ECHINODERMATA 95 



features of the group. They are cylindrical or elon- 

 gate and many (such as Synapta) resemble the 

 worms. 



The mouth is surrounded by a crown of ten- 

 tacles. The whole body is very flexible and although 

 lube feet are present, the usual method of locomotion 

 of many Sea Cucumbers is by contracting and ex- 

 panding the body in a worm-like manner. 



Like other Echinoderms, Sea Cucumbers have 

 the power of regenerating injured parts. One very 

 peculiar habit is possessed by certain of these ani- 

 mals. Just as the Brittle Star may throw off its 

 arms in an attempt to elude its enemies, some of 

 the Sea Cucumbers may eject a large part of the 

 internal organs, growing them again when they have 

 escaped. 



In its diet the Sea Cucumber resembles some 

 of the worms. It ingests sand and mud and utilizes 

 as food the small organic particles contained therein. 



Thyone briareus Lesueur (Sea Cucumber) 



PLATE VIII. Fig. 2 



Sac-like, about 3 to 6 inches long. At one end 

 there is a crown of tentacles which may be retracted. 

 It usually buries itself deep in mud in a U-shaped 

 position; its color is brown or dark purine. Fairly 

 common in mud flats and muddy bottoms off shore 

 from Cape Cod to the Gulf of Mexico. In Xew 

 Jersey it is found in Delaware Bay and other brack- 

 ish water associations, as well as in the open ocean. 



