BEAUTIFUL FERNS. . 87 
towards the base. The section is round, and shows a firm 
exterior sclerenchymatous sheath, within which is a broad 
circle of brownish parenchyma, and in the middle a single 
fibro-vascular bundle obtusely triangular in shape, but with 
the sides slightly hollowed in. 
The fronds vary from a few inches to over a foot in 
length ; their general shape is ovate-lanceolate, or oblong-lan- 
ceolate ; they are in general of a grayish color from the 
abundance of a fine entangled tomentum, which covers both 
surfaces, though it is a little thinner and whiter on the upper 
surface. The large fronds are fully tripinnate. The primary 
pinnae are oblong-ovate, short-stalked, one to nearly two 
inches long, and a half to three-fourths of an inch broad at 
the base. They are either opposite or alternate, the lower 
ones, as usual, more separated than those that are higher up 
on the frond. The secondary pinn^ are close-placed, oblong, 
obtuse, and again pinnated into from two to five minute 
rounded or rounded-obovate sessile or adnate-decurrent pin- 
nules on each side, besides a terminal oval pinnule which 
is twice as large as the lateral ones. These ultimate pin- 
nules are innumerable, and it is in allusion to their very 
great number in this and the allied species that the generic 
name Myriopteris was proposed by Fee for the group. 
The whole margin of the pinnule is recurved, and from 
the edge of it is produced a very delicate whitish involucre, 
the whole forming a sort of pouch, as is admirably repre- 
sented in the figure given by Fee. The^sporangia have a ring 
