EXPLANATION OF THE PLATES. 



Genera of Filices. 



Tab. IX. 



POLTPOBItJM.— Plant; piece of the frond (1) ; a magnlfled sporangium with itB stalk, 

 and another bursting and discharging spores, of P. mlgare, L. 



STRUTHIOPTEEIS.— Pinna of the sterile firond (1) of 8. Germanica, Willd.; portion of a 

 fertile Arond (2) ; a piece of one pinna cut off to show the manner in which It is rolled 

 up (8) ; and a portion of the last, magnified, with one side anrolled (4) ; towards the 

 base the sporangia lUI removed, to show how the ftnit-dots are borne each on the 

 middle of a rein. 



ALLOBOEUS. — Sterile and fertile plants of A. gracilis, Preal.; and a portion of the fertile 

 Arond (1) enlarged, with a piece of the marginal Indnslum turned back to display 

 the fruit ; the sporangia are all removed A-om the ftuit-bearing tips of the two forks 

 of the lower vein. 



Tab. X. 



PTEEIS.— A pinnule of P. aquilina, L., var. caudata; and a piece of one of the lobes, 



enlarged (2), the marginal indusium rolled back on one side, displaying the fruit ; 



the sporangia all removed from the lower part to show the receptacle that bears 



them, viz. a cross line connecting the tips of the veins. 

 ADI ANTUM. — Piece of the IVond of A. pedatum. L. (1) ; a pinnule somewhat enlarged (3) ; 



and a piece of one (8) more enlarged, with the Indusium of one fruit-dot turned back 



to show the attachment of the fruit. 

 CHEILANTHES.— Small plant of C. vestlta (1) ; and a fruit-bearing pinnule, enlarged (2). 

 "WOODWAEDIA.— Portion of the sterile (1) and of the fertile frond (2) of "W. angustl- 



folia ; a piece of the latter enlarged (8) ; piece of the frond of W. Vlrginica (4) ; and 



part of a fruiting lobe (6), enlarged. 



Tab. XI. 



CAMPT0S0EU8.— Plant of 0. rhizophyllns, LMe.; and a portion of a frond, with frult- 



dota, enlarged CI). 

 BCOLOPEITDEI DM.— Tip of a fertile frond of 8. offlcinaram ; and (2) a piece enlarged, 



with two fruit-dots. 

 iSPIiENIUM.— A pinna of A. tlielypteroides, Michsc (1) ; and part of a lobe (2) in fruit, 



enlarged. 



