FAUNA OF THE AFRICAN LAKES. 585 



In tlie course of my expedition I collected in Tiinganyika a few 

 Treinatodes which are parasitic on fish. They constitute a new- 

 record for this lake, but have not yet been examined and 

 descriJ^ed. The specimens were taken from large Siluroids, in 

 one case from the gill-arches, in another from tlie gut. 



Cestoda. 



As far as I have been able to ascertain, no records have beeii 

 published of tape-worms from tlie lakes included in this .survey, 

 although Daday described two new larvse which he observed in 

 East African Copepods. Different forms of tape-worm proved 

 common in the gut of fishes examined for parasites by my 

 expedition, and I succeeded in getting a considerable nnmber of 

 specimens. These all came from Tanganyika, where I had better 

 opportunity than elsewliere to seek such organisms, bnt it is 

 clear that systematic examination would not only bring to light 

 enteric parasites from the fishes of other lakes, but would result 

 in a far richer series from Tanganyika. My material has only 

 received a preliminar}' examination, so that little information 

 can yet be given as to the nature of the Tanganyika forms. A 

 species which occurred abundantly in an endemic Siluroid proves 

 to be one of the unsegmented Cestodes, and has been refeired to 

 the genus Caryophyllceus. It has not been more fully identified. 

 Almost all the remaining specimens come likewise from endemic 

 fishes belonging to diflferent genera of Cichlids and Siluroids. 

 Thus it is quite probable that other species of tape-woi'm-- perhaps 

 new forms — are represented in the collection. It is to be hoped 

 that the investigation will shortly be completed. 



CCELENTERATA. 



The only representatives of this group at present recorded are 

 the common fresh-water Hydra and the medusa which so stimu- 

 lated interest in the fauna of Tanganyika. Stuhlmann obtained 

 specimens of Hydra from Victoria Nyanza which resemble the 

 common II. fasca, though Weltner, reporting on this material, 

 would not venture to identify the species in the absence of eggs 

 (199, p. 2). Hydra has never been discovered in any of the other 

 lakes so far as I am aware, which is perhaps rathei' strange. 



The Tanganyika medusa was described by R. T. Giinther under 

 the name of Liinnocnida tanganicce * (94), and being peculiar to 

 the lake, was. of course, regaixled by Moore as one of the most 

 striking ha.lolimnic or relict forms. The significance of its 

 occurrence in this lake in the heart of Africa, which communicates 

 with the sea only by some r.housand miles of river, broken by falls 

 and rapids, was obvious, especially since the number of fresh- 

 water medusae then known was very small. Discoveries made since 

 Moore's expeditions, however, have put a very different complexion 



* The specific name is that of Bohm, the discoverer of the medusa, who wrote it 

 " tanffanjicce." I follow Giinther (96, p. 651) and most subsequent writers in 

 adopting tanganiccB as a more rational spelling. 



Proc. Zool. Soc— 1920, No. XXXIX, 39 



