132 
THE TANGANYIKA PROBLEM. 
a shallow, saucer-shaped depression, lying between distant 
eastern and western lines of mountains and valleys running 
north and south. 
Further to the east again we have another series of 
lakes, lying mostly along the course of the great fold 
which runs from the vicinity of Kilima Njaro to the Red 
Sea. In these lakes Rudolf, Stephani, Beringo, Nivasha, 
Elimantita and Nakaroo, there is little of zoological 
interest. 
But it cannot be said the faunistic characters of Rudolf 
are as yet fully known, still at the same time, from the 
observations of Mr. Donaldson Smith and Mr. Harrison, 
who both spent some time about the lake, it is quite clear 
that neither in the direction of fishes nor shells is it 
faunistically remarkable in any way. In Rudolf there 
have been recorded the following forms of fishes : — 
POI.YPTEKID.I-:. 
I. Polypterus Senegal us. 
Characintd.-e. 
2. Hydrocyon forskalii. 
3. Alestes baremose. 
4. ,, nurse. 
5. Citharinus geoffroyi. 
6. Distichodus. 
RUDOLF. 
FISHES.* 
Si lurid.*:. 
8. Clarias mossambicus. 
9. Auchenoglanis biscutatus. 
10. Synodontis schall. 
11. ,, zanzibaricus. 
12. ,, citernii. 
13. Mochocus niloticus. 
Serkanid.e. 
1 4. Lates niloticus. 
ClCHI.ID/E. 
Cyprin ID,®. 15. Tilapia nilotica. 
7. Neobola bottegi. | 16. ,, zillii. 
Nothing sufficiently definite appears to be known of the 
invertebrate fauna of Lake Rudolf to make a list advisable. 
* This list of fishes from Lake Rudolf is partly taken from Vinciguerra Ann. Mus. 
Civ. Genova (2) xix., 1898, p. 241, the nomenclature having been kindly revised for 
the present work by Mr. Boulenger. 
