108 FILICES 
11. Hart’s-TONGUE (Scolopéndrium).—Clusters on the back of the frond, 
long, narrow, straight, and in pairs; indusium double; the two portions 
opening towards each other. Name from scolopendra, a centipede, from a 
fancied similarity between the lines of fructification and the feet of that 
animal. 
12. HArD FERN (Blechnum).—Fructification at the back of the frond, in 
two narrow lines, one on each side the mid-rib, and covered each by a con- 
tinuous indusium. Name from the Greek dblechnon, a name for a fern. Also 
known as Lomaria. 
13. Brake (Pééris).—Fructification seated at the back of the frond, or 
rather in a line at its margin ; the indusium formed of the reflected edge of 
the frond, which dilates into a membrane. Name in Greek, pteris, a fern, 
from pteron, a plume or feather. 
14. Mamen Harr (Adidntum).—Fructification at the back of the frond, 
in roundish or oblong clusters, covered by distinct portions of the reflexed 
membrane-like margin of the frond, opening towards the mid-rib. Name 
in Greek denoting unwetted, from the peculiar tendency of the fronds to 
throw off water. 
Sub-Order 11. HYMENOPHYLLACEZ. 
* * Capsules opening irregularly, having a horizontal or oblique ring, and enclosed 
in a 2-valved, membrane-like involucre, terminating a vein at the margin of the 
frond. 
15. BristLE Fern (Yrichémanes).—Fructification on the margins of the 
frond, the clusters having a cup-shaped indusium or involucre of the same 
texture as the frond, and terminating a vein. Name from the Greek, signi- 
fying hair and excess, from its bristle-like receptacles. 
16. Finmy FERN (Hymenophyllum).—Fructification on the margin of the 
fern ; the clusters seated within a 2-valved involucre, which is an expansion 
of the frond. Name from the Greek hymen, a membrane; and phyjllon, 
a leaf. 
Sub-Order III. OSMUNDACEA. 
Ferns having the young fronds rolled up in a scroll-like manner, the 
capsules clustered on the margin of a transformed frond, and forming a 
panicle, without an indusium; capsule destitute of a ring, and opening 
vertically by two valves. 
17, Royau FERN (Osiiinda).—Capsules clustered into a branched panicle, 
terminating the frond. Name apparently given from the Saxon words os, 
house, and mund, peace, or from Osmunder, a name of the god Thor. 
Sub-Order IV. OPpHIOGLOSSACEA., 
Ferns having their young fronds folded straight and not coiled, capsules 
arranged on a separate branch of the frond, without a ring or indusium, 
coriaceous, and opaque in texture. 
18. Moonwort (Lotrychium).—Capsules roundish, sessile clustered at the 
