Annulata. 



99 



kinds of parts or organs that the earthworm possesses ; it has simply 

 lost a part of the intestine, nerve cord, blood tubes, etc., but not all of 

 any one set of organs. 



Color of the Earthworm. The color of the earthworm is largely due 

 to the color of the blood and to the matter contained within the diges- 

 tive tube. But besides this, the dorsal surface is darker than the ven- 

 tral, as is the case with most animals. 



The Sandworm. One of the commonest of the sea 

 worms (Nereis) is known as the sandworm or clam worm. 

 It is cylindric, bluish green, and from six inches to a foot 



FIG. 61. A MARINE WORM. 



A, appearance at breeding season, and B, at other times. 

 From Jordan and Heath's Animal Forms. 



long. It is abundant along the Atlantic coast, and is an 

 excellent type to study, especially when the earthworm 

 cannot be readily obtained. One can usually find them at 

 low tide along the sandy or muddy beaches. They make 

 burrows in the sand, but they are to be found at night, 

 swimming freely, especially during the breeding season. 



One of the first points of difference between Nereis and 

 the earthworm is that Nereis has a distinct head. On the 

 top of the head are two pairs of eyes. There are also sev- 

 eral pairs of antennae and a pair of palps. Back of the 



