THE FILMY FEENS. 
443 
They have short wire-like stems, and the leafy or 
filmy portion consists of a series of branched veins 
arranged alternately on each side of the rachis. The 
primary veins are divided into veinlets, which are 
usually arranged in pairs oneach side of the primary 
veins. Each vein, whether primary or secondary, 
is bordered by a narrow, filmy, leafy wing. The 
seeds, when they are formed, are placed in little 
cup-shaped receptacles in the angles made by the 
rachis and the primary branches of the frond. 
The general outline of the latter is somewhat egg- 
shaped. The leafy filaments are of a dull, 
brownish-green colour, and semi-transparent. 
