846 W. H. HUDLESTON, ESQ., M.A._, F.E.S., ON THE ORIGIN 



Discussion. 



The Chairman. — As we have the pleasure of Mr. J. E. S. Moore 

 being present, we will ask him to open the discussion. 



Mr. J. E. S. Moore, F.L.S. — I should like to say a few words 

 with respect to the nature of the Tanganyika problem, as it 

 presents itself more to the zoologist than the geologist. We have 

 just heard a very able exposition from Mr. Hudleston on the 

 bearing of the one position on the other ; but I should like to point 

 out, from my own point of view, that that is not really the main 

 aspect of the Tanganyika problem. The main aspect is that you 

 have a large number of animals besides gasteropods, such as jelly- 

 fish, prawns, sponges, protozoa, etc., which are not present in other 

 lakes, and which are of a marine character, and it would appear 

 there is very little doubt that these animals have no relation what- 

 ever to any fresh-water areas ; and, consequently, whether they have 

 originated from a Jurassic source, or some other, is simply a minor 

 matter for discussion. But the fact which remains is that they are of 

 marine origin, and I do not see that it can be disputed. Whether they 

 have originated from Jurassic fauna is a matter of hypothesis, and, as 

 Mr. Hudleston points out, there is a striking similarity between the 

 shells of gasteropods and certain genera of the Inferior Oolite of the 

 Anglo-Norman basin. Unfortunately geologists, as Mr. Hudleston 

 has said, have not been able to find any evidence that makes their 

 origin more certain ; but if you do not associate them with the 

 Jurassic sea, I should much like to know where they did come from. 



There are one or two other points upon which, possibly, it may 

 be necessary to say a few words. Mr. Hudleston pointed out that 

 the peculiar jelly-fish that inhabits Tanganyika has recently turned 

 up in the Victoria lakes, and one would suppose that implied that 

 the whole of the Halolimnic fauna was present in Lake Victoria. 

 There are cogent reasons for doubting this. But as a matter of fact 

 not many years ago one of the few fresh- water jelly-fishes turned up 

 in the Eoyal Horticultural Society's Gardens in London, and has not 

 been seen since; it had been probably transported among water plants. 

 Well within recent years communication has been opened up 

 between Tanganyika and Victoria Nyanza, and the natives have a 

 habit of carrying a large quantity of water. It is only about forty 

 miles from the basin of the Tanganyika to the water-shed of one of 



