502 



CCELENTERA TES. 



illustration, has, immediately round the mouth, several circles of delicate grasping 

 tentacles, shaped like curly cabbage or endive leaves. Below these comes a circle 

 of numerous thick arms altogether unlike the others, being rough-skinned, and of 

 a simple spindle shape, the body itself forming a thick disc. All the tentacles of 



ENDIVE-ANEMONE, Crambactis (somewhat less than nat. size). 



the sea-anemones are hollow, with a fine aperture at the tip, through which, when 

 the animal contracts, the water contained in the body-cavity can be expelled, but 

 in the deep-sea forms these organs are very curiously modified. For instance, in 

 the genus Polysiphonia, here illustrated, the tentacles are short and unsuited for 



catching and holding prey ; 

 but the aperture at the tip 

 is large, and through it 

 flows in water containing 

 organic detritus which can 

 be used as food. The allied 

 Sicyonis has sixty - four 

 wart - like tentacles with 

 wide apertures standing in 

 a double circle round the 

 mouth, and in Liponema 

 the body- wall is perforated 

 by several hundred aper- 

 tures leading into the 

 digestive cavity and corre- 

 sponding to the tentacles. 



Although most mem- 

 SHORT-TENTACLED ANEMONE, Polysiphonia (nat size). bers of the group arise as 



