Worms. 



bristle-bearing worms, a class of which the lug-bait or 

 the hairy- bait of fishermen may be taken as represen- 

 tatives. These worms have bodies 

 made up of a succession of simi- 

 lar joints, and their locomotion, 

 either creeping or swimming, is 

 accomplished by means of little 

 stumpy bristle-bearing eminences, 

 with which their bodies are pro- 

 vided. Each joint of the body 

 exhibits two pairs of these pro- 

 cesses, two of which are on the 

 upper or dorsal surface, and two 

 are on the ventral or under sur- 

 face, oae on each side of each 

 surface ; these are known as dorsal 

 and ventral oars. The mouth is 

 on the second segment, and is 

 often armed with sharp teeth. 

 The intestine is usually straight 

 and very often has lateral pouches 

 appended to it like those in the 

 leeches. There is a vascular 

 system consisting of long tubes, 

 dorsal, ventral and lateral, and the 

 blood contained in these is often 

 red, green, or white. The gills 

 are usually arranged along the 

 dorsal surface of the body spring- 

 ing close to the root of the dorsal 

 oar, and in these the blood is purified by being exposed 

 to the oxygen held in solution in the sea-water. 



Arenicola piscatorutit 

 Lug-bait worm. 



