STAGS "G" 5, 1/2 DAYS. 



Larvae a few hours older than "F" show a de- 

 cided degeneration in the larval organ, Fig 31. lo. 

 but other wise the external j-ppocronce of the two 

 stages is about the same. 



The grooves caused by the invagination of 

 nervous system have begun to disappear by the grow- 

 ing together of their edges and instead of the deep 

 furrows we find a sleightly depressed line where 

 the edges of the grooves have met. Fig.28.rg. 



In the norvcue system a pair of tentacle nerves 

 has been formed from each radial nerve. Fig.31.nl. 

 They grow out laterally from the radial nerves at 

 points proximal to the first pair of foot tentacles 

 around which they grow and to which they belong. 



A 



ho nerves have as yet appeared to supply the buccal 

 tentacles. 



In "F" the buccal tentacles had only begun to 

 eurve away from the end of the arm but in "G" this 

 proximal bending has continued until they curve over 

 the nerve ring and point toward the mouth . 



Beside, this change in the water vascular sys- 

 tem, we find in "G" the first appearence of the rud- 

 iments of the polian vesicles. They are four in nun- 



