Preface. 
The generic nomenclature is, with few exceptions, that 
of the " Synopsis Filicum," but the sub-genera have been 
raised to the rank of genera ; this avoids the inconvenience 
of double generic names, and may be admitted on this score 
even by those who do not consider the wide difference in 
habit of such genera as Phegopteris, Polypodium, Pleopeltis, 
and Drynaria of any value generically, and who base their 
genera on the sori alone, without reference to habit, vena- 
tion, or vernation. 
The geographical limits of the work comprise the whole 
of British India, Ceylon and the Malay Peninsula. 
West Hill, Putney, 
May, 1833. 
