504 



MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



Fig. 13 (J, g). 



Manieina areolata —Mesenterial development in larval polyps continued. /. Seven pairs of metacnemes of the second cycle have now 

 appeared. <j. Stage with second cycle of twelve pairsof metacnemes complete. The young polyps now very rarely exhibit perfect 

 regularity, the development being more advanced in some regions than in others. The members of the first cycle of metacnemes :it 



i In stage begin to unite with the slomodieum. 



