It is more like the process irx Pilema as described b}j Glaus. 

 Each of the primary funnels is represented at first by one of 

 ithe folds in the margin of the lips referred to above. Fig. 25. 

 :The fold deepens and its edges are brought together on the 

 ventral side and fused, leavin^j an opening at the apex of the 

 Ifold, the osculiim. At tlie same time the labial groove in this 

 :region is converted into a canal by the fusion of the lips on 

 'its two siaes. After the fusion all trace of what has occur- 

 red quickly disappears. 



With the division of the oesophagus into four tubes and 

 the completion of the oral disk our larva comes to be distinct- 

 ly a rhizostomatous medusa. Further development of the mouth 

 parts consists in the continued division of the labial or bra- 

 chial groove into oral funnels and brachial canal, together 

 with the development of oral veiscles. By the time two or 

 three vesicles have been formed on the end of each arm a ves- 

 icle appears in the centre of the oral disk. Except for this 

 interruption the development of the mouth parts proceeds regu- 

 larly in a centripetal direction. The funnels and vesicles 

 are formed first at the tips of tlie anns and then one after a- 

 nother in regular succession towards the centre. Each of 

 these primary funnels is the rudiment of one of tlie primary 

 branches of the arm. When the process of forming funnels has 



