308 THE TANGANYIKA PROBLEM. 



life cycle in Limnocnida, and this cycle is complete with- 

 out any hydroid phase, in fact, no hydroid was ever found 

 in the lake, although I searched persistently for them. 

 This being so, the many peculiarities which the life-cycle 

 presents are at once striking and significant. At the present 

 time, however, I do not think it advisable to attempt to 

 dilate upon the medusae's proximate affinities, as I intend to 

 return to this matter in a special memoir. But it may be 

 useful to point out that the animal has most conspicuously 

 primitive attributes, coming in this sense exactly into line 

 with the halolimnic gastropods. It is certainly a marine 

 derivative, probably from its life-history related to the 

 Xarco-medusse of the ocean. 



