X Preface. 



logique" as this work stands by itself; besides the synonyms 

 of the species mentioned therein can be found in the other 

 papers. The „Enumeratio" and the two „Conspectus" men- 

 tioned above, were also excluded as they already consist 

 of lists. But notwithstanding these restrictions, about 22000 

 labels had to be written, on each of them being noted the 

 name of the genera and species, the paper and the page 

 where the name was to be found. These notes were after- 

 wards combined in so far as they contained identical genera 

 and species. 



That this enormous task was brought to a succesful close 

 is mainly due to the accuracy, perseverance and patience 

 of Miss C. H. W. Met, who accomplished this work under 

 our supervision and to whom every one must be grateful 

 who takes any interest in Bleeker's papers. 



The arrangement of the Index is as follows: it is opened by 

 an „ Index Bibliographicus" of Bleeker's ichthyological papers. 

 This bibliography is slightly different to that given by Bleeker 

 in his autobiography, some papers being added that Bleeker 

 himself overlooked, besides being arranged according to the 

 date of their publication, whereas Bleeker arranged them 

 according to the date on which he finished his manuscript, 

 which two dates in many instances lie far apart. It often 

 was difficult and sometimes even impossible to ascertain the 

 exact date of publication, moreover some of the periodicals 

 in which he published were — from a bibliograpical point of 

 view — sometimes rather unusually edited. For instance the 

 five papers (mentioned in our Index as n°. 13, 14, 15, 16 

 and 17) which appeard in Vol. 22 of „Verhandelingen van 

 het Bataviaasch Genootschap van Kunsten en Wetenschappen" 

 bear the signature ,,23. deel 1849" as they were really inten- 

 ded for that volume when being printed, but one of the 

 authors failing to send his manuscript, promised for vol. 22, 

 the 5 papers were after all included in vol. 22. 



The „ Index Bibliographicus" is followed by a list of the 

 500 papers arranged according to localities. 



