130 THE OCEANIC HYDROZOA. 



The hydrophyllia are about eight lines long, and three and a half lines broad, thicker in 

 the middle than at the sides, and somewhat concave on their inner faces. They are frequently 

 devoid of lateral processes or teeth. They are not fixed by their upper ends to the crenosarc, 

 but by a proper peduncle, which is inserted a httle behind their proximal ends, which are free 

 and solid. 



The reproductive organs are hke those of Stephanomia, and they are attached directly to 

 the coenosarc. 



Halistemma rubrum attains a length of three feet, and appears to be not uncommon 

 in the Mediterranean, especially in winter. 



