9 
green cover (indusium.) The first family have no covers 
and are called Polypodies. FolypodiecB. The second have 
a roundish cover* and are designated 
Shieldworts. Aspidiece, The third have 
a linear one, as appears in the Hkart’s- 
tongue, Plate II. fig. 17, not parallel 
to the mid-rib, and bear the name of 
Spleens. Aspleniece, The fourth have a 
linear cover, either parallel to the edge 
of the leaflet, or formed by that edge 
bent back and rolled in. These are 
Maidenworts. Adiantece, Thus we have 
four families of Polypods. The names of these, and their 
distinctive marks, and their respective genera, are 
POLTPODS. POLTPODIACE^. 
Family I. 
I. Polypodies. FolyjpodiecB. Covers none. Clusters 
seated on the back of the side-veins. 
1 Genus, 
Polypody. Folypodium, Clusters round on the middle 
of the underside of the lobes or leaflets of the frond. 
Family II. 
II. Shieldworts. Aspidiece. Clusters round. Covers 
roundish not attached by the outer edge. 
2 Genera. 
1. Shield Ferns. Lastrea. Covers roundish or kidney- 
shaped, having a slit in it, and attached by the inmost point 
of that slit to the back of the side-vein. Veins distinct and 
separate after leaving the mid-rib. The best type of this 
genus is the Male Fern. The cover of etching c. is that 
of this genus. 
2. Prickly Ferns. Covers round, attached by the centre. 
The bristles on the edges of the leaflets are a leading cha- 
racter of this genus. 
Family III. 
III. Spleens. Aspleniece. Clusters of fruit linear or 
oblong, or rarely roundish.f Covers linear,^ but not parallel 
* This etching is magnified, as the covers in Plate I, fig. 7 are rather less than 
the natural size. 
t In one variety of Lady Fern this is the case. $ Not always a straight but 
sometimes a curved line. 
