THE TANGANYIKA PROBLEM. 129 



There was a small variety of Planorbis, a small Bithynia 

 and Melanin hiberculata among the gastropodean molluscs, 

 one or two species of fresh-water bivalves, closely allied 

 to the unios found generally in the African lakes, and 

 apparently nothing else ; the most striking feature about 

 the fauna of Lake Kivu being the apparent absence of 

 Viviparas. 



North of Kivu we have the Albert Edward and the 

 Albert Nyanzas, the faunas of which can very well be 

 treated together. These two lakes are distinctly interesting. 

 They lie at the respective altitudes of 3,000 and 1,700 

 feet above the level of the sea ; or, in other words, they 

 repeat the conditions with respect to altitude and climate 

 which were encountered in the case of Tanganyika and 

 Nyassa. The fauna of both the Nyanzas is abundant — 

 perhaps quite as abundant as that of Nyassa — but in both 

 lakes it is composed of only a very few forms of fishes, 

 and half a dozen species of mollusca at the most. In many 

 portions of both the Nyanzas the beach is composed of 

 actually nothing else but the shells of Melania tuberculata. 

 In the Albert, so far as is at present known, the fauna 

 consists of the following types : — 



ALBERT NYANZA. 



FISHES. 

 Petrochromis Andersoni (Blgr.).* 



MOLLUSCA. 



1. Planorbis adowensis Bgt. 



2. ,, apertus Marts. 



3. Ampullaria stuhlmanni Marts. 



4. Vivipara rubicunda Marts. 



5. Cleopatra pirothi Jick. 



6. Bithynia alberti E. Sm. 



7. ,, walleri E. Sm. 



8. Melania tuberculata Mull. 



9. ,, liricincta E. Sm. 



10. Unio acuminatus H. Ad. 



11. ,, bakeri H. Ad. 



12. Mutela nilotica Fer. 



13. Corbicula radiata Phil. 



14. Sphserium species indeterminate. 



* It is to be noted that most, if not all, the other species of fish found in the Albeit 

 Edward occur in the Albert as well. Only the new forms were, however, collected. 



