J32 MABINE INVERTEBRATES 



long, which is divided into a number of concentric, communicating com- 

 partments. The margin of the float is entire, and a triangular sail 

 extends diagonally across the top. On the under side is a single mouth 

 on a manubrium, and surrounding it are a large number of short thread- 

 like appendages having different functions. Some of them are feelers, 

 others bear reproductive buds, and others have stinging-cells. Associ- 

 ated with Vellela is an allied hydroid called Porpita, which has no sail, 

 and in company with these two is a jellyfish called Bataria, which is 

 supposed to be the offspring of one or the other of them. 



Vellela limbosa. 



