VII. LASTREA. 113 
with long narrow sharp-pointed reddish-brown membranous 
scales, which become smaller and less abundant upwards, 
but are continued in a hair-like form up the rachis. The 
fronds are bipinnate, more or less lanceolate; in some 
cases where the lower pinnae are slightly shorter than 
those above them, they are truly lanceolate ; in other in- 
stances the lowest pinnae are somewhat the longest, the 
upper ones gradually decreasing in size, and when this is 
so, they are of a narrow and elongated triangular outline, 
which appears to be the normal form in the mature plants. 
The longest pinnae in vigorous fronds measure from two to 
three and a half inches in length. The short lower pinnae 
of the lanceolate form are broader and more distant than 
the upper ones, and have a triangular outline ; whilst the 
lower pinnae of the triangular form are of about the same 
width as those of the lanceolate form, but twice their 
length, and therefore much narrower hi proportion. The 
pinnae are all pinnate, alternate, tapering from the base 
upwards, broadest in the lower part of the frond, the upper 
ones gradually becoming narrower. The pinnules are 
oblong, truncate below, usually with a narrow stalk-like 
attachment, but sometimes slightly decurrent, more or 
less deeply pinnatifid, the lobes serrated, with from two to 
five acute, but not spinulose teeth. They have a sinuous 
mid-vein, with alternate veins, each of these producing 
three or more venules, the lowest anterior one of which 
bears a sorus a short distance from its origin. One vein 
is projected into each of the lobes, and the number of 
venules is accordant with the number of marginal teeth, 
one being directed to each serrature. From this disposition 
of the veins the sori become ranged in a line on each side 
and near to the mid-vein, and are usually so near together 
as soon to become confluent, and occupy the central part 
of the pinnule. They are each covered by a persistent 
renifonn indusium, the sinus of which is turned towards 
the base of the pinnule, and the margin is fringed with 
stalked glands. 
