THK MOLLUSCS OF THE GREAT AFRICAN LAKES. 159 



The Molluscs of the Great African Lakes. 

 I. Distribution. 



By 

 J. E. S. Moore. 



The present paper forms the first instalment of the 

 zoological report of an expedition which, through the 

 generous support of the Royal Society and the British 

 Association, I was able to make to Lake Tanganyika during 

 1895 and 1896. 



The primary objects of this expedition were — 



1. To study the unique fauna of Lake Tanganyika on the 

 spot; 



2. To make what observations were possible in the Nyassa 

 region while I was en route; and — 



3. To bring back properly preserved material for the com- 

 plete morphological investigation of the more remarkable 

 lake organisms after I returned. 



Before proceeding to the purely zoological matters with 

 which I propose to deal, it is appropriate that I should here 

 express my sincere thanks to Professor Ray Lankester, to 

 whom I have been indebted for the primary suggestion of the 

 whole inquiry, and for much kindly help since my return. I 

 have also to thank Professor G. B. Howes for the use of the 

 Huxley Laboratory and invaluable advice, without both of 

 which I should never have been able to get the subject 

 through, while I have been very materially indebted to Sir 

 John Kirk, who procured for the expedition the necessary 

 introductions to the administrative gentlemen through whose 

 districts it had to pass. And last, but not least, I have to 



