ON A FRESHWATER MEDUSA FROM RHODESIA. 
427 
On a Freshwater Medusa from Rhodesia. 
By 
Charles L.. Boulenger, M.A., 
Lecturer on Zoology in the University of Birmingham. 
With Plate 42 and 2 Text-figures. 
The material on which this note is based consists of a 
number of slides which I received from Mr. C. F. Rousselet, 
to whom my best thanks are due for his generosity in 
entrusting me with the description of these valuable 
specimens. 
Mr. Rousselet had obtained the material from his friend, 
Mr. R. H. Thomas, who discovered the first specimen of the 
medusa in a tributary of the Hunyani River 1 in Southern 
Rhodesia in September, 1908. This specimen was sent to 
England, but, owing to its poor state of preservation and to 
the fact that an air-bubble was left in the tube in which it was 
sent, it arrived in a much damaged and macerated condition. 
Mr. Rousselet wrote immediately to ask for better pre- 
served material, and a few more specimens were obtained 
and sent in December of the same year ; these were, unfor- 
tunately, also somewhat damaged in transit. Mr. Thomas 
endeavoured to collect more medusas but found that they 
had completely disappeared ; he has since left the district 
and the chance of receiving further specimens is somewhat 
remote. 
The tubes containing the medusae were accompanied by 
some pencil sketches of the living animal, and, whilst con- 
1 The River Hunyani (or Hanyani), is one of the largest of the 
southern tributaries of the Middle Zambesi. 
