332 



ORGANS OF DIGESTION. 



protruded with the intestines in such circumstances. The 

 mucous coat of the intestine, near its commencement, 

 sometimes presents internal longitudinal plicae. The ali- 

 mentary canal is most variable in its extent and convolutions 

 in different species of holothurite, and also the forms of 

 their dental plates, according to the nature of their food. 

 In the holothuria ananas (Fig. 115) which is nearly two 



FIG. 115. 



feet long, found in the South Sea, and prized as an article 

 of food in the Molucca islands, there are twenty long 

 pedunculated tentacula (115. b. b.) around the mouth (115. 

 a.) which terminate each in a concave disk, embracing nu- 

 merous red-coloured tubercles. The tubular fleshy feet 

 here cover irregularly the delicate inferior or ventral surface 

 ^f the abdomen ; and those of the upper coriaceous surface 



