JELLY FISHES VARIETY AND BEAUTY. 121 



I must, however, spare two or three lines to the 

 wonderful fresh-water Medusa, discovered by Mr. W. 

 Sowerby on June 10th, 1880. On that day he was 

 looking into the warm-water tank of the Eoyal Botanic 

 Society, when he saw a number of tiny Medusae swim- 

 ming in it. Up to that time Medusae were thought to 

 be exclusively marine, but here was a species inhabiting 

 fresh water. Space is lacking for a full description of 

 these wonderful little beings, and I can only say that 

 some of them which were transferred to Kew multiplied 

 rapidly, and I have seen them there swimming merrily 

 about. The disc is about as large as a threepenny 

 piece, and it pulsates about one hundred and twenty 

 times in a minute. The scientific name of this little 

 anomaly is Limnocodium Soiverbii. 



