34 



The pajier also contained observations on the oeciu-rence of 

 haii-s in wliales ; the auditory organ of the Balanioptera ; the 

 asymmetry of the odontocete skidl ; and a few remarks upon the 

 habits of whales. In conclusion, attention was called to the present 

 dilHcult}' in obtaining information as to their method of copula- 

 tion, period of gestation, I'ate of bi-eeding, etc., and a means of 

 overcoming this difficulty was suggested. 



Mr. C. F. RoussELET, F.R.IVr.S., read a paper, communicated 

 by Dr. W. A. Clxxingtox, F.Z.S., on the collection of Ilotifera 

 made by the Third Tanganyika Expedition, 1 904-1 9G5. Amongst 

 the specimens brought back by Dr. W. A. Cunnington were a 

 number of tubes containing fine surface plankton nettings from 

 Tanganyika and other lakes of that region. These the author 

 searched for Rotifera, and the result was contained in the present 

 paper. From Lake Tanganyika only 11 species were obtained, 

 all already known in other pai-ts of the world ; whilst the River 

 Lofu, which enters the lake at its south-western corner, yielded 

 23 species, one of which is a very remarkable nev,- kind. In 

 Lake Nyassa only 6 species were found, and a single gathei'ing of 

 Victoria Nyansa yielded 9 species. This collection is interesting 

 and important from the fact that no previous record of Rotifera 

 from Lake Tanganyika had been made, and very few species were 

 known from the Central African Region. 



A complete list of species of Rotifera so far known from this 

 region was appended. 



Mr. R. Kirk PATRICK, F.Z.S., communicated two papers by 

 James Ritchie, M.A,, B.Sc, of the Royal tScottish Museum, on 

 the Hydroids of the INIergui Archipelago, collected by ]\Ir. J. J. 

 Simpson and ]^r. R. N. Rudmose Brown ; and on the Hydroids 

 of Christmas Island, collected by Dr. C. W. Andrews, F.R.S. 

 The chief interest of these two papers was faunistic. In the 

 former 30 species were recorded, in the latter 13. It was 

 apparent that the Hydroid fauna of the Eastern Indian Ocean, 

 of which hitherto little had been known, lacked distinctness, and 

 that its closest affinities were with the faunas of the neighbouring 

 Malay Archipelago and Australian areas. 



