304 W. H. HUDLESTON, ESQ., M.A., F.R.S., ON THE ORIGIN 



Valley system and its obvious physical connection with the 

 great Eed Sea depression, that the " halolimnic " fauna might 

 have entered Lake Tanganyika from that quarter, and would 

 consequently be found in some of the Rift- Valley lakes to the 

 northwards, and especially in Lake Kivu, with which at the 

 present day Tanganyika is hydrographically connected through 

 the River Rusizi. It was therefore indeed a surprise when 

 Mr. Moore, had to announce as the result of his second expe- 

 dition, commenced in the spring of 1899, that no trace of the 

 " halolimnic " fauna had been discovered in any of the lakes, 

 such as Kivu, the Albert Edward, or the Albert Nyanza, 

 which lie to the northward of Tanganyika in the western arm 

 of the Rift- Valley system. Nay, more, it would seem that no 

 such thing as the halolimnic fauna was to be found in the 

 great upland basin of the Victoria Nyanza, nor in the chain 

 of lakes associated with Lake Rudolf (Basso Narok), which lie 

 towards the northern termination of the eastern arm of the 

 Rift-Valley system.* 



To quote Mr. Moore's own conclusions on this point : " It 

 has been shown that throughout Equatorial Africa, as in other 

 great continents, there is a normal fresh-water fauna which has 

 nothing peculiar about it . . . Subsequently, the fauna of L. 



^ There appears to be no longer any doubt as to the presence in Lake 

 Victoria Nyanza ot medusae indistinguishable from those of Lake 

 Tanganyika, and the fact cannot be without its effect upon the 

 acceptance of the view put forward by Mr. J. E. S. Moore, that the fauna 

 of Lake Tanganyika differs from that of the other East African lakes in 

 alone possessing evidences of a marine origin. On December 1, 1903, 

 Prof. Ray Lankester exhibited- at^ the Zoological Society some medusae 

 from Victoria Nyanza obtained by Mr. Hobley on August 31, 1903, and 

 sent to London by Sir Charles Eliot. A doubt being raised by some 

 supporters of Mr. Moore's theory as to these medusae having really come 

 from Lake Victoria and not from Lake Tanganyika, Sir Charles Eliot, in 

 a letter dated Mombasa, December 20, 1903, wrote to Prof. Lankester 

 saying that the medusae were collected by Mr. Hobley himself, in the 

 Kavirondo Gulf, by the side of which the railway terminus is situated, 

 and that the water was full of them. Mr. Hobley, at the request of 

 Sir Charles Eliot, had endeavoured to study the life-history of the 

 medusae, but he failed to keep them alive for more than a few days. The 

 specimens sent to London were said by Dr. R. T. Gunther to be 

 indistinguishable from the Limnocnida tanganyicae of Lake Tanganyika. 

 It is interesting in this connection to note that the Victoria medusae were 

 discovered quite independently in the same locality (Kavirondo, in the 

 Kisuma district), and apparently at about the same time of year. 

 According to Globus (January 28, p. 84), M. Ch. Alluaud, on the day of 

 his arrival at Lake Victoria, discovered a marine medusa similar to that 

 of Lake Tanganyika, and communicated an account of his discovery to 

 the Paris Geographical Society on September 19, 1903. — Nature. 



