PROCEEDINGS OF THE UNITED STATES NATIONAL MUSEUM 



H5uc(/h^$(\v4 0?» by the 



SMITHSONIAN INSTITUTION 



U. S. NATIONAL MUSEUM 

 Vol. 84 Washington: 1936 No. 2998 



REPOKT ON THE FISHES COLLECTED BY H. C. RAVEN 

 IN LAKE TANGANYIKA IN 1920 



By George S. ISIyers 

 Assistant Curator, Division of Fishes, United States National Museum 



The present paper deals with a small collection of fishes obtained 

 by Harry C. Raven for the United States National Museum during 

 the Universal Films Co. expedition to East Africa in 1920. None of 

 the specimens is over 3 or 4 inches in length. They were obtained 

 with a small seme in shallow water, chiefly at two localities, Ujiji 

 and Kigoma, on the east shore of Lake Tanganyika. Several of 

 them represent the young of larger species, while others are the 

 adults of the smaller, shallow-w^ater forms. 



The fish fauna of the East African lakes is of great interest. It 

 is composed largely of perciform fishes of the family Cichlidae, 

 which here present a vast and confusing array of closely related 

 forms, mostly autochthonous in single lakes. Particularly in Lakes 

 Tanganyika and Nyasa, the cichlids (see especially Regan, 1920a, 

 1920b, 1921, 1922, and Trewavas, 1935) form faunas so rich in genera 

 and species as to be scarcely comparable to any others in the world. 

 These tAvo rift valley lakes are probably no older than the Pliocene, 

 and the present cichlid fauna of each has evidently developed from 

 two or three ancestral forms that gained access to the lakes not long 

 after their formation. This evolution of varied but closely related 



79426—36 1 



