X11 INTBODUCTION. 



fish-fauna of that lake, which differs so markedly from that of the Blue Nile. Three 

 species new to science and a few new to the Nile Basin were discovered shortly after 

 in the upper affluents of the Blue Nile by Mr. Zaphiro. 



Very little was known of the fishes of the Great Southern Lakes whence the White 

 Nile takes its source. Fortunately, important collections were made whilst this work 

 was in preparation, Mr. J. E. S. Moore, on his return from the second Tanganyika 

 Expedition, discovering 4 new species in Lakes Albert and Albert Edward, and the 

 labours of the late Mr. Doggett resulting in the addition of 8 species to the fauna of 

 Lake Victoria. By the collection made soon after in the latter lake by M. Alluaucl 

 for the Paris Museum 6 species were further added. But it was left to Mr. Degen, 

 when assisting Prof. E. A. Minchin on Lake Victoria, to bring together a series which in 

 importance eclipses the results of all his predecessors, out of which no less than 26 new 

 species have been described, and which further illustrates the very special character of 

 the fish-fauna of that lake, and the little it has in common with that of the Nile. 



This work was already entirely set up in type when I received from my friend 

 Dr. F. Werner a copy of his paper " Beitrage zur Kenntniss der Fischfauna des 

 Nils," published in the ' Sitzungsberichte ' of the Vienna Academy (cxv. i. 1906, 

 p. 1097), too late for me to be able to refer to it beyond this Introduction. The 

 60 species enumerated were all previously known *. 



Thanks to all this activity, the number of species of fishes known from the whole 

 Nile system has risen from 100 to 192, which are enumerated in the following 

 systematic table showing their distribution in the present state of our knowledge. 

 The 17 columns refer to the following divisions : — 



1. Lakes of the Mediterranean Coast, and their immediate vicinity. 



2. Lower Nile (North of Assuan). 



3. Upper Nile (Assuan to Khartum). 



4. Blue Nile (up to Rosaires). 



5. Upper affluents of the Blue Nile (above 1500 feet altitude). 



6. Lake Tsana (about 6000 feet). 



7. White Nile (Omdurman to Bahr-el-Ghazal). 



8. Bahr-el-Gebel. 



9. Albertine and Victoria Niles (above 1500 feet). 



10. Lake Albert (about 2000 feet) . 



11. Southern tributaries of Lake Albert. 



3 2. Lake Albert Edward (about 3000 feet). 



13. Lake Victoria (about 4000 feet). 



14. Occurrence East of the Nile System. 



15. „ West „ „ 

 lo. „ South ., J5 

 17. „ North ' 



* It should be pointed out that the fish figured by Dr. Werner as Chelceihiops bibie does not belong to 

 that species, but is referable to Barilius niloticus. 



