Class XXIV. Order I. 381 



lightness. It is the principal material used in the manufacture 

 of carriage frames, of light agricultural implements, of oars, 

 blocks, boxes, Sec. May. 



Class XXIV. CRYPTOGAMIA. fructification 

 anomalous or concealed. 



Order I. FIL1CES. Ferns. 



441. EQUISETUM. Floral receptacles peltate, many 

 angled, collected into a spike ; indusium corniculate j 

 stamina four ; style none ; seed one. 



442. LYCOPODIUM. Capsules reniform, one celled, 

 two valved, many seeded ; seeds very minute, resem- 

 bling powder. 



443. BOTRYCHIUM. Capsules subglobose adnate to 

 the rachis of the compound raceme, separate, naked, 

 one celled ; valves two, connected behind, opening 

 transversely. 



444. LYGODIUM. Spikes unilateral ; capsules in 

 two series, opening on the inner side from the base to 

 the summit ; indusium (or veil) squamiform, cover- 

 ing each capsule. 



445. OSMUNDA. Capsules subglobose, pedicellate, 

 striate, semibivalvular and paniculated ; indnsium none. 



446. POLYPODIUM. Sori (or small clusters of cap- 

 sules) roundish, scattered j indusium none. 



447. WOODSIA. Sori roundish, scattered ; indusi- 

 um calyciform, open, with a hairy margin, including 

 the pedicellate capsules. 



448. ASPIDIUM. Sori roundish scattered ; indusium 

 umbilicate or opening on one side. 



449. OJNOCLEA. Capsules densely covering the back 



