INTRODUCTION The collections made by Burger and Von Siebold during the second quarter of the previous century, in the neighbourhood of Nagasaki, were so extensive that they gave Temminck & Schlegel the opportunity to build the foundation for the knowledge of the Japanese ichthyofauna. In her publication "'s Rijks Museum van Natuurlijke Historie, 1820-1915", Dr. A. Gijzen states: "Burger sent among others fishes"; "25 December 1832 Temminck gives him a list of the desired species of animals." As she further states, Burger's position in Japan is not quite clear; in a letter from 9 November 1839, Temminck writes to the Minister that he knows Burger as a collector only, but that he knows no further particulars about him. Burger's name has been mentioned in several publications, generally as Bürger, but according to an original signature in our archives, this spelling must be regarded as erroneous. Burger not only collected an excellent collection of Japanese fishes, more than 650, generally dry preserved and stuffed, specimens, but he had also a number of beautifully coloured drawings of Japanese fishes made by (a) Japanese artist(s), while he also made a manuscript on this subject containing the descriptions of 200 species. Almost all this material still is in the possession of the Museum of Natural History at Leiden. About Von Siebold we know more particulars : according to Dr. A. Gijzen (l.c.), "Von Siebold has been sent to Japan by Van der Capellen, then Gouverneur-Generaal of the Dutch East-Indies, for explorations. He wanted to give a description of his voyage and invoked Temminck's assistance for