980 | Bulletin American Museum of Natural History [Vol. LIT] 
species of fishes are known to occur, but three of them are endemic and 
three others are found in Kivu and Tanganyika only (in one case also in 
the Ruzizi). The lower invertebrates include but four crustaceans (2 
crabs and 2 copepodes) and two oligochetes (one endemic). Schubotz 
was unable to discover Polyzoa, although he paid especial attention to 
that group. Meduse or jelly-fish have also been vaguely reported, but 
Schubotz was unable to confirm their presence. Otherwise the fauna of 
Kivu is typically fluviatile and it is noteworthy that, although in direct 
communication with Tanganyika, it possesses none of the thalassoid forms 
of that lake. 
The malacological fauna of Kivu is exceptionally poor. J. E. S. 
Moore sums up his own experience as follows: ‘‘There was a small 
variety of Planorbis, a small Bithynia and Melania tuberculata 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.’! Schubotz only obtained in 
the lake Plan:rbis choanomphalus and Melanoides tuberculata and these 
are also the two species recently collected by Mr. René Van Saceghem at 
Kisenje, near the northern end. It would be of great interest to know 
in how far Moore’s statements with regard to the remainder of the 
mollusk fauna are correct. Cunnington says that no Pelecypoda appear 
to occur.? Moreover, it is quite possible that the fauna is much richer in 
the southern part of the lake, near Kwidjwi and the outlet of the Ruzizi, 
where the waters are better sheltered from the deleterious.effects of the 
Mfumbiro volcanoes. 
Kirchstein® has noted the existence along the shores of Kivu of cal- 
careous tufa forming beaches raised as much as 8 m. above the present 
level of the water. These deposits contain fossil mollusks which, he Says, 
belong to the same species now living in Lake Edward, but apparently 
extinct in Kivu.* This observation, if confirmed, will be of considerable 
zo0geographic significance, since it would point to rather recent and far- 
reaching changes in the topographic, hydrographic and ecological condi- 
tions of this region. It is therefore unfortunate that no taxonomic study 
of these fossils and critical comparison with the Lake Edward mollusks 
dave been undertaken. 
11903, ‘The Tanganyika problem,’ p. 129. 
21920, Proc. Zool. Soc. London, p. 605. 
Bis: Adolf Friedrich zu Mecklenburg, 1909, ‘Ins Innerste Afrika,’ p. 159. 
*These shore formations probably induced Moore’s remark quoted above, that the few mollusks 
now living in Kivu become incrusted with mineral! matter. 
