62 STAR-FISHES AND SEA-URCHINS, 



have a long cylindrical form like a large worm : you 

 would then have an animal like the one of which I speak. 

 The rays would of course be stretched out also, and 

 would extend from one end of the body to the other. 

 This is the case with the Sea-Cucumber. It has no 

 spines, being soft throughout ; but the suckers are ar- 

 ranged in rows along the body, alternating with spaces 

 having no appendages, but corresponding to those on 

 which the spines are arranged in Star- Fishes and Sea- 

 Urchins. The mouth is at one end of the body, and is 

 surrounded by a wreath of tentacles ; and the animal, 

 resting on one side, moves along like the Star- Fish and 

 the Sea-Urchin, by means of the suckers, always turn- 

 ing that end of the body at which the mouth is placed 

 in the direction of its motion. Its body is, as I have 

 said, soft throughout, and can contract and expand, 

 making itself broader and shorter, or longer and nar- 

 rower, by taking in or letting out the sea-water, which 

 enters at the opening opposite the mouth, at the other 

 end of the body. The main tubes for the circulation 

 of food and water throughout the body, answering to 

 those which in the Star- Fish run along the arms, and in 

 the Sea- Urchins along the rows of suckers, extend in the 

 Sea-Cucumber from one end of the body to the other, 

 whib the sieve through which the water is filtered is 

 within the body instead of being on the outside, as in 

 the two others. The animals of this kind found on our 

 coast are very small. Larger kinds, however, abound 

 in the Bay of Fundy and upon the mud-flats of the 

 Reef of Florida. Some of those from Florida are as 

 large as your arm, and more than a foot long. 

 This curious animal furnishes a very important arti- 



