72 OCEANIA LANGUIDA. 



reproductive calycles in March, April, or September ; I am therefore 

 unable to state whether it is the Hydrarium of our common Oce- 

 ania. 



A very young Oceania (Fig. 96), soon after its escape from the 

 reproductive calycle, has a very deep bell (Fig. 96), two long tentacles 

 and two rudimentary ones at the base of the chymiferous tubes. It 

 resembles in its general appearance and motion the Medusa of Clytia 

 bicoiihora ; the bell is covered with large lasso cells, scattered irregu- 

 larly over the surface ; it can at once be distinguished from the latter 



Fig. 97. t ' 



^aatflHtt 



Fig. 96. Fig. 98. 



Medusa by the absence of ovaries, the two long tentacles (/, Fig. 97), 

 and by what characterizes at once this genus, the position of the mar- 

 ginal capsules (c, Fig. 97) on each side of the primary tentacles (t, t', 

 Fig. 97), at the base of the chymiferous tubes, while in Clytia they are 

 placed on each side of the secondary rudimentary tentacle, half-way be- 

 tween the chymiferous tubes. The young Medusa, in more advanced 

 Fig 99 stages, has become quite conical (Fig. 98), 



the ovaries are forming, and, besides the two 

 original long tentacles, we have the two ru- 

 dimentary primary tentacles fully formed, as 

 well as eight others half-way between the 

 chymiferous tubes, and rudiments of eight 



c/ O 



additional tentacles half-way between these 

 and the chymiferous tubes. The proboscis 

 has likewise somewhat lengthened. In still 

 older specimens, in which the fourth set of 

 rudimentary tentacles has developed ( 4 , Fig. 

 99), and in which we can trace the position of 

 the remaining sixteen tentacles (t", Fig. 99), 

 the ovaries have also taken a greater development, and are now ellipti- 



Fig. 96. Young Medusa of Oceania languida, immediately after escaping from the reproduc- 

 tive calycle. 



Fig. 97. The same, seen from the actinal pole, to show the position of the marginal capsules, 

 r, on the sides of the tentacles, t, C. 



Fig. 98. Somewhat more advanced Medusa, in which traces of the ovaries can be detected. 



Fig. 99. Quarter of the disk of a still more advanced Oceania, where the remaining tentacles 

 of the adult (/") are developing between the tentacles, t 1 , t\ t 3 , t\ t, as well as additional marginal 

 capsules, c. 



