PREFACE. 



A preliminary catalogue of Japanese conchological specimens 

 in the Museum, consisting of two parts, was published in 1900 

 1903. The number of species enumerated in that catalogue 

 amounted to only 649, covering the five classes of Mollusca 

 Cephalopoda, Gasteropoda, P.eropoda, Scaphopoda and Pelecypoda. 



Since that time specimens have greatly been increased by our 

 own collecting done nearly every year, by exchanges, &c, and as 

 many species had been either doubtfully, or not at all, determined, 

 we have felt the necessity of rearranging the specimens, reviewing 

 more extensively the literature important for their identification. 



The specimens now catalogued relate to marine Gasteropoda 

 only ; nevertheless the number of species determined amounts to 

 731, of which 276 represent the new addition to this class in our 

 collection. Those belonging to other classes of Mollusca will be 

 catalogued later, after necessary rearrangement and determination 

 shall have been done. 



In the preparation of the catalogue I have been greatly assist- 

 ed by both Mr. K. Matsuura and Mr. R. Saito, but especially by 

 the former gentleman, who has done the proof-reading for me. 



T. Iwakawa 



Curator of the Department 

 of Natural History. 



Tokyo Imperial Museum, 

 December, 1908. 



