7 o2 THE NERESIS. 



Along the sides runs a double row of the wonderful bristles by means of which the 

 creature is enabled to propel itself through the sand, and projecting from the back are 

 thirteen pairs of light scarlet tufts, which, on examination, are found to be the gills of 

 the worm. These are most beautiful organs, and when magnified are seen to be com- 

 posed of many tufts, like the branches of a thick shrub. 



The Lug-worm has some of the habits of the tube-making annelids, for, although it 

 is perfectly free and able to move where it likes, it does not push its way through the 

 sand at random, but forms a tunnel of moderate strength, through which it can pass 

 and repass at pleasure. As it bores its way through the sand, it pours out a small 

 quantity of the glutinous matter which has already been mentioned in the Terebella, 

 and thus cements the sides of the tunnel together in a manner somewhat resembling 

 the brickwork of a railway tunnel. Like that work of engineering skill, moreover, the 

 tube of the Lug-worm cannot bear removal, breaking up when it is unsupported by the 

 surrounding earth. It is, however, amply strong enough for its use, and will withstand 

 the beatings of ordinary waves without yielding. 



GREAT EUNICE. -Eun/ce glgantea. 

 LUG-WORM. Arcnicola plscatorum. 



In the whole of the genus Arenicola there are no eyes nor jaws, and the head is not 

 distinct. Several species of this genus are known. 



THE second figure in the illustration represents another annelid closely allied to the 

 Nereidae. In this family the body is very long and composed of numerous segments. 



The proboscis has, at least, seven, and sometimes nine, pairs of horny jaws. The 

 species which is given in the illustration will sometimes attain a length of more than 

 four feet, and comprise upwards of four hundred segments in its body, each segment 

 furnished with its paddles, some seventeen hundred or more in number. 



When in a living state, this is a most lovely creature, winding along its serpentine 

 course with easy grace, and gleaming with all the colors of the rainbow as the sunbeams 

 fall on its polished surface and active propellers. 



AN example of the beautiful genus Nereis is now given. The Nereidae have both 

 tentacles and eyes, and the proboscis is large, often being furnished with a single pair of 



