Io6 EDWARD POTTS : 



passed since the first determination of the bud, and the libe- 

 rated medusa lived but two days longer, so that this specimen 

 did not secure us any better sight of possible sense organs 

 than had those seen ten years before. 



While I am far from presuming that a complete life history 

 of this interesting organism, in its hydroid phase, has been 

 supplied by our observations during the past year, I think 

 that much has been learned as to its larval gemmation and 

 mode of feeding ; and some progress has been made towards 

 a full discovery of the development of the medusa bud and 

 the liberation of the free-swimming medusa of this genus. 



It is no cause of astonishment that announcements are 

 frequently made of the discovery of fresh water medusa in 

 new localities, as Africa, Japan, Washington, D. C, etc., 

 but so far as I am aware none other have been traced back to 

 their derivation from a hydroid phase — which should give 

 this paper additional importance. 



