On Fishes from the Cameroon Mountain. 135 



XV, — On some Fishes from the Lakes of the Cameroon 

 Mountain. By Dr. EiNAR LoNNBEEG, C.M.Z.S. &c. 



A FEW weeks af^o I received from my friend Gunnar Liiinell, 

 residing at Cape Debundscha, a small collection of fish which is 

 of considerable interest, having been obtained from the small 

 isolated lakes of volcanic origin on the Cameroon Mountain, 

 viz. Lake Barombi-ba-kotta and the Elephant Lake. 



The natural conditions of the latter lake have been men- 

 tioned in my previous paper on fishes from the Cameroon 

 (Ann. & Mag. Nat. Hist. ser. 7, vol. xii., July 1903) and need 

 not be repeated. Concerning the Lake Barombi-ba-kotta^ 

 the Swedish civil engineer P. Dusen aives the followinof 

 information * : — In the middle of the lake is a small islet of 

 basalt. On the western side there is a steep slope about 

 10 metres in height, but the surroundings are not very high 

 and crater-walls seem to be absent. Mr. Dusea is therefore 

 uncertain whether to regard this lake as a very old crater 

 or a " Maar " formation. The lake receives only a small 

 tributary, the rivulet Manatunge, at the mouth of which 

 basalt-rocks were seen ; but there is no watercourse leading 

 from the lake or draining it, so that it is thus fully isolated. 

 The lake appears to be situated about 20 kilometres from 

 Mungo River as the crow flies, and about twice as far from 

 the nearest sea-sliore. Mr. Dusen puts its altitude above the 

 sea-level at 90 m. In these circumstances it is therefore 

 the more interesting to find that it has a fish-fauna consisting 

 of at least five species of Cichlidse, which have been sent to 

 me by Mr. Linnell, namely : — 



Hemichromis fasciatus, Peters. 

 A small specimen. 



Pel matochr amis longirostris, Boulenger. 

 A specimen in good condition. 



Tilapia macrocephala (Bleeker). 

 A fine large specimen, measuring 189 mm., wilh quite 

 normal dentition. 



Tilapia kottce, sp. n. 



Scales cycloid, without marginal denticulations. About 

 10 gill-rakers on lower part of anterior arch. An outer series 

 of teeth of moderate size, two or three inner series of vciy 



* Geol. Foren. Forh. no. 15o, Bd. xvi. (Stockholm, 1894). 



