PART I 



RHIPIDOGLOSSA and D0C0GL0SSA 



WITH AN APPENDIX BY Prof. R. BERGH. 



INTRODUCTION. 



As the number of species of prosobranchiate Gastropods, collected during the cruise of 

 the "Siboga" is rather large (the collection contains far more than two thousand bottles and 

 tubes, besides a considerable number of boxes) I proposed to Prof. Weber, to publish the results 

 of my researches in four or five parts, in order to save priority. The first part dealing with 

 the Rhipidoglossa and Docoglossa is now ready. It is the most interesting but I think the most 

 difficult group to deal with, as the systematic position of many of the Trochidae and of the 

 patelliform shells is very uncertain. By preparing the radulae of doubtful species, I have been 

 able to throw some light in a few cases, and have been induced to erect some new genera. In 

 many respects I have foliowed the systematic arrangement of Fischer (Manuel de Conchylio- 

 logie etc. Paris, 1880 — 87) unless changes proved to be desirable on anatomical grounds or on 

 account of other new investigations. 



As to synonymy I have not tried to render it complete-, as a rule I have only cited the 

 author who first described the species, and those of the larger monographs I could consult; 

 moreover I have cited the descriptions and figures of Rumph, in the "Amboinsche Rariteitkamer", 

 as this publication is in fact the only faunistic work on marine Mollusks of a considerable 

 part of the East Indian Archipelago, and finally a few other authors, in whose works I found 

 interesting particulars on, or better figures of the species mentioned in this part. 



The number of species dealed with in this part, amounts to about 210, amongst which 

 68 which I consider to be new, moreover a few new varieties. In order to avoid as much as 

 possible the description of species already known, I have in many cases, before describing them, 

 asked the assistance of Mr. E. A. Smith of the British Museum of Natural History, who with 

 his usual kindness has compared the specimens with those of the conchological collections, for 



1 



SIBOGA-EXrEDITIE XLlx'n. ' 



