80 NATURAL HISTORY OF OUR SHORES 



its mouth. The five-part arrangement is still present, 

 being represented in the whole of this division by grooves 

 with rows of suckers along the sides. Like the star-fishes, 

 they are covered with a leathery skin, which is strengthened 

 by calcareous plates embedded in its cuticle (Fig. 34). 



The " Trepang," or Beche de mer, largely used as an article 

 of food in Eastern countries, is a large species of Holothuria. 



The form named, the common one of our coasts, is about 

 five inches long, of a light brown colour, and lives among 

 shell gravel and in ground on which there is broken stone. 



Fig. 34. A. Plates of Cucumaria. B. Plates of 

 Synapta. All much magnified 



The prettiest species, if the term pretty can be applied 

 to them, is Cucumaria niger. It is about three inches long, 

 the body creamy white and the cluster of tentacles black. 

 It lives in rock crevices at extreme low-tide limit, and is 

 not common (see Fig. 33). 



The Synaptidce belong to the Holothurians. These 

 are structurally the same, but of more elongated and 

 wormlike form. 



Synapta digitata, graphically described by Canon Kingsley 

 in " Glaucus," is the type. It is about five inches long, and 

 about as stout as an ordinary cedar pencil. The tentacles, 



