534 



DR. W. A. CUNNINGTON ON THE 



Lakes Eilward and Kivu and nowhere else. This is a matter of 

 some interest, since there is evidence for believing that these two 

 lakes, between which there is now no connection whatever, were 

 in relatively recent times in connnnnication with one another 

 {cf. Moore, 137, p. 89). The genns Paratilapia is another repre- 

 sented in the lust by a large number of species, these being- 

 associated in groups which in most cases are peculiar to one of 

 the three bigger lakes. Felmatochromis, which is widely dis- 

 tributed in "West Africa, occuis in Tanganyika and in Victoria 

 Nyanza. but otherwise only in a single instance (Lake Edward) 

 in tiie lakes with which this paper is concerned. 



There is no occasion to refer individually to the numerous- 

 Cichlid genera which are endemic in the African lakes, the 

 important point being th.at so many of them are found in Tan- 

 ganyika. Attention may, however, be called to Charnj^sochromis 

 from Nyasa with three species, and Bathyhates from Tanganyika 

 with six, as these exhibit the gieates^t number of species among 

 the different endemic genera. The genu.s Lamjyi'oloijus is of 

 considerable interest and importaiice, being represented by a 

 total of 27 species from the Congo and Lake Tanganyika. It is 

 nevertheless essentially characteristic of the latter, for 24 endemic 

 species are recorded from the lake, while the remaining three 

 species are peculiar to various parts of the Congo river system.. 

 The distribution of the three forms of Hemitilapia is quite 

 different from anything else met with in the list, since the genus 

 is only known from Lakes ISTyasa and Victoria. A single endemic 

 species occurs in the former lake and two endemic species in the 

 latter. 



Since the Cichlids are so pre-eminent among the fishes of 

 Tanganyika, and indeed constitute a most striking feature of the 

 lake fauna as a whole, it becomes necessary to refer to certain 

 conclusions which have been drawn from a study of the anatomy 

 of these particular forms. From various considerations, such as^ 

 the number of rays, the multiple lateral lines, and the number of 

 vertebrae, Boulenger (20, p. 2 : 25, p. 393) at one time regarded 

 certain Tanganyika genera as showing features of generalisation. 

 At a later date, however, after a fui-ther investigation into the 

 anatomical evidence bearing on the j)hylogeny of the group, 

 he arrived (26, "p. 422 : 38, p. 43) at a different conclusion^ 

 and considers the Tanganyika genera and species as essentially 

 specialised. This is an important pronouncement, since it brings 

 the case of these fishes into line with most of the other animal 

 groups under discushion, in which certain marks of specialisation 

 are found to be characteristic of the endemic Tanganyika forms. 



Passing now to the family Anabantidae, a solitary representative 

 (Anahas muriei) has been obtained from Victoria Nyanza.. It is 

 a Nilotic type, and its existence here calls for no particular com - 

 ment. — The last group in the list, that of the Mastacembelid^e, is 

 i-epresented in Africa only by the genus JIastacembekts itself. 

 Many species are known fiom the fresh-waters of the continent^ 



