THE AXXALS 



AND 



MAGAZINE OF NATURAL mSTOUY. 



[SIXTH SERIES.] 

 No. Qi. APRIL 1893. 



XLV. — Prelim I nart/ Account of the Freshioater Medusa of 

 Lake Tanganyika. By R. T. GiJNTHER, B.A. 



[Plates XIII. & XIV.] 



In August 1891 Mr. F. L. M. Moir, Manager of tlie African 

 Lakes Company, informed Dr. A. Giinther that lie liad 

 observed Meduste in large numbers in one of the bays of Lake 

 Tanganyika. " They were about | of an inch in diameter, 

 and their rounded top was so clear as to give the idea they 

 were merely circular bodies and not the shape of an ordinary 

 Medusa ; the more opaque ovaries gave this appearance." At 

 the same time Mr. ^loir kindly undertook to obtain specimens 

 properly prepared with osmic acid ; and, thanks to the assist- 

 ance of Mr. A. J. Swann, these specimens arrived in good 

 condition at the end of last year. This material was placed 

 by my father in my hands for examination and description. 



Although Mr. Moir has thus the merit of having been the 

 lirst to succeed in having specimens brought to Europe, he is 

 not the original discoverer of the species. In fact, from April 

 and during our summer months the Medusae seem to be 

 exceedingly abundant about the bays of the lake, so much so, 

 that they attract the notice of all visitors. 



In December 1883 Professor E. von Martens * communi- 



* Sitzgsb. naturf. Fr. Berl. 188-3, p. 197. 

 Ann. ii: Mag. N. Hist. Ser. 6. lo/. xi. 20 



