ese 3 
XXIII. Remarks on some British Ferns. By Mr. Davip il Libr. L.S. 
Read March 18th, 1834. 
M Y attention having been lately directed to the examination of some species 
of Ferns more recently added to the British Flora, with a view to determine 
how far they merited the rank which has been assigned to them, I beg leave 
to lay the results of my investigation before the Linnean Society, being per- 
suaded that any attempts to clear up the synonymy of our native plants will 
meet with its approbation and encouragement. I shall commence with the 
ASPIDIUM DUMETORUM, 
a species first proposed by our late President in the 4th volume of the English 
Flora. This is made up of two plants, the one from Cromford Moor being a 
dwarf state of 4. dilatatum, and the other from Ravelston Wood, near Edin- 
burgh, having the segments of the frond abruptly truncate, and the habit, at 
first sight, altogether peculiar; but an inspection of the original specimens 
in the Smithian herbarium proves it to be nothing more than an accidental 
variety of the same species, namely, Aspidium dilatatum, arising from dis- 
ease, which is shown by the sudden termination of the coste, and by the 
partial decay of the other segments. Specimens of the more ordinary state of 
A. dilatatum gathered at the same time and from the same locality are similarly 
affected, but in a less degree. The distinctions derived from the fructification 
in the English Flora are altogether fallacious, and are partly dependent on the 
age of the frond, and partly on that of the individual plant. It is clear, there- 
fore, that the Aspidium dumetorum must be erased from the list of species. 
The next species I shall have to notice is the 
NEPHRODIUM RIGIDUM. ^" 
I formerly expressed a suspicion of the correctness of the plant published 
VOL. XVII. 3L 
