ON THE FAUNA OF THE AFRICAN LAKES. 



507 



32. The Fauna of the African Lakes: a Study in Compara- 

 tive Liinnolooy ^vith special reference to Tanganyika. 

 By William A. Cunnington, M.A., Ph.D., F.Z.S." 



[Received May 31, 1920 : Read November 16, 1920.] 

 (Text-figures 1-2.) 

 Index, 



Pa^e 



Historical Surve}' 5(i7 



(rcneral Introduction 512 



Systematic Account and Lists of Species 518 



General Discussion and Conclusions 592 



Summary 609 



liiblioj^raphy , 613 



1. HISTORICAL SURVEY. 



Ev^er since the days of the great African explorers and their 

 quest of tlie sources of the Nile, tliere has existed a certain 

 fascination about the big lakes of Central Africa. AVhile tlie 

 scientific world was at first concerned principally with the 

 geography of tlie heart of the continent, opportunity soon ofiered 

 of learning something of tlie organisms which live in the vast 

 inland seas, and it then became evident that matters of no little 

 biological interest were involved. 



It is the object of this paper to deal in comparati\'e fashion 

 with the animals of the principal lakes, and since Tanganyika* 

 holds a unique position as regai-ds its fauna, a somewhat detailed 

 account of its zoological exploration seems fitting, as it will afford 

 both an introduction to a study of the lakes and an enumeration 

 of certain outstanding facts. 



Little moi-e than sixty years have passed away since Burton 

 and Speke, the first Europeans to penetrate to Lake Tanganyika, 

 reached the shores of this big inland sea. Their expedition, after 

 encountering numberless hardships, airived at the lake between 

 the Malagarasi River and Ujiji on the thirteenth of February, 

 1858. Although little was done in the way of exploring Tan- 

 ganyika, Burton described, with a surprising degree of accuracy, 

 various facts concerning it which he learned from the Arabs and 

 natives, while tSpeke, on his return, brought certain shells from 

 the lake shore, which came into the possession of the British 

 Museum. 



* Some years ago I called attention to the orthograpliy ot the name 'Tanganyika,' 

 advocating the adoption of the spelling 'Tanganika' bj'- English writers (69). 

 The ai-guments advanced in favour of the change have not lost their force, and still 

 seem worthy of consideration. As tlierc is no indication tliat writers in this countr_\ 

 are prepared to accept the moditication, I adhere reluctantlv to tlie old form. 



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