are covered 
by kidney-shaped indusia, having the margin entire. 
This Fern is met with in marshy places and damp woods ; 
and in such places it does not appear to be uncommon. It 
is very easily cultivated on damp banks or rockwork, and, 
when grown in pots, requires to be plentifully supplied 
with water. 
Lastrea cristataV^^ received the additional names of 
Polypodium, Aspidium ^cvAPolystichum cristatum^ Dryo- 
pteris cristata and LopJiodium Callipteris, A similar series 
of synonymes belong to the variety spinulosa. 
