526 Mr LOWE, ON MADERAN BOTANY. 



are both at right angles to the rhachis: whilst in N. Filix mas, the 

 lower or inner margin, i. e. that towards the main rhachis. quits its 

 condition of parallelism with its opposite upper or outer one towards 

 the base, and forms a curve downwards towards the pinnule next below 

 it; which is what I have called arcuato-decurrent. Thus the incisure 

 in A^. Filix mas is either irregular, or abrupt, open, and broad at the 

 base; not regularly acuminate; so that the spaces between the pinnules 

 being larger, or at least not regularly narrower downwards, these last 

 appear more remote and distinct than in N. affine. In fact the incisures 

 (not at all the pinnules) of N. affine rather resemble those of Nephrodium 

 {Aspidium Auct.) Oreopteris than of iV. Filia; mas. The pinnules of 

 the lower pinnaj, instead of having any tendency by incision to a farther 

 degree of decomposition, as they have both in N. Filix mas and N. elon- 

 gatum, are quite simple, and even more entire than the upper ones. 

 Sori precisely similar in their arrangement and indusia to those of N. 

 Filix mas. 



I possess specimens of A^. affine from various localities, differing in 

 exposure, shadiness, and elevation; but all agree in the foregoing cha- 

 racters. By these, this fern approaches nearer to N. elongatum than to 

 any other Maderan species : the true European N. Filix mas being the 

 connecting hnk; from which it is curious to observe, these two Maderan 

 ferns reciprocally recede in opposite directions : A^. elongatum having 

 the serratures much more aristate, and the stipes and rhachis, especially 

 the latter, less chaffy than the European A^. Filix mas; while N. affine 

 has the serratures much less developed, but the stipes and rhachis much 

 more copiously chaffy than the same. 



The specimens of A^. Filix mas, which I have particularly examined 

 for comparison with A'^. affine, are British only : but my friend Mr J. Ben- 

 nett has also compared specimens in the Banksian Herbarium, and noticed 

 the same differences. Indeed his observations, exactly corresponding with 

 my own, here made before and apart, have led me with considerable con- 

 fidence to the conclusions and results here stated. 



I subjoin, for facility of comparison, the specific characters of A^. 

 Filix mas and elongatum ; eliminated however solely in reference to 

 the three present species. 



