PREFACE 
D the last year several pteridologists have asked me to compile al- 
ready now a supplement to my »Index Filicum., although but seven 
years have gone since the publication of the Index. The number of new 
species described since 1905 are increased to a degree, that the lack of a 
supplement was felt grievously by all botanists, who have had to do with 
ferns. Originally I intended to prepare a supplement not till ten years after 
the puhlication of the Index, but I agreed in making the work now, as HIS 
HIGHNESS, PRINCE ROLAND BONAPARTE offered me a pecuniary support, 
without which I hardly should succeed in bringing the tedious and time- 
claiming work to a good end. For this Iowe HIS HIGHNESS my most sincere 
thanks. My best thanks I shall also render to the Directors of the »Raben- 
Levetzau'ske Fond« for the aid received from that Fund. To not a few pte- 
ridologists I am indebted for their informing me of errors and omissions of 
the Index; a special thank I owe Herr H. WOYNAR of Graz, who have con- 
tributed largely to fill out the holes found in the Index. 
The present volume is divided into two parts: 
IL. SUPPLEMENTUM, which contains all names of ferns published in the 
years 1906—1912 together with some older names that were omitted in 
the Index, 
II, CORRIGENDA, containing corrections and additional synonyms to several 
species adopted in the Index. 
The descriptive fern.literature published since 1905 is very comprehensive, 
and our knowledge of several older species is much widened. 4A considerable 
number of forms, in Index adopted as valid species, are now justly reduced 
to synonyms, and not a few older species, in Index treated as synonyms, are 
now by authors considered good species. All such changes in the conception 
of the species are listed in the first part, the Supplementum, if the alteration 
has caused a new combination, in the second part, the Corrigenda, if the 
restored species was named previously by the right combination by an earlier 
. author and subsequently the name is to be found in the Index. 
Some of the generic names adopted in the Index have been subject 
of heavy criticisms and in several cases I agree with tae criticisers; still I - 
have preferred to let the supplement follow the Index in the nomenclature 
of the genera, fearing that changes in generic names should cause a confusion, 
