206 
TRAVELS JN CENTRAL AFRICA. 
Upper. Further, when we consider that our knowledge of West 
African fishes is very far from being complete, and that every fresh 
collection contains some other fish previously known from the Nile, 
we may venture to state that the Faunse of the Nile and the West 
African rivers belong to the same zoological district ; that there is 
an uninterrupted continuity of the Fish -Fauna from west to east ; 
and that the species known to be common to both extremities in- 
habit also the great reservoirs of water in the centre of the African 
continent. 
On the other hand, there are few fishes known at present which 
the Nile has in common with East Africa; with the exception of 
Chromis niloticus, Malapterurus eleciricus, one species of ikfor- 
myrus, two of Labeo and Lepidosiren : the affinity is merely generic, 
there being nineteen genera out of thirty-five in common. The 
locality nearest to the system of the Nile whence fishes have been 
obtained is Lake Nyassa, and all the fishes collected there by Dr. 
Kirk proved to be distinct from those of the Nile, and even from 
those of the other parts of the system of the Zambezi, 
PERCIDJE. (PERCHES.) 
Lates» 
J aws, vomer and palatine bones, with bands of very small villi- 
form teeth ; no canine teeth. Two distinct dorsal fins, the first 
