22 



HYDROIDS, ETC. 



they resemble cylinders attached to the bottom, the oppo- 

 site end containing the mouth, which is surrounded by 

 numbers of hollow tentacles, armed with lasso-cells (Fig. 

 21), while near the base of the tentacles are the minute 



FIG. 20. Anemone with ten- 

 tacles expanded, attached 

 by sucking disc to the bot- 

 tom. 



FIG. 21. Lasso-cell of an anemone. 



FIG. 22. Cross-section of anem- 

 one, showing septa. 



eye-spots. If a dead anemone that has become somewhat 

 hardened is cut open horizontally, we first notice the stom- 

 ach, that, divided into mouth and stomach proper, seems 

 suspended in the body, held in place by six partitions 

 {Mesenteries) (Fig. 22), that also divide the body cavity 

 into as many distinct chambers. Each of the six prin- 

 cipal partitions is perforated with an opening, and the 

 chambers connect with the tentacles, so that water, and 

 food captured by the tentacles, is taken in at the mouth, 

 and penetrates, by the opening at the bottom of the stom- 

 ach, to every part of the animal. 



The anemones vary greatly in size, from delicate un- 

 attached forms that live up among the folds of the great 

 icily-fish Cyanea to enormous ones two feet across. The 



