56 



Animal Life by the Sea-shore. 



like a worm, looking more like a hairy slug, is tlie larger 

 ally of Polynoc, the Sea-mouse {Aphrodite aadeata), one of 

 our most extraordinary Polych^etcs (Fig. 69). Oval in sliape 

 and three to six inches in length, this animal is distinguished 

 by the enormous development of the bristles, soine of which 

 arc highly iridescent and occupy the sides of the body, while 

 others are long and hair-like and woven into a kind of felt 

 protecting the whole dorsal surface. If this coating of hair- 

 like bristles be removed, fifteen pairs of scales, similar to those 

 of Polynoc, will be found to cover the body. The Sea-mouse 

 lives in fairly deep water, but specimens are frequently washed 

 ashore after storms. 



The Lug-worm, Arenicola marina (Fig. 68), so much sought 

 for as bait for fishing, is very different in its mode of life from 

 the forms just mentioned ; it is a burrower, and occupies much 

 the same position in the sea as the earth-worms on land, its shape 

 as well as its brownish colour being highly suggestive of those 

 well-known creatures. It is, however, by no means closeh' 

 related to the earth-worms, being a Polychjete, with the feet much 

 reduced in accordance with the burrowing habit ; on the front 

 segments of the body these organs are represented by a few 

 bristles only, while further back they are somewhat better 

 developed, and bear, in addition, branching filaments, modified 

 cirri, which act as gills. Everyone who has ^valked along the 

 sea-shore must be familiar witli the curious castings or sand-ropes 



FIG. 6S. LUG-WORM (aRENICOLA 1M.\RINa). 



made by the Lug-worm burrowing in muddy sand ; the worm 

 swallows great quantities of sand in order to assimilate the small 

 organic particles mixed with it, and passes through the vent the 

 indigestible residue, which is heaped up on the surface in 



