ANIMALS OF UNCERTAIN RELATIONSHIPS 



71 



B 



by the retreating tide. They are usually highly colored 

 with yellow, green, violet, or various shades of red, and are 

 so twisted into tangled 

 masses that the differ- 

 ent parts of the body 

 are indistinguishable. 

 As the animal crawls 

 about, a long thread- 

 like appendage, the pro- 

 boscis, is frequently shot 

 out from its sheath at 

 the forward end of the 

 body and appears to be 

 used as a blind man 

 uses his stick. At other 



times, when Small WOrmS spine-tipped proboscis. 



and other animals are 



encountered, the proboscis is shot out farther and with 

 greater force, impaling the victim on a sharp terminal spine 

 (Fig. 44). The food is now borne to the mouth, located 

 near the base of the proboscis, is passed into the digestive 

 tract, traversing the entire length of the body, and is far- 

 ther operated on by systems of organs too complex to be 

 considered here. 



FIG. 44. A band or nemertean worm. A, entire 

 worm ; B, head, bearing numerous eyes and 



