84 WORMS, ROTIFERS, LEECHES, POLYZOA 



of sand ropes which dot the shore when the tide is out, and have 

 also probably noticed that it is where these little mounds are 

 most plentiful that the fishermen go to dig for bait for their lines. 

 The men are digging up the worm which produced the mound, 

 and which is called the Lug Worm (Arenicola piscatorum). It is 

 a long, cylindrical worm, sometimes measuring 10 or 12 inches in 

 length, and is generally of a blackish-green colour, the tint varying 

 with the locality in which the worm is found. The front part of 

 the body is somewhat swollen, and thirteen of the body segments 

 bear beautiful red arborescent branchiae. The worm lives in a 

 burrow which it has literally eaten in the sand at a depth of about 

 2 feet from the surface, its position being readily detected by 

 the spiral ropes of sandy excrement coiled about the entrance of 

 the burrow. 



Visitors to a wide sandy shore at low tide may sometimes be 

 rewarded by finding a specimen of the beautiful Aphrodite aculeata, 

 a singularly unwormlike animal, popularly called " the Sea 

 Mouse." It is fairly common on the south coast of England, and 

 frequently attains the length of 8 or 10 inches. The body is oval 

 in outline, and the numerous feet bear long bristles which flash 

 back all the glorious colours of the rainbow in the sunlight, while 

 the back is covered with a dense coat of fine mouse-coloured 

 bristles, from which the worm has gained its popular name of 

 " Sea Mouse." This soft felting hides from view a series of scales 

 or elytra with which the back is covered. The Aphrodite burrows 

 in the sand as the tide goes out, and remains safely hidden from 

 view until about a quarter of an hour before the tide turns, when, 

 as if impatient for the return of the sea, the little animal comes 

 to the surface, thickly coated with sand, and proceeds slowly 

 down towards the incoming waves. 



The Nereidae are a very numerous family of marine worms, 

 with long, slender, segmented bodies and flat heads, and two 

 small and two large feelers on each side of the mouth. The 

 pharynx is protrusible ; there are two large, horizontally moving 

 jaws, and the parapodia are double and have sharp spines. Speci- 

 mens are frequently to be found hidden under flat stones at low- 

 tide mark on the seashore. The Red Cat Worm (Nereis diversi- 

 color) is a familiar example, taking its name from its varied tints 

 and growing to a length of about 10 inches. It is a predaceous 



