MANY-BRISTLED GROUP 



3409 



proboscis. The creatures spend their days in tubes, from which they can only be 

 extracted by force. In Hermella the body ends in a long unjointed, limbless, hair- 

 less tail, while the rest of the body bears well-developed bristly parapodia, upon the 

 upper side of each of which there is a tongue-shaped gill. The head is remarkable 



TUBEWORM (Hermella}. 



in that the two large feelers blend into 

 one and bear a few rows of broad, flat 

 bristles. They are thus converted into 

 a stopper, which closes the mouth of the 

 tube when the worm is retracted. In 

 Terebella, forming the i'amily Tere- 

 bellidce, the tubes are formed of frag- 

 ments of sand or shell. 



In the family Serpulidce the gills 

 are restricted to the fore part of the 



Chatopterus. bod y> and the water Set in mOti n by 



their glistening hairs brings the food to 



the mouth, which is situated immediately beneath. The head lobe is blended with 

 the first segment, and not sharply marked off from it, as in most, of the worms 

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