VI INTRODUCTION. 
margin of the leant, inserted in the covering; covering, 
being a continuation of the leafit's outer skin, scale-like, 
opening on inner side. 
HYMENOPHYLLACE^:. 
Fructification placed on a receptacle at the margin of the 
frond at the end of a vein. Ring horizontal. Vernation 
coiled. 
THICHOMANES. Masses on the margin in a somewhat 
bell-shaped receptacle, with a central bristle-like column, to 
which the masses are attached. 
HYMENOPHYLLUM. Masses attached to a central, rather 
club- like column, in an erect two-valved receptacle. 
OSMTJNDACEJB. 
Fructification naked, arranged in a cluster on a stalk at 
the end of a frond. Vernation coiled. 
OSMIWDA. Masses in cases nearly globular, netted, 
stalked, opening lengthwise from their base as high as a 
transparent dorsal projection ; the cases borne in a cluster 
or panicle. 
OPHIOGLOSSACES:. 
Fructification naked, arranged in a cluster on a stalk 
attached to a frond. Vernation straight. 
OPHIOGLOSSUM. Masses in a jointed two-rowed spike, in 
cases joined at the base, one-celled, opening at the side. 
BOTRYCHIUM. Masses in compound one-sided spike, 
adnate; capsules globular, stalkless, leathery, half two- 
valved, opening rather on the side. 
