250 GENERAL ZOOLOGY 



into the intestine at the aboral end, and an exchange of gases 

 takes place through internal gills that join the intestine. 



The tentacles in the picture are not extended in the usual 

 radial direction. The reason is that when photographed the 





LA 



, A 



T* 



FIG. 125. Photograph of Living Sea-Cucumber. Natural size 



animal was using its tentacles as well as its tube-feet to crawl 

 along the bottom of a dish of sea-water. When the animal is 

 at rest, the tentacles are probably used to capture small 

 animals, and to pass them to the mouth. 



Relatives of Cucumaria have been known by observers 

 to disgorge the entire set of internal organs through the 



