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XI. On Woodsia, a new. Genus of Ferns. By Robert u Esq. 
F.R.S. Lib. L.S. 
Read November 17, 1812. 
Tuznz is perhaps no tribe of cryptogamous plants which since 
the time of Linneus has received greater additions to its number 
of species, or more considerable improvements in its systematic 
arrangement, than the Filices: and certainly no botanist has so 
essentially contributed to those improvements as the President of 
this Society; whose ingenious Essay on Dorsiferous Ferns may 
justly be considered as the groundwork of the more complete 
dissertations of Professors Swartz and Bernhardi, which have 
appeared since its publication *. 
Linneus, in his latest work, the 13th edition of the Saidia 
Vegetabilium, enumerates scarcely more than 200 Ferns, which he 
referred to twelve genera: while the Species Plantarum of the late 
Professor Willdenow contains upwards of a thousand plants of the 
same order, arranged under forty-three genera. It is however 
remarkable, that of this vast number of species nearly one half 
belong to four of the Linnean genera, namely Polypodium, Acro- 
stichum, Asplenium, and Pteris, all of which were first proposed 
by Ray in his Methodus Plantarum Emendata, published in 1703 ; 
* An. 1793, in Mém, de V Académie Royale des Sciences de Turin, vol. v. p. 401. 
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