142 MR. G. A. BOULENGEK ON A COLLECTION 



1 am therefore disposed to conelude that we do not know much more than one-half 

 of the species whicli will ultimately be found to inhabit Lake Tanganyika. 



As regards facts of distribution, I can only emphasize again the quite extraordinary 

 abundance and variety of the Cichlidce, the salient feature of the Lake which might be 

 named the kingdom of the Ciclilidce: 60 species (divided into 21 genera), being more 

 than are known from the whole of the rest of Africa (including Madagascar) with 

 Syria, and about as many as can be listed from South America. 



As to the affinity shown by the Tanganyika Fish-fauna to other basins of Africa, 

 we may at once dismiss all connection with Nyasa and the Zambesi. Of the genera 

 that are not ubiquitous in Tropical Africa, two (Capoeta and Anoplopterus) have 

 representatives in East Africa only, and two {Lamprologus and Pehnatochromis) in the 

 Congo and West Africa only ; whilst of the species, five occur also in the Nile or East 

 Africa, and four in the Congo. We are therefore justified in concluding that this fauna 

 shows no more special affinity to the one watershed than to the other. 



List of the Fishes represented in the Collection, with Descriptions of the new 



Genera and Species ^. 



CEOSSOPTERYGII. . 



P L Y P T E K I D .E. 

 1 . POLYPTERUS CONGICUS Blgr. 



Four specimens were brought home of the large Folypterris observed by Mr. Moore 

 on his first visit, and identified by him under the provisional name of P. hichir. They 

 prove to be referable to the allied species from the Congo, described by me in 1898 as 

 P. congicus (Ann. & Mag. N. H. [7] ii. p. 418). 



Particulars are appended of the four specimens, from the middle of the lake off 

 Kalambo, at about 5 fathoms, caught in trammel-nets : — 



1. ± a 4. 



Total length (in millimetres) 620 580 530 520 



Length of head (in millimetres) 130 110 105 100 



Kumber of dorsal spines 13 13 14 13 



Number of scales along the side 56 55 57 57 



Number of scales round the body 47 47 47 47 



Number of scales between occiput and first dorsal spine. 14 14 12 13 



A small azygous shield usually separates the nasals in this species ; it is, however, 

 absent in two of the specimens (3, 4). 



' Of which preliminary diagnoses have already appeared in Ann. & Mag. N. H. (7) vi. 1900, p. 478, and 

 vii. 1900, p. 1, 



