GENERA. Ixxxi 



i. Polypodies. Clusters of Fruit from a point on the veins, or from a small terminal 



disc. 

 ii. AspleniEjE. Clusters disposed along the veins. 



iii. Pterides. Covering of the Fniit dependent on, or connected with, the margin of 

 the frond. 



b. Fruit marginal. 



iv. Hymenophylle^. Fruit in a sort of marginal cup. 



B. Capsule without a ring. 



V. OsMUNDE^. Vernation cireinate. Caps, on the altered extremity of the frond. 



vi. OphioglossEjE. Vernation straight ! Caps, sessile, on a separate branch of the 

 frond. 



IV. MARSILEACEjJ]. Caps, not splitting, placed near the root, and at the base of the L. 



V. LYCOPODIACEiE. Stem leafy. Caps, axillary, splitting. Seeds a fine powder. 



I. CHARACE^. 



916. CHARA. Anther? lateral, sessile, globose; the cover spKtting into several portions. 

 Fr. covered with spiral valves, and containing minute 'granules, which appear at last to unite in a 

 single seed. Green, aquatic, leafless plants, p. 421. 



II. EQUISETACEiE. 



917. EQUISETUM. Catkin terminal. Scales peltate, bearing Spore-vessels on the under 

 sm'face. Spores accompanied by spiral threads. Leafless plants, with a jointed stem and 

 branches, p. 422. 



III. FILICES. 



A. Capsule furnished with an elastic ring. 



a. Fruit dorsal. 



i. Polypodies. 



918. POLYPODIUM. Clusters of Fr. without an indusium. p. 423. 



919. POLYSTICHUM. Indusium peltate, attached by its centre, p. 423. 



920. LASTB-^A. Indusium reniform, attached in the sinus, p. 423. 



931. CYSTEA. Indusium attached by its hooded base under the clusters, with a length- 

 ened, fringed, free extremity, p. 424. 



922. "WOODSIA. Clusters with an inferior indusium divided into capiUaiy segments, 

 p. 424. 



ii. ASPLENIES. 



923. GEAMMITIS. Indusium 0. p. 424. 



924. ATHYBIUM, Clusters oblong, curved. Indusium opening towards the central 

 nerve, p. 424. 



925. ASPLEKIUM. Clusters oblong, straight. Indusium neai'ly flat, opening towards 

 the centi'al nerve or midrib, p. 424. 



926. CETEEACH. Lateral Veins anastomosing. Indusium a narrow membrane, hardly 

 distinguishable from the scales, with which the whole back of the frond is covered, p. 425. 



927. SCOLOPENDRIUM. Clusters long, in pairs ; the Indusia opening towai'ds each 

 other, p. 425. 



928. BLECHNUM. Clusters in a continued line, parallel to the midrib of the pinna. 

 Pinna of the fertile Frond much narrower than those of the barren, p. 425. 



