70 



MARINE ANIMALS OF MASSACHUSETTS BAY. 



or clusters at the junction of the radiating tubes with the cir 

 cular tube, from which they may be seen extending in every 



Fig. 92. 



direction whenever these animals re 

 main quietly suspended in the water, 

 a favorite attitude with them, and 

 one which they retain sometimes for 

 days, seeming to make no effort be 

 yond that of gently playing their ten 

 tacles to and fro (Fig. 92). These 

 tentacles are capable of immense ex 

 tension, sometimes to ten or fifteen 

 times the diameter of the bell. The 

 proboscis is not simple as in the Sar- 

 sia, but looks like a yellow urn sus 

 pended at its four corners from the 

 chymiferous tubes. The oral opening 

 is entirely concealed by clusters of 

 shorter tentacles surrounding the 

 mouth in a close wreath, on which the 

 eggs are supported. A highly magni 

 fied branch of the Hydroid stock from 



Fig. 92. Bougainvillia ; magnified. 



Fig. 93. Hydrarium of Bougainvillia ; magnified. 



