MARINE WORMS 179 



part has no bristles or appendages of any kind, and is so well filled 

 with the sand or mud that it is quite hard and firm to the touch. 

 As is the case with our common earthworms, the sand or mud is 

 swallowed in enormous quantities, and this is not only the means 

 by which the lugworm derives its food, but also assists it consider- 

 ably in making its burrows; the extent to which this creature 

 carries on its work of excavation may be estimated by the thousands 

 of little contorted, worm-like heaps of sand that lie on the surface 

 at every period of low water. These little heaps are known as 

 1 castings,' and consist of the sand that passed through the worm's 

 body as the burrowing proceeded. 



The Eagworm is another species that is highly valued as bait. 

 It burrows into the odorous mud that is so commonly deposited 

 in harbours and the mouths of sluggish rivers. In this species 



FIG. 118. THE SEA MOUSE 



the segments are similar throughout the length of the body, and 

 the numerous flattened appendages give it the ragged appearance 

 that has suggested its popular name. Quite a number of marine 

 worms closely allied to the common ragworm, and resembling it 

 in general form, are to be found on our shores. Many of these 

 may be seen by turning over stones that are left exposed at low 

 tide, while others hide themselves in snug little crevices of the rock, 

 or in the empty shells of the acorn barnacle and various molluscs ; 

 and some species, including one of a bright-green colour, creep 

 freely over the wet rocks in search of food or home, often exposing 

 themselves to the rays of a fierce summer sun. 



The Sea Mouse (ApTirodita aculeata) is certainly one of the 

 most interesting of the roving marine worms, and, though seldom 

 seen above low-water line, may often be obtained by the sea-side 



