EXPLANATION OF THE PLATES. 



DICKSONlA, SITOLOBIUM. Pinna of D. punctilobula, /Too^.(l); portion of a pinnule 

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



TAB. XII. 



CYSTOPTERIS. Piece of the frond of C. bulbifera, Bernh. (1); a lobe tn fruit (2), 

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

 siom thrown back. 



WOODSIA. Small frond of~W. glabella,/?. Br. (1): a part of a fruiting pinna of the same 

 (2), magnified ; and a separate indusium (3), 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. 



ASPID1UM, Pinna of A. (Dryopteris) marginale, Swarfc: (1); and a magnified fruiting 

 portion (2) ; piece of A. (Polystichum) acrostichoides (3); and a small fruiting por- 

 tion (4), magnified. 



ONOOLE A. Sterile arid 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 Bide (2)' 

 on one lobe the sporangia are removed from the veins. 



TAB. XIII. 



SCH12.iEA. Plant of S. pnsilla, Purxh; a fertile pinna with eleven sporangia (1), mag- 

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



LYGODIUM. Summit of frond of L. palmatum, Swart3(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, L. (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, Swarta; and a portion of the fruit (1), with sb 

 sporangia, magnified. 



OPH1OQLOSSUM. Frond of 0. vulgatum, L.; and a portion of the fruiting spike en- 

 larged (1). 



Genera of Eqniftetaceae, I^ycopodiaccaB, and 

 1 ydroptcrides. 



TAB. XIV. 



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

 Khnped 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. 



LYXJOPODIirM. Plant of L. Carolinianum, /,., and (1) a magnified scale of the spike 

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



8ELAG I NELL A. Plant of 8. rupestria. Spring ; part of a fertile spike, enlarged (1) ; scale 

 from the tipper part of it (2), with its sporangium, contai nine in numerable powdery 

 spores; scale from the base (3), with its sporangium coiituiiiing few huge sporea 

 and (4j three large spores. 



