368 . REPORT— 1897. 



Ajrican Lake Fauna. — Report of the Committee, consisting of Dr. 

 P. L. ScLATER (Chairman), Dr. John Murray, Professor E. Eay 

 Lankester, Professor W. A. Herdman, and Professor G. B. 

 Howes (Secretary). 



Mr. J. E. S. MooRE, A.R.C.S., London, left England on September 7, 

 1895, and returned to Europe on January 1, 1897. 



The primary object of his expedition was the collection, by means of 

 dredging, tow-netting, and other resources, of material for the adequate 

 working out of the structure, and, as far as possible, the development, of 

 the singular fresh-water Medusa (Limnocnida tanganyikoi), and some 

 other remarkable animal forms which, from their shells brought home by 

 travellers, were known to inhabit Lake Tanganyika, and to present a 

 combination of characters unlike that of any other fresh -water stock. 

 Incidentally, the faunas of Lakes Shirwa, Kela, and Nyassa were as far 

 as possible studied ; and in this way much light has been thrown on the 

 geographical distribution of the fauna of the great African lakes. It 

 has been ascertained that Tanganyika contains at least two distinct 

 faunas — one which is more or less fully represented in all the great 

 African lakes, and another peculiar to Tanganyika itself. The latter 

 embraces the Medusa, some of the fresh -water fishes yet to be determined, 

 some new species of Crabs and Prawns, a deep-water Sponge, and mem- 

 bers of some eight or nine genera of Gastropods. Some of the latter are 

 already known from their shells (such as Typliobia, Lithoglyphus limno- 

 irochus, and Paranielania), but there are others which have yet to be 

 described. All these animals, like the Medusa, exhibit marked marine 

 affinities, but they cannot be directly associated with any living oceanic 

 forms ; and it is suggested they may represent the remains of a special 

 fauna which has persisted in the lake for a vast period. 



Observations were also made upon the Protozoa of Lake Tanganyika, 

 with the result that there were discovered apparently new species of 

 C ondylostoma and Peridinium, both of which are widely distributed 

 over the surface of the lake. 



A number of topographical observations were made, and rock speci- 

 mens were collected which will add to our knowledge of the geology of the 

 districts visited. Besides this, representatives of classes and orders of 

 animals other than those referred to above were collected. Mr. Moore 

 is at present working out the collections at the Royal College of Science, 

 South Kensington, and the full results will be published in a series of 

 papers to be communicated to the Royal and Zoological Societies, and in 

 the ' Quarterly Journal of Microscopical Science.' 



The following is a diary of Mr. Moore's movements while in Africa : — 

 Arrived at Capetown on September 21, 1895, and at Durban on Sep- 

 tember 28. Left Durban on October 18 (having been detained by the 

 loss of a steamer), and arrived at Chinde on November 2. Left Chinde 

 on November 4, and arrived at Blantyre, via the Zambesi and Shire 

 Rivers, on November 27. Being detained by the war in progress at the 

 north-east end of Nyassa, Mr. Moore left Blantyre for Zomba on Decem- 

 ber 23, and after an interview with Sir Harry Johnston, to whom Mr. 



