ALTERNATE GENERATIONS. 



259 



brilliant crested float. In this curious Acale- 

 phian Hyclroid, or P/ii/sa/ia, the individuality of 

 function is even more marked than in the Hy- 



Fhysalia, or Portuguese Man -of-War. 



ilractinia. As in the latter, some of the indi- 

 viduals are Medusae-bearings and others simple 



