THE CRESTED BUCKLER FERN. 219 
almost to the midrib, with oblong acute lobes; the lobes strongly 
serrated, with spinulose teeth, whose points are directed towards 
the apex of the lobe, and often curved upwards above the plane 
of its surface; the upper pinnules are either inciso-lobate with 
spinulosely serrate lobes, or coarsely serrate with spinulose teeth. 
The barren fronds usually, and some of the fertile ones, are broader 
and more lax in habit than those above described, and sometimes 
entire plants assume this character. 
Venation of the pinnules (the basal ones of fertile pinnz near the 
centre of the frond,) consisting of a stout midvein, from which a 
primary vein extends into each lobe, where it forms a flexuous 
secondary midvein, bearing alternate forked venules, on the short 
anterior fork of which, nearly at its point, and standing just beneath 
the sinus of the serrature, the sorus is placed, the sori then forming 
two rows along the lobes of the pinnules. In the less divided 
pinnules at the middle of the pine, the primary midvem produces 
branched veins, and the anterior basal venule also in this case bears 
the sorus, near to its termination, so that the sori then form two 
lines along the pinnule itself. This latter being the structure of the 
greater number of pinnules, the general aspect of the fructification 
is to form two lines lengthwise on the pinnule. The venules are 
directed one towards each serrature, but terminate before reaching 
it, in a thickened point. 
Fructification on the back of the frond, usually occurring on the 
upper half, but sometimes extending over the whole surface. Sort 
numerous, round, indusiate, medial or subterminal on the anterior 
basal venules, (or on several venules in the deeply pinnatifid basal 
pinnules,) forming a line on each side the midvein ; usually distinct, 
but often crowded. Indusium flat, reniform, membranaceous, per- 
sistent, with an entire margin, wavy or with angular projections, but 
without glands. Spore-cases brown, numerous, rotundate. Spores 
oblong, granulated. 
Duration. The caudex is perennial. The fronds are annual, the 
first growth appearing early in May, and others growing up at 
intervals through the summer; they perish in autumn when 
exposed, but under shelter, though decaying near the base of the 
stipes so as to be unable to stand erect, they nevertheless retain 

