OF THE HALOLIMNIC FAUNA OF LAKE TANGANYIKA. 303 



History of the subject and statement of Mr. Moore's vietvs. — The 

 history of the recognition of the haloliinnic fauna is important 

 as tending to show what were men's views from time to time 

 as each step in the progress of discovery was made. It will be 

 remembered that Lake Tanganyika was discovered by Burton 

 in 1857, and that his companiou, Speke, picked up a few dead 

 shells from the shores and brought them to England. The 

 well-known conchologist, iJr. Sam. P. AVoodward (Froc. Zool. 

 Sac., 1859, p. 348, PL XLYII) was struck with the peculiar forms 

 of some of the gasteropods, which he considered had a certain 

 marine look about them. Subsequently when further supplies 

 were procured, Mr. Edgar Smith (Froc. Zool. Soc., 1881, p. 276), 

 in a paper on a collection of shells from Lakes Tanganyika and 

 Nyassa, expressed an opinion that they might turn out to be the 

 relics of a former sea. The subsequent discovery of medusae in 

 Lake Tanganyika seemed to confirm these views as far as that 

 lake was concerned. Hence before Mr. Moore appeared upon the 

 scene, most of those who had paid attention to the subject had 

 expressed themselves as favouring the view of the marine origin 

 of this peculiar fauna. 



Mr. Moore, as a result of his first journey in 1896, found 

 " that in Nyassa and Shirwa there were no jelly-fishes, nor 

 anything except purely fresh-water forms; while in Tangan- 

 yika there w^ere not only jelly-fishes, but a whole series of 

 molluscs, crabs, prawns, sponges, and smaller things, none of 

 which appeared in any of the lakes he then knew, and all of 

 which were distinctly marine in type.* Further than this, 

 however, he found that none of these strange marine looking 

 animals were to bs compared directly with any living marine 

 forms, yet, in their structure, some of them certainly seemed 

 to antecede a number of marine types in the evolutionary 

 series, and, in consequence, they appeared to hail from the 

 marine fauna of a departed age. The most definite result of 

 the first Tanganyika expedition, therefore, appeared to be that 

 the sea had at some former time been connected with the lake, 

 but when or how remained a mystery." 



The above are Mr. Moore's own words in explanation of his 

 views after the termination of his first expedition. It should 

 be borne in mind that at this period, viz., in 1898, when his 

 inferences were laid before the Eoyal Society {Froc. Boy. Soc, 

 vol. 62), there was an idea then partially and perhaps generally 

 prevailing, that owing to the peculiar structure of the liift- 



* J. E. S. Moore, The Tanganyika Problem (1903), p. 3. 



