ON Tfin: FAUNA OF THE AFRICAN LAKES. 507 



?)'2. Tho Fauna of the Africim Lakes: a Study in C-ompara- 

 tive Linmolooy with special reference to Tano-anvika. 

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



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



(Text-figures 1-2.) 



Index. 



Pap:e 



Historical Survey 507 



General Introduction 512 



Systematic Account and Lists of Species 518 



General Discussion and Conclusions 592 



Summary 609 



IJililiography 613 



1. HISTORICAL SURVEY. 



Ever since the days of the great African explorers and their 

 quest of the sources of the Nile, there has existed a certain 

 fascination about the big lakes of Central Africa. While the 

 scientific world was at first concerned principally with the 

 geography of the heart of the continent, oppoi'tunity soon ofiered 

 of learning something of the 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 comparative fashion 

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

 holds a unique position as refiurds its fauna, n, somewhat detailed 

 account of its zoological exploration seems fitting, as it will aftbi'd 

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

 of certain outstanding facts. 



Little more 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, arrived at the lake between 

 the Malagai'asi River and Ujiji on the thirteenth of Februar}^ 

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

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

 various facts concerning it which he learned from the Arabs and 

 natives, while Speke, 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 theorthograpliy ot the name 'Tanganyika,' 

 advocating the adoption ot the spelling- 'Tanganiia' liy English writers (69). 

 The arguments advanced in favour of tho change have not lost their force, and still 

 seem wortlrv of consider.ation. As tlierc is no indication tliat writers in tliis country 

 are preiiarcd to accei>t the modiiication, I adhere reluctantlv to the old form. 



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