CLYTIA. 57 



is easily recognized by the black base of its tentacles, at their 

 point of juncture with the margin of the disk. It is more corn- 

 Fig. 70. Fig. 71. 



monly found at night, than in the day-time, being nocturnal in 

 its habits. 



Fig. 72. Fig. 73. 



Zygodactyla. {Zygodactyla groenlandica AG.) 



Little has been known, and still less published, of this remark- 

 able genus of Jelly-fish (Figs. 74, 75) up to the present time. 

 The name Zygodactyla, or Twinfinger, was given to it by Brandt, 

 from drawings made by Mertens, who had some opportunity of 

 studying it in his journey around the world. These drawings 



Fig. 70. Young Clytia just escaped from the reproductive calycle. 

 Fig. 71. Clytia somewhat older than Fig. 70. 

 Fig. 72 Magnified portion of Hydrarium of Clytia. 

 Fig. 73. Adult Clytia ; twice natural size. 

 8 



