— 20 — 



culo spiriductunm unico v. in caudice pluribus. Sporangia 

 sessilia , globosa v. oviformia , longitrorsum dehisc, annulo 

 completo operculari , radiato , ad segmenta folii contracta , 

 saepius pinnata , v. dentes spicata di - tetraslicha , rarius ad 

 marginem segmentor. latorum uniseriata, nuda, piUs stipata 

 V. denticulis imbricatis alteratis singula (spiculae Lygodii) v. 

 margine revoluto indusiata. Sporae tetraedro - sphsericae v, 

 conicae, passim echinulatae: — Muhria^ Ajieijma^ Schizaea^ 

 Lygodium. 



Ordd IV. Equiseta. 



Caules articulatr, herbacei, rigidi, vaginulati (foHis conna-> 

 tis verticillalis ? ) , cortice lacunoso , medulla evanida <1 , 

 tubulo ligneo c. spiriductibus , ramis verticillatis <*, strobih 

 sporophori terminales. — Calamiteis fossiUbus , Casuarinis 

 aUisque Strobilanthis quodammodo afUnes. 



F A M. 29. E Q U I S E T A C E iE. 



Caules teretes, articulati, simpl. v. ramosi, steriles. v. fertiles' 

 arlicuU tubulosi <j clausi sulcati , cortice lacunoso , apice 

 vaginiferi, vaginis 10-18-fidis (foUa epiladia connata?), sulcis 

 articulorum contiguorum aUernantibus; fascicuU Ugnei contigui, 

 lacunis interjecti, spiriductibus veris et annularibus ac pros- 

 enchymate provisi, hinc vaginam, iUinc articukim sup^erpo- 

 situm intrant; epidermis firma viridis stomatiis seriatis <* et 

 siUcia scatet. Rami ad basin vaginarum extraxillares , verti- 

 ciUati V. depauperati, cauU consimiles, sed soUdi, ut et c«wJe:t; 

 terrestris v. Umnobius , perennis repens, fibriUis verticiUatis 

 et ramis passim tuberosis. Strohili sporophori ? terminales 

 (et ramorum), iis Cupressi v. Zamia3 subsimiles , recep- 

 tacuUs peltatis , axi continuis, ^-7-gonis : sporangia sena , 

 rarius 7-4, cuique receptaculo subdita, introrsum fissa, sporis 

 subglobosis foeta : quaeUbet spora fiUs duobus decussatO" 

 suppositis, elasticis, utrinque clavatis, granuUferis circumvoluta 



