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IV. Second Contribution to the Ichthyology of Lake Tanganyika. — On the Fishes 

 obtained by the Congo Free State Expedition under Lieut. Lemaire in 1898. By 

 G. A. Boulbkobb, F.B.S., F.Z.S. 



Received May 13, read May 16, 1899. 



[Plates XVIIL-XX.] 



iHE extraordinary richness of Lake Tanganyika in Perciform fishes of the family 

 Cichlidce, first revealed by Mr. Moore's collection, reported upon in these Transactions, 

 vol. xv. 1898, pp. 1-30, pis. i.-viii., is further shown by the collection made in July- 

 August 1898 by the Lemaire Expedition at Moliro, at the southern extremity of the 

 Lake, already explored by Mr. Moore. Although consisting of no more than 31 

 specimens, the collection entrusted to me for description by the Government of the 

 Congo Free State contains the types of ten new species, three of which warrant the 

 establishment of new genera. These new genera are of further interest in emphasizing 

 a feature of the Tanganyika Cichlidce to which I have drawn special attention in my 

 previous contribution, p. 2, viz. the extent of the lateral lines in many of the forms 

 discovered by Mr. Moore. The knowledge of forms with three lateral lines, a 

 condition previously unrepresented in the Cichlidce, adds force to the remarks I have 

 made with regard to the morphological significance of the so-called "interrupted 

 lateral line." 



The Lemaire collection is further valuable for the care with which coloured sketches 

 of most of the fishes have been taken on the spot by M. Dardenne, the excellent artist 

 attached to the expedition. These sketches have enabled me to represent some of the 

 more strikingly coloured forms in chromolithography. 



In addition to the definitions of the new species, I am able to draw up descriptions 

 of the two species of Ectodus of which very incomplete definitions were given in the 

 previous contribution, owing to the bad condition of the type-specimens. I have also 

 added notes on the known species of which specimens are contained in the Lemaire 

 collection, or of which coloured drawings, accompanied by an indication of the native 

 names, have been supplied by M. Dardenne. 



vol. xv. — part iv. No. 1. — December, 1899. o 



