EXPLANATION OF THE PLATES. 



DIOK80N1A, fSITOLOBIUM. Pinna of D.punctilobula, Hook. (I); portion of a pinnule 

 (2), enlarged; and a fruit-dot in its cup-Bhaped indusium (8). 



TAB. XII. 



OYBTOPTEEIS. Piece of the frond of 0. bulbifera, Bernh. (1); a lobe in fruit (2), 

 enlarged ; and a small portion more magnified (8), bearing a fruit-dot with its indu- 

 sium thrown back. 



WOOD8IA. Small frond of W. glabella, JR. JSr. (1) ; a part of a fruiting pinna of the same 

 (2), magnified; and a separate indusium (8), more magnified ; a piece of a fruitful 

 pinnule of W. obtusa, Torr. (4), enlarged ; and a fruit with the opened indusium 

 beneath (5), more magnified. 



ASPIDIUM. Pinna of A, (Dryopteris) marginale, Swarte (1); and a magnified fruiting 

 portion (2) ; piece of A. (Polystichum) acrostichoides (8) ; and a small fruiting por- 

 tion (4), magnified. 



ONOCLEA. Sterile and fertile frond of O. sensibilis, L.; front view of a fruiting contracted 

 pinnule, enlarged (1) ; and the same laid open and viewed from the other side (2) : 

 on one lobe the sporangia are removed from the veins. 



TAB. 



8CHI2LEA. Plant of 8. pusilla, Pivrsh; a fertile pinna with eleven sporangia (1), mag- 

 nified ; and a separate sporangium (2), more magnified. 



LYGODIUM. Summit of frond of L. palmatum, Swarte(L), with fertile and sterile divi- 

 sions ; a fruiting lobe enlarged (2), with two of the lower scales, or indusia, removed, 

 displaying a sporangium under each ; and a sporangium more magnified (8). 



OSMUND A. Small piece of the frond of O. Claytoniana, Z. (1), with a fertile and a 

 sterile pinna; a portion of the fruit magnified (2) ; and one sporangium more mag- 

 nified (8). 



BOTRYCH1UM. Plant of B. lunarioides, Suxirte; and a portion of the fruit (1), with six 

 sporangia, magnified. 



OPHIOGLOSSUM. Frond of O. vulgatum, L.; and a portion of the fruiting spike en- 

 larged (1). 



Genera of Equisetaceae, Lycopodiaceae, and 

 Hydropterides. 



TAB. XIV. 



EQUISETUM. Upper part of fertile plant of E. limosum, L. (1) ; one of the shield- 

 shaped scales or receptacles of the spike, with the six sporangia underneath (2), 

 enlarged; same seen from below, discharging the spores (8); a magnified spore 

 with the club-shaped filaments spreading (4) ; and (5) the same with the filaments 

 coiled up. 



LYCOPODIUM. Plant of L. Carolinianum, L.; and (1) a magnified scale of the spike 

 * removed, with the sporangium in its axil, discharging powdery spores. 



SELAGINELLA. Plant of 8. rupestris, Spring ; part of a fertile spike, enlarged (1) ; scale 

 from the upper part of it (2), with its sporangium, containing innumerable powdery 

 spores; scale from the base (8), with its sporangium containing few large spores; 

 and (4) three large spores. 



